Co-reporter:Lijin Huang, Chuyu Peng, Qian Cheng, Man He, Beibei Chen, and Bin Hu
Industrial & Engineering Chemistry Research November 22, 2017 Volume 56(Issue 46) pp:13696-13696
Publication Date(Web):October 24, 2017
DOI:10.1021/acs.iecr.7b03093
Magnetic porous organic polymers (MOPs) with abundant thiol groups were synthesized successfully in high yield through a template-free and catalyst-free diazo-coupling reaction. The reaction was conducted under mild conditions in aqueous solution, in which the introduction of magnetism and thiol-functionalization was realized simultaneously, avoiding the use of environment-unfriendly organic solvents. The magnetic nanoparticles (MNPs) were embedded into hierarchical porous network structures of porous organic polymers (POPs) physically and the magnetism of thiol-functionalized MOPs (MOP-SH) was easily controlled by varying the amount of spiked MNPs. The obtained MOP-SH exhibited high thermal stability and chemical stability within a wide pH range (2–13), and good adsorption performance for Hg(II) over a wide pH range due to the abundant thiols in its hierarchical structure. After the adsorption process by using MOP-SH, the concentration of Hg in the spiked domestic sewage reached 1.1 μg L–1, which is even lower than the acceptable limit of national standard for drinking water (2 μg L–1). Besides, the prepared MOP-SH exhibited high adsorption capacity, fast adsorption kinetics, and easy-recycling behavior, providing a new avenue for the preparation of green functionalized adsorbents with good performance for water decontamination.
Co-reporter:Han Wang, David J. Cocovi-Solberg, Bin Hu, and Manuel Miró
Analytical Chemistry November 21, 2017 Volume 89(Issue 22) pp:12541-12541
Publication Date(Web):October 17, 2017
DOI:10.1021/acs.analchem.7b03767
In this work, the concept of 3D-printed microflow injection (3D-μFI) embodying a dedicated multifunctional 3D-printed stator onto a rotary microvalve along with a mesofluidic sample preparation platform is proposed for the first time. A transparent 3D-printed stereolithographic mesofluidic chip device accommodating polyaniline (PANI) decorated magnetic nanoparticles (32.5 ± 3.8 mg) is harnessed to in-line sorptive microextraction as a front end to liquid chromatography with peak focusing. As a proof-of-concept application, the 3D-μFI assembly was resorted to matrix cleanup and automatic programmable-flow determination of organic emerging contaminants (4-hydroxybenzoate analogues and triclosan as antimicrobial model analytes) in human saliva and urine samples. By using a sample volume of 1.0 mL with a loading flow rate of 200 μL min–1, an eluent volume of 120 μL at 80 μL min–1, and online HPLC injection of 300 μL of the mixture of eluate and Milli-Q water (in a 1:2 ratio) to prevent band broadening effects of the most polar analytes, the limits of detection (3σ criterion) ranged from 1.1 to 4.5 ng mL–1 for methylparaben (MP), ethylparaben (EP), propylparaben (PrP), phenylparaben (PhP), butylparaben (BP), and triclosan (TCS). Enhancement factors of 16–25 were obtained for the target analytes. Spike recoveries ranged from 84 to 117% for both saliva and urine samples. The online 3D-μFI hyphenated method is synchronized with the chromatographic separation and features a chip lifetime of more than 20 injections with minimal losses of moderately nonpolar compounds on the walls of the mesofluidic device.
Co-reporter:Lijin Huang, Man He, Beibei Chen, Qian Cheng, and Bin Hu
ACS Sustainable Chemistry & Engineering May 1, 2017 Volume 5(Issue 5) pp:4050-4050
Publication Date(Web):March 27, 2017
DOI:10.1021/acssuschemeng.7b00031
Herein, magnetic porous organic polymers composites (MOPs) with abundant free phenolic hydroxyl group were synthesized via a simple and green azo coupling reaction under mild conditions in water. Remarkably, Fe3O4@SiO2 nanoparticles were encapsulated in the disordering porous organic polymers during the coupling reaction. The prepared MOPs possessed excellent stability, high special surface areas, controllable magnetism, and high adsorption capacity (1153 mg g–1) toward cationic dye methylene blue. Moreover, the MOPs could be easily and rapidly recovered from the solution by using a magnet due to their superparamagnetic property and could be reused at least 5 times without decreasing the adsorption capacity, demonstrating a potential application in pollutants removal.Keywords: Azo coupling reaction; Dye separation; Dyes removal; Magnetic composites; Porous organic polymers; Water treatment;
Co-reporter:Yabing Cai, Beibei Chen, Man He, Xiaolan Liu, Hu Bin
Spectrochimica Acta Part B: Atomic Spectroscopy 2017 Volume 127() pp:56-63
Publication Date(Web):1 January 2017
DOI:10.1016/j.sab.2016.11.009
•MSA modified poly(GMA-EDMA-Au NPs) monolithic capillary was prepared.•The on-line monolithic CME-ICP-MS was developed for the analysis of trace REEs.•The adsorption capacity of the monolith towards REEs has been obviously improved.•The method was applied in seawater and blood sample analysis with good recoveries.In this work, a novel method of Au nanoparticles (NPs) modified polymer monolithic capillary microextraction (CME) on-line coupling with inductively coupled plasma-mass spectrometry (ICP-MS) was developed for the determination of trace rare earth elements (REEs) in environmental and biological samples. The poly(glycidyl methacrylate-ethylene dimethacrylate) monolithic capillary was prepared, functionalized with thiol ligands for the attaching of Au NPs, and then modified with mercaptosuccinic acid to provide massive carboxyl groups which have high affinity to REEs. With the modification of Au NPs, the adsorption capacity of the monolith towards target REEs has been improved by 3 to 6.5 times. Under the optimized conditions, the limits of detection of the developed method for REEs were in the range of 0.16 (Tb)–0.85 (Gd) ng L− 1. The enrichment factor was 25-fold with the sample throughput of 10 h− 1. And the relative standard deviations were between 2.7 (Lu) and 9.8% (Dy) (c = 10 ng L− 1, n = 9). The accuracy of the method was validated by the analysis of a standard stock solution of GSB04-1789-2004 and a Certified Reference Material of GBW07301a stream sediment. The proposed method was applied for the analysis of trace REEs in seawater samples as well as human whole blood with good recoveries. The prepared monolith is featured with strong anti-interference ability, superior adsorption capacity as well as long lifespan, and the developed monolithic CME-ICP-MS is sensitive, simple and rapid for the analysis of trace/ultra-trace REEs in environmental and biological samples with complex matrix.
Co-reporter:Dr. Hanyong Peng; Bin Hu;Dr. Qingqing Liu;Jinhua Li; Xing-Fang Li; Hongquan Zhang; X. Chris Le
Angewandte Chemie 2017 Volume 129(Issue 24) pp:6779-6779
Publication Date(Web):2017/06/06
DOI:10.1002/ange.201704555
Hunderte Millionen Menschen …… weltweit sind Arsen-Belastungen ausgesetzt, und es ist bislang nicht bekannt, wie Phenylarsen-Verbindungen, die als Futtermittelzusätze an Hühner verfüttert werden, metabolisieren. In der Zuschrift auf S. 6877 ff. zeigen B. Hu, X. C. Le et al., dass Phenylarsen-Verbindungen in Hühnern methyliert werden, und beschreiben im Jahr des Hahns die toxikologische Relevanz dieser neu entdeckten Arsen-Metaboliten.
Co-reporter:Dr. Hanyong Peng; Bin Hu;Dr. Qingqing Liu;Jinhua Li; Xing-Fang Li; Hongquan Zhang; X. Chris Le
Angewandte Chemie 2017 Volume 129(Issue 24) pp:6877-6881
Publication Date(Web):2017/06/06
DOI:10.1002/ange.201700736
AbstractWe report the discovery of three toxicologically relevant methylated phenylarsenical metabolites in the liver of chickens fed 3-nitro-4-hydroxyphenylarsonic acid (ROX), a feed additive in poultry production that is still in use in several countries. Methyl-3-nitro-4-hydroxyphenylarsonic acid (methyl-ROX), methyl-3-amino-4-hydroxyphenylarsonic acid (methyl-3-AHPAA), and methyl-3-acetamido-4-hydroxyphenylarsonic acid (or methyl-N-acetyl-ROX, methyl-N-AHPAA) were identified in such chicken livers, and the concentration of methyl-ROX was as high as 90 μg kg−1, even after a five-day clearance period. The formation of these newly discovered methylated metabolites from reactions involving trivalent phenylarsonous acid substrates, S-adenosylmethionine, and the arsenic (+3 oxidation state) methyltransferase enzyme As3MT suggests that these compounds are formed by addition of a methyl group to a trivalent phenylarsenical substrate in an enzymatic process. The IC50 values of the trivalent phenylarsenical compounds were 300–30 000 times lower than those of the pentavalent phenylarsenicals.
Co-reporter:Dr. Hanyong Peng; Bin Hu;Dr. Qingqing Liu;Jinhua Li; Xing-Fang Li; Hongquan Zhang; X. Chris Le
Angewandte Chemie International Edition 2017 Volume 56(Issue 24) pp:6679-6679
Publication Date(Web):2017/06/06
DOI:10.1002/anie.201704555
Arsenic affects …… hundreds of millions of people around the world, and it is not clear how phenylarsenicals that are fed to chickens as food additives are metabolized. In their Communication on page 6773 ff., B. Hu, X. C. Le, and co-workers reveal that phenylarsenicals are methylated in chicken and demonstrate the toxicological relevance of the new arsenic metabolites in the Year of the Rooster.
Co-reporter:Dr. Hanyong Peng; Bin Hu;Dr. Qingqing Liu;Jinhua Li; Xing-Fang Li; Hongquan Zhang; X. Chris Le
Angewandte Chemie International Edition 2017 Volume 56(Issue 24) pp:6773-6777
Publication Date(Web):2017/06/06
DOI:10.1002/anie.201700736
AbstractWe report the discovery of three toxicologically relevant methylated phenylarsenical metabolites in the liver of chickens fed 3-nitro-4-hydroxyphenylarsonic acid (ROX), a feed additive in poultry production that is still in use in several countries. Methyl-3-nitro-4-hydroxyphenylarsonic acid (methyl-ROX), methyl-3-amino-4-hydroxyphenylarsonic acid (methyl-3-AHPAA), and methyl-3-acetamido-4-hydroxyphenylarsonic acid (or methyl-N-acetyl-ROX, methyl-N-AHPAA) were identified in such chicken livers, and the concentration of methyl-ROX was as high as 90 μg kg−1, even after a five-day clearance period. The formation of these newly discovered methylated metabolites from reactions involving trivalent phenylarsonous acid substrates, S-adenosylmethionine, and the arsenic (+3 oxidation state) methyltransferase enzyme As3MT suggests that these compounds are formed by addition of a methyl group to a trivalent phenylarsenical substrate in an enzymatic process. The IC50 values of the trivalent phenylarsenical compounds were 300–30 000 times lower than those of the pentavalent phenylarsenicals.
Co-reporter:Bin Yang, Beibei Chen, Man He, and Bin Hu
Analytical Chemistry 2017 Volume 89(Issue 3) pp:
Publication Date(Web):January 12, 2017
DOI:10.1021/acs.analchem.6b04314
We report a sensitive, selective, simple, and reliable magnetic immunoassay protocol for detection and imaging of HepG2 cells. After being captured by Cs-doped multicore magnetic nanoparticles (MMNPs), HepG2 cells were labeled by CdSe/ZnS quantum dots (QDs), which could be visualized by fluorescence imaging using the photoluminescence property of QDs, and subsequently, they can be counted by inductively coupled plasma mass spectrometry (ICP-MS) with Cd/Cs as elemental tag. Because of the superior photoluminescence properties and the large quantities of detectable Cd atoms contained in the QDs core, QDs play a dual function role in this assay, making the method easier and more comprehensive than other similar approaches. Under the optimal conditions, the limit of detection of 61 HepG2 cells and the relative standard deviation of 5.4% (800 HepG2 cells, n = 7) were obtained. The linear range was 200–30 000 cells, and the recoveries in human whole blood were in the range of 86–104%. The proposed method enables us not only to count but also to see the cancer cells with the same labeling process, opening a promising avenue for research and clinical application.
Co-reporter:Xiaolan Liu, Beibei Chen, Yabing Cai, Man He, and Bin Hu
Analytical Chemistry 2017 Volume 89(Issue 1) pp:
Publication Date(Web):December 8, 2016
DOI:10.1021/acs.analchem.6b03532
An online hydrophilic polymer monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICPMS) analytical system was developed for the size-based analysis of Au NPs in the range of 3–40 nm. Au NPs with different particle sizes retained on the poly(acrylamide-vinylpyridine-methylene bis(acrylamide)) (poly(AA-VP-Bis)) monolithic capillary showed different elution behavior when cysteamine was used as the eluent, and the napierian logarithm of the critical eluent concentration (Ln C (cysteamine)) was linearly dependent on the particle size of Au NPs. This means that the unknown particle size of Au NPs can be deduced based on their critical eluent concentrations. The developed method was successfully used for the baseline separation of 3 and 20 nm Au NPs, as well as 10 and 30 nm Au NPs. Compared with chromatographic-based methods for the size analysis of Au NPs, the developed online poly(AA-VP-Bis) monolithic CME-ICPMS method is featured with simultaneous separation and enrichment of Au NPs, simple operation, low cost, high analytical speed, and high adsorption capacity.
Co-reporter:Lijin Huang, Man He, Bei-bei Chen, Qian Cheng, and Bin Hu
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 3) pp:
Publication Date(Web):January 4, 2017
DOI:10.1021/acsami.6b15106
Hydrophilic magnetic N-doped porous carbon composites (MNPCs) with high special surface areas and rich nitrogen content was prepared via simple one-step carbonization of zinc oxide nanoparticles (ZnO NPs), 2-methylimidazole (HmIm), and Fe3O4@SiO2 magnetic nanoparticles (MNPs) mixture directly. During the carbonization process, ZnO NPs directly reacts with HmIm to yield porous ZIF-8 while the MNPs are incorporated into the frameworks to generate magnetic metal–organic frameworks (MFCs), and the MFCs acts as a self-sacrificing template to prepare MNPC. The obtained MNPCs via simple one-step carbonization strategy display higher adsorption capacity (429 mg g–1) for Hg2+ ions than MNPC-T700-M3-T (382 mg g–1) which was obtained by two-step synthesis strategy for comparison. It also exhibits very fast adsorption dynamics (adsorption rate constant (K2) = 2.45 g mg–1 min–1) for Hg2+ and could efficiently remove 95% Hg2+ in 2 min for 20 mg L–1 Hg2+ solution. Furthermore, the prepared MNPC exhibits good chemical stability and the adsorption capacity is still more than 95% even after 10 adsorption–elution cycles. The proposed method is easy-processing and economic, which not only provides highly efficient MNPCs for metal ions capture but also paves the ways toward various MFCs with different ligands through solvent/additive-free synthesis approaches.Keywords: cost-effective; Hg2+ removal; magnetic porous carbon; metal−organic frameworks; one-step carbonization;
Co-reporter:Chuyu Peng;Man He;Beibei Chen;Lijin Huang
Analyst (1876-Present) 2017 vol. 142(Issue 23) pp:4570-4579
Publication Date(Web):2017/11/20
DOI:10.1039/C7AN01195D
A novel magnetic sulfur-doped porous carbon (MSPC) was fabricated via a simple one-step carbonization of a mixture of sucrose, basic magnesium sulfate whiskers and Fe3O4@SiO2 nanoparticles. Due to the high S content, the prepared MSPC possessed high adsorption capacity for Hg2+ (343 mg g−1) with good selectivity. Based on this, a method coupling magnetic solid phase extraction (MSPE) with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace Hg2+ in environmental water samples. Various parameters such as pH, desorption solvent and its concentration, desorption volume and time, sample volume, and adsorption time that affect the determination have been optimized. Under the optimal conditions, a high enrichment factor of 100-fold was obtained, the limit of detection (LOD) was found to be 0.52 pg mL−1 with a relative standard deviation (c = 10 pg mL−1, n = 7) of 7.1%, and a good linearity was obtained within the concentration range of 2–5000 pg mL−1 for Hg2+. Besides, the proposed method has very fast adsorption/desorption kinetics, target Hg2+ could be rapidly adsorbed on the prepared MSPC in 2 min and desorbed from the MSPC in 2 min with the assistance of a permanent magnet. Therefore, the proposed method of MSPE-ICP-MS exhibits good application potential in the determination of trace Hg2+ in environmental water samples.
Co-reporter:Zhengru Liu;Bin Yang;Beibei Chen;Man He
Analyst (1876-Present) 2017 vol. 142(Issue 1) pp:197-205
Publication Date(Web):2016/12/19
DOI:10.1039/C6AN01919F
Upconversion nanoparticles (UCNPs) have received increasing attention due to their unique optical properties. Recognizing that UCNPs are lanthanide-doped nanoparticles, we incorporated UCNPs into an immunoassay with inductively coupled plasma mass spectrometry (ICP-MS) detection for the determination of specific proteins, e.g., alpha-fetoprotein (AFP). The sensitivity of the assay was enhanced because of the ICP-MS detection of UCNPs that contained large numbers of lanthanide elemental tags. Conjugates of UCNPs and antibodies were prepared and the morphology of the conjugates was characterized by transmission electron microscopy. After a sandwich immunoreaction, the AFP was determined by the ICP-MS analysis of UCNPs. Under the optimized conditions, a limit of detection (3σ) of 0.31 ng mL−1 based on 89Y signal and 0.22 ng mL−1 based on 174Yb signal was obtained for AFP, with a dynamic range of 0.5–35 ng mL−1 and a relative standard deviation of 4.8% (c = 5 ng mL−1, n = 9). The developed method was applied to the determination of AFP in human serum and the recovery for the spiked sample was in the range of 98.6–123%. The proposed method is simple, rapid, selective and sensitive, and has a good tolerance for the complex biological matrix, indicating great potential for the application of UCNP in biological research as an elemental tag.
Co-reporter:Han Wang;Xiaolan Liu;Kai Nan;Beibei Chen;Man He
Journal of Analytical Atomic Spectrometry 2017 vol. 32(Issue 1) pp:58-77
Publication Date(Web):2017/01/04
DOI:10.1039/C6JA00077K
The biochemical reactions involving trace elements depend on the nature and form of their chemical species in a biological system. Consequently, the study of the chemical speciation of a given element in biological samples has become essential for understanding their bioavailability and toxicity. Inductively coupled plasma-mass spectrometry (ICP-MS) hyphenated techniques are the most powerful and widely used for elemental speciation combining both high sensitivity and good selectivity for the determination of ultra-trace elements in biological samples. However, direct analysis of biological samples can suffer from matrix interferences, and both the low concentrations of chemical species, and in some cases, the limited amount of sample available can present analytical challenges. Therefore, there is a need to develop sample pre-treatment methods that can be used to remove the matrix and pre-concentrate the species of interest prior to analysis. This review will focus specifically on the state-of-the-art sample pre-treatment methods published in the last ten years including liquid and solid phase micro-extraction, and chip-based manifolds that can be coupled to ICP-MS hyphenated techniques. The different methods are evaluated for their ability to be deployed for the pre-treatment of actual biological samples. The development trends in this area of research are discussed, and integrated automated miniaturized systems are also reviewed.
Co-reporter:Man He, Lijin Huang, Bingshan Zhao, Beibei Chen, Bin Hu
Analytica Chimica Acta 2017 Volume 973(Volume 973) pp:
Publication Date(Web):22 June 2017
DOI:10.1016/j.aca.2017.03.047
•Advanced functional materials for SPE-ICP-MS determination of trace elements/species are reviewed.•The adsorption capacity, selectivity, dynamics, and operation efficiency of AFMs are discussed.•Various AFMs are involved, along with perspectives and possible challenges in future work.For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials.Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future development.Download high-res image (285KB)Download full-size image
Co-reporter:Bin Yang, Yuan Zhang, Beibei Chen, Man He, Xiao Yin, Han Wang, Xiaoting Li, Bin Hu
Biosensors and Bioelectronics 2017 Volume 96(Volume 96) pp:
Publication Date(Web):15 October 2017
DOI:10.1016/j.bios.2017.04.041
•The successful application of UCNPs as the elemental tag in ICP-MS based cell counting.•ICP-MS based cell counting and FL/UCL imaging were realized using a multifunctional probe.•The developed method was sensitive, simple, and reliable for cells multimodal detection.Inductively coupled plasma-mass spectrometry (ICP-MS) based bioassay and multimodal imaging have attracted increasing attention in the current development of cancer research and theranostics. Herein, a sensitive, simple, timesaving, and reliable immunoassay for cancer cells counting and dual-modal imaging was proposed by using ICP-MS detection and down-conversion fluorescence (FL)/upconversion luminescence (UCL) with the aid of a multifunctional probe for the first time. The probe consisted of a recognition unit of goat anti-mouse IgG to label the anti-EpCAM antibody attached cells, a fluorescent dye (Cy3) moiety for FL imaging as well as upconversion nanoparticles (UCNPs) tag for both ICP-MS quantification and UCL imaging of cancer cells. Under the optimized conditions, an excellent linearity and sensitivity were achieved owing to the signal amplification effect of nanoparticles and low spectral interference. Accordingly, a limit of detection (3σ) of 1×102 HepG2 cells and a relative standard deviation of 7.1% for seven replicate determinations of 1×103 HepG2 cells were obtained. This work proposed a method to employ UCNPs with highly integrated functionalities enabling us not only to count but also to see the cancer cells, opening a promising avenue for biological research and clinical theranostics.
Co-reporter:Xiaoting Li, Beibei Chen, Man He, Han Wang, Guangyang Xiao, Bin Yang, Bin Hu
Biosensors and Bioelectronics 2017 Volume 90(Volume 90) pp:
Publication Date(Web):15 April 2017
DOI:10.1016/j.bios.2016.11.030
•Simultaneous detection of MCF-7 and HepG2 cells by ICP-MS with element tagging was realized.•AuNPs and QDs labeling strategies were developed for cell counting by ICP-MS.•The method has the potential for simultaneous multiple CTC lines detection in human blood.•The method was simple, efficient, specific, sensitive for multiple CTC lines detection.In this work, we demonstrate a novel method based on inductively coupled plasma mass spectrometry (ICP-MS) detection with gold nanoparticles (Au NPs) and quantum dots (QDs) labeling for the simultaneous counting of two circulating tumor cell lines (MCF-7 and HepG2 cells) in human blood. MCF-7 and HepG2 cells were captured by magnetic beads coupled with anti-EpCAM and then specifically labeled by CdSe QDs-anti-ASGPR and Au NPs-anti-MUC1, respectively, which were used as signal probes for ICP-MS measurement. Under the optimal experimental conditions, the limits of detection of 50 MCF-7, 89 HepG2 cells and the linear ranges of 200-40000 MCF-7, 300-30000 HepG2 cells were obtained, and the relative standard deviations for seven replicate detections of 800 MCF-7 and HepG2 cells were 4.6% and 5.7%, respectively. This method has the advantages of high sensitivity, low sample consumption, wide linear range and can be extended to the simultaneous detection of multiple CTC lines in human peripheral blood.
Co-reporter:Zijun Yan, Man He, Beibei Chen, Bo Gui, Cheng Wang, Bin Hu
Journal of Chromatography A 2017 Volume 1525(Volume 1525) pp:
Publication Date(Web):24 November 2017
DOI:10.1016/j.chroma.2017.10.025
•CTFs/Ni magnetic composite was prepared by in-situ reducing Ni ions on CTF matrix.•It exhibits good preparation reproducibility and chemical stability.•MSPE-GC-FID was used for the analysis of six PAEs in plastic packaging materials.•It is sensitive with short operation time and low consumption of organic solvents.Covalent triazine frameworks (CTFs), featuring with high surface area, good thermal, chemical and mechanical stability, are good adsorbents in sample pretreatment. Herein, magnetic CTFs/Ni composite was prepared by in situ reduction of nickel ions on CTFs matrix with a solvothermal method. The prepared CTFs/Ni composite exhibited good preparation reproducibility, high chemical stability, and high extraction efficiency for targeted phthalate esters (PAEs) due to π-π interaction and hydrophobic effect. The porous structure of CTFs/Ni composite benefited the fast transfer of target PAEs from aqueous solution to the adsorbents, and the integrated magnetism contributed to the rapid separation of adsorbents from sample and elution solution. Based on it, a novel method of magnetic solid phase extraction (MSPE) combined with gas chromatography-flame ionization detector (GC-FID) was developed for the analysis of PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), di-2-ethylhexl phthalate (DEHP), and di-n-octyl phthalate (DNOP) in plastic packaging materials. Under the optimal experimental conditions, the limits of detection (LODs, S/N = 3) for six PAEs were found to be in the range of 0.024-0.085 mg/kg. The linear range was 0.32–16 mg/kg for DMP, DEP, 0.08–80 mg/kg for DBP, 0.16–32 mg/kg for BBP, DEHP, and 0.32–32 mg/kg for DNOP, respectively. The enrichment factors ranged from 59 to 88-fold (theoretical enrichment factor was 133-fold). The proposed method was successfully applied to the analysis of PAEs in various plastic packaging materials with recoveries in the range of 70.6-119% for the spiked samples. This method is characterized with short operation time, high sensitivity, low consumption of harmful organic solvents and can be extended to the analysis of other trace aromatic compounds.
Co-reporter:Cheng Zhong, Beibei Chen, Man He, Bin Hu
Journal of Chromatography A 2017 Volume 1483(Volume 1483) pp:
Publication Date(Web):3 February 2017
DOI:10.1016/j.chroma.2016.12.073
•Covalent triazine framework-1 (CTF–1) was used for nitroimidazole extraction.•CTF-1 has high extraction efficiency (87%–98%) and adsorption capacity.•In-line SPE-HPLC was developed for the analysis of nitroimidazoles with low LODs.•CTF–1 was suitable for aromatic compounds in environmental and biological samples.In this study, covalent triazine framework-1 (CTF-1) was adopted as solid phase extraction (SPE) sorbents, and a method of SPE inline coupled with high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for trace analysis of three nitroimidazolaes (including metronidazole, ronidazole and dimetridazole) in porcine liver and environmental water samples. CTF-1 has rich π-electron and N containing triazine, thus can form π–π interaction and intermolecular hydrogen bond with three target polar nitroimidazoles, resulting in high extraction efficiency (87%–98%). Besides, CTF-1 has large specific area, which benefits rapid mass transfer and low column pressure, leading to fast adsorption/desorption dynamics. Several parameters affecting inline SPE including pH, sample flow rate, sample volume, desorption reagents, elution flow rate, elution volume, and ionic strength were investigated. Under the optimal experimental conditions, the limits of detection (S/N = 3) were found to be in the range of 0.11-0.13 μg/L. The enrichment factors (EFs) ranged from 52 to 59 fold (theoretical EF was 60-fold). The relative standard deviations were in the range of 4.3–9.4% (n = 7, c = 1 μg/L), and the linear range was 0.5–500 μg/L for three target analytes. The sample throughput is 7/h. The proposed method was successfully applied to the analysis of nitroimidazoles in porcine liver and environmental water samples with good recoveries for the spiked samples.
Co-reporter:Linna You, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A 2017 Volume 1524(Volume 1524) pp:
Publication Date(Web):17 November 2017
DOI:10.1016/j.chroma.2017.10.001
•ZIF-8/poly (MMA-EGDMA) monolith stir bar coating was in situ synthesized by one-pot polymerization.•The preparation process is simple-to-operate and low-cost.•A method of ZIF-8/monolith-SBSE-HPLC-UV was proposed for analysis of phytohormones in fruits.•It is sensitive and selective towards polar phytohormones.In this work, zeolitic imidazolate framework-8 (ZIF-8)/poly (methyl methacrylate-ethyleneglycol dimethacrylate) (MMA-EGDMA) composite monolith was in situ synthesized on stir bar by one-pot polymerization. Compared with the neat monolith, ZIF-8/poly(MMA-EGDMA) composite monolith has larger surface area and pore volume. It also exhibits higher extraction efficiency for target phytohormones than poly(MMA-EGDMA) monolith and commercial polyethylene glycol (PEG) coated stir bar. Based on it, a method of ZIF-8/poly(MMA-EGDMA) monolith coated stir bar sorptive extraction (SBSE)-high performance liquid chromatography-ultraviolet detection (HPLC-UV) was established for the analysis of five phytohormones in apple and pear samples. The developed method exhibited low limits of detection (0.11–0.51 μg/L), wide linear range (0.5–500 μg/L) and good recoveries (82.7–111%), which demonstrated good application potential of the ZIF-8/monolith coated stir bar in trace analysis of organic compounds.
Co-reporter:Ping Yan, Man He, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2017 Volume 136(Volume 136) pp:
Publication Date(Web):1 October 2017
DOI:10.1016/j.sab.2017.08.011
•P204 was grafted to Fe3O4@TiO2 NPs by Lewis acid-basic interaction between Ti and phosphate group.•Fe3O4@TiO2@P204 NPs show good selectivity for REEs and good anti-interference ability.•A method of MSPE-ICP-MS was developed for fast analysis of trace REEs in environmental samples.In this work, di(2-ethylhexyl)phosphoric acid (P204) grafted magnetic nanoparticles were synthesized by fabricating P204 onto Fe3O4@TiO2 nanoparticles based on Lewis acid-base interaction between Ti and phosphate group under weakly acidic condition. The prepared Fe3O4@TiO2@P204 nanoparticles exhibited excellent selectivity for rare earth elements, and good anti-interference ability. Based on it, a method of magnetic solid phase extraction (MSPE) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for fast preconcentration and determination of trace rare earth elements in environmental samples. Under the optimal conditions, the detection limits of rare earth elements were in the range of 0.01 (Tm)–0.12 (Nd) ng L− 1 with an enrichment factor of 100-fold, and the relative standard deviations ranged from 4.9 (Pr) to 10.7% (Er). The proposed method was successfully applied to the determination of rare earth elements in environmental samples, including river water, lake water, seawater and sediment.Graphical abstractDownload high-res image (43KB)Download full-size image
Co-reporter:Guangyang Xiao, Beibei Chen, Man He, Kaiwen Shi, Xing Zhang, Xiaoting Li, Qiumei Wu, Daiwen Pang, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2017 Volume 138(Volume 138) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.sab.2017.10.015
•An ICP-MS based immunoassay for the determination of avain influenza A (H9N2) virions was firstly established.•The stable and easy-prepared immuno-Au NPs probe was utilized for the labeling of H9N2 virions.•This method is simple, rapid, sensitive, selective, reliable and has a good application potential for virions detection in real-world samples.Avian influenza viruses are the pathogens of global poultry epidemics, and may even cause the human infections. Here, we proposed a novel inductively coupled plasma mass spectrometry (ICP-MS) based immunoassay with gold nanoparticles (Au NPs) labeling for the determination of H9N2 virions. Magnetic-beads modified with anti-influenza A H9N2 hemagglutinin mono-antibody (mAb-HA) were utilized for the capture of H9N2 virions in complex matrix; and Au NPs conjugated with mAb-HA were employed for the specific labeling of H9N2 virions for subsequent ICP-MS detection. With a sandwich immunoassay strategy, this method exhibited a high specificity for H9N2 among other influenza A virions such as H1N1 and H3N2. Under the optimized conditions, this method could detect as low as 0.63 ng mL− 1 H9N2 virions with the linear range of 2–400 ng mL− 1, the relative standard deviation for seven replicate detections of H9N2 virions was 7.2% (c = 10 ng mL− 1). The developed method was applied for the detection of H9N2 virions in real-world chicken dung samples, and the recovery for the spiking samples was 91.4–116.9%. This method is simple, rapid, sensitive, selective, reliable and has a good application potential for virions detection in real-world samples.Download high-res image (186KB)Download full-size image
Co-reporter:Siqi Zhu, Beibei Chen, Man He, Tong Huang, Bin Hu
Talanta 2017 Volume 171(Volume 171) pp:
Publication Date(Web):15 August 2017
DOI:10.1016/j.talanta.2017.04.068
•A method of MSPE-HPLC-ICP-MS was proposed for the speciation of Hg2+, MeHg+ and PhHg+.•HPLC separation of Hg2+, MeHg+ and PhHg+ was completed within 8 min.•The developed method provided high EFs, short analysis time, low LODs and wide linear range.•It is suitable for speciation of trace/ultra-trace mercury in real samples with complex matrix.In this paper, Fe3O4@SiO2@γ-mercaptopropyltrimethoxysilane (γ-MPTS) magnetic nanoparticles was prepared and a new method of magnetic solid phase extraction (MSPE)-high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the speciation of mercury including inorganic mercury (Hg2+), methylmercury (MeHg+) and phenylmercury (PhHg+) in environmental water, wastewater, tap water and fish samples. A rapid separation of three target mercury species was achieved in 8 min by employing relatively high ratio of methanol in HPLC mobile phase. Various parameters affecting Fe3O4@SiO2@γ-MPTS-based MSPE of target mercury species have been investigated. Under the optimized conditions, the limits of detection for Hg2+, MeHg+ and PhHg+ were in the range of 0.49–0.74 ng L−1. The intra- and inter-day relative standard deviations (n=5) were less than 9.0% and 12%, respectively. The developed MSPE-HPLC-ICP-MS method was validated by the speciation of mercury in the Certified Reference Material of DORM-2 dogfish as well as real-world samples including environmental water, wastewater, tap water and fish samples, and it has the advantages of simple operation, rapid separation, high sensitivity, high enrichment factor and is suitable for the analysis of mercury species in samples with complex matrix.Download high-res image (154KB)Download full-size image
Co-reporter:Yu Qiao, Xi Huang, Beibei Chen, Man He, Bin Hu
Talanta 2017 Volume 171(Volume 171) pp:
Publication Date(Web):15 August 2017
DOI:10.1016/j.talanta.2017.04.074
•The antagonism mechanism of glutathione, Se(IV) and Hg(II) was systematically studied.•GSH-Se(IV) system was studied based on stoichiometry, thermodynamics and kinetics.•Multiple hyphenated techniques were applied to the study of antagonism system.•The antagonism involves Hg/Se with GSH competitive binding and (HgxSey)n(GS)m complex forming.It has been broadly recognized that the antagonism between selenium (Se) and mercury (Hg) can reduce the toxicity of mercury in organism. Glutathione (GSH) can participate in the metabolism of Se and Hg in vivo and promote the formation of low-toxic Hg-Se complexes, which is a vital way of detoxification for Hg. In this paper, the reaction mechanism of GSH-Se(IV) binary system, GSH-Hg(II) binary system and GSH-Se(IV)-Hg(II) ternary system were systematically studied from the aspects of stoichiometry, thermodynamics and kinetics, via hyphenated techniques including high performance liquid chromatography (HPLC)-ultraviolet (UV) detection, HPLC-inductively coupled plasma mass spectrometry (ICP-MS) and HPLC-electrospray ionization mass spectrometry (ESI-MS). For GSH-Se(IV) binary system, selenodiglutathione (GSSeSG) was the crucial intermediate; the reaction was exothermic and irreversible at constant pressure; it followed second-order kinetics with a fast kinetics (rate constant (k)=4534.2 mol−1 L s−1). For GSH-Se(IV)-Hg(II) ternary system, GSSeSeSG would form by the extremely weak dissociation of two molecules of GSSeSG; Hg(II) would rapidly coordinate with GSSeSeSG to generate (HgxSey)n(GS)m precipitates. The mechanism of GSH-Se(IV)-Hg(II) antagonism system involves two processes, the competitive combination of Hg and Se with GSH and the formation of (HgxSey)n(GS)m complexes.Download high-res image (125KB)Download full-size image
Co-reporter:Zhengru Liu, Xiaoting Li, Guangyang Xiao, Beibei Chen, Man He, Bin Hu
TrAC Trends in Analytical Chemistry 2017 Volume 93(Volume 93) pp:
Publication Date(Web):1 August 2017
DOI:10.1016/j.trac.2017.05.008
•The artificial tag was discussed as the key point in detail for the first time.•The basic principles and different strategies of artificial tag were discussed.•The applications of artificial tag in different targets were summarized.Inductively coupled plasma mass spectrometry (ICP-MS) with the merits of high sensitivity and accuracy, strong tolerance to interference and multi-element simultaneous detection ability has shown its great potentials in the quantification of biomolecules with elemental labeling strategies in the past decade. Exogenous elemental tags play essential roles on the performance of ICP-MS based analytical strategies for biomolecules. In this review, the state of the art of ICP-MS based analytical techniques with exogenous tags for the quantification of biomolecules is provided. The basics of exogenous tags, such as the labeling strategies and classification of tags, are summarized, and the applications of ICP-MS based analytical techniques with elemental tags for the quantification of biomolecules (including proteins and nucleic acids) and cell analysis are discussed in detail. Finally, several prospects for the further development of this area are proposed.Download high-res image (240KB)Download full-size image
Co-reporter:Lijin Huang, Man He, Beibei Chen and Bin Hu
Journal of Materials Chemistry A 2016 vol. 4(Issue 14) pp:5159-5166
Publication Date(Web):08 Mar 2016
DOI:10.1039/C6TA00343E
A facile preparation of magnetic MOF composites with flexible mercapto group pendants in their pores is realized through solvent-assisted ligand exchange (SALE) under mild conditions in water, and terephthalate in UIO-66 is replaced with mercaptoacetic acid (MAA). After the SALE processing, the crystallinity, porosity, and superparamagnetism of the mercapto functionalized magnetic Zr-MOF (MFC-S) are well maintained, and the obtained MFC-S exhibits a higher adsorption capacity (282 mg g−1) for Hg2+ than that of the magnetic Zr-MOF (MFC-O). Furthermore, the prepared MFC-S can be regenerated easily by liquid desorption after adsorption of metal ions and be reused more than 5 times without obvious decrease in removal performance. The proposed SALE method for the preparation of mercapto functionalized magnetic MOF composites (MFCs) is easy-to-operate and low cost, providing not only a reliable porous MFC platform for the removal of metal ions, but also a simple and efficient synthesis route for the preparation of functionalized MFCs which cannot be achieved through conventional approaches.
Co-reporter:Han Wang, Beibei Chen, Siqi Zhu, Xiaoxiao Yu, Man He, and Bin Hu
Analytical Chemistry 2016 Volume 88(Issue 1) pp:796
Publication Date(Web):November 25, 2015
DOI:10.1021/acs.analchem.5b03130
Trace mercury speciation in cells is critical to understand its cytotoxicity and cell protection mechanism. In this work, we fabricated a chip-based magnetic solid-phase microextraction (MSPME) system, integrating a cell lysis unit as well as a sample extraction unit, and online combined it with micro high-performance liquid chromatography (microHPLC)–inductively coupled plasma mass spectrometry (ICPMS) for the speciation of mercury in HepG2 cells. Magnetic nanoparticles with sulfhydryl functional group were synthesized and self-assembled in the microchannels for the preconcentration of mercury species in cells under an external magnetic field. The enrichment factors are ca. 10-fold, and the recoveries for the spiked samples are in the range of 98.3–106.5%. The developed method was used to analyze target mercury species in Hg2+ or MeHg+ incubated HepG2 cells. The results demonstrated that MeHg+ entered into the HepG2 cells more easily than Hg2+, and part of the MeHg+ might demethylate into Hg2+ in HepG2 cells. Besides, comprehensive speciation of mercury in incubated cells revealed different detoxification mechanisms of Hg2+ and MeHg+ in Hg2+ or MeHg+ incubated HepG2 cells.
Co-reporter:Zhengru Liu, Beibei Chen, Man He, Xing Zhang, Han Wang and Bin Hu
Analyst 2016 vol. 141(Issue 3) pp:926-933
Publication Date(Web):16 Nov 2015
DOI:10.1039/C5AN01485A
Apoptosis is a main type of cell death in which caspase-3 plays a key role. In this work, a simple, fast and sensitive immunoassay for caspase-3 is established by using inductively coupled plasma mass spectrometry (ICP-MS) detection and signal enhancement gold nanoparticle (Au-NP) labelling of the secondary antibody (IgG). After the immunoreaction of caspase-3, primary antibody and Au-NP labeled IgG, the concentration of caspase-3 was determined by ICP-MS analysis of the Au-NPs released from the immunocomplex. Under the optimized conditions, a limit of detection (LOD, 3σ) of 0.42 ng mL−1 (0.31 nM) was obtained for caspase-3, with a dynamic range of 1–200 ng mL−1 and a relative standard deviation of 4.1% (c = 5 ng mL−1, n = 11). The proposed method has good specificity towards caspase-3. To demonstrate the application potential of the proposed method, the cell lysates of Hg2+-induced HepG2 cells were analyzed, and it was found that the concentration of caspase-3 increased when increasing the incubation concentration of Hg2+. This method is easy, sensitive and selective, and has excellent capability of tolerating a complex biological matrix, indicating the potential of the ICP-MS-based assay in the study of apoptosis.
Co-reporter:Xing Zhang, Beibei Chen, Man He, Yuan Zhang, Lu Peng and Bin Hu
Analyst 2016 vol. 141(Issue 4) pp:1286-1293
Publication Date(Web):15 Jan 2016
DOI:10.1039/C5AN02402A
Sialic acids are special sugars widely expressed at the termini of glycan chains on the cell surface, and their expression level on the cancer cell surface is much higher than on the normal cell surface. Herein, we reported an inductively coupled plasma mass spectrometry (ICP-MS) based method with elemental tags for the analysis of sialic acids on the cancer cell surface. The method is based on the selective recognition of sialic acids by biotinylated phenylboronic acid (biotin-APBA) at physiological pH and signal enhancement of gold nanoparticles (AuNPs) in ICP-MS when AuNPs were used as elemental tags labeled on biotin-APBA. A specificity test reveals that the proposed method has high specificity towards cancer cells. Taking HepG2 and MCF-7 cells as two model cancer cells, competitive experiments were performed to estimate the expression level of sialic acids on the cancer cell surface, and it was found that the average numbers of sialic acids expressed on the single MCF-7 and HepG2 cell surface were 7.0 × 109 and 5.4 × 109, respectively. With sialic acid as the biomarker for cancer cells, the method was further used for cell detection. The limits of detection in terms of cell number for HepG2 and MCF-7 cells were 120 and 64, respectively. And the relative standard deviations for nine replicate determinations of ca. 1000 HepG2 and MCF-7 cells were 9.6% and 8.9%, respectively. The linear ranges for HepG2 cells and MCF-7 cells were 300–10000 and 170–11000, respectively. The proposed approach is sensitive as well as selective for the analysis of sialic acids on the cancer cell surface, and is potentially applicable for the study of tumor malignancy and metastasis, which is helpful for biological research and clinical diagnostics.
Co-reporter:Wenying Fan, Man He, Linna You, Xuewei Zhu, Beibei Chen, Bin Hu
Journal of Chromatography A 2016 Volume 1443() pp:1-9
Publication Date(Web):22 April 2016
DOI:10.1016/j.chroma.2016.03.017
•A GO/MIP coating was prepared with good water compatibility and adsorption performance.•GO/MIP coating showed high chemical stability and good selectivity for propranolol.•GO/MIP-SBSE-HPLC-UV method exhibited good application potential in urine analysis.Due to the high selectivity and stability, molecularly imprinted polymers (MIPs) have been successfully applied in stir bar sorptive extraction (SBSE) as a special coating to improve the selective extraction capability for target analytes. However, traditional MIPs usually suffer from incompatibility in aqueous media and low adsorption capacity, which limit the application of MIP coated stir bar in aqueous samples. To solve these problems, a water-compatible graphene oxides (GO)/MIP composite coated stir bar was prepared in this work by in situ polymerization. The prepared water-compatible GO/MIP coated stir bar presented good mechanical strength and chemical stability, and its recognition ability in aqueous samples was improved due to the polymerization of MIP in water environment, the adsorption capacity for target analytes was also increased by the addition of GO in MIP pre-polymer solution. Based on it, a method of water-compatible GO/MIP coated stir bar sorptive extraction combined with high performance liquid chromatography-ultraviolet detector (HPLV-UV) was proposed for the analysis of propranolol (PRO) in aqueous solution. The influencing factors of SBSE, such as sample pH, salt effect, stirring rate, extraction time, desorption solvent and desorption time, were optimized, and the analytical performance of the developed SBSE-HPLC-UV method was evaluated under the optimized conditions. The limit of detection (LOD) of the proposed method for PRO was about 0.37 μg L−1, and the enrichment factor (EF) was 59.7-fold (theoretical EF was 100-fold). The reproducibility was also investigated at concentrations of 5 μg L−1 and the relative standard deviation (RSD) was found to be 7.3% (n = 7). The proposed method of GO/MIP coating-SBSE-HPLC-UV was successfully applied for the assay of the interested PRO drug in urine samples, and further extended to the investigation of the excretion of the drugs by monitoring the variation of the concentration of PRO in urine within 10 h after drug-taking.
Co-reporter:Cheng Zhong, Man He, Huaping Liao, Beibei Chen, Cheng Wang, Bin Hu
Journal of Chromatography A 2016 Volume 1441() pp:8-15
Publication Date(Web):8 April 2016
DOI:10.1016/j.chroma.2016.02.073
•PDMS/covalent triazine frameworks (CTFs) coated stir bar was prepared by sol–gel technique.•The preparation of PDMS/CTFs coated stir bars is simple and reproducible.•PDMS/CTFs exhibit better extraction efficiency than commercial PEG and PDMS for phenols.•PDMS/CTFs SBSE exhibits good application potential for polar OH-containing compounds.In this work, covalent triazine frameworks (CTFs) were introduced in stir bar sorptive extraction (SBSE) and a novel polydimethylsiloxane(PDMS)/CTFs stir bar coating was prepared by sol–gel technique for the sorptive extraction of eight phenols (including phenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, 2,4-dimethylphenol, p-chloro-m-cresol and 2,4-dichlorophenol, 2,4,6-trichlorophenol) from environmental water samples followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection. The prepared PDMS/CTFs coated stir bar showed good preparation reproducibility with the relative standard deviations (RSDs) ranging from 3.5 to 5.7% (n = 7) in one batch, and from 3.7 to 9.3% (n = 7) among different batches. Several parameters affecting SBSE of eight target phenols including extraction time, stirring rate, sample pH, ionic strength, desorption solvent and desorption time were investigated. Under the optimal experimental conditions, the limits of detection (LODs, S/N = 3) were found to be in the range of 0.08–0.30 μg/L. The linear range was 0.25–500 μg/L for 2-nitrophenol, 0.5–500 μg/L for phenol, 2-chlorophenol, 4-nitrophenol as well as 2,4-dimethylphenol, and 1–500 μg/L for p-chloro-m-cresol, 2,4-dichlorophenol as well as 2,4,6-trichlorophenol, respectively. The intra-day relative standard deviations (RSDs) were in the range of 4.3–9.4% (n = 7, c = 2 μg/L) and the enrichment factors ranged from 64.9 to 145.6 fold (theoretical enrichment factor was 200-fold). Compared with commercial PDMS coated stir bar (Gerstel) and PEG coated stir bar (Gerstel), the prepared PDMS/CTFs stir bar showed better extraction efficiency for target phenol compounds. The proposed method was successfully applied to the analysis of phenols in environmental water samples and good relative recoveries were obtained with the spiking level at 2, 10, 50 μg/L, respectively.
Co-reporter:Xueqin Guo, Man He, Kai Nan, He Yan, Beibei Chen and Bin Hu
Journal of Analytical Atomic Spectrometry 2016 vol. 31(Issue 2) pp:406-414
Publication Date(Web):15 Sep 2015
DOI:10.1039/C5JA00286A
Magnetic solid phase extraction (MSPE) was combined with hollow fiber liquid liquid liquid microextraction (HF-LLLME) for the extraction of seleno-amino acids. Graphene oxide (GO) modified magnetic nanoparticles (MNPs) were prepared and loaded with Cu2+ for the adsorption of target seleno-amino acids based on the interaction between Cu2+ and seleno-amino acids. Aqueous ethylenediamine was employed as the desorption solvent, and the desorption solution was directly employed as the donor solution in the subsequent HF-LLLME procedure for further preconcentration of target seleno-amino acids. In HF-LLLME, 1-octanol was employed as the extraction solvent, ionic liquid trioctylmethylammonium chloride ([MTOA]+[Cl]−) was employed as the carrier for the extraction of target seleno-amino acids, and aqueous NaNO3 solution was employed as the acceptor solution. The target seleno-amino acids were extracted from the donor solution into the organic phase and then back into the acceptor solution under the driving force of ion-pair formation between target seleno-amino acids and [MTOA]+[Cl]− and the gradient counter ions between the donor phase and the acceptor phase. Various factors influencing the extraction of target seleno-amino acids by MSPE and HF-LLLME were investigated thoroughly. Based on it, a method of MSPE-HF-LLLME coupled with high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) was developed and the analytical performance was evaluated under optimized conditions. After preconcentration by MSPE-HF-LLLME, the enrichment factors (EFs) for target seleno-amino acids ranged from 152 to 278-fold, and the LODs for target seleno-amino acids were in the range of 0.0075–0.013 μg L−1. A certified reference material of SELM-1 was used to validate the accuracy of the proposed method, and the determined value of SeMet was in good agreement with the certified values. The proposed method was successfully applied to the speciation of seleno-amino acids in rice and Se-enriched yeast cell samples.
Co-reporter:Jing Zhang, Beibei Chen, Han Wang, Xi Huang, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2016 vol. 31(Issue 7) pp:1391-1399
Publication Date(Web):25 Apr 2016
DOI:10.1039/C6JA00105J
Microfluidic devices provide a potential platform that can specialize in miniaturization, integration and automation. In this study, we prepared ethanediamine modified poly glycidyl methacrylate trimethylol propane triacrylate monolithic columns (poly (GMA-co-TRIM-NH2)) in a microfluidic chip channel and established a novel method by combining chip-based poly (GMA-co-TRIM-NH2) monolithic microextraction with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of bismuth in cell samples. Various factors affecting chip-based monolithic microextraction of bismuth were investigated. Under the optimized conditions, the limit of detection was 0.21 ng mL−1 and the relative standard deviation for bismuth was 6.0% (c = 5 ng mL−1, n = 7). The method was successfully applied to the analysis of HepG2 cells incubated with bismuth. With consumption of ∼600 cells, the average amount of bismuth was determined to be at the sub picogram level in a single cell. The prepared chip-based poly (GMA-co-TRIM-NH2) monolithic column had a high-surface area and exhibited high extraction efficiency towards bismuth. The proposed chip-based monolithic microextraction method combined with ICP-MS provides a novel strategy for the analysis of trace metals in cells.
Co-reporter:Feiya Suo, Beibei Chen, Man He and Bin Hu
Analytical Methods 2016 vol. 8(Issue 23) pp:4680-4688
Publication Date(Web):04 May 2016
DOI:10.1039/C6AY01008C
In this study, an ethylenediamine modified poly(glycidyl methacrylate-co-divinyl benzene) monolithic capillary column was prepared, and a novel method based on monolithic capillary microextraction on-line combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for determining Ni, Cu and Cd in biological samples. In order to improve the sample throughput, two polymer monolithic capillary columns were on-line parallelly combined with ICP-MS by employing a flow injection system. Various factors affecting the extraction efficiency, such as pH value, sample flow rate, sample volume, elution conditions and coexisting ions, were investigated in detail. Under the optimal conditions, the limits of detection were 14.7, 17.1 and 1.5 ng L−1 for Ni, Cu and Cd, with the relative standard deviations (c = 50 ng L−1, n = 7) of 3.0%, 3.9% and 3.5% for Ni, Cu and Cd, respectively. The proposed method was successfully applied to Ni, Cu and Cd analysis in human hair and urine samples with the recovery for the spiked samples in the 85–114% range.
Co-reporter:Qiangying Zhang, Man He, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2016 Volume 121() pp:1-10
Publication Date(Web):1 July 2016
DOI:10.1016/j.sab.2016.04.005
•Saussurea tridactyla Sch-Bip (STSB) is prepared and characterized as a new green adsorbent.•Alkali treated STSB presents high adsorption capacity, fast adsorption kinetics for REEs.•A method of on-line SPE-ICP-OES was developed for trace REE analysis in water samples.This paper deals with preparation, characterization and application of the Saussurea tridactyla Sch-Bip (STSB) as a new green adsorbent for separation of matrix elements and preconcentration of rare earth elements (REEs) in environmental water samples. The pretreated STSB adsorbent with 2 mol L− 1 NaOH is characterized with higher surface area and adsorption capacities in comparison with a raw STSB material. The new adsorbent was used for the development of on-line solid phase extraction (SPE) for the determination of REEs by radial viewing 27 MHz inductively coupled plasma optical emission spectrometry (ICP-OES). Various parameters affecting the adsorption/desorption procedure were optimized. The adsorption capacities for the STSB were found to be 62.2 (Y)–153 mg g− 1 (Tm). Under the optimized conditions, the limits of detection (LODs, 3σ) for REEs were in the range of 0.06 (Yb)–8.77 (Sm) ng mL− 1. The relative standard deviations (RSDs) for 7 replicate determinations of target REEs at low concentration level ranged from 2.4 (Yb) to 8.9 (Sm)%. The adsorption isotherm fitted Langmuir model and the adsorption kinetics fitted well with both Pseudo-first order and Pseudo-second order models. The predominant adsorption mechanism is ion exchange. The STSB pretreated with 2 mol L− 1 NaOH has been demonstrated to be low cost, green and environment friendly adsorbent, featuring with high adsorption capacity, wide pH range, and fast adsorption/desorption kinetics for target REEs with long lifetime. The proposed method was applied to the determination of REEs in East Lake, Yangtze River and rain water samples.
Co-reporter:Ying Liu, Man He, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2016 Volume 122() pp:94-102
Publication Date(Web):1 August 2016
DOI:10.1016/j.sab.2016.04.009
•SA-DLLME combined with ETV-ICP-MS was proposed for the analysis of AuNPs in environmental water.•AuNPs with both different sizes and different coatings could be extracted.•AuNPs could preserve their morphology in terms of the size and shape during the extraction process.•The proposed method is simple, sensitive, selective, and no digestion or dilution required.A new method by coupling surfactant assisted dispersive liquid liquid microextraction (SA-DLLME) with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was proposed for the analysis of gold nanoparticles (AuNPs) in environmental water samples. Effective separation of AuNPs from ionic gold species was achieved by using sodium thiosulphate as a complexing agent. Various experimental parameters affecting SA-DLLME of AuNPs, such as the organic solvent, organic solvent volume, pH of the sample, the kind of surfactant, surfactant concentration, vortex time, speed of centrifugation, centrifugation time, and different coating as well as sizes of AuNPs were investigated carefully. Furthermore, the interference of coexisting ions, dissolved organic matter (DOM) and other metal nanoparticles (NPs) were studied. Under the optimal conditions, a detection limit of 2.2 ng L− 1 and an enrichment factor of 152-fold was achieved for AuNPs, and the original morphology of the AuNPs could be maintained during the extraction process. The developed method was successfully applied for the analysis of AuNPs in environmental water samples, including tap water, the East Lake water, and the Yangtze River water, with recoveries in the range of 89.6–102%. Compared with the established methods for metal NPs analysis, the proposed method has the merits of simple and fast operation, low detection limit, high selectivity, good tolerance to the sample matrix and no digestion or dilution required. It provides an efficient quantification methodology for monitoring AuNPs' pollution in the environmental water and evaluating its toxicity.
Co-reporter:Xing Zhang, Beibei Chen, Man He, Han Wang, Bin Hu
Biosensors and Bioelectronics 2016 Volume 86() pp:736-740
Publication Date(Web):15 December 2016
DOI:10.1016/j.bios.2016.07.073
•AuNPs labeling and HCR dual amplification strategy was developed for ICP-MS cells counting.•anti-EpCAM conjugated magnetic beads were used for selective capture of tumor cells.•AuNPs labeled DNA concatamer was used as signal probe for tumor cell labeling and detection.•The method was validated by the detection of HepG2 cells in the peripheral blood samples.•The developed method was efficient, specific and sensitive for tumor cells detection.Sensitive detection of circulating tumor cells (CTCs) is of great significance in the early detection of cancer and cancer metastasis. This work reported an efficient, specific, and sensitive immunoassay protocol for detection of tumor cells by using inductively coupled plasma mass spectrometry (ICP-MS) with gold nanoparticles (AuNPs) labeling and hybridization chain reaction (HCR) amplification. In the established approach, antibodies against epithelial cell adhesion molecule (anti-EpCAM) conjugated magnetic beads (MBs) were used for selective capture of tumor cells from peripheral blood, aptamer was applied for the recognition of captured tumor cells, and AuNPs labeled DNA concatamer was used as the signal probe for tumor cell labeling and ICP-MS detection. Due to the dual amplification effect of AuNPs and HCR, the limit of detection of this ICP-MS based method for HepG2 cells was as low as 15 cells, and the linear range was 40–8000 cells with the relative standard deviation for seven replicate detections of 200 HepG2 cells was 8.7%. Furthermore, the applicability of the method for the analysis of peripheral blood samples was demonstrated by the spiking tests. The established method was highly specific and sensitive for the detection of HepG2 cells, and has a good application potential in clinical diagnosis.
Co-reporter:Yun Lei, Man He, Beibei Chen, Bin Hu
Talanta 2016 Volume 150() pp:310-318
Publication Date(Web):1 April 2016
DOI:10.1016/j.talanta.2015.12.025
•PANI/α-CD composite coated stir bar was prepared for analyzing PCBs in waters.•It presented high extraction efficiency and fast desorption kinetics for PCBs.•It exhibited faster extraction kinetics (50 min) than PDMS-SBSE (14 h) for PCBs.•PANI/α-CD-SBSE-HPLC-UV was successfully used for analyzing PCBs in waters.A novel polyaniline/α-cyclodextrin (PANI/α-CD) composite coated stir bar was prepared by sol–gel process for the analysis of polychlorinated biphenyls (PCBs) in this work. The preparation reproducibility of the PANI/α-CD-coated stir bar was good, with relative standard deviations (RSDs) ranging from 2.3% to 3.7% (n=7) and 2.0% to 3.8% (n=7) for bar to bar and batch to batch, respectively. Based on it, a novel method of PANI/α-CD-coated stir bar sorptive extraction (SBSE) followed by high performance liquid chromatography-ultraviolet (HPLC-UV) detection was developed for the determination of trace PCBs in environmental waters. To obtain the best extraction performance for target PCBs, several parameters affecting SBSE, such as extraction time, stirring rate, and ionic strength were investigated. Under optimal experimental conditions, the limits of detection (LODs) of the proposed method for seven PCBs were in the range of 0.048–0.22 μg/L, and the RSDs were 5.3–9.8% (n=7, c=1 μg/L). Enrichment factors (EFs) ranging from 39.8 to 68.4-fold (theoretical EF, 83.3-fold) for target analytes were achieved. The proposed method was successfully applied for the determination of seven target PCBs in Yangtze River water and East Lake water, and the recoveries were in the range of 73.0–120% for the spiked East Lake water samples and 82.7–121% for the spiked Yangtze River water samples, respectively.
Co-reporter:Shishuai Ma, Man He, Beibei Chen, Wenchao Deng, Qi Zheng, Bin Hu
Talanta 2016 Volume 146() pp:93-99
Publication Date(Web):1 January 2016
DOI:10.1016/j.talanta.2015.08.036
•CH3Hg+ and Hg2+ exhibit different desorption behavior on Fe3O4@SiO2@γ-MPTS.•A method of MSPE ICP-MS was proposed for the speciation of CH3Hg+ and Hg2+.•It is selective for target species with fast dynamics and good anti-interference ability.In this work, γ-mercaptopropyltrimethoxysilane (γ-MPTS) modified Fe3O4@SiO2 magnetic nanoparticles (MNPs) was successfully prepared, and characterized by Fourier transform infrared spectrometer (FT-IR), Transmission electron microscope (TEM) and Vibrating sample magnetometer (VSM). The sorption performance of the prepared Fe3O4@SiO2@γ-MPTS MNPs towards methylmercury (CH3Hg+) and inorganic mercury (Hg2+) was investigated. It was found that CH3Hg+ and Hg2+ could be simultaneously retained on the prepared Fe3O4@SiO2@γ-MPTS MNPs, and the quantitative elution of CH3Hg+ and total mercury (THg) was achieved by using 1.5 mol L−1 HCl containing 0.01% and 3% thiourea (m/v), respectively. And the levels of Hg2+ were obtained by subtracting CH3Hg+ from THg. Based on the above facts, a method of magnetic solid phase extraction (MSPE) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the speciation of CH3Hg+ and Hg2+. Various experimental parameters affecting MSPE of CH3Hg+ and Hg2+ such as pH, eluent, sample volume, and co-existing ions have been studied. Under the optimized conditions, the limits of detection (LODs) for CH3Hg+ and THg were 1.6 and 1.9 ng L−1, respectively. The accuracy of the proposed method was validated by analysis of a Certified Reference Material NRCC DORM-2 dogfish muscle, and the determined values are in good agreement with the certified values. The proposed method has also been successfully applied for the speciation of CH3Hg+ and Hg2+ in environmental water and human hair samples.
Co-reporter:Lijin Huang, Man He, Beibei Chen and Bin Hu
Journal of Materials Chemistry A 2015 vol. 3(Issue 21) pp:11587-11595
Publication Date(Web):21 Apr 2015
DOI:10.1039/C5TA01484K
A magnetic MOF composite was successfully prepared by a novel and green strategy through reasonable design. The nano Fe3O4@SiO2 core was first coated by a shell of Cu(OH)2 as the self-template, followed by a conversion of Cu(OH)2 into HKUST-1 at room temperature in a water–ethanol mixture solvent, and Fe3O4@SiO2@HKUST-1 core–shell nanostructures were obtained successfully. Based on this, a Bi-I-functionalized-magnetic HKUST-1 composite was prepared through a flexible coordination-based post-synthetic strategy. Powder X-ray diffraction spectrometry, N2 sorption–desorption isotherms and Fourier transform infrared spectroscopy were used for the characterization of the magnetic MOF composites. The core–shell morphology was confirmed by transmission electron microscope images and the result of thermogravimetric analysis showed that the magnetic composites had excellent thermal stability. Besides, the adsorption of Hg2+ on Fe3O4@SiO2, Fe3O4@SiO2@HKUST-1 and Bi-I-functionalized magnetic MOF composites was investigated, and a good adsorption selectivity of Bi-I-functionalized magnetic MOF composites towards Hg2+ was demonstrated, with high adsorption capacity (264 mg g−1) and fast adsorption dynamics. The Bi-I-functionalized magnetic HKUST-1 composite was then successfully employed for the selective removal of Hg2+ from water, demonstrating great potential application of the prepared magnetic MOF composite as a fascinating adsorbent in environmental monitoring.
Co-reporter:Xiaolan Liu, Beibei Chen, Lin Zhang, Shiyao Song, Yabing Cai, Man He, and Bin Hu
Analytical Chemistry 2015 Volume 87(Issue 17) pp:8949
Publication Date(Web):August 4, 2015
DOI:10.1021/acs.analchem.5b02111
In this work, a novel method of TiO2 nanoparticles (NPs) functionalized monolithic capillary microextraction (CME) online coupling with inductively coupled plasma mass spectrometry (ICPMS) was developed for the sequential determination of Gd3+ and Gd-based contrast agents in human urine samples. The monolithic capillary was prepared by embedding anatase TiO2 NPS in the poly(methacrylic acid-ethylene glycol dimethacrylate) (MAA-EDMA) framework. The Gd3+ and Gd-based contrast agents (such as gadolinium-diethylene triamine pentaacetic acid (Gd-DTPA) and Gd-DTPA-bismethylamide (Gd-DTPA-BMA)) display different adsorption behaviors on the prepared monolithic capillary which possesses the adsorption properties of both anatase TiO2 NPS and poly(MAA-EDMA) monolith. Under the optimized conditions, the limits of detection (LODs) were found to be 3.6, 3.2, and 4.5 ng L–1 for Gd3+, Gd-DTPA, and Gd-DTPA-BMA, respectively, which are the lowest up to date. The enrichment factor was 25-fold with the sample throughput of 5 h–1. The proposed method was validated by the analysis of Gd3+ and Gd-DTPA in the healthy human urine samples as well as Gd3+ and Gd-DTPA-BMA in patient urine samples. It was found that only a small amount of the free Gd3+ was released from Gd-DTPA-BMA, and accurate results could be obtained since no oxidation/reduction or subtraction is involved in this method. This method is simple, sensitive, and rapid and provides a very attractive nonchromatography strategy for the speciation of Gd3+ and Gd-based contrast agents in urine samples.
Co-reporter:Lin Zhang, Beibei Chen, Man He, Xiaolan Liu, and Bin Hu
Analytical Chemistry 2015 Volume 87(Issue 3) pp:1789
Publication Date(Web):January 9, 2015
DOI:10.1021/ac503798c
In this study, the hydrophilic polymer monolithic capillary (poly(acrylamide-vinylpyridine-methylene bis(acrylamide)), poly(AA-VP-Bis)) was prepared for the separation and enrichment of carboxyl group-containing gold nanoparticles (Au NPs) from environmental waters followed by online ICPMS determination. The extraction mechanism of the prepared poly(AA-VP-Bis) monolithic capillary for Au NPs is based on the static electrical and hydrogen bond interactions between the carboxyl group on the surface of Au NPs and pyridine/amide groups on the surface of the monolith. Under the optimal conditions, a detection limit of 24.2 fmol L–1 and a sample throughput of 6 h–1 were achieved for 3 nm citrate stabilized Au NPs, and the original morphology of the Au NPs could be maintained during the extraction process. The developed method was successfully applied for the analysis of carboxyl group-containing Au NPs in environmental water samples, such as tap water, the Yangtze River water, and the East Lake water, with recoveries in the range of 77–103%. Compared with the reported approaches for analysis of Au NPs, this method is an online strategy for carboxyl group-containing Au NPs determination and has the merits of low detection limit, small sample consumption, fast extraction/desorption kinetics, wide linear range, high selectivity, and high throughput.
Co-reporter:Xiaoqing Zhou, Man He, Beibei Chen and Bin Hu
Analyst 2015 vol. 140(Issue 5) pp:1662-1671
Publication Date(Web):07 Jan 2015
DOI:10.1039/C4AN02209B
An effective dual preconcentration method involving off-line hollow fiber liquid–liquid–liquid microextraction (HF-LLLME) and on-line sweeping micellar electrokinetic chromatography (sweeping-MEKC) was proposed for the determination of five second-generation antidepressants, including fluoxetine, sertraline, paroxetine, fluvoxamine and citalopram. In HF-LLLME, the analytes were extracted from the sample solution into phenetole impregnated in the pores of the hollow fiber and then back-extracted into 10 μL 0.1 mol L−1 HAc inside the hollow fiber. Then, the acceptor phase was spiked with 2.8 μL isopropanol (IPA) and introduced into CE for sweeping. In the sweeping-MEKC process, five target analytes were separated in less than 15 min with a background electrolyte consisting of 76% (v/v) 50 mmol L−1 citric acid (pH 2.2) containing 100 mmol L−1 sodium dodecyl sulfate (SDS) and 24% (v/v) IPA. The hydrodynamic injection was performed at 50 mbar for 140 s. Under optimized conditions, the limits of detection were in the range of 0.40–1.55 μg L−1 with enrichment factors of 1897- to 5952-fold for target analytes, with a dynamic linear range of 0.6/5.0–200 μg L−1. The developed method demonstrated excellent clean-up ability and high enrichment factors and was successfully applied to the analysis of target analytes in human urine and plasma samples.
Co-reporter:Wenying Fan, Mingqi Gao, Man He, Beibei Chen and Bin Hu
Analyst 2015 vol. 140(Issue 12) pp:4057-4067
Publication Date(Web):30 Mar 2015
DOI:10.1039/C5AN00325C
In this work, a molecularly imprinted polymer (MIP) coated stir bar was prepared using a self-designed polytetrafluoroethylene (PTFE) mold and in situ polymerization, with cyromazine as the dummy template for the target melamine. The prepared MIP coated stir bar presented a uniform and porous surface as well as good chemical stability and selectivity for melamine. Based on it, a method of MIP coated stir bar sorptive extraction (SBSE) combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for the quantification of melamine in food samples. Significant factors affecting the extraction efficiency of melamine by MIP-SBSE, such as the extraction solvent and time, stirring rate, desorption solvent and time, were investigated thoroughly. Under the optimal conditions, the analytical performance of this method was evaluated. The detection limit of the developed method was 0.54 μg L−1 for melamine with an enrichment factor of 42-fold and the relative standard deviation (RSD) of 6.1% (c = 5 μg L−1, n = 7), and the linear range was 2–200 μg L−1. The established method was applied for the determination of melamine in a variety of real samples including cat food, dog food, chicken feed A, chicken feed B and milk powder, and the recoveries for melamine in the spiked samples were in the range of 76.2–98.2%, 80.0–85.5%, 89.5–113%, 85.0–95.5% and 65.0–111%, respectively. The proposed method presented a good specific recognition ability and matrix interference resistance, and was demonstrated to be effective and sensitive for the analysis of melamine in animal food and milk samples.
Co-reporter:Ping Yan, Man He, Beibei Chen and Bin Hu
Analyst 2015 vol. 140(Issue 12) pp:4298-4306
Publication Date(Web):23 Apr 2015
DOI:10.1039/C5AN00385G
Herein, restricted accessed magnetic nanoparticles were synthesized by self-assembly of a non-ionic surfactant (Tween-20) onto the 4-(2-pyridylazo)resorcinol (PAR) functionalized magnetic nanoparticles (MNPs). A series of analytical techniques were employed for the characterization of the as-prepared restricted accessed Fe3O4@SiO2@PAR, and it was found that the as-prepared restricted accessed Fe3O4@SiO2@PAR nanoparticles have a porous structure with a BET surface area of around 99.4 m2 g−1, an average pore size of about 6.14 nm and a pore volume of 0.47 cm3 g−1. Besides, the prepared restricted accessed Fe3O4@SiO2@PAR showed good size exclusion properties toward proteins, providing application potential for the direct analysis of biological samples. Based on this, a novel method of restricted accessed magnetic solid phase extraction (MSPE) combined with inductively coupled plasma-mass spectrometry (ICP-MS) was developed for the direct determination of trace metal ions in human fluids. The parameters affecting the extraction of the target metals by MSPE were studied and the optimized conditions were established. Under the optimum conditions, the adsorption capacity of Cr(III), Cd(II), La(III), Nd(III) and Pb(II) on the as-prepared restricted accessed Fe3O4@SiO2@PAR was 62.9, 56.6, 33.7, 36.9 and 43.3 mg g−1, respectively. With an enrichment factor of 30, the limits of detection for Cr(III), Cd(II), La(III), Nd(III) and Pb(II) were as low as 11.9, 0.8, 0.7, 1.6 and 4.1 ng L−1, and the relative standard deviations were 7.6, 8.7, 8.4, 8.1 and 5.0 (CCr, Pb = 0.05 μg L−1, CCd, La = 0.005 μg L−1, CNd = 0.01 μg L−1, n = 7), respectively. The developed method was successfully applied for the direct analysis of free metal ions in human urine and serum samples, and has the advantages of good anti-interference ability, high sensitivity and exhibits great application potential in the direct analysis of trace metals in biological fluids.
Co-reporter:Han Wang, Zhekuan Wu, Beibei Chen, Man He and Bin Hu
Analyst 2015 vol. 140(Issue 16) pp:5619-5626
Publication Date(Web):10 Jun 2015
DOI:10.1039/C5AN00736D
Determination of trace elements in cells is critical to metallomics research and still faces tremendous difficulties even with the help of highly sensitive inductively coupled plasma mass spectrometry (ICP-MS). Microfluidic chips offer a functional tool-set for cell analysis with features of miniaturization, integration and automation. In this work, we proposed a chip-based array magnetic solid phase microextraction (MSPME) system and on-line combined it with ICP-MS via microflow concentric nebulization for the determination of trace Cu, Zn, Cd, Hg, Pb and Bi in cells. Under the optimized conditions, the limits of detection of the developed on-line chip-based array MSPME-ICP-MS system are 49, 43, 4.2, 6.1, 13 and 18 ng L−1 for Cu, Zn, Cd, Hg, Pb and Bi, respectively. The proposed method was applied to the analysis of target heavy metals in three kinds of cells (HepG2, Jurkat T and MCF7), and the recoveries for the spiked samples were in the range of 83.8%–117%. The extractable species of the target metals in cells were also studied and the results demonstrated a high selectivity of the developed methods towards free metal ions and/or their small molecular species.
Co-reporter:Cong Hu, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A 2015 Volume 1394() pp:36-45
Publication Date(Web):15 May 2015
DOI:10.1016/j.chroma.2015.03.046
•PANi/MWCNTs-OH composite-coated stir bar was prepared via the adhesion technique.•The preparation of PANi/MWCNTs-OH composite-coated stir bars is simple and reproducible.•PANi/MWCNTs-OH composite coating can simultaneously extract polar and apolar analytes.•A novel method of PANi/MWCNTs-OH-SBSE-HPLC–UV was developed for environmental analysis.Developing novel coatings for stir bar sorptive extraction (SBSE) is essential for extending the application of SBSE. Herein, a polyaniline/hydroxyl multi-walled carbon nanotubes (PANi/MWCNTs-OH) composite-coated stir bar was prepared via the adhesion technique for the simultaneous extraction of polar and apolar compounds, and a novel method of PANi/MWCNTs-OH-coated SBSE coupled with high performance liquid chromatography-ultraviolet detection (HPLC–UV) was proposed. To test the extraction performance of PANi/MWCNTs-OH-coated stir bar, phenols, non-steroidal anti-inflammatory drugs, and polychlorinated biphenyls were selected as representatives for polar, semi-polar and apolar compounds, respectively. High enrichment factors (EFs) ranged from 20.4 to 60.4-fold (theoretical EF, 100-fold) for target analytes were achieved, indicating that the proposed method is applicable in simultaneous analysis of the compounds with different polarities. The prepared PANi/MWCNTs-OH-coated stir bar has a good preparation reproducibility and can be reused for 20 times. The limits of detection (LODs, S/N = 3) were found to be in the range of 0.09–0.81 μg/L. To validate the applicability, the proposed method was successfully applied to the analysis of eight target analytes in Yangtze River water after filtration and in the extract from sediment samples.
Co-reporter:Xiangju Mao, Wenying Fan, Man He, Beibei Chen and Bin Hu
Journal of Analytical Atomic Spectrometry 2015 vol. 30(Issue 1) pp:162-171
Publication Date(Web):22 Oct 2014
DOI:10.1039/C4JA00294F
In this paper, a new approach of C18-coated stir bar sorptive extraction (SBSE) coupled with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was developed for the speciation of butyltins in environmental samples. The butyltin compounds, including monobutyltin trichloride (MBT), dibutyltin dichloride (DBT) and tributyltin chloride (TBT), were first extracted with a C18-coated stir bar, and then desorbed with 40% (v/v) methanol for subsequent HPLC-ICP-MS analysis. The factors affecting C18-SBSE were systematically studied. To reduce the percentage of organic solvents in the mobile phase loaded on the plasma and to improve the separation resolution, a CN column with carboxylic acids as the mobile phase additives was used for butyltin separation. Quick separation (<8 min) was accomplished using a methanol–formic acid–water (16:8:76, v/v/v) mobile phase containing 5 mmol L−1 mercaptoacetic acid, and the mobile phase was compatible with the conventional quadrupole ICP-MS detector without addition of oxygen gas or desolvation and post-column dilution systems. Under the optimal conditions, the limits of detection for three target butyltins ranged from 15.6 to 29.4 ng L−1, with a linear range of 0.05–50 μg L−1. The enrichment factors (EFs) were 85- to 127-fold (the theoretical EF is 200-fold). The developed method is simple and rapid, with no derivatization involved, and is successfully applied to the speciation of butyltins in the Certified Reference Material of PACS-2 sediment and real water as well as sediment samples from the East Lake, Yangtze River and Bohai Sea in China.
Co-reporter:Beibei Chen, Yunli Wu, Xueqin Guo, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2015 vol. 30(Issue 4) pp:875-881
Publication Date(Web):27 Oct 2014
DOI:10.1039/C4JA00312H
A novel method by combining hollow fiber-liquid–liquid–liquid microextraction (HF-LLLME) with HPLC-ICP-MS was developed for the speciation of inorganic mercury (Hg2+) and organomercury including methylmercury (MeHg+), ethylmercury (EtHg+) and phenylmercury (PhHg+), in the micro-ecosystem of East Lake (Wuhan, China). The factors affecting HF-LLLME were systematically investigated. Under the optimized conditions, the limits of detection for four mercury species were in the range of 2.9–5.6 ng L−1 with the relative standard deviations (c = 0.5 μg L−1, n = 7) ranging from 5.6 to 10.6%. The developed method was validated by analyzing a certified reference material of DORM-2, and the determined values were in good agreement with the certified values. The method has been applied for the speciation of mercury in five representative samples from the micro-ecosystem of East Lake including atmospheric particles, lake water, fish, plant and sediment.
Co-reporter:Chao Cui, Hanyong Peng, Yanan Zhang, Kai Nan, Man He, Beibei Chen and Bin Hu
Journal of Analytical Atomic Spectrometry 2015 vol. 30(Issue 6) pp:1386-1394
Publication Date(Web):23 Mar 2015
DOI:10.1039/C5JA00035A
Ti-containing mesoporous silica was prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectrometry (UV-Vis) and the N2 adsorption technique. The adsorption behaviours of Cr(III), Cu(II), Cd(II) and Pb(II) on Ti-containing mesoporous silica were studied and the adsorption mechanism was also investigated by FT-IR and X-ray photoelectron spectroscopy (XPS). With Ti-containing mesoporous silica as the adsorbent, a new method of microcolumn solid phase extraction (SPE) combined with inductively coupled plasma-mass spectrometry (ICP-MS) was established for the determination of Cr(III), Cu(II), Cd(II) and Pb(II) in environmental samples. The parameters affecting extraction and desorption of the target analytes, such as pH, sample flow rate, desorption reagent, desorption flow rate and sample volume, were investigated. Under optimized conditions, the limits of detection (LODs) of Cr(III), Cu(II), Cd(II) and Pb(II) were 19, 39, 7 and 13 pg mL−1 with a preconcentration factor of 10, respectively, and the relative standard deviations (RSDs) varied from 6.1 to 7.3% (n = 7, c = 1 ng mL−1). The developed method was applied to analyze environmental water and soil samples with recovery in the range of 85–119% for the spiked samples. In order to validate the accuracy of the method, certified reference materials of GSBZ50009-88 (environmental water), GBW07429 and GBW07425 (soil sample) were analyzed and the determined values were in good agreement with the certified values. The developed method is simple, rapid, sensitive and suitable for the analysis of trace elements in environmental samples with complex matrices.
Co-reporter:Ying Liu, Man He, Beibei Chen and Bin Hu
Analytical Methods 2015 vol. 7(Issue 15) pp:6182-6189
Publication Date(Web):18 Jun 2015
DOI:10.1039/C5AY01181G
A method based on solidification of floating organic drop microextraction (SFODME) with vortex-assisted (VA) emulsification was proposed for the preconcentration of organophosphorus pesticides (OPPs) in water samples, followed by gas chromatography (GC) with flame photometric detection (GC-FPD). A binary mixed solvent whose density is lower than water was used as an extractant to improve the extraction efficiency of the five target OPPs and avoid the employment of traditional organic solvents that are usually highly toxic and expensive. Moreover, vortex agitation accelerated the dispersion of extraction solvents in aqueous samples. The significant parameters affecting the VA-SFODME of target OPPs were studied in detail and the optimal extraction conditions were established. With the use of tributyl phosphate (TBP) as the internal standard, the limits of detection (S/N = 3) were found to be in the range of 0.12–0.56 μg L−1 for the five target OPPs, and the linear range was from 0.6 μg L−1 to 100 μg L−1. The RSDs of the proposed method were in the range of 5.4–13.9% (n = 7, c = 3 μg L−1) and the enrichment factors varied from 117 to 215-fold. The proposed method was successfully applied to the analysis of five OPPs in East Lake water, well water and rainwater samples, and the recoveries for spiked samples were in the range of 83.7–112%.
Co-reporter:Fan WANG, Man HE, Bei-Bei CHEN, Yang XIANG, Bin HU
Chinese Journal of Analytical Chemistry 2015 Volume 43(Issue 9) pp:1313-1321
Publication Date(Web):September 2015
DOI:10.1016/S1872-2040(15)60853-2
TiO2 coated hollow fiber (HF) was prepared by sol-gel method and characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of the self-prepared TiO2 coated HF for interest metal ions was explored and a series of affecting factors including sample pH, extraction time, stirring rate and desorption condition were investigated and optimized. On basis of this, a method combining TiO2 coated HF micro-solid phase extraction with electrothermal vaporization (ETV)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace metal ions in environmental water samples. Under the optimized conditions, the limits of detection obtained by the proposed method were 0.039, 0.021, 0.009 and 0.018 ng mL−1 for Cr(III), Cu(II), Cd(II) and Pb(II) with enrichment factors of 12.5, 11.7, 10.3 and 18.6, respectively. The preparation reproducibility of self-prepared TiO2 coated HF ranged from 4.5% to 6.8% (n = 9) in one batch, and from 7.7% to 9.6% (n = 7) in batch-to-batch. The developed method was validated by analyzing a certified reference material (GSBZ50009-88 200925) and also applied to the analysis of target metal ions in East Lake water and snow water successfully. Meanwhile, TiO2 coated HF stir bar was prepared for a comparison and it was demonstrated that TiO2 coated HF displayed higher extraction efficiency and adsorption capacity for the target ions.TiO2 coated hollow fiber microextraction combined with ETV-ICP-MS detection for the determination of trace metal ions in environmental water.
Co-reporter:Hanyong Peng, Nan Zhang, Man He, Beibei Chen, Bin Hu
Talanta 2015 Volume 131() pp:266-272
Publication Date(Web):January 2015
DOI:10.1016/j.talanta.2014.07.054
•A new sorbent was synthesized with good selectivity and fast kinetics for target species.•Simultaneous speciation inorganic As, Cr and Se was realized by SPE-ICP-MS.•The method is characterized with simplicity, safety, cheapness and rapidness.Speciation analysis of inorganic arsenic, chromium and selenium in environmental waters is of great significance for the monitoring of environmental pollution. In this work, 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS) functionalized multi-wall carbon nanotubes (MWCNTs) were synthesized and employed as the adsorbent for simultaneous speciation analysis of inorganic arsenic, chromium and selenium in environmental waters by microcolumn solid-phase extraction (SPE)-inductively coupled plasma mass spectrometry (ICP-MS). It was found that As(V), Cr(VI) and Se(VI) could be selectively adsorbed on the microcolumn packed with AAPTS-MWCNTs adsorbent at pH around 2.2, while As(III), Cr(III) and Se(IV) could not be retained at this pH and passed through the microcolumn directly. Total inorganic arsenic, chromium and selenium was determined after the oxidation of As(III), Cr(III) and Se(IV) to As(V), Cr(VI) and Se(VI) with 10.0 μmol L−1 KMnO4. The assay of As(III), Cr(III) and Se(IV) was based on subtracting As(V), Cr(VI) and Se(VI) from the total As, Cr and Se, respectively. Under the optimized conditions, the detection limits of 15, 38 and 16 ng L−1 with the relative standard deviations (RSDs) of 7.4, 2.4 and 6.2% (c=1 µg L−1, n=7) were obtained for As(V), Cr(VI) and Se(VI), respectively. The developed method was validated by analyzing four Certified Reference Materials, rainwater, Yangtze River and East Lake waters.A novel method of simultaneous speciation analysis of inorganic arsenic, chromium and selenium was developed and successfully applied for environmental waters.
Co-reporter:Ying Liu, Man He, Beibei Chen, Bin Hu
Talanta 2015 Volume 142() pp:213-220
Publication Date(Web):1 September 2015
DOI:10.1016/j.talanta.2015.04.050
•DLLME combined with ETV-ICP-MS was proposed for simultaneous multi-element speciation.•DDTC was used both as a cheating reagent in DLLME and chemical modifier in ETV-ICP-MS.•This method is simple, fast, inexpensive, sensitive and suitable for batch operation.A new method based on dispersive liquid liquid microextraction (DLLME) combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was developed for the simultaneous speciation of inorganic arsenic (As), selenium (Se) and tellurium (Te) with sodium diethyldithiocarbamate (DDTC) as both chelating reagent and chemical modifier. As(III), Se(IV) and Te(IV) were transformed into DDTC-chelates at pH 7 and extracted into the fine droplets formed by injecting the binary solution of bromobenzene (extraction solvent) and methanol (dispersive solvent) into the sample solution. After phase separation by centrifugation, As(III), Se(IV) and Te(IV) preconcentrated in the organic phase were determined by ETV-ICP-MS. Total inorganic As, Se and Te were obtained by reducing As(V), Se(VI) and Te(VI) to As(III), Se(IV) and Te(IV) with l-cysteine, which were then subjected to the same DLLME-ETV-ICP-MS process. The concentration of As(V), Se(VI), Te(VI) were calculated by subtracting the concentration of As(III), Se(IV) and Te(IV) from the total inorganic As, Se and Te, respectively. The main factors affecting the microextraction efficiency and the vaporization behavior of target species were investigated in detail. Under the optimal conditions, the limits of detection were 2.5, 8.6 and 0.56 ng L−1 for As(III), Se(IV) and Te(IV), respectively, with the relative standard deviations (n=7) of 8.5–9.7%. The developed method was applied to the speciation of inorganic As, Se and Te in Certified Reference Materials of GSBZ50004-88, GBW(E)080395 and GBW(E)080548 environmental waters, and the determined values are in good agreement with the certified values. The method was also successfully applied to the simultaneous speciation of inorganic As, Se and Te in different environmental water samples with the recoveries in the range of 86.3–107% for the spiked samples.Figure optionsDownload full-size imageDownload as PowerPoint slide
Co-reporter:Lu Peng, Man He, Beibei Chen, Yu Qiao, and Bin Hu
ACS Nano 2015 Volume 9(Issue 10) pp:10324
Publication Date(Web):September 21, 2015
DOI:10.1021/acsnano.5b04365
Toxicity of quantum dots (QDs) has been a hot research concern in the past decade, and there is a lot of challenge in this field. The physicochemical characteristics of QDs can affect their toxicity, while little is known about the specific chemical form of QDs in living cells after incubation so far. In this work, speciation of four CdSe/ZnS QDs in HepG2 cells was carried out from the metallomics’ point of view for the first time by using size exclusion chromatography (SEC) coupled with inductively coupled plasma-mass spectrometry (ICP-MS). On the basis of the signal of Cd, two kinds of chemical forms, named as QD-1 and QD-2, were observed in HepG2 cells incubated with CdSe/ZnS QDs. QD-1 was demonstrated to be a kind of QD-like nanoparticles, confirmed by chromatographic retention time, transmission electron microscopy (TEM) characterization, and fluorescence detection. QD-2 was demonstrated to be cadmium–metallothioneins complex (Cd-MTs) by reversed phase liquid chromatography (RPLC) synchronously coupled with ICP-MS and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-Q-TOF-MS) analysis. Meanwhile, speciation of QDs in HepG2 cells incubated with different conditions was analyzed. With the variation of QDs incubation concentration/time, and elimination time, the species of QD-1 and QD-2 were also observed without other obvious species, and both the amount of QD-1 and QD-2 increased with incubation concentration and time. The obtained results provide valuable information and a strategy for the study of existing chemical form of QDs, greatly benefiting the understanding of QDs toxicity in living cells.Keywords: CdSe/ZnS quantum dots; HepG2 cells; inductively coupled plasma mass spectrometry; metallomics; speciation; toxicity;
Co-reporter:Xing Zhang, Beibei Chen, Man He, Yiwen Zhang, Guangyang Xiao, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2015 Volume 106() pp:20-27
Publication Date(Web):1 April 2015
DOI:10.1016/j.sab.2015.01.011
•4-Mercaptophenylboronic acid functionalized magnetic beads were prepared and characterized.•ICP-MS based magnetic immunoassay approach was developed for quantification of glycoproteins.•AFP and CEA were quantified simultaneously with Au and Ag NPs as element tags.•The developed method exhibited good selectivity and sensitivity for target glycoproteins.The absolute quantification of glycoproteins in complex biological samples is a challenge and of great significance. Herein, 4-mercaptophenylboronic acid functionalized magnetic beads were prepared to selectively capture glycoproteins, while antibody conjugated gold and silver nanoparticles were synthesized as element tags to label two different glycoproteins. Based on that, a new approach of magnetic immunoassay-inductively coupled plasma mass spectrometry (ICP-MS) was established for simultaneous quantitative analysis of glycoproteins. Taking biomarkers of alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) as two model glycoproteins, experimental parameters involved in the immunoassay procedure were carefully optimized and analytical performance of the proposed method was evaluated. The limits of detection (LODs) for AFP and CEA were 0.086 μg L− 1 and 0.054 μg L− 1 with the relative standard deviations (RSDs, n = 7, c = 5 μg L− 1) of 6.5% and 6.2% for AFP and CEA, respectively. Linear range for both AFP and CEA was 0.2–50 μg L− 1. To validate the applicability of the proposed method, human serum samples were analyzed, and the obtained results were in good agreement with that obtained by the clinical chemiluminescence immunoassay. The developed method exhibited good selectivity and sensitivity for the simultaneous determination of AFP and CEA, and extended the applicability of metal nanoparticle tags based on ICP-MS methodology in multiple glycoprotein quantifications.
Co-reporter:Bingshan Zhao, Man He, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2015 Volume 107() pp:115-124
Publication Date(Web):1 May 2015
DOI:10.1016/j.sab.2015.03.005
•Novel Cd(II)-II-MMS was prepared by surface imprinting combined with a sol–gel process.•Cd(II)-II-MMS has a high selectivity and adsorption capacity for Cd(II).•A sensitive and selective method of Cd(II)-IIMSPE-GFAAS was developed for trace cadmium analysis.•The method can be applied to determine trace Cd in various samples with complicated matrix.Determination of trace Cd in environmental, biological and food samples is of great significance to toxicological research and environmental pollution monitoring. While the direct determination of Cd in real-world samples is difficult due to its low concentration and the complex matrix. Herein, a novel Cd(II)-ion imprinted magnetic mesoporous silica (Cd(II)-II-MMS) was prepared and was employed as a selective magnetic solid-phase extraction (MSPE) material for extraction of trace Cd in real-world samples followed by graphite furnace atomic absorption spectrometry (GFAAS) detection. Under the optimized conditions, the detection limit of the proposed method was 6.1 ng L− 1 for Cd with the relative standard deviation (RSD) of 4.0% (c = 50 ng L− 1, n = 7), and the enrichment factor was 50-fold. To validate the proposed method, Certified Reference Materials of GSBZ 50009–88 environmental water, ZK018-1 lyophilized human urine and NIES10-b rice flour were analyzed and the determined values were in a good agreement with the certified values. The proposed method exhibited a robust anti-interference ability due to the good selectivity of Cd(II)-II-MMS toward Cd(II). It was successfully employed for the determination of trace Cd(II) in environmental water, human urine and rice samples with recoveries of 89.3–116%, demonstrating that the proposed method has good application potential in real world samples with complex matrix.
Co-reporter:Bin Hu;Man He;Beibei Chen
Analytical and Bioanalytical Chemistry 2015 Volume 407( Issue 10) pp:2685-2710
Publication Date(Web):2015 April
DOI:10.1007/s00216-014-8429-9
This review presents a comprehensive update on the state-of-the-art of nanometer-sized materials in solid-phase extraction (SPE) of trace elements followed by atomic-spectrometry detection. Zero-dimensional nanomaterials (fullerene), one-dimensional nanomaterials (carbon nanotubes, inorganic nanotubes, and nanowires), two-dimensional nanomaterials (nanofibers), and three-dimensional nanomaterials (nanoparticles, mesoporous nanoparticles, magnetic nanoparticles, and dendrimers) for SPE are discussed, with their application for trace-element analysis and their speciation in different matrices. A variety of other novel SPE sorbents, including restricted-access sorbents, ion-imprinted polymers, and metal–organic frameworks, are also discussed, although their applications in trace-element analysis are relatively scarce so far.
Co-reporter:Yuan Zhang, Beibei Chen, Man He, Bin Yang, Jing Zhang, and Bin Hu
Analytical Chemistry 2014 Volume 86(Issue 16) pp:8082
Publication Date(Web):July 23, 2014
DOI:10.1021/ac500964s
This work reports an efficient, specific, and sensitive immunoassay protocol for detection of tumor cells by using inductively coupled plasma mass spectrometry (ICP-MS) with two probes. Magnetic nanobeads modified with anti-CD3 were used as capture probes for efficient and fast magnetic separation of Jurkat T cells from a mixture of cells, and gold nanoparticles (Au NPs) conjugated with anti-CD2 were used as detection probes for ICP-MS measurement. The capture and detection probes target the Jurkat T cells with high affinity and specificity, while they do not target other CD2/CD3-negative cells such as 97L cells and A549 cells. On the basis of these results, we proposed a new immunoassay for specific detection of Jurkat T cells. The conditions for this immunoassay were carefully optimized, including the incubation time and temperature, the concentration of the labeling probe, and the elution conditions. Under the optimized conditions, the linear range of 300–30 000 and the limit of detection of 86 Jurkat T cells were obtained, and the relative standard deviation for seven replicate detection of Jurkat T cells was 5.2% (3000 Jurkat T cells). This method has numerous advantages, including ease of preparation, low sample consumption, and high sensitivity and selectivity. Importantly, the methodology could be extended to the simultaneous detection of other cells based on their cellular biomarkers.
Co-reporter:Linfang Huang, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A 2014 Volume 1343() pp:10-17
Publication Date(Web):23 May 2014
DOI:10.1016/j.chroma.2014.03.053
•LPME and on-column sample stacking in CE were combined for the high enrichment of phytohormones.•A method of MS-LLLME-ASEI-CE–UV was developed for trace phytohormones quantification.•The developed method provides high sensitivity, wide linear range, and good sample cleanup ability.•It is suitable for the determination of trace analytes in complicated real samples by CE–UV.A novel method based on off-line membrane-supported liquid–liquid–liquid microextraction (MS-LLLME) combined with on-column anion-selective exhaustive injection (ASEI) capillary electrophoresis–ultraviolet (CE–UV) detection was established for the analysis of seven phytohormones (abscisic acid (ABA), jasmonic acid (JA), 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthalene acetic acid (NAA), indole-3-acetic acid (IAA), salicylic acid (SA) and gibberellic acid (GA)). In MS-LLLME, the target phytohormones were extracted from the acid donor phase to the alkaline acceptor phase, and the acceptor solutions were directly analyzed by ASEI-CE–UV. Under the optimal experimental conditions, the analytical performance of the method was evaluated. The limits of detection (LODs) of ABA, JA, 2,4-D, NAA, IAA, SA and GA were determined to be 1.00, 2.21, 0.33, 0.17, 0.67, 0.05 and 16.5 ng/mL, respectively. The relative standard deviations (RSDs, n = 7) ranged from 4.7% to 12.9%, and the enrichment factors were in the range of 307 to 20,160. The proposed method was successfully applied for the determination of multiple phytohormones in banana, cabbage and cucumber extracts, and ABA, IAA and SA were detected in these samples. The recoveries for the spiked samples were in the range of 79.0 to 116.4%. The proposed method was demonstrated to be suitable for the simultaneous quantification of multiple phytohormones with high sensitivity and good sample cleanup ability.
Co-reporter:Beibei Chen, Man He, Cheng Zhong, Bin Hu
Journal of Chromatography A 2014 Volume 1363() pp:62-70
Publication Date(Web):10 October 2014
DOI:10.1016/j.chroma.2014.07.098
•The “state of the art” of chiral speciation of SeAAs is reviewed.•Hyphenation technique is most effective for chiral speciation of SeAAs.•More methodological development and application in biological samples is expected.•Chiral speciation benefits to understand the metabolism of SeAAs in organism.In this paper, the “state of the art” of chiral speciation of selenoamino acids (SeAAs) in biological samples is critically reviewed. The significance and the features of such studies are highlighted. A special focus lies on chiral speciation of SeAAs by hyphenation techniques in which a chiral separation method (such as gas chromatography (GC), high performance liquid chromatography (HPLC) and capillary electrophoresis (CE)) is on-line coupled with an elemental specific detector, especially inductively coupled plasma mass spectrometry (ICP-MS). The advances in the development and application of hyphenation techniques in chiral speciation of SeAAs in biological samples are summarized and a perspective for future developments including sophisticated and innovative applications is discussed. Overall, HPLC-ICP-MS is more applicable than GC/CE-ICP-MS for chiral speciation of SeAAs. In the future, more novel chiral HPLC methods with high enantio-resolution, low cost and robustness, and their more applications in real biological samples analysis are expected.
Co-reporter:Cong Hu, Man He, Beibei Chen, Cheng Zhong, Bin Hu
Journal of Chromatography A 2014 Volume 1356() pp:45-53
Publication Date(Web):22 August 2014
DOI:10.1016/j.chroma.2014.06.062
•PDMS/MOFs-coatings are easily prepared, low cost and have good preparation reproducibility.•The PDMS/MOFs coating exhibits excellent selectivity for target PAHs.•A sensitive and selective PDMS/MOFs-SBSE-LD-HPLC-FLD method was developed for PAHs analysis.In this work, metal–organic frameworks (MOFs, Al-MIL-53-NH2) were synthesized via the hydrothermal method, and novel polydimethylsiloxane/metal–organic framework (PDMS/MOFs, PDMS/Al-MIL-53-NH2)-coated stir bars were prepared by the sol–gel technique. The preparation reproducibility of the PDMS/MOFs-coated stir bar was good, with relative standard deviations (RSDs) ranging from 4.8% to 14.9% (n = 7) within one batch and from 6.2% to 16.9% (n = 6) among different batches. Based on this fact, a new method of PDMS/MOFs-coated stir bar sorptive extraction (SBSE) and ultrasonic-assisted liquid desorption (UALD) coupled with high performance liquid chromatography-fluorescence detection (HPLC-FLD) was developed for the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental water samples. To obtain the best extraction performance for PAHs, several parameters affecting SBSE, such as extraction time, stirring rate, and extraction temperature, were investigated. Under optimal experimental conditions, wide linear ranges and good RSDs (n = 7) were obtained. With enrichment factors (EFs) of 16.1- to 88.9-fold (theoretical EF, 142-fold), the limits of detection (LODs, S/N = 3) of the developed method for the target PAHs were found to be in the range of 0.05–2.94 ng/L. The developed method was successfully applied to the analysis of PAHs in Yangtze River and East Lake water samples.
Co-reporter:Pingjing Li, Bin Hu, Man He, Beibei Chen
Journal of Chromatography A 2014 Volume 1356() pp:23-31
Publication Date(Web):22 August 2014
DOI:10.1016/j.chroma.2014.06.046
•Ion-pair-hollow fiber-LLLME was proposed for extraction of six thyroxines.•The method is used with CE-UV for human serum analysis.•The developed IP-HF-LLLME-CE-UV method has good clean-up ability and high sensitivity.In this study, a novel, inexpensive, sensitive and selective analytical method that combines ion pair hollow fiber liquid–liquid–liquid microextraction (IP-HF-LLLME) with capillary electrophoresis-ultraviolet detection (CE-UV) was developed for the simultaneous determination of six thyroid hormones (including diiodothyronine (T2), 3,3,5-triiodo-l-thyronine (T3), 3,5,3,5-tetraiodolthyronine (T4), 3,3,5-triiodothyronine (rT3), monoiodotyrosine (MIT) and diiodotyrosine (DIT)) in human serum samples. By the addition of a low concentration of sodium dodecyl sulfate (SDS) into the donor phase as an ion pair reagent, octanol as the organic extraction solvent and 30 mmol/L Na2CO3 as acceptor phase, six analytes with different polarity and water solubility were successfully extracted simultaneously using HF-LLLME. To the best of our knowledge, this is the first time that a liquid phase microextraction technique was proposed for the extraction of thyroid hormones in real samples. The CE separations were investigated in detail. When 20 kV of voltage was applied, the six compounds were separated within 13 min in 25 mmol/L phosphate buffer (pH 2.15) containing 10% (v/v) acetonitrile and 0.5% (m/v) polyethylene glycol (PEG). Under the optimized conditions, enrichment factors (EFs) ranging from 183- to 366-fold were obtained and the limits of detection (at a signal-to-noise ratio of 3) were at sub μg/L level. The established IP-HF-LLLME-CE-UV method was successfully applied to simultaneous determination of thyroid hormones and relative compounds in human serum samples with good recoveries for the spiked samples.
Co-reporter:X. Q. Guo, X. T. Tang, M. He, B. B. Chen, K. Nan, Q. Y. Zhang and B. Hu
RSC Advances 2014 vol. 4(Issue 38) pp:19960-19969
Publication Date(Web):16 Apr 2014
DOI:10.1039/C4RA01576B
A simple and efficient two-step method based on dispersive solid phase extraction (D-SPE) and dispersive liquid–liquid microextraction (DLLME) has been developed for the separation and preconcentration of 15 rare earth elements (REEs) from environmental water and sediment samples, followed by electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS) detection. With Chelex 100 as the adsorbent of D-SPE, target REEs were firstly extracted and the retained REEs were then desorbed by 0.1 mol L−1 HNO3. After 125 mmol L−1 Tris and 40 mmol L−1 1-phenyl-3-methyl-4-benzoylpyrazolone (PMBP) were added into the above elution solution, target REEs were further preconcentrated into CCl4 by DLLME. The developed dual extraction technique exhibited high enrichment factors (234 to 566-fold) and good anti-interference ability. Various parameters affecting the extraction of target REEs by D-SPE and DLLME were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) for target REEs were in the range of 0.003–0.073 ng L−1 with the relative standard deviations (CY,La,Ce,Pr,Nd,Gd,Dy = 1.0 ng L−1, CSm,Eu,Tb,Ho,Er,Tm,Yb,Lu = 0.2 ng L−1, n = 7) ranging from 6.7 to 11.5%. The proposed method of D-SPE-DLLME-ETV-ICP-MS was successfully applied to the determination of 15 REEs in water and sediment samples with the recoveries of 78–115% and 75–117% for the spiked water and sediment samples, respectively. To validate the accuracy of the method, a Certified Reference Material of GBW07301a stream sediment was analyzed and the determined values were in good agreement with the certified values.
Co-reporter:Shaowei Su, Beibei Chen, Man He, Zuowei Xiao and Bin Hu
Journal of Analytical Atomic Spectrometry 2014 vol. 29(Issue 3) pp:444-453
Publication Date(Web):28 Nov 2013
DOI:10.1039/C3JA50342A
In this work, Al3+ immobilized Fe3O4@SiO2@iminodiacetic acid (IDA) was prepared and its extraction performance for gold nanoparticles (AuNPs) and gold ions (Au ions) was investigated. It was found that AuNPs and Au ions could be simultaneously retained on this adsorbent and their separation was achieved by sequential elution of Au ions and AuNPs with Na2S2O3 and NH3·H2O, respectively. Based on it, a novel strategy by coupling magnetic solid phase extraction (MSPE) with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the speciation of AuNPs and Au ions in environmental water samples. Various experimental parameters affecting MSPE of AuNPs and Au ions have been investigated carefully. AuNPs in a size range of 14–140 nm and with different coatings, including citrate, 11-mercaptoundecanoic acid (MUA), polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB), could be quantitatively determined by the proposed method. And the size and shape of the AuNPs were found to remain unchanged during the extraction process; thus the elution solutions could be directly introduced into ICP-MS without digestion. The developed MSPE-ICP-MS method has been applied in the analysis of AuNPs in natural water, sewage water and even sea water samples and Au ions in natural water samples with satisfactory results. Compared with the established methods for metal nanoparticle analysis, the developed method is more sensitive, faster, easier-to-operate, requires no digestion, and provides more valuable information for environmental monitoring and the assessment of nanoparticles' toxicity.
Co-reporter:Hanyong Peng, Yang Jiao, Xiao Xiao, Beibei Chen, Man He, Zhengru Liu, Xing Zhang and Bin Hu
Journal of Analytical Atomic Spectrometry 2014 vol. 29(Issue 6) pp:1112-1119
Publication Date(Web):05 Mar 2014
DOI:10.1039/C4JA00003J
Carbohydrate biomolecules are difficult targets for analysis due to their branched structure and diverse modifications of saccharidic monomers. The variety of biochemical functions of carbohydrate biomolecules have attracted great and extensive attention, which has spurred a pressing need for rapid development of analytical methods for absolute quantification of glycoproteins in recent years. Herein a sensitive and selective method using magnetic separation coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection is proposed for simultaneous determination of multiple glycoproteins. Haptoglobin (HP), hemopexin (HPX) and ovalbumin (OVA) were selected as target glycoproteins. They were firstly selected by lectin conjugated magnetic particles due to the glycol-structure, and then immunoreacted with antibodies labeled with Cd, Hg, Pb through poly(acrylic acid), respectively. The metal ions, corresponding to the concentration of glycoproteins, were released from antibody with an acid-dissolution step and subjected to subsequent ICP-MS detection. With consumption of only 50 μL sample solution, the established method presents a limit of detection of 0.032, 0.027 and 0.13 ng mL−1 for HP, HPX and OVA, with the relative standard deviation of 7.4%, 6.8% and 7.6% (c = 5 ng mL−1, n = 7), respectively. The response of magnetic immuno-ICP-MS assay for HP, HPX and OVA was linear over a dynamic range of 0.1–100 ng mL−1, 0.1–100 ng mL−1 and 0.5–100 ng mL−1, respectively. The recoveries for HP, HPX and OVA in spiked human serum samples are in the range of 97.6–105%. The developed method is demonstrated to be versatile to multiple glycoproteins quantification in complicated samples.
Co-reporter:Xiaolan Liu, Man He, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2014 101() pp: 254-260
Publication Date(Web):
DOI:10.1016/j.sab.2014.09.008
Co-reporter:Shaowei Su, Beibei Chen, Man He, Bin Hu, Zuowei Xiao
Talanta 2014 Volume 119() pp:458-466
Publication Date(Web):15 February 2014
DOI:10.1016/j.talanta.2013.11.027
•Magnetic graphene oxide (GO) composite was prepared through a noncovalent method.•The abundant functional groups of GO were reserved in the prepared composite.•The magnetic GO composite has a high adsorption capacity and stability.•The magnetic GO composite possesses excellent extraction performance to REEs.•A MSPE-ICP-MS analytical method was developed to analysis of trace REEs.A novel Fe3O4@SiO2@polyaniline–graphene oxide composite (MPANI-GO) was prepared through a simple noncovalent method and applied to magnetic solid phase extraction (MSPE) of trace rare earth elements (REEs) in tea leaves and environmental water samples followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. The prepared MPANI-GO was characterized by transmission electron microscopy and vibrating sample magnetometer. Various parameters affecting MPANI-GO MSPE of REEs have been investigated. Under the optimized conditions, the limits of detection (LODs, 3σ) for REEs were in the range of 0.04–1.49 ng L−1 and the relative standard deviations (RSDs, c=20 ng L−1, n=7) were 1.7–6.5%. The accuracy of the proposed method was validated by analyzing a Certified Reference Material of GBW 07605 tea leaves. The method was also successfully applied for the determination of trace REEs in tea leaves and environmental water samples. The developed MPANI-GO MSPE-ICP-MS method has the advantages of simplicity, rapidity, high sensitivity, high enrichment factor and is suitable for the analysis of trace REEs in samples with complex matrix.
Co-reporter:Shaowei Su, Beibei Chen, Man He, Bin Hu
Talanta 2014 Volume 123() pp:1-9
Publication Date(Web):June 2014
DOI:10.1016/j.talanta.2014.01.061
•Graphene oxide (GO)–silica composite coating was prepared.•The prepared GO–silica coating possesses excellent extraction performance to metal ions with high adsorption capacity and stability.•An on-line GO–silica coated HF-SPME–ICP-MS method was developed for the quantification of trace metal ions in real-world samples.In this work, a novel graphene oxide–silica (GO–silica) composite coating was prepared for hollow fiber solid phase microextraction (HF-SPME) of trace Mn, Co, Ni, Cu, Cd and Pb followed by on-line inductively coupled plasma mass spectrometry (ICP-MS) detection. The structure of the prepared graphene oxide and GO–silica composite was studied and elucidated by atomic force microscopy (AFM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The GO–silica composite coated hollow fiber was characterized by scanning electron microscope (SEM), and the results show that the GO–silica composite coating possessed a homogeneous and wrinkled structure. Various experimental parameters affecting the extraction of the target metal ions by GO–silica composite coated HF-SPME have been investigated carefully. Under the optimum conditions, the limits of detection (LODs, 3σ) for Mn, Co, Ni, Cu, Cd and Pb were 7.5, 0.39, 20, 23, 6.7 and 28 ng L−1 and the relative standard deviations (RSDs, cMn, Co, Cd=0.05 μg L−1, cNi, Cu, Pb=0.2 μg L−1, n=7) were 7.2, 7.0, 5.6, 7.3, 7.8 and 4.6%, respectively. The accuracy of the proposed method was validated by the analysis of Certified Reference Material of GSBZ 50009-88 environmental water and the determined values were in a good agreement with the certified values. The proposed method has been successfully applied for the determination of trace metals in real environmental water samples with recoveries ranging from 85 to 119%.Figure optionsDownload full-size imageDownload high-quality image (172 K)Download as PowerPoint slide
Co-reporter:Ling Li, Xiao Lan Liu, Hong Yun Geng, Bin Hu, Gong Wu Song and Zu Shun Xu
Journal of Materials Chemistry A 2013 vol. 1(Issue 35) pp:10292-10299
Publication Date(Web):21 Jun 2013
DOI:10.1039/C3TA11478C
The adsorption of methylene blue (MB) from aqueous solution on a HKUST-1/GO (MOFs:HKUST-1) composite was studied in view of the adsorption isotherm, kinetics and regeneration of the sorbent. The adsorption isotherms of methylene blue (MB) on the HKUST-1/GO composite followed both the Freundlich isotherm and the Langmuir isotherm. Adsorption kinetics and thermodynamic parameters were determined from the experimental data. The used HKUST-1/GO could be regenerated by acetone, so it can be recycled for reuse. The high adsorption capacity and excellent reusability make HKUST-1/GO attractive for the removal of MB from aqueous solution.
Co-reporter:Cong Hu, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A 2013 Volume 1275() pp:25-31
Publication Date(Web):1 February 2013
DOI:10.1016/j.chroma.2012.12.036
In this work, a new method of polydimethylsiloxane/polythiophene (PDMS/PTH) coated stir bar sorptive extraction (SBSE) coupled to liquid desorption-large volume injection-gas chromatography-flame photometric detection (LD-LVI-GC-FPD) was proposed for the determination of organophosphorus pesticides (OPPs, including phorate, fenitrothion, malathion, parathion and quinalphos) in environmental water samples. Polythiophene was synthesized by chemical oxidative polymerization method, and the PDMS/PTH coated stir bar was prepared by sol–gel technique. The preparation reproducibility of PDMS/PTH coated stir bar was good with the relative standard deviations (RSDs) ranging from 3.9% to 8.1% (n = 7) in one batch, and from 5.9% to 14.9% (n = 6) among different batches. To get the best extraction performance for OPPs, the operation parameters affecting the extraction efficiency of SBSE, including extraction time, desorption time, stirring rate and ionic strength, were investigated. Under the optimal conditions, the limits of detection (S/N = 3) were found to be in the range of 0.011–0.038 μg/L for the five target OPPs, and the linear range was from 0.2 to 100 μg/L for phorate and 0.1–100 μg/L for other four OPPs. The RSDs of the proposed method were in the range of 4.0–9.8% (n = 8, c = 1 μg/L) and the enrichment factors were varied from 56.7 to 80.9-fold (theory enrichment factor was 100-fold). The proposed method was applied to the analysis of OPPs in East Lake water and ground water samples with recovery in the range of 77.7–119.8% and 79.1–109.8% for the spiked East Lake water and ground water samples, respectively.Highlights► Novel PDMS/PTH coating was prepared to enhance the extraction efficiency of OPPs. ► The coating was inexpensive, stable and robust. ► PDMS/PTH-SBSE-GC-FPD method was sensitive, and could comply with the regulation of EPA for OPPs.
Co-reporter:Jin Xu, Beibei Chen, Man He, Bin Hu
Journal of Chromatography A 2013 Volume 1278() pp:8-15
Publication Date(Web):22 February 2013
DOI:10.1016/j.chroma.2012.12.061
A new concept of “dual-phase dual stir bar sorptive extraction (SBSE)” was proposed to simultaneously extract six preservatives with different polarities (log Ko/w values of 1.27–3.41), namely, benzoic acid (BA), sorbic acid (SA), methyl p-hydroxybenzoate (MP), ethyl p-hydroxybenzoate (EP), propyl p-hydroxybenzoate (PP), and butyl p-hydroxybenzoate (BP). The dual-phase dual SBSE apparatus was consisted of two differently coated stir bars, a 3-aminopropyltriethoxysilane (APTES)-hydroxy-terminated silicone oil (OH-TSO)-coated stir bar that was prepared by sol–gel technique and a C18 silica (C18)-polydimethylsiloxane (PDMS)-coated stir bar that was prepared by adhesion. In dual-phase dual SBSE, the two stir bars with different coatings were placed in the same sample solution for the simultaneous extraction of the target analytes with different polarities, and then the bars were desorbed in the same desorption solvent. The extraction performance of the dual-phase dual SBSE for the six preservatives was evaluated by comparing with the conventional SBSE (individual stir bar) with different coatings, including commercial PDMS, homemade PDMS, C18-APTES–OH-TSO, APTES–OH-TSO, and C18-PDMS. The experimental results showed that the dual-phase dual SBSE had the highest extraction efficiency for the six target preservatives. Based on this fact, a novel method by combining the dual-phase dual SBSE which was consisted of the APTES–OH-TSO-coated and C18-PDMS-coated stir bars with high-performance liquid chromatography-ultraviolet detection (HPLC–UV) was developed for the simultaneous analysis of six target beverage preservatives in beverages. Under optimal conditions, the limits of detection (LODs) for six target preservatives ranged from 0.6 to 2.7 μg L−1 with the relative standard deviations (RSDs) of 4.6–9.2% (CBA,SA = 5 μg L−1, CMP = 20 μg L−1, CEP,PP,BP = 10 μg L−1, n = 7). The enrichment factors (EFs) were approximately 16–42-fold (theoretical EF was 50-fold). The proposed method was validated by the analysis of six target preservatives in three kinds of beverage samples, and the recoveries for the spiked samples were in the range of 76.6–118.6% for cola, 74.6–17.5% for orange juice, and 83.0–119.1% for herbal tea, respectively.Highlights► A new concept of “dual-phase dual stir bar sorptive extraction” was proposed. ► Six preservatives with different polarities were simultaneously analyzed. ► The dual-phase dual SBSE had the high extraction efficiency. ► The proposed method was sensitive, low-cost, simple, and efficient. ► The proposed method was applied for preservatives analysis in beverage samples.
Co-reporter:Wenying Fan, Xiangju Mao, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A 2013 Volume 1318() pp:49-57
Publication Date(Web):29 November 2013
DOI:10.1016/j.chroma.2013.10.022
•A new composite coating was prepared for SBSE of thyroxines with high extraction efficiency.•A method of PEG/OH-PDMS/γ-MPTS SBSE-HPLC-UV/ICP-MS was developed for human urine analysis.•The method provided low LODs, high extraction efficiency and wide linear range.In this work, polyethyleneglycol (PEG)/hydroxyl polydimethylsiloxane (OH-PDMS)/γ-mercaptopropyl trimethoxysilane (γ-MPTS) coated stir bar was prepared by sol–gel process and its extraction performance for the extraction of amphoteric thyroxines (3,3′,5,5′-tetraiodothyronin, T4; 3,3′,5-triiodothyronine, T3; reversed-3,3′,5-triiodothyronine, rT3) and their metabolite (3,5-diiodothyronine, T2) was studied. The preparation reproducibility of PEG/OH-PDMS/γ-MPTS coated stir bar was investigated, and the relative standard deviations (RSDs) in the same batch and among different batches were 3.3–14.3% (n = 5) and 7.7–16.6% (n = 3), respectively. The prepared PEG/OH-PDMS/γ-MPTS coated stir bar could be reused for more than 20 times. Based on this fact, a novel method of stir bar sorptive extraction (SBSE) combined with high performance liquid chromatography (HPLC)-ultraviolet (UV) and HPLC-inductively coupled plasma mass spectrometry (ICP-MS) for the analysis of target thyroxines in human urine samples was developed. The influencing factors of SBSE, such as sample pH, extraction time, stirring rate, salt effect, desorption solution and desorption time, were studied in detail, and the analytical performance of the proposed method was evaluated under the optimized conditions. The enrichment factors (EFs) of the developed method for four target thyroxines were in the range of 14.9–70.4 (theoretical enrichment factor was 100). The RSDs were ranging from 4.0% to 13.8% for SBSE-HPLC-UV (c = 25 μg/L, n = 6) and from 3.7% to 6.1% for SBSE-HPLC-ICP-MS (c = 0.5 μg/L, n = 5). The linear range obtained by SBSE-HPLC-UV was 2–500 μg/L for T2 and 5–500 μg/L for rT3, T3 and T4, with correlation coefficients (r) ranging from 0.9957 to 0.9998, respectively, while the linear range obtained by SBSE-HPLC-ICP-MS was 0.05–500 μg/L for T2 and rT3, 0.10–200 μg/L for T3 and 0.05–200 μg/L for T4 with r ranging from 0.9979 to 0.9998, respectively. The limits of detection (LODs) for the target thyroxines were 0.60–2.20 μg/L for SBSE-HPLC-UV and 0.0071–0.0355 μg/L SBSE-HPLC-ICP-MS, respectively. The developed method was applied for the determination of target thyroxines in urine samples, and the recovery for the spiking samples obtained by SBSE-HPLC-UV was in the range of 81.6–137.6% for human urine, while the recovery for the spiking urine samples obtained by SBSE-HPLC-ICP-MS were in the range of 72.0–121.5%.
Co-reporter:Beibei Chen, Yunlin Huang, Man He, Bin Hu
Journal of Chromatography A 2013 Volume 1305() pp:17-26
Publication Date(Web):30 August 2013
DOI:10.1016/j.chroma.2013.06.029
•Eight estrogens with different polarity were simultaneously extracted by HF-LLLME.•High EFs of 88–376-folds and low LODs of 0.055–1.46 ng/mL were obtained.•The proposed method was applied in spiked environmental and biological samples.A new method of hollow fiber liquid-liquid-liquid microextraction (HF-LLLME) combined with high performance liquid chromatography-ultraviolet detection (HPLC-UV) was developed for simultaneous analysis of various environmental estrogens. Taking eight environmental estrogens (17β-estradiol (E2), estrone (E1), estriol (E3), 17α-ethynylestradiol (EE), diethylstilbestrol (DES), dienestrol (DIS), bisphenol-A (BPA) and 4-t-octylphenol (OP)) as the target analytes, the factors affecting HF-LLLME-HPLC-UV were investigated in detail. Under the optimized experimental conditions, the extraction efficiency of HF-LLLME for eight target estrogens was in the range of 13.9–62.8%, and the enrichment factor was 88–376-fold. The limits of detection (LODs) of the proposed method for eight target estrogens of ES, BPA, E2, EE, E1, DES, DIS and OP were 0.11, 0.055, 0.66, 0.55, 0.51, 0.20, 0.11 and 1.46 ng/mL, respectively, which are lower than that obtained by some other sample pretreatment methods followed by HPLC-UV analysis. The relative standard deviations of the method (RSDs, cE3, BPA, DIS =5 ng/mL, cE1, E2, EE, OP = 40 ng/mL, cDES = 15 ng/mL, n = 7) are in the range of 5.5–8.4%. The developed method was applied for the determination of environmental estrogens in environmental and biological samples (sediment and fish), and none of the eight target estrogens was detected. The recoveries for the spiking samples with low, medium and high spiking levels were in the range of 73.2–117.5%. The proposed method has been demonstrated to be suitable for simultaneous determination of multiple environmental estrogens with high sensitivity, high enrichment factors, good sample clean-up ability and no derivatization required.
Co-reporter:Beibei Chen, Bin Hu, Man He, Qian Huang, Yuan Zhang and Xing Zhang
Journal of Analytical Atomic Spectrometry 2013 vol. 28(Issue 3) pp:334-343
Publication Date(Web):18 Dec 2012
DOI:10.1039/C2JA30280B
Elemental speciation in cells is significant for metallomics research. In this study, novel methods of (on-chip) magnetic solid phase extraction (MSPE) combined with high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) were proposed for selenium speciation in selenium-enriched yeast cells. An integrated microfluidic chip consisting of reaction, mixing, and extraction units was designed and fabricated for on-chip MSPE. Sulfonated polystyrene-coated magnetic nanoparticles (Fe3O4@PSS MNPs) were prepared as adsorption material for MSPE of selenoamino acids and selenopeptide. The factors affecting the extraction performance of the target selenium species by (on-chip) MSPE-HPLC-ICP-MS were systematically investigated. The analytical performance of the (on-chip) MSPE-HPLC-ICP-MS was evaluated under individual optimal conditions. The limits of detection for five target selenium species were 0.025 μg L−1 to 0.090 μg L−1 and 0.057 μg L−1 to 0.149 μg L−1 for MSPE-HPLC-ICP-MS and on-chip MSPE-HPLC-ICP-MS, respectively. The MSPE-HPLC-ICP-MS method is sensitive, fast, easy-to-operate, and economical. The on-chip MSPE-HPLC-ICP-MS method has the unique advantages of low sample consumption and high integration; thus, it is suitable for selenium speciation in a small number (∼800) of selenium-enriched yeast cells. A Certified Reference Material of SELM-1 yeast was used to validate the accuracy of the developed (on-chip) MSPE-HPLC-ICP-MS methods. The proposed methods were successfully applied to the speciation of selenium in selenium-enriched yeast cells. Analysis of approximately 800 cells by on-chip MSPE-HPLC-ICP-MS revealed that the average amounts of selenocystine (SeCys2) and selenomethionine (SeMet) in a single selenium-enriched yeast cell are in the order of subpicograms.
Co-reporter:Chao Cui, Bin Hu, Beibei Chen and Man He
Journal of Analytical Atomic Spectrometry 2013 vol. 28(Issue 7) pp:1110-1117
Publication Date(Web):03 May 2013
DOI:10.1039/C3JA50108F
Ionic liquids of methyltrioctylammonium chloride modified magnetic nanoparticles were prepared, and a new method of magnetic solid phase extraction combined with inductively coupled plasma-optical emission spectrometry was established for the determination of Cu, Zn, and Cd in human hair and urine samples. The effect of pH on the extraction of Cu, Zn, and Cd was investigated. The results show that the ionic liquid played a key role in the extraction of target analytes. The magnetic nanoparticles served as the carriers of the ionic liquid and the base of the phase separation. Several parameters affecting the extraction and desorption of the target analytes were investigated including the sample volume, extraction time, eluent concentration and volume, desorption time, sedimentation time, amount of the ionic liquid and Fe3O4@Si–OH, and the optimized conditions were established. Under the optimized conditions, the detection limits of Cu, Zn, and Cd were 0.54, 0.56, and 0.33 μg L−1, respectively, and the relative standard deviations (n = 7) were 4.9% (c = 2 μg L−1), 3.7% (c = 2 μg L−1), and 5.1% (c = 1 μg L−1), respectively. To validate the accuracy of the proposed method, it was applied to analyze certified reference materials of GBW07601 human hair and GBW09103 human urine. The determined values agree with the certified values. The developed method was also employed to analyze human hair and urine, and the recoveries for the spiked samples were in the range of 89.1% to 120%. The developed method was simple, highly sensitive, solvent-free, chelate-free, and could be considered as a green analytical technique.
Co-reporter:Xueqin Guo, Beibei Chen, Man He, Bin Hu and Xiaoqing Zhou
Journal of Analytical Atomic Spectrometry 2013 vol. 28(Issue 10) pp:1638-1647
Publication Date(Web):14 Aug 2013
DOI:10.1039/C3JA50243K
A novel method of ionic liquid based carrier mediated hollow fiber liquid liquid liquid microextraction (IL-carrier mediated HF-LLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed for the speciation of five phenylarsenic compounds and arsenate in chicken and feed samples. The target arsenic species were extracted from 6 mL aqueous samples (pH = 10.2) into an organic phase (20% (v/v) [MTOA]+[Cl]− in toluene) impregnated in the pores of a hollow fiber, then back extracted into a 10 μL acceptor phase of 0.3 mol L−1 NaBr in the lumen of the hollow fiber. The main driving force for the extraction was the gradient concentration of the counter ion from the donor phase to the acceptor phase. Factors affecting the extraction of the target arsenic species were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) for five target phenylarsenic compounds and arsenate were in the range of 1.4–16.0 ng L−1 with the relative standard deviations (CAs(V),4-OH,3-NHPAA,PA,4-NPAA = 0.05 μg L−1, Cp-ASA = 0.10 μg L−1, n = 7) ranging from 3.6 to 10.0%, and the enrichment factors were varied from 86 to 372-fold. The proposed method of IL-carrier mediated HF-LLLME-HPLC-ICP-MS was successfully applied to the determination of five phenylarsenic compounds and arsenate in chicken and feed samples with the recoveries of 79.2–105.4% and 81.1–117.8% for the spiked chicken and spiked feed samples, respectively.
Co-reporter:Han Wang, Zhekuan Wu, Yuan Zhang, Beibei Chen, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2013 vol. 28(Issue 10) pp:1660-1665
Publication Date(Web):29 Jul 2013
DOI:10.1039/C3JA50223F
Metal determination in precious biological samples is critical to metallomics research. Microfluidic chips provide an excellent platform for the miniaturization of extraction. In this work, a chip-based liquid phase microextraction (chip-based LPME) device was fabricated and combined with electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of trace Cu, Zn, Cd, Hg, Pb and Bi in cell samples and human serum samples. With sodium diethyldithiocarbamate (DDTC) as both the chemical modifier for low-temperature ETV-ICP-MS and the extracting reagent for the chip-based LPME, the chip parameters influencing the extraction efficiency including central channel width, branch channel ratio and central channel length were optimized by orthogonal design experiments. Under the optimized conditions, the limits of detection (LODs) are in the range of 6.6–89.3 pg mL−1 with the RSDs ranging from 4.23–8.15% (n = 7, c = 1 ng mL−1) for the target metal ions. The linear range covers three magnitudes with correlation coefficients higher than 0.99. The proposed method was validated by analyzing the target metal ions in certified reference materials of GBW07605 human hair and GBW09152 human serum, and metal determination in HepG2 cells, Jurkat T cells and a human serum sample were achieved with the recoveries in the range of 86.6–119%. The developed method is fast, has a low sample and reagent consumption and is highly sensitive, thus it is quite suitable for the analysis of precious biological samples such as cells.
Co-reporter:Lin Zhang;Beibei Chen;Man He
Journal of Separation Science 2013 Volume 36( Issue 13) pp:2158-2167
Publication Date(Web):
DOI:10.1002/jssc.201300100
A rapid and sensitive method based on polymer monolithic capillary microextraction combined on-line with microconcentric nebulization inductively coupled plasma MS has been developed for the determination of trace/ultratrace rare earth elements in biological samples. For this purpose, the iminodiacetic acid modified poly(glycidyl methacrylate-trimethylolpropane trimethacrylate) monolithic capillary was prepared and characterized by SEM and FTIR spectroscopy. Factors affecting the extraction efficiency, such as sample pH, sample flow rate, sample/eluent volume, and coexisting ions were investigated in detail. Under the optimal conditions, the LODs for rare earth elements were in the range of 0.08 (Er) to 0.97 ng/L (Nd) with a sampling frequency of 8.5 h−1, and the RSDs were between 1.5% (Sm) and 7.4% (Nd) (c = 20 ng/L, n = 7). The proposed method was successfully applied to the analysis of trace/ultratrace rare earth elements in human urine and serum samples, and the recoveries for the spiked samples were in the range of 82–105%. The developed method was simple, rapid, sensitive, and favorable for the analysis of trace/ultratrace rare earth elements in biological samples with limited sample volume.
Co-reporter:Bin Hu, Man He, Beibei Chen, Linbo Xia
Spectrochimica Acta Part B: Atomic Spectroscopy 2013 Volume 86() pp:14-30
Publication Date(Web):1 August 2013
DOI:10.1016/j.sab.2013.05.025
•The state of art of LPME for trace elements and their speciation analysis is updated.•Different extraction formats of LPME are described.•The application potential and future prospect of LPME for inorganic analysis are discussed.Trace/ultra-trace elements and their speciation analysis in complex matrices usually require sample preparation procedures to achieve sample clean-up and analyte preconcentration. Sample preparation is often the bottleneck in trace elements and their speciation analysis which has a direct impact on accuracy, precision and limits of detection and is often the rate-determining step of the analytical process. Recent trends in sample preparation include miniaturization, automation, high-throughput performance and reduction in solvent/sample consumption and operation time. Liquid-phase microextraction (LPME) technique as a novel and promising alternative in sample preparation can meet these requirements and has become a very efficient sample preparation technique. This review updates the state of art of LPME for trace elements and their speciation analysis and discusses its promising prospects. The major thrust of the article highlights the applications of LPME including single-drop microextraction (SDME), hollow fiber-liquid phase microextraction (HF-LPME), dispersive liquid liquid microextraction (DLLME) and solidified floating organic drop microextraction (SFODME) to the fields of elemental and their speciation analysis by atomic spectrometry-based methods, especially inductively coupled plasma mass spectrometry. General and specific concepts, different extraction formats and characteristics of LPME are described and compared, along with examples of recent innovations and applications presented to demonstrate its potential for trace elements and their speciation analysis in biological and environmental fields. Moreover, the application potential and an outlook on the combination of LPME and atomic spectrometry-based techniques for inorganic analysis are commentated.
Co-reporter:Lu Peng, Man He, Beibei Chen, Qiumei Wu, Zhiling Zhang, Daiwen Pang, Ying Zhu, Bin Hu
Biomaterials 2013 34(37) pp: 9545-9558
Publication Date(Web):
DOI:10.1016/j.biomaterials.2013.08.038
Co-reporter:Cong Hu, Man He, Beibei Chen, Cheng Zhong, Bin Hu
Journal of Chromatography A 2013 1310() pp: 21-30
Publication Date(Web):
DOI:10.1016/j.chroma.2013.08.047
Co-reporter:Cong Hu, Beibei Chen, Man He, Bin Hu
Journal of Chromatography A 2013 1300() pp: 165-172
Publication Date(Web):
DOI:10.1016/j.chroma.2013.05.004
Co-reporter:Shaowei Wu, Chengguo Hu, Man He, Beibei Chen, Bin Hu
Talanta 2013 Volume 115() pp:342-348
Publication Date(Web):15 October 2013
DOI:10.1016/j.talanta.2013.05.044
•The congo red modified SWCNT coated fused-silica capillary was successfully prepared.•CME-FETV-ICP-OES was developed for high sensitive determination of La, Eu, Dy and Y.•The developed method is suitable for the analysis of ultratrace REEs in complicated samples.In this work, a congo red modified single wall carbon nanotubes (CR-SWCNTs) coated fused-silica capillary was prepared and used for capillary microextraction (CME) of trace amounts of lanthanum (La), europium (Eu), dysprosium (Dy) and yttrium (Y) in human hair followed by fluorinating assisted electrothermal vaporization-inductively coupled plasma-optical emission spectrometry (FETV-ICP-OES) determination. The adsorption properties and stability of the prepared CR-SWCNTs coated capillary along with the various factors affecting the separation/preconcentration of La, Eu, Dy and Y by CME were investigated in detail. Under the optimized conditions, with a consumption of 2 mL sample solution, a theoretical enrichment factor of 50 and a detection limit (3σ) of 0.12 ng mL−1 for La, 0.03 ng mL−1 for Eu, 0.11 ng mL−1 for Dy and 0.03 ng mL−1 for Y were obtained, respectively. The preparation reproducibility of the CR-SWCNTs coated capillary was investigated and the relative standard deviations (RSDs) were ranging from 4.1% (Eu) to 4.4% (La) (CLa, Dy=1.4 ng mL−1; CY, Eu=0.25 ng mL−1, n=7) in one batch, and from 5.7% (Eu) to 6.1% (Y) (CLa, Dy=1.4 ng mL−1; CY, Eu=0.25 ng mL−1, n=5) among different batches. The proposed method was applied to the analysis of real-world human hair sample and the recoveries for the spiked sample were in the range of 93–105%. The method was also applied to the determination of La, Eu, Dy and Y in Certified Reference Material of GBW07601 human hair, and the determined values were in good agreement with the certified values.CR-SWCNTs coated capillary for extraction of La, Eu, Dy and Y from human hair.
Co-reporter:Nan Zhang, Bin Hu
Analytica Chimica Acta 2012 Volume 723() pp:54-60
Publication Date(Web):20 April 2012
DOI:10.1016/j.aca.2012.02.027
Cd(II) imprinted 3-mercaptopropyltrimethoxysilane (MPTS)-silica coated stir bar was prepared by sol–gel technique combining with a double-imprinting concept for the first time and was employed for stir bar sorptive extraction (SBSE) of trace Cd(II) from water samples followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. A tetramethoxysilane (TMOS) coating was first in situ created on the glass bar surface. Afterward, a sol solution containing MPTS as the functional precursor, ethanol as the solvent and both Cd(II) and surfactant micelles (cetyltrimethylammonium bromide, CTAB) as the template was again coated on the TMOS bar. The structures of the stir bar coating were characterized by FT-IR spectroscopy. Round-bottom vial was used for the extraction of Cd(II) by SBSE to avoid abrasion of stir bar coatings. The factors affecting the extraction of Cd(II) by SBSE such as pH, stirring rate and time, sample/elution volume and interfering ions have been investigated in detail, and the optimized experimental parameters were obtained. Under the optimized conditions, the adsorption capacities of non-imprinted and imprinted coating stir bars were found to be 0.5 μg and 0.8 μg bar−1. The detection limit (3σ) based on three times standard deviations of the method blanks by 7 replicates was 4.40 ng L−1 and the relative standard deviation (RSD) was 3.38% (c = 1 μg L−1, n = 7). The proposed method was successfully applied for the analysis of trace Cd(II) in rain water, East Lake and Yangtze River water. To validate the proposed method, certified reference material of GSBZ 50009-88 environmental water was analyzed and the determined value is in a good agreement with the certified value. The developed method is rapid, selective, sensitive and applicable for the analysis of trace Cd(II) in environmental water samples.Graphical abstractIon imprinted 3-mercaptopropyltrimethoxysilane (MPTS) coated stir bar for selective extraction of trace Cd(II).Highlights► Ion imprinted polymers were proposed as the coating for SBSE for the first time. ► Cd(II) imprinted MPTS-silica coating was prepared by a double-imprinting concept. ► A novel method of SBSE–ICP-MS was developed for the determination of Cd in waters. ► This method is rapid, selective, sensitive and applicable for determining trace Cd(II) in waters.
Co-reporter:Pingjing Li, Bin Hu, Xiaoyong Li
Journal of Chromatography A 2012 Volume 1247() pp:49-56
Publication Date(Web):20 July 2012
DOI:10.1016/j.chroma.2012.05.059
In this study, a sensitive, selective and reliable analytical method by combining zirconia (ZrO2) coated stir bar sorptive extraction (SBSE) with large volume sample stacking capillary electrophoresis-indirect ultraviolet (LVSS-CE/indirect UV) was developed for the direct analysis of chemical warfare agent degradation products of alkyl alkylphosphonic acids (AAPAs) (including ethyl methylphosphonic acid (EMPA) and pinacolyl methylphosphonate (PMPA)) and methylphosphonic acid (MPA) in environmental waters. ZrO2 coated stir bar was prepared by adhering nanometer-sized ZrO2 particles onto the surface of stir bar with commercial PDMS sol as adhesion agent. Due to the high affinity of ZrO2 to the electronegative phosphonate group, ZrO2 coated stir bars could selectively extract the strongly polar AAPAs and MPA. After systematically optimizing the extraction conditions of ZrO2-SBSE, the analytical performance of ZrO2-SBSE-CE/indirect UV and ZrO2-SBSE-LVSS-CE/indirect UV was assessed. The limits of detection (LODs, at a signal-to-noise ratio of 3) obtained by ZrO2-SBSE-CE/indirect UV were 13.4–15.9 μg/L for PMPA, EMPA and MPA. The relative standard deviations (RSDs, n = 7, c = 200 μg/L) of the corrected peak area for the target analytes were in the range of 6.4–8.8%. Enhancement factors (EFs) in terms of LODs were found to be from 112- to 145-fold. By combining ZrO2 coating SBSE with LVSS as a dual preconcentration strategy, the EFs were magnified up to 1583-fold, and the LODs of ZrO2-SBSE-LVSS-CE/indirect UV were 1.4, 1.2 and 3.1 μg/L for PMPA, EMPA, and MPA, respectively. The RSDs (n = 7, c = 20 μg/L) were found to be in the range of 9.0–11.8%. The developed ZrO2-SBSE-LVSS-CE/indirect UV method has been successfully applied to the analysis of PMPA, EMPA, and MPA in different environmental water samples, and the recoveries for the spiked water samples were found to be in the range of 93.8–105.3%.Highlights► The ZrO2 coated stir bar is easy to prepare. ► The ZrO2 coated stir bar has excellent pH stability, organic solvent resistance. ► The ZrO2 coated stir bar can selectively extract high polar alkylphosphonic acids. ► ZrO2-SBSE-LVSS-CE/indirect UV was developed for AAPAs and MPA analysis in waters. ► The developed method is sensitive, selective, accurate and low-cost.
Co-reporter:Xiangju Mao, Bin Hu, Man He, Beibei Chen
Journal of Chromatography A 2012 Volume 1256() pp:32-39
Publication Date(Web):21 September 2012
DOI:10.1016/j.chroma.2012.07.080
In this work, partially sulfonated polystyrene-titania (PSP-TiO2) organic–inorganic hybrid stir bar coating was prepared by sol–gel and blending methods, and a new method of PSP-TiO2 coating stir bar sorptive extraction (SBSE)-high performance liquid chromatography (HPLC)–inductively coupled plasma mass spectrometry (ICP-MS) was established for the analysis of seleno-amino acids (selenocystine (SeCys2), methylseleno-cysteine (MeSeCys), selenomethionine (SeMet) and selenoethionine (SeEt)) and seleno-oligopeptides (γ-glutamyl-Se-methyl-selenocysteine (γ-GluMeSeCys) and selenodiglutathione (GS-Se-SG)) in biological samples. The prepared high polar PSP-TiO2 hybrid coating avoided the swelling of PSP and cracking of TiO2 coating by combining the good film-forming property of PSP with the high mechanical strength of TiO2. The scanning electron microscope (SEM) showed that no obvious swelling and damage occurred for the PSP-TiO2 hybrid stir bar coating after 30 extraction/desorption cycles. The preparation reproducibility of PSP-TiO2 coated stir bar, evaluated with the relative standard deviations (RSDs), was in the range of 6.7–12.6% (n = 5) in one batch, and 9.9–17.6% (n = 7) among different batches. The limits of detection (LODs) of the developed method for six target selenium species were in the range of 50.2–185.5 ng L−1 (as 77Se) and 45.9–158.8 ng L−1 (as 82Se) with the RSDs within 4.9–11.7%. The dynamic linear range was found to cover three orders of magnitude with correlation coefficient of 0.9995–0.9999. The developed method was applied for the analysis of Certified Reference Material SELM-1 selenium enriched yeast and the determined values were in good agreement with the certified values. The method has also been applied for the analysis of seleno-amino acids and seleno-oligopeptides in human urine and garlic samples. Different from the conventional organic polymer SBSE coatings (such as polydimethylsiloxane, PDMS), the extraction mechanism of PSP-TiO2 organic–inorganic hybrid SBSE coating was based on the cation exchange interaction, which made it feasible to directly extract high polar seleno-amino acids and seleno-oligopeptides in biological samples without derivatization. This coating could also be suitable for stir bar sorptive extraction of other cationic compounds from the environmental and biological samples.Highlights► Polar PSP-TiO2 coated SBSE was proposed for simultaneous extraction of different Se species. ► PSP-TiO2 hydrid coating allows extraction of other cationic compounds by SBSE. ► SBSE-HPLC–ICP-MS was developed for speciation of Se in biological samples. ► The developed method is sensitive, accurate, simple, rapid and low-cost.
Co-reporter:Beibei Chen, Bin Hu, Man He, Xiangju Mao, Wanqing Zu
Journal of Chromatography A 2012 Volume 1227() pp:19-28
Publication Date(Web):2 March 2012
DOI:10.1016/j.chroma.2011.12.086
A novel method based on in-tube hollow fiber-solid phase microextraction (in-tube HF-SPME) on-line coupled with ion pair reversed phase high performance liquid chromatography (IP-RP-HPLC)–inductively coupled plasma mass spectrometry (ICP-MS) was developed for arsenic speciation. Partially sulfonated poly(styrene) (PSP) and mixed-sol of 3-mercapto propyltrimethoxysilane (MPTS) and N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS) were prepared and immobilized in the pores and the inner surface of polypropylene hollow fiber (HF). The prepared MPTS–AAPTS/PSP immobilized HF was characterized by FT-IR spectroscopy and scanning electron microscope (SEM). With arsenite (As(III)), arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), arsenobetaine (AsB) and arsenocholine (AsC) as model arsenic species, a series of factors that influence the extraction of target arsenic species by in-tube HF-SPME, including pH value, sample volume and flow rate, elution conditions and interference of co-existing ions were investigated in details, and the conditions for subsequent HPLC–ICP-MS determination were also optimized. Under the optimal conditions, the sampling frequency was 6.5 h−1, the detection limits for six target arsenic species were in the range of 0.017–0.053 μg L−1 with the relative standard deviations (cAs(V),MMA = 0.1 μg L−1, cAs(III),DMA,AsB,AsC = 0.5 μg L−1, n = 5) ranging in 3.1–8.7%, and the enrichment factors were varied from 4 to 19-fold. To validate the accuracy of this method, certified reference materials DORM-2 (dogfish) and CRM No. 18 (human urine) were analyzed, and the determined values were in good agreement with the certified values. The proposed method was also successfully applied for arsenic speciation in human urine samples, and the recoveries for the spiked samples were in the range of 92.6–107%. The self-designed in-tube HF-SPME–HPLC–ICP-MS system shows high efficiency and good stability, and the proposed method is sensitive and suitable for simultaneous speciation of organic and inorganic arsenic species (including anions and cations) in biological samples.Highlights► Mixed coating in-tube HF-SPME was proposed for simultaneous extraction of different As species. ► In-tube HF-SPME-IP-RP–HPLC–ICP-MS was developed for speciation of As in urine. ► The proposed method was successfully applied for As speciation in human urine. ► It has the advantages of good precision, high sensitivity, labor- and time-saving.
Co-reporter:Jiankun Duan, Man He, Bin Hu
Journal of Chromatography A 2012 Volume 1268() pp:173-179
Publication Date(Web):14 December 2012
DOI:10.1016/j.chroma.2012.10.002
A new phenylalanine derivative (l-N-(2-hydroxy-propyl)-phenylalanine, l-HP-Phe) was synthesized and its chelate with Cu(II) (Cu(II)–(l-HP-Phe)2) was used as the chiral selector for the ligand-exchange (LE) chiral separation of d,l-selenomethionine (SeMet) in selenized yeast samples by micelle electrokinetic capillary chromatography (MEKC). In order to improve the sensitivity of MEKC–UV, two-step preconcentration strategy was employed, off-line solid phase extraction (SPE) and on-line large volume sample stacking (LVSS). d,l-SeMet was first retained on the Cu(II) loaded mesoporous TiO2, then eluted by 0.1 mL of 5 mol L−1 ammonia, and finally introduced for MEKC–UV analysis by LVSS injection after evaporation of NH3. With the enrichment factors of 1400 and 1378, the LODs of 0.44 and 0.60 ng mL−1 for l-SeMet and d-SeMet was obtained, respectively. The developed method was applied to the analysis of d,l-SeMet in a certified reference material of SELM-1 and a commercial nutrition yeast, and the results showed that most of SeMet in the SELM-1 selenized yeast was l isomer and the recovery for l and d isomers in the spiked commercial nutrition yeast was 96.3% and 103%, respectively. This method is featured with low running cost, high sensitivity and selectivity, and exhibits application potential in chiral analysis of seleno amino acids in real world samples.Highlights► Cu(II)–(l-HP-Phe)2 was used as the chiral selector for separation of SeMet enantiomers by CE. ► Off-line SPE combined with on-line LVSS was employed to improve the sensitivity of CE–UV. ► A novel method of SPE–LE–LVSS–CE–UV was proposed to the analysis of d,l-SeMet in yeast. ► The developed method is featured with low running cost, high sensitivity and selectivity.
Co-reporter:Cong Hu, Man He, Beibei Chen, and Bin Hu
Journal of Agricultural and Food Chemistry 2012 Volume 60(Issue 42) pp:10494-10500
Publication Date(Web):October 1, 2012
DOI:10.1021/jf303269c
A poly(dimethylsiloxane) (PDMS)/β-cyclodextrin (β-CD)/divinylbenzene (DVB)-coated stir bar was prepared by the sol–gel technique for the stir bar sorptive extraction (SBSE) of four estrogens from animal-derived foods, followed by liquid desorption (LD) and high-performance liquid chromatography–ultraviolet (HPLC–UV) detection. The influence of the coating composition on SBSE of target estrogens was investigated by an orthogonal experiment design, and the prepared PDMS/β-CD/DVB-coated stir bars show good reproducibility. Under the optimal experimental conditions, the limits of detection (S/N = 3) of the developed PDMS/β-CD/DVB SBSE–LD–HPLC–UV method were 0.21–1.6 μg/L for the target estrogens with enrichment factors of 19–51-fold, the dynamic linear range was 2–2000 μg/L, and the relative standard deviations of the method ranged from 6.0% to 9.7% (n = 8, c = 100 μg/L) and from 8.4% to 11.7% (n = 8, c = 10 μg/L). The developed method was simple, sensitive, and selective and was successfully applied to the analysis of estrogens in pork and chicken samples.
Co-reporter:Xiangju Mao, Bin Hu, Man He, Wenying Fan
Journal of Chromatography A 2012 1260() pp: 16-24
Publication Date(Web):
DOI:10.1016/j.chroma.2012.08.062
Co-reporter:Chunhe Yu, Bin Hu
Talanta 2012 Volume 90() pp:77-84
Publication Date(Web):15 February 2012
DOI:10.1016/j.talanta.2011.12.078
A simple, rapid, sensitive, inexpensive and less sample consuming method of C18-stir bar sorptive extraction (SBSE)–high performance liquid chromatography (HPLC)–tandem mass spectrometry (MS/MS) was proposed for the determination of six sulfonamides in milk and milk powder samples. C18 silica particles coated stir bar was prepared by adhesion method, and two kinds of adhesive glue, polydimethylsiloxane (PDMS) sol and epoxy glue were tried. It was found that the C18-coated stir bar prepared by PDMS sol as adhesive glue is more robust than that prepared by epoxy glue when liquid desorption was employed, in terms of both lifetime and organic solvent tolerance. The preparation of C18 stir bar was simple with good mechanic strength and the stir bar could be reused for more than 20 times. Granular coating has relatively high specific surface area and is propitious to sorptive extraction based process. Compared to conventional PDMS SBSE coating, C18 coating shows good affinity to the target polar/weak polar sulfonamides. To achieve optimum SBSE extraction performance, several parameters including extraction and desorption time, ionic strength, sample pH and stirring speed were investigated. The detection limits of the proposed method for six sulfonamides were in the range of 0.9–10.5 μg/L for milk and 2.7–31.5 μg/kg for milk powder. Good linearities were obtained for sulfonamides with the correlation coefficients (R) above 0.9922. Finally, the proposed method was successfully applied to the determination of sulfonamides in milk and milk powder samples and satisfied recoveries of spiked target compounds in real samples were obtained.Highlights► C18-coated stir bar using PDMS-sol as adhesive glue was prepared and characterized. ► A new method of C18-coated SBSE–HPLC–MS/MS was developed to determine sulfonamides. ► Compared to PDMS, C18 shows good affinity to the polar/weak polar sulfonamides. ► The proposed method is sensitive, accurate, simple, rapid and low-cost. ► It can be applied to the analysis of compounds with different polarity.
Co-reporter:Guihong Cheng, Man He, Hanyong Peng, Bin Hu
Talanta 2012 Volume 88() pp:507-515
Publication Date(Web):15 January 2012
DOI:10.1016/j.talanta.2011.11.025
A fast and simple method for analysis of trace amounts of Cr(III), Cu(II), Pb(II) and Zn(II) in environmental and biological samples was developed by combining magnetic solid phase extraction (MSPE) with inductively coupled plasma-optical emission spectrometry (ICP-OES) detection. Dithizone modified silica-coated magnetic Fe3O4 nanoparticles (H2Dz-SCMNPs) were prepared and used for MSPE of trace amounts of Cr(III), Cu(II), Pb(II) and Zn(II). The prepared magnetic nanoparticles were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and Fourier transform infrared spectroscopy (FT-IR). The factors affecting the extraction of the target metal ions such as pH, sample volume, eluent, and interfering ions had been investigated and the adsorption mechanism of the target metals on the self-prepared H2Dz-SCMNPs was investigated by FT-IR and X-ray photo electron spectroscopy (XPS). Under the optimized conditions, the detection limits of the developed method for Cr(III), Cu(II), Pb(II) and Zn(II) were 35, 11, 62, and 8 ng L−1, respectively, with the enrichment factor of 100. The relative standard deviations (RSDs, c = 10 μg L−1, n = 7) were in the range of 1.7–3.1% and the linear range was 0.1–100 μg L−1. The proposed method had been validated by two certified reference materials (GSBZ50009-88 environmental water and GBW07601 human hair), and the determined values were in good agreement with the certified values. The method was also applied for the determination of trace metals in real water and human hair samples with recoveries in the range of 85–110% for the spiked samples. The developed MSPE-ICP-OES method has the advantages of simplicity, rapidity, selectivity, high extraction efficiency and is suitable for the analysis of samples with large volume and complex matrix.Highlights► We prepared dithizone modified silica-coated magnetic Fe3O4 nanoparticles. ► A method of magnetic SPE-ICP-OES was proposed for trace heavy metal analysis. ► The developed method is simple, highly selective and sensitive. ► It is suitable for the analysis of samples with large volume and complex matrix. ► The adsorption mechanism was investigated by FT-IR and XPS.
Co-reporter:Xueqin Guo, Man He, Beibei Chen, Bin Hu
Talanta 2012 Volume 101() pp:516-523
Publication Date(Web):15 November 2012
DOI:10.1016/j.talanta.2012.10.017
A new method of phase transfer hollow fiber liquid phase microextraction (PT-HF-LPME) combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) has been developed for the determination of trace Co, Pd, Cd and Bi in environmental and biological samples. In PT-HF-LPME, an intermediate solvent (1-butanol) was added into the sample solution to ensure the maximum contact area between the target metal ions and the chelating reagent (8-hydroxyquinoline, 8-HQ), which accelerated the formation of 8-HQ-metal complexes and their subsequent extraction by extraction solvent (toluene). The experimental parameters affecting the extraction efficiency of PT-HF-LPME for the target metals were studied by simplex optimization and orthogonal array design (OAD) experiments. Under the optimized conditions, the enrichment factors for Co, Pd, Cd and Bi were 110, 393, 121 and 111-fold, respectively, the limits of detection (LODs, 3σ) ranged from 3.7 to 8.3 ng L−1. The relative standard deviations (RSDs, c=0.5 ng mL−1, n=7) were 8.7, 6.2, 12.4 and 12.9% for Co, Pd, Cd and Bi, respectively. To validate the accuracy of the proposed method, two Certified Reference Materials of GSBZ50009-88 Environment Water and GBW09103 Human Urine were analyzed, and the results obtained for Cd were in good agreement with the certified values. Finally, the developed method was successfully applied to the analysis of Co, Pd, Cd and Bi in lake water and human urine samples.Highlights► PT-HF-LPME was proposed for extraction of trace metal ions. ► Enhanced extraction efficiency within short extraction time was obtained. ► 8-HQ served as both chelating agent in PT-HF-LPME and chemical modifier in ETV. ► PT-HF-LPME-ETV-ICP-MS was developed for real-world samples analysis.
Co-reporter:Nan Zhang, Hanyong Peng, Bin Hu
Talanta 2012 Volume 94() pp:278-283
Publication Date(Web):30 May 2012
DOI:10.1016/j.talanta.2012.03.040
We report here the preparation of high-magnetization Fe3O4@SiO2@TiO2 nanoparticles for solid phase extraction of trace amounts of Cd(II), Cr(III), Mn(II) and Cu(II) from environmental waters. The prepared nanoparticles were characterized by scanning electron micrograph (SEM) and transmission electron microscopy (TEM). The high-magnetization nanoparticles carrying the target metals could be easily and fast separated from the aqueous solution simply by applying an external magnetic field while no filtration or centrifugation was necessary. A light-induced hydroxide ion emitter, molecular malachite green carbinol base (MGCB) was applied to adjust pH value of solution for quantitative adsorption instead of the conventional used buffer. In the presence of UV light, MGCB gives out OH− ions, and this leads to an increase in the pH value without the aid of buffer solution. Using high-magnetization Fe3O4@SiO2@TiO2 nanoparticles as the extraction material and the light-induced MGCB for pH adjustment, we developed an efficient and convenient two-step method for separation/preconcentration trace amounts of Cd(II), Cr(III), Mn(II) and Cu(II) in environmental water samples followed by inductively coupled plasma mass spectrometry (ICP-MS) detection. The parameters affecting the extraction such as MGCB concentration, exposal time, sample volume, eluent condition, and interfering ions have been investigated in detail. Under the optimized conditions, the limits of detection for Cd(II), Cr(III), Mn(II) and Cu(II) were 4.0, 2.6, 1.6 and 2.3 ng L−1, respectively, and the relative standard deviations (RSDs, c = 1 μg L−1, n = 7) were 3.6%, 4.5%, 4.0 and 4.1%, respectively. The proposed method has been validated using certified reference materials, and it has been successfully applied in the determination of trace Cd(II), Cr(III), Mn(II) and Cu(II) in environmental water samples.Highlights► Fe3O4@SiO2@TiO2 magnetic nanoparticles were prepared as extraction materials for SPE. ► A light-induced hydroxide ion emitter, MGCB, was applied to adjust solution pH for extraction. ► An efficient and convenient MSPE–ICP-MS method was developed for trace metals analysis in waters.
Co-reporter:Xueqin Guo, Man He, Beibei Chen, Bin Hu
Talanta 2012 Volume 94() pp:70-76
Publication Date(Web):30 May 2012
DOI:10.1016/j.talanta.2012.02.053
A new method of solidified floating organic drop microextraction (SFODME) combined with electrothermal vaporization (ETV)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace heavy metals in environmental water samples with sodium diethyldithiocarbamate (DDTC) as both chelating reagent in SFODME and chemical modifier in ETV. The factors affecting the microextraction efficiency were studied in detail and the optimal extraction conditions were established. Under the optimal conditions, the limits of detection (LODs) for SFODME-ETV-ICP-MS determination of Co, Pd, Cd, Hg, Pb and Bi were found to be 0.0060, 0.0091, 0.0020, 0.0041, 0.0170 and 0.0041 ng mL−1, respectively, with the relative standard deviations (RSDs) of 2.8–10.0% (c = 0.5 ng mL−1, n = 7). The developed method was successfully applied to the analysis of six target metals in Yangtze River and East Lake water samples with recoveries ranging from 77.7 to 119.1%. To validate the accuracy of the method, a certified reference material of Environmental Water (GSBZ50009-88) was analyzed and the determined values were in good agreement with the certified values.Highlights► The combination of SFODME and ETV-ICP-MS has been successfully realized. ► p-Xylene/1-dodecanol mixture was used as extraction solvent originally. ► DDTC served as both chelating agent and chemical modifier. ► The method was applied for determination of trace metal ions in real samples.
Co-reporter:Pingjing Li, Bin Hu
Journal of Chromatography A 2011 Volume 1218(Issue 29) pp:4779-4787
Publication Date(Web):22 July 2011
DOI:10.1016/j.chroma.2011.05.058
A novel method based on off-line hollow fiber based liquid liquid liquid microextraction (HF-LLLME) combined with on-column anion selective exhaustive injection (ASEI)-capillary electrophoresis/ultraviolet (CE/UV) detection was proposed for the speciation of five phenylarsenic compounds including phenylarsonic acid (PAA), 4-aminophenylarsonic acid (4-APAA), 4-hydroxyphenylarsonic acid (4-HPAA), 4-nitrophenylarsonic acid (4-NPAA) and 3-nitro-4-hydroxyphenylarsonic acid (NHPAA) in this paper. In HF-LLLME, the target analytes were extracted from 5 mL aqueous samples (donor solution pH 2.15) through a thin phase of tributyl phosphate (TBP) inside the pores of a polypropylene hollow fiber and finally into an 18 μL 0.8 mmol/L Tris acceptor solution inside the lumen of the hollow fiber. Following HF-LLLME, the acceptor solutions were directly analyzed by ASEI-CE/UV. For ASEI, a large plug of water (91% length of total capillary) was introduced into the separation capillary before sample injection in order to prolong the sample injection time, and thus enhance the stacking efficiency. Under the optimized ASEI conditions, up to 236-fold of enrichment factor (EF) was obtained for the ASEI-CE/UV determination of target phenylarsenic compounds. By combining HF-LLLME with ASEI-CE/UV, EFs ranging from 155 to 1780-fold were achieved and the limits of detection (LODs) (at a signal-to-noise ratio of 3) were in the range of 0.68–6.90 μg/L for five phenylarsenic compounds; the relative standard deviations (RSDs) of corrected peak area were 5.6–11.8%. The proposed HF-LLLME–ASEI-CE/UV method was applied for the determination of five target phenylarsenic compounds in pig feed from a local pig farm, and storage pig litter, soil in agricultural field and lake water collected near this pig farm, the recoveries for the spiked samples were in the range of 85.7–104.5%, 66.7–96.2%, 28.9–46.9% and 86.9–107.8% for pig feed, pig litter, soil and lake water, respectively.
Co-reporter:Pingjing Li, Xing Zhang, Bin Hu
Journal of Chromatography A 2011 Volume 1218(Issue 52) pp:9414-9421
Publication Date(Web):30 December 2011
DOI:10.1016/j.chroma.2011.10.071
In this paper, a novel sample pretreatment technique termed phase transfer based liquid–liquid–liquid microextraction (PT-LLLME) was proposed for the simultaneous extraction of inorganic and organic mercury species. In PT-LLLME, an intermediate solvent (acetonitrile) was added into the donor phase to improve the contacting between target mercury species and complexing reagent. Meanwhile, a membrane supported (MS)-LLLME unit was designed to realize the PT-LLLME procedure. By using nylon membrane as supporting carrier, larger than 50 μL of acceptor solution could be hung up. Following PT/MS-LLLME, the acceptor solutions were directly analyzed by large volume sample stacking capillary electrophoresis/ultraviolet detection (LVSS-CE/UV). Accordingly, a new method of PT/MS-LLLME combined with LVSS-CE/UV was developed for the simultaneous speciation of inorganic and organic mercury species. Parameters affecting the extraction efficiency of PT/MS-LLLME were investigated in details. Under the optimized conditions, enrichment factors (EFs) ranging from 160- to 478-fold were obtained for the extraction of target mercury species by PT/MS-LLLME. By combining PT/MS-LLLME with LVSS-CE/UV, EFs were magnified up to 12,138-fold and the limits of detection (at a signal-to-noise ratio of 3) were at sub ppb level. The established approach of PT/MS-LLLME–LVSS-CE/UV was successfully applied to simultaneous determination of inorganic and organic mercury species in biological samples and environmental water samples.Highlights► We proposed a phase transfer based liquid–liquid–liquid microextraction technique. ► It is featured with high sensitivity and selectivity and fast extraction kinetics. ► A new approach was developed for the simultaneous speciation of inorganic/organic Hg. ► The CE–UV-based approach is applicable for Hg speciation in real sample analysis.
Co-reporter:Xiangju Mao, Beibei Chen, Chaozhang Huang, Man He, Bin Hu
Journal of Chromatography A 2011 Volume 1218(Issue 1) pp:1-9
Publication Date(Web):7 January 2011
DOI:10.1016/j.chroma.2010.10.103
The bottleneck of applying stir bar sorptive extraction (SBSE) to elemental speciation analysis is lack of suitable extraction phases with good affinities to different elemental species. In this paper, a newly high polar extraction phase of titania immobilized polypropylene hollow fiber (TiO2-PPHF) was prepared by sol–gel immersion and low temperature hydrothermal process and the obtained TiO2-PPHF inherits the adsorption properties of TiO2 and the toughness of PPHF. With a suitable size of stainless steel magnetic bar inserted into the prepared TiO2-PPHF, a disposable TiO2-PPHF coating stir bar was obtained. The prepared TiO2-PPHF was characterized by X-ray diffraction spectrometry and scanning electron microscopy and the significant parameters affecting the extraction efficiency of different arsenic species were studied. Based on the above facts, a new method of SBSE combined with high performance liquid chromatography (HPLC)–inductively coupled plasma mass spectrometry (ICP-MS) was developed for the speciation of phenyl arsenic compounds and their possible transformation products in chicken tissues. Under the optimal conditions, limits of detection (LODs) of the developed method for eight target arsenic species were in the range of 11.4–64.6 ng L−1 with enrichment factors of 8.5–22.3 (theory enrichment factor was 50), and the relative standard deviations (RSDs) were varying from 6.3 to 12.6% (cAsIII/V = 5 μg L−1, cMMA,DMA,p-ASA,4-OH,3-NHPAA,PA,4-NPAA = 10 μg L−1, n = 7). The proposed method was successfully applied to the speciation of arsenic in chicken meat/liver samples and the recoveries for the spiked samples were in the range of 78.5–120.4%. In order to validate the accuracy of the proposed method, a certified reference material of BCR-627 tuna fish tissue was analyzed and the determined values were in good agreement with the certified values. The TiO2-PPHF was demonstrated to be a highly selective coating for the target arsenic species, and could be easily prepared in batches with low cost. In addition, with the disposable coating, the carry-over effect commonly encountered in conventional SBSE was avoided.
Co-reporter:Beibei Chen, Bin Hu, Ping Jiang, Man He, Hanyong Peng and Xing Zhang
Analyst 2011 vol. 136(Issue 19) pp:3934-3942
Publication Date(Web):22 Aug 2011
DOI:10.1039/C1AN15387K
A sensitive and selective on chip magnetic immunoassay method, based on a sandwich-type immunoreaction with PbS nanoparticle (NPs) labels in combination with electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS), was proposed for the determination of carcinoembryonic antigen (CEA). We designed and fabricated a microfluidic chip for magnetic immunoassay, and the prepared iminodiacetic acid modified silica coated magnetic nanoparticles (IDA-SCMNPs) were packed into the central microchannel to form a solid phase column by self-assembly under the magnetic field. After completion of the immunoreaction involving a primary antibody, CEA and a secondary antibody labeled with PbS NPs on a magnetic solid phase packed-column, ETV-ICP-MS was used to determine the concentration of Pb that was released from the captured PbS NPs using an acid-dissolution step. The concentrations of CEA can be correlated with that of Pb. The established method demonstrated a limit of detection of 0.058 μg L−1 for CEA, with a relative standard deviation (RSD) of 6.7% (c = 10 μg L−1, n = 7). A linearity ranging from 0.2 μg L−1 to 50 μg L−1 and a 2-fold enrichment factor (from 60 μL sample solution to 30 μL eluent) were achieved. The proposed method was further validated by analyzing CEA in human serum. The results were in good agreement with those obtained by chemiluminescent immunoassay, which is currently used as a clinical method. Overall, this method offers the advantages of high speed, high sensitivity, high selectivity, low sample/reagents consumption, high integrity and versatility. Moreover, it can be easily applied to other biological and medical assays.
Co-reporter:Chaozhang Huang and Bin Hu
Analyst 2011 vol. 136(Issue 7) pp:1425-1432
Publication Date(Web):07 Feb 2011
DOI:10.1039/C0AN00660B
A titania hollow fiber membrane was successfully synthesized in a macro range via a template method coupled with a sol–gel process. Thermal gravimetric and differential thermal analysis (TG-DTA) was employed to study the effect of heat treatment on the synthesized hollow fiber, and the crystal forms of the titania hollow fiber membranes at different temperatures were studied by X-ray diffraction (XRD). The pore structure of the prepared titania hollow fiber was characterized by scanning electron micrograph (SEM) and nitrogen adsorption/desorption measurements. The prepared titania hollow fiber membrane was explored as a new adsorption material for trace metals for the first time and a new method of titania hollow fiber membrane solid phase microextraction (MSPME) online coupled to inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace amount of Cd, Co, V and Ni in human serum samples. In order to validate the developed method, two certified reference materials of NIES.No.10-b rice flour and BCR No.184 bovine muscle were analyzed and the determined values were in good agreement with the certified values.
Co-reporter:Lin Zhang;Beibei Chen;Hanyong Peng;Man He
Journal of Separation Science 2011 Volume 34( Issue 16-17) pp:2247-2254
Publication Date(Web):
DOI:10.1002/jssc.201100173
Abstract
A simple and sensitive method based on aminopropyltriethoxysilane (APTES)-silica hybrid monolithic capillary microextraction (CME) combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace elements in biological samples. Under the optimized conditions, the adsorption capacities of APTES-silica hybrid monolithic capillary were 42.5, 55, 57.5, 82.5, 52.5, and 40 μg/m for Mn(II), Co(II), Ni(II), Cu(II), Cd(II), and Pb(II), respectively. The LODs were in the range of 1.2 (Cd)–14 (Pb) ng/L with the relative standard deviations (RSDs) of <5.1% (c=1 μg/L, n=7). The reproducibility of APTES-silica hybrid monolithic preparation ranged from 1.6 to 5.6% in one batch, and from 2.3 to 6.2% in batch-to-batch, respectively. To validate the developed method, two certified reference materials of NIES No. 10-b rice flour and GBW 07601 (GSH-1) human hair were analyzed and the determined values were in good agreement with the certified values. The proposed method has also been applied for the analysis of human hair and urine samples with the recoveries for the spiked samples in the range of 89–106%.
Co-reporter:Fei Zheng, Nan Zhang and Bin Hu
Journal of Analytical Atomic Spectrometry 2011 vol. 26(Issue 7) pp:1521-1525
Publication Date(Web):24 Feb 2011
DOI:10.1039/C1JA10025D
Mn(II) imprinted 3-mercaptopropyltrimethoxysilane (MPTS)-silica coated capillary was synthesized by sol–gel technique combining with a double-imprinting concept. The prepared capillary was employed for capillary microextraction (CME) of trace Mn(II) followed by on-line inductively coupled plasma mass spectrometry (ICP-MS) detection. This coating was in situ created on the inner wall of tetramethoxysilane (TMOS) coated silica capillary using a sol solution containing MPTS as the functional precursor, ethanol as the solvent and both Mn(II) and surfactant micelles (cetyltrimethylammonium bromide, CTAB) as the templates. The factors affecting on the CME of Mn(II) such as sample pH, sample flow rate and volume, elution solution and interfering ions have been investigated. Under the optimized conditions, the adsorption capacities of non-imprinted and imprinted capillary were found to be 1.24 and 2.38 μg m−1, respectively. With a sampling frequency of 9 h−1, an enrichment factor of 16.7 was obtained for Mn(II). The detection limit (3σ) based on three times the standard deviations of the blanks by seven replicates was 10.3 ng L −1 and the relative standard deviation (RSD) was 4.3% (c = 0.1 μg L−1, n = 7). The proposed method was successfully applied for the determination of trace Mn(II) in serum samples and validated by two certified reference materials. The method is rapid, selective, sensitive and applicable for the analysis of trace Mn(II) in biological samples with limited sample volume.
Co-reporter:Yuefei Zhang, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2011 Volume 66(Issue 2) pp:163-169
Publication Date(Web):February 2011
DOI:10.1016/j.sab.2011.01.006
Platform and wall vaporization for electrothermal vaporization (ETV)-inductively coupled plasma mass spectrometry (ICP-MS) determination of some refractory elements (Ti, V, Cr, Mo, La and Zr) and Pb were comparatively studied with the use of poly (tetrafluoroethylene) (PTFE) as fluorinating reagent. The factors affecting the vaporization behaviors of the target analytes in the platform and tube wall vaporization including vaporization temperature and time, pyrolytic temperature and time were studied in detail, and the flow rates of carrier gas/auxiliary carrier gas, were carefully optimized. Under the optimal conditions, the signal profiles, signal intensity, interferences of coexisting ions and analytical reproducibility for wall and platform vaporization ETV–ICP-MS were compared. It was found that both wall and platform vaporization could give very similar detection limits, but the platform vaporization provided higher signal intensity and better precision for some refractory elements and Pb than the wall vaporization. Especially for La, the signal intensity obtained by platform vaporization was 3 times higher than that obtained by wall vaporization. For platform vaporization ETV–ICP-MS, the limits of detection (LODs) of 0.001 μg L−1 (La) ~ 0.09 μg L− 1 (Ti) with the relative standard deviations (RSDs) of 1.5% (Pb) ~ 15.5% (Zr) were obtained. While for wall vaporization ETV–ICP-MS, LODs of 0.005 μg L− 1 (La) ~ 0.4 μg L− 1 (Pb) with RSDs of 3.2% (Mo) ~ 12.8% (Zr) were obtained. Both platform and tube wall vaporization techniques have been used for slurry sampling fluorination assisted ETV–ICP-MS direct determination of Ti, V, Cr, Mo, La, Zr and Pb in certified reference materials of NIES No. 8 vehicle exhaust particulates and GBW07401 soil, and the analytical results obtained are in good agreement with the certified values.
Co-reporter:Fei Zheng, Bin Hu
Talanta 2011 Volume 85(Issue 2) pp:1166-1173
Publication Date(Web):15 August 2011
DOI:10.1016/j.talanta.2011.05.039
The poly(N-isopropylacrylamide) (PNIPA) gel is a widely studied thermo-responsive material that exhibits discontinuous change in volume when the external temperature is increased. In this paper, PNIPA gel was prepared and applied as a novel polymer coating for fiber-in-tube capillary microextraction of trace Co, Ni and Cd followed by on-line ICP-MS detection. The PNIPA coating was synthesized by using ethylene triethoxysilane (ETEOS) as the cross-linking agent under acidic conditions. This siloxane incorporated PNIPA gel achieves a dramatically rapid response rate when the external temperature is changed. The micro-structure of PNIPA coating was examined by scanning electron micrograph (SEM). Various experimental parameters including pH, temperature, sample flow rate and volume, elution solution and interfering ions affecting the extraction of the target analytes have been carefully investigated and optimized. Under the optimized conditions, the limits of detection were 0.45, 4.6 and 6.9 ng L−1 for Co, Ni and Cd, respectively. With a sampling frequency of 13 h−1, the relative standard deviations (RSDs) for Co, Ni and Cd were 4.8, 5.1 and 6.4% (C = 1 μg L−1, n = 7), respectively. The proposed method had been successfully applied to the determination of Co, Ni and Cd in human urine. To validate the proposed method, certified reference materials of NIES No. 10-b rice flour and GBW07601 (GSH-1) human hair were analyzed and the determined values were in a good agreement with the certified values. The PNIPA coated fiber-in-tube capillary can be reused for more than 150 times without decreasing the extraction efficiency.
Co-reporter:Beibei Chen, Man He, Xiangju Mao, Ran Cui, Daiwen Pang, Bin Hu
Talanta 2011 Volume 83(Issue 3) pp:724-731
Publication Date(Web):15 January 2011
DOI:10.1016/j.talanta.2010.10.023
Room-temperature ionic liquids (RTILs) improved reversed-phase high performance liquid chromatography (RP-HPLC) on-line combined with inductively coupled plasma mass spectrometry (ICP-MS) was developed for selenium speciation. The different parameters affecting the retention behaviors of six target selenium species especially the effect of RTILs as mobile phase additives have been studied, it was found that the mobile phase consisting of 0.4% (v/v) 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 0.4% (v/v) 1-butyl-2,3-dimethylimidazolium tetrafluroborate ([BMMIM]BF4) and 99.2% (v/v) water has effectively improved the peak profile and six target selenium species including Na2SeO3 (Se(IV)), Na2SeO4 (Se(VI)), l-selenocystine (SeCys2), d,l-selenomethionine (SeMet), Se-methylseleno-l-cysteine (MeSeCys), seleno-d,l-ethionine (SeEt) were separated in 8 min. In order to validate the accuracy of the method, a Certified Reference Material of SELM-1 yeast sample was analyzed and the results obtained were in good agreement with the certified values. The developed method was also successfully applied to the speciation of selenium in Se-enriched yeasts and clover. For fresh Se-enriched yeast cells, it was found that the spiked SeCys2 in living yeast cells could be transformed into SeMet. Compared with other ion-pair RP-HPLC–ICP-MS approaches for selenium speciation, the proposed method possessed the advantages including ability to regulate the retention time of the target selenium species by selecting the suitable RTILs and their concentration, simplicity, rapidness and low injection volume, thus providing wide potential applications for elemental speciation in biological systems.
Co-reporter:Nan Zhang;Hanyong Peng;Shen Wang
Microchimica Acta 2011 Volume 175( Issue 1-2) pp:
Publication Date(Web):2011 October
DOI:10.1007/s00604-011-0659-3
We have immobilized iminodiacetic acid on mesoporous Fe3O4@SiO2 microspheres and used this material for efficient and cost effective method of magnetic solid phase extraction (SPE) of trace levels of Cd, Mn and Pb. The microspheres were characterized by infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. The loaded microspheres can be easily separated from the aqueous sample solution by applying an external magnetic field. The effects of pH, sample volume, concentration and volume of eluent, and of interfering ions were investigated in detail. The method has detection limit of 0.16, 0.26 and 0.26 ng L−1 for the ions of Cd, Mn and Pb, respectively, and the relative standard deviations (RSDs, c = 1 μg L−1, n = 7) are 4.8%, 4.6% and 7.4%. The method was successfully applied to the determination of these metals in biological and environmental samples using ICP-MS. Two certified reference materials were analyzed, and the results coincided well with the certified values.
Co-reporter:Lidan Lan, Bin Hu, Chunhe Yu
Journal of Chromatography A 2010 Volume 1217(Issue 45) pp:7003-7009
Publication Date(Web):5 November 2010
DOI:10.1016/j.chroma.2010.09.006
An organic–inorganic hybrid titania-hydroxy-terminated silicone oil (titania-OH-TSO) stir bar coating was prepared by sol–gel method. The extraction performance of titania-OH-TSO coated stir bar was evaluated and compared with poly(dimethysiloxane) (PDMS), poly(dimethysiloxane)–divinylbenzene (PDMS–DVB), poly(dimethysiloxane)–β-cyclodextrin (PDMS–β-CD) and C18 coated stir bar with five polar drugs of abuse including amphetamine (PA), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA) and ketamine (Ke) as the model analytes. The experimental results revealed that the titania-OH-TSO coated stir bar exhibited highly pH-resistant ability, good preparation reproducibility, superior selectivity and high extraction efficiency for the target compounds. Based on this fact, a new method of titania-OH-TSO coated stir bar sorptive extraction (SBSE) combined with high performance liquid chromatography (HPLC)–ultraviolet visible (UV) detection was developed for the analysis of five drugs of abuse in urine samples. The factors affecting the extraction efficiency of SBSE such as sample pH, desorption solvent, sample volume, extraction time, desorption time, stirring rate and ionic strength were investigated and the optimal extraction conditions were established. Under the optimized conditions, the limits of detection (LODs) for titania-OH-TSO coated SBSE–HPLC–UV determination of five polar drugs of abuse were in the range of 2.3–9.1 μg/L with relative standard deviations (RSDs) ranging from 7.3 to 8.9% (c = 300 μg/L, n = 6), and all of the target compounds exhibited good linearity over a concentration range of 30–3000 μg/L. The developed method was applied to the determination of amphetamines and Ke in urine samples of drug abusers with satisfactory results.
Co-reporter:Dahui Chen, Bin Hu, Man He, Chaozhang Huang
Microchemical Journal 2010 Volume 95(Issue 1) pp:90-95
Publication Date(Web):May 2010
DOI:10.1016/j.microc.2009.10.013
A novel adsorbent of thiacalix[4]arene tetracarboxylate derivative modified mesoporous TiO2 was prepared and was used as a packing material for flow injection (FI) micro-column (20 mm × 4.0 mm i.d.) separation/preconcentration on-line coupled to inductively coupled plasma optical emission spectrometry (ICP-OES) simultaneous determination of trace metals (V, Cu, Pb, Cr) in environmental water samples. The experimental conditions for modified mesoporous TiO2 packed micro-column separation/preconcentration of the target metals were optimized and the interference of commonly coexisting ions was examined. The adsorption capacities of thiacalix[4]arene tetracarboxylate derivative modified mesoporous TiO2 for V, Cu, Pb and Cr were found to be 14.0, 11.7, 17.7 and 14.5 mg g− 1, respectively. The detection limits of the method were 0.09, 0.23, 0.50 and 0.15 µg L− 1 for V, Cu, Pb and Cr, respectively, with a preconcentration factor of 20. The precision of this method were 1.7% (V), 3.9% (Cu), 4.6% (Pb) and 2.9% (Cr) (n = 7, C = 5 µg L− 1), respectively. The developed method was applied to the determination of trace heavy metals in real samples and the recoveries for spiked samples were found to be in the range of 88.7–107.1%. For validation, a certified reference material of GSBZ50009-88 environmental water sample was analyzed and the determined values were in good agreement with the certified values.
Co-reporter:Chunhe Yu
Journal of Separation Science 2010 Volume 33( Issue 14) pp:2176-2183
Publication Date(Web):
DOI:10.1002/jssc.201000091
Abstract
Automated methods of PDMS/β-CD/divinylbenzene-coated stir plate sorptive extraction (SPSE) coupled to HPLC-fluorescence detector were reported for the first time. Three automation modes, static SPSE, circular flow SPSE and continuous flow SPSE, were evaluated and critically compared with stir bar sorptive extraction by using six polycyclic aromatic hydrocarbons as model analytes. It was found that the operable sample volume for circular flow SPSE and continuous flow SPSE was larger than that for static SPSE. Under the same extraction conditions, continuous flow SPSE exhibited the highest extraction efficiencies in all automated modes and manual stir bar sorptive extraction for the target compounds. Compared with the manual operation (approximately 5–10 min), automated SPSE required a relatively short time (117–180 s) to finish sampling, washing and sample loading. Besides being labor-saving and time-saving, automated SPSE has other advantages, such as no time limit and non-attended operation. The proposed continuous flow PDMS/β-CD/divinylbenzene-coated SPSE-HPLC-fluorescence detector was successfully applied to environmental water analysis.
Co-reporter:Beibei Chen, Hanyong Peng, Fei Zheng, Bin Hu, Man He, Wei Zhao and Daiwen Pang
Journal of Analytical Atomic Spectrometry 2010 vol. 25(Issue 11) pp:1674-1681
Publication Date(Web):28 May 2010
DOI:10.1039/C003029E
A sensitive and selective method of immunoaffinity monolithic capillary microextraction (CME) based on a sandwich immunoreaction with quantum dots (QDs) labels coupled with micro-concentric nebulizer inductively coupled plasma mass spectrometry (MCN-ICP-MS) was proposed for the determination of antigen human IgG in human serum. Aminopropyltriethoxysilane (APTES)-silica hybrid monolithic capillary which was prepared by room temperature ionic liquid (RTIL)-mediated sol–gel method was immobilized with primary goat-anti-human antibody. After a complete immunoreaction among primary antibody, IgG antigen and secondary antibody labeled with CdSe QDs in monolithic capillary, the concentration of IgG was quantified by MCN-ICP-MS simultaneous analysis of Cd and Se released from captured QDs labels with an acid-dissolution (pH 2.0) step. With consumption of only 50 μL sample solution, the established method presented a limit of detection of 0.058 μg L−1 based on the Cd signal and 0.097 μg L−1 based on the Se signal for human IgG antigen, with the relative standard deviations (RSDs) of 7.2% based on the Cd signal and 13% based on the Se signal (chumanIgGantigen = 5 μg L−1, n = 7), respectively. The response of CME-MCN-ICP-MS method for human IgG was linear over a dynamic range from 0.2 to 10 μg L−1 based on the Cd signal and from 0.5 to 10 μg L−1 based on the Se signal, respectively. The proposed method was successfully applied for the determination of IgG in real human serum with good recoveries. For validation, the same sample was also analyzed by the commonly used clinical method of immunoturbidimetry, and the analytical result obtained by the proposed method is in good agreement with that the result obtained by immunoturbidimetry. By using CdSe QDs labels, the quantification of human IgG antigen could be performed by ICP-MS determination of both Cd and Se, and the analytical results for human IgG antigen could be validated in one run. The developed method was fast, sensitive, selective, versatile and could be easily extended to other protein quantification schemes as well as in DNA analysis.
Co-reporter:Beibei Chen, Shujing Heng, Hanyong Peng, Bin Hu, Xu Yu, Zhiling Zhang, Daiwen Pang, Xin Yue and Ying Zhu
Journal of Analytical Atomic Spectrometry 2010 vol. 25(Issue 12) pp:1931-1938
Publication Date(Web):07 Oct 2010
DOI:10.1039/C0JA00003E
Quantitative analysis of trace levels of heavy metals in human cells is critical to environmental and toxicological research. We describe here a new strategy of determining ultratrace levels of cadmium, lead, and mercury in cultured cells. It involves the integration of cell sample introduction and magnetic nanoparticle solid phase microextraction (MSPME) on a microfluidic chip, combined with electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS) detection. γ-mercaptopropyltrimethoxysilane (γ-MPTS) modified silica-coated magnetic nanoparticles were synthesized and demonstrated for the microextraction of Cd, Pb, and Hg. Under an external magnetic field, these magnetic nanoparticles self-assembled in microchannels to form a solid phase packed column. The formation mechanism of the on-chip magnetic solid phase packed column and the main factors influencing the packing and analytical performance were investigated. Under the optimized conditions, MSPME enabled enrichment of Cd, Hg, and Pb by a factor of >40, and resulted in improved limits of detection for Cd (0.72 ng L−1), Hg (0.86 ng L−1), and Pb (1.12 ng L−1) using ETV-ICP-MS. Quantitative analyses of trace Cd, Hg and Pb in HepG2 cells were achieved by applying the microfluidic system that integrated cell rupture, mixing, magnetic extraction and elution into one device, followed by ultrasensitive detection by ETV-ICP-MS, which required only a microlitre amount of sample. Analysis of approximately 5000 cells revealed that the average amounts of Cd, Hg and Pb in a single HepG2 cell were of the order of a few femtograms, and that the cellular levels increased with increasing concentrations of these metals in cell cultures. The concentrations of Cd, Hg, and Pb detectable in HepG2 cells were several orders of magnitude lower than their IC50 values, suggesting that the technique is potentially useful for measuring these heavy metals in studies of chronic metal toxicity.
Co-reporter:Beibei Chen, Yan Zeng, Bin Hu
Talanta 2010 Volume 81(1–2) pp:180-186
Publication Date(Web):15 April 2010
DOI:10.1016/j.talanta.2009.11.057
A C18 column dynamically coated with zwitterionic bile acid derivative, 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate (CHAPS), was used for direct injection high performance liquid phase chromatography (HPLC)–ultraviolet visible (UV)/inductively coupled plasma mass spectrometry (ICP-MS) speciation of aluminum in non-spiked human serum. Small-molecule Al-complex compounds of Al-citrate (Al-Cit) and large-molecule Al-protein compounds of Al-transferrin (Al-Tf) were chosen as the model species and their retention behaviors on CHAPS modified C18 column were studied with UV and on-line ICP-MS detection in detail. Under the optimal conditions, large-molecule Al-protein compounds and small-molecule Al-complex compounds could be separated in 4 min, and their concentrations were on-line determined by ICP-MS. The detection limits of the method were 0.74 and 0.83 ng mL−1 with the RSD of 2.8% and 3.0% (n = 7) for Al-Tf and Al-Cit, respectively. The developed method was applied to the speciation of Al in healthy human serum and chronic hemodialysis patient serum. To the best of our knowledge, this is the first report on the simultaneous quantification of both Al-protein compounds (e.g. Al-Tf) and small-molecule Al-complex compounds (e.g. Al-Cit) in healthy human serum at low concentration levels. Compared with the reported methods in the literature, this method has several attractive features such as simplicity, rapidness, no sample preparation required, and it provides a new strategy for the speciation of trace elements in human body fluids.
Co-reporter:Qin Xiao, Bin Hu
Journal of Chromatography B 2010 Volume 878(Issue 19) pp:1599-1604
Publication Date(Web):1 June 2010
DOI:10.1016/j.jchromb.2010.04.023
A simple method of hollow fiber-liquid phase microextraction (HF-LPME) combined with gas chromatography (GC) was developed for the analysis of four phenothiazine drugs (promethazine, promazine, chlorpromazine and trifluoperazine) in human urine samples. All variables affecting the extraction of target analytes including organic solvent type, stirring rate, extraction time, extraction temperature, pH of sample solution and ionic strength were carefully studied and optimized. Under the optimal conditions, the analytical performance of HF-LPME-GC-flame photometric detector (FPD) and HF-LPME-GC-flame ionization detector (FID) were evaluated and compared. The results showed that the HF-LPME-GC-FID was more sensitive than HF-LPME-GC-FPD for the determination of four target phenothiazine drugs, while the signal peak shape and resolution obtained by HF-LPME-GC-FPD was better than that obtained by HF-LPME-GC-FID. HF-LPME-GC-FPD/FID was successfully applied for the assay of the interested phenothiazine drugs in urine sample, and the excretion of the drugs was also investigated by monitoring the variation of the concentration of chlorpromazine in urine of a psychopath within 8 h after drug-taking. The proposed method provided an effective and fast way for the therapeutic drug monitoring (TDM) of phenothiazine.
Co-reporter:Chaomei Xiong, Bin Hu
Talanta 2010 Volume 81(1–2) pp:578-585
Publication Date(Web):15 April 2010
DOI:10.1016/j.talanta.2009.12.034
A new, simple and sensitive method by combining headspace Pd(II)-coated graphite bar microextraction (GBME) with electrothermal vaporization–inductively coupled plasma mass spectrometry (ETV–ICP-MS) was developed for the determination of trace Se, Te and Bi in seawater and human hair. In this method, the graphite bar was coated with Pd(II) and then used for headspace trapping of the hydrides of Se(IV), Te(IV) and Bi(III). The graphite bar with enriched hydrides of analytes was inserted directly into the graphite tube and subsequently determined by ETV–ICP-MS according to the established temperature program. The experimental parameters, which may affect the extraction and vaporization of target analytes, were systematically investigated and the optimal experimental conditions were established. Under the optimal conditions, the detection limits of the method were 8.6, 2.6 and 0.2 ng l−1 and the relative standard deviations (RSDs) were 7.0%, 6.2% and 8.0% (C = 0.20 μg l−1, n = 7) for Se, Te and Bi, respectively. Linearity was obtained over the range of 0.05–20.00, 0.01–5.00 and 0.01–20.00 μg l−1 with the correlation coefficients of 0.9942, 0.9997 and 0.9976 for Se, Te and Bi, respectively. The proposed method was successfully applied for the determination of trace Se, Te and Bi in seawater and human hair samples. In order to validate the method, the proposed method has also been applied for the determination of trace Se, Te and Bi in the certified material of GBW07601 human hair, and the determined values were in good agreement with the certified values.
Co-reporter:Jun Xiong, Jie Chen, Man He, Bin Hu
Talanta 2010 Volume 82(Issue 3) pp:969-975
Publication Date(Web):15 August 2010
DOI:10.1016/j.talanta.2010.06.001
A method of hollow fiber (HF) liquid phase microextraction (LPME) combined with gas chromatography (GC)-flame ionization detection (FID) was developed for the simultaneous quantification of trace amphetamine (AP), methamphetamine (MA), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), caffeine and ketamine (KT) in drug abuser urine samples. The factors affecting on the extraction of six target analytes by HF-LPME were investigated and optimized, and the subsequent analytical performance evaluation and real sample analysis were performed by the extraction of six target analytes in sample solution containing 30% NaCl (pH 12.5) for 20 min with extraction temperature of 30 °C and stirring rate of 1000 rpm. Under such optimal conditions, the limits of detection (LODs, S/N = 3) for the six target analytes were ranged from 8 μg/L (AP, KT) to 82 μg/L (MDA), with the enrichment factors (EFs) of 5–227 folds, and the relative standard deviations (RSDs, n = 7) were in the range of 6.9–14.1%. The correlation coefficients of the calibration for the six target analytes over the dynamic linear range were higher than 0.9958. The application feasibility of HF-LPME-GC-FID in illegal drug monitoring was demonstrated by analyzing drug abuser urine samples, and the recoveries of target drugs for the spiked sample ranging from 75.2% to 119.3% indicated an excellent anti-interference capability of the developed method. The proposed method is simple, effective, sensitive and low-cost, and provides a much more accurate and sensitive detection platform over the conventional analytical techniques (such as immunological assay) for drug abuse analysis.
Co-reporter:Hongmei Jiang, Bin Hu, Beibei Chen, Linbo Xia
Analytica Chimica Acta 2009 Volume 634(Issue 1) pp:15-21
Publication Date(Web):16 February 2009
DOI:10.1016/j.aca.2008.12.008
A new method of hollow fiber liquid phase microextraction (HF-LPME) using ammonium pyrrolidine dithiocarbamate (APDC) as extractant combined with electrothermal atomic absorption spectrometry (ETAAS) using Pd as permanent modifier has been described for the speciation of As(III) and As(V). In a pH range of 3.0–4.0, the complex of As(III)–APDC complex can be extracted using toluene as the extraction solvent leaving As(V) in the aqueous layer. The post extraction organic phase was directly injected into ETAAS for the determination of As(III). To determine total arsenic in the samples, first As(V) was reduced to As(III) by l-cysteine, and then a microextraction method was performed prior to the determination of total arsenic. As(V) assay was based on subtracting As(III) form the total arsenic. All parameters, such as pH of solution, type of organic solvent, the amount of APDC, stirring rate and extraction time, affecting the separation of As(III) from As(V) and the extraction efficiency of As(III) were investigated, and the optimized extraction conditions were established. Under optimized conditions, a detection limit of 0.12 ng mL−1 with enrichment factor of 78 was achieved. The relative standard deviation (R.S.D.) of the method for five replicate determinations of 5 ng mL−1 As(III) was 8%. The developed method was applied to the speciation of As(III) and As(V) in fresh water and human hair extracts, and the recoveries for the spiked samples are 86–109%. In order to validate the developed method, three certified reference materials such as GBW07601 human hair, BW3209 and BW3210 environmental water were analyzed, and the results obtained were in good agreement with the certified values provided.
Co-reporter:Chunhe Yu, Zhimin Yao, Bin Hu
Analytica Chimica Acta 2009 Volume 641(1–2) pp:75-82
Publication Date(Web):8 May 2009
DOI:10.1016/j.aca.2009.03.031
A “dumbbell-shaped” stir bar was proposed to prevent the friction loss of coating during the stirring process, and thus prolonged the lifetime of stir bars. The effects of the coating components, including polydimethylsiloxane (PDMS), β-cyclodextrin (β-CD) and divinylbenzene (DVB) were investigated according to an orthogonal experimental design, using three polycyclic aromatic hydrocarbons (PAHs) and four polycyclic aromatic sulfur heterocycles (PASHs) as model analytes. Four kinds of stir bars coated with PDMS, PDMS/β-CD, PDMS/DVB and PDMS/β-CD/DVB were prepared and their extraction efficiencies for the target compounds were compared. It was demonstrated that PDMS/β-CD/DVB-coated stir bar showed the best affinity to the studied compounds. The preparation reproducibility of PDMS/β-CD/DVB-coated stir bar ranged from 3.2% to 15.2% (n = 6) in one batch, and 5.2% to 13.4% (n = 6) among batches. The “dumbbell-shaped” stir bar could be used for about 40 times, which were 10 extractions more than a normal stir bar. The prepared PDMS/β-CD/DVB-coated “dumbbell-shaped” stir bar was used for stir bar sorptive extraction (SBSE) of PAHs and PASHs and the desorbed solution was introduced into HPLC-UV for subsequent analysis. The limits of detection of the proposed method for seven target analytes ranged from 0.007 to 0.103 μg L−1, the relative standard deviations were in the range of 6.3–12.9% (n = 6, c = 40 μg L−1), and the enrichment factors were 19–86. The proposed method was successfully applied to the analysis of seven target analytes in lake water and soil samples.
Co-reporter:Bin Hu, Fei Zheng, Man He, Nan Zhang
Analytica Chimica Acta 2009 Volume 650(Issue 1) pp:23-32
Publication Date(Web):14 September 2009
DOI:10.1016/j.aca.2009.04.002
As a solvent-free miniaturized sample preparation technique, capillary microextraction (CME) has been hyphenated with different analytical instruments for trace elements analysis of environmental, biological, food and pharmaceutical samples. This review discusses the fundamentals and recent development of CME, including the theoretical basis, extraction modes (packed, open-tubular and monolithic CME) and capillary materials for CME. The emphasis is placed on the application of CME to trace/ultra-trace elements analysis and their speciation. Existing coating/monolithic materials used for CME are summarized together with a detailed overview of their preparation methods.
Co-reporter:Yunli Wu, Bin Hu
Journal of Chromatography A 2009 Volume 1216(Issue 45) pp:7657-7663
Publication Date(Web):6 November 2009
DOI:10.1016/j.chroma.2009.09.008
A simple, selective, sensitive and inexpensive method of hollow fiber-based liquid–liquid–liquid microextraction (HF-LLLME) combined with high performance liquid chromatography (HPLC)-ultraviolet (UV) detection was developed for the determination of four acidic phytohormones (salicylic acid (SA), indole-3-acetic acid (IAA), (±) abscisic acid (ABA) and (±) jasmonic acid (JA)) in natural coconut juice. To the best of our knowledge, this is the first report on the use of liquid phase microextraction (LPME) as a sample pretreatment technique for the simultaneous analysis of several phytohormones. Using phenetole to fill the pores of hollow fiber as the organic phase, 0.1 mol L−1 NaOH solution in the lumen of hollow fiber as the acceptor phase and 1 mol L−1 HCl as the donor phase, a simultaneous preconcentration of four target phytohormones was realized. The acceptor phase was finally withdrawn into the microsyringe and directly injected into HPLC for the separation and quantification of the target phytohormones. The factors affecting the extraction efficiency of four phytohormones by HF-LLLME were optimized with orthogonal design experiment, and the data was analyzed by Statistical Product and Service Solutions (SPSS) software. Under the optimized conditions, the enrichment factors for SA, IAA, ABA and JA were 243, 215, 52 and 48, with the detection limits (S/N = 3) of 4.6, 1.3, 0.9 ng mL−1 and 8.8 μg mL−1, respectively. The relative standard deviations (RSDs, n = 7) were 7.9, 4.9, 6.8% at 50 ng mL−1 level for SA, IAA, ABA and 8.4% at 500 μg mL−1 for JA, respectively. To evaluate the accuracy of the method, the developed method was applied for the simultaneous analysis of several phytohormones in five natural coconut juice samples, and the recoveries for the spiked samples were in the range of 88.3–119.1%.
Co-reporter:Chunhe Yu
Journal of Separation Science 2009 Volume 32( Issue 1) pp:147-153
Publication Date(Web):
DOI:10.1002/jssc.200800486
Abstract
A PDMS/poly(vinylalcohol) (PDMS/PVA) film prepared through a sol–gel process was coated on stir bars for sorptive extraction, followed by liquid desorption and large volume injection–GC–flame photometric detector (LVI–GC–FPD) for the determination of five organophosphorus pesticides (OPPs) (phorate, fenitrothion, malathion, parathion, and quinalphos) in honey. The preparation reproducibility of PDMS/PVA-coated stir bar ranged from 4.3 to 13.4% (n = 4) in one batch, and from 6.0 to 12.6% (n = 4) in batch to batch. And one prepared stir bar can be used for more than 50 times without apparent coating loss. The significant parameters affecting stir bar sorptive extraction (SBSE) were investigated and optimized. The LODs for five OPPs ranged from 0.013 (parathion) to 0.081 μg/L (phorate) with the RSDs ranging from 5.3 to 14.2% (c = 1 μg/L, n = 6). The proposed method was successfully applied to the analysis of five OPPs in honey.
Co-reporter:Jun Yin, Bin Hu, Man He, Mingming Zheng and Yu-Qi Feng
Journal of Analytical Atomic Spectrometry 2009 vol. 24(Issue 1) pp:76-82
Publication Date(Web):24 Oct 2008
DOI:10.1039/B810442E
A novel method of polymer monolith microextraction (PMME) using a poly(acrylamide-vinylpyridine-N,N′-methylene bisacrylamide) (AA-VP-Bis) monolithic column combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of trace Cd, Tl, and Pb with Pd as chemical modifier has been proposed. Several factors that influence the microextraction efficiency including pH value, sample flow rate, extraction time, sample volume, eluent volume, and coexisting ions, were investigated and the optimal microextraction conditions were established. The chemical modification of Pd in ETV-ICP-MS has been studied and the results indicated that the pyrolysis temperature for the target analytes could be increased up to 600 °C and the signal intensities were increased by 4.1, 2.1, and 13.8 times for Cd, Tl, and Pb, respectively. Under the optimized conditions, with a consumption of 0.4 mL sample, the limits of detection (LODs) were 1.1, 0.5, and 0.2 ng L−1 for Cd, Tl, and Pb, and the relative standard deviations (RSDs) were 10.3, 9.7, and 9.2% (C = 0.05 µg L−1, n = 5) for Cd, Tl, and Pb, respectively. The proposed method was successfully applied to the determination of trace Cd, Tl, and Pb in human serum and urine samples, and the recovery for the spiked samples were in the range of 90–110%. In order to validate the proposed method, certified reference material of GBW09103 human urine was analyzed, and the determined values were in good agreement with the certified values. The poly(AA-VP-Bis) monolith can be used more than 40 times without decrease in the extraction efficiency.
Co-reporter:Jiankun Duan, Xuan Li, Chunhe Yu and Bin Hu
Journal of Analytical Atomic Spectrometry 2009 vol. 24(Issue 3) pp:297-303
Publication Date(Web):23 Jan 2009
DOI:10.1039/B813182A
A new method for the determination of volatile organo seleno compounds (dimethylselenide (DMSe) and dimethyldiselenide (DMDSe)) has been developed using a headspace sorptive extraction combined with capillary gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS). The DMSe and DMDSe retained on the sorptive bar were desorbed by methanol and introduced into GC-ICP-MS for separation and determination. The extraction performance of various sorptive bar coatings, including poly(dimethylsiloxane) (PDMS), PDMS-poly(vinyl alcohol) (PVA), carbowax (CW)-PDMS-PVA, PDMS-β-cyclodextrin (β-CD) has been studied, and the best extraction efficiencies for DMSe and DMDSe were obtained by PDMS-PVA sorptive bar coating. The factors affecting extraction and desorption of DMSe and DMDSe were studied and the optimized operation conditions were established. The limits of detection were 33 and 7.1 ng L−1 for DMSe and DMDSe, respectively, and the correlation coefficients of 0.9986 for DMSe and 0.9998 for DMDSe were obtained in the concentration range 0.5–500 ng mL−1 and 0.025–50 ng mL−1, respectively. Repeatability, based on seven replicate determinations, expressed as relative standard deviations (RSDs), were 8.0% (CDMSe = 5 ng mL−1) and 6.1% (CDMDSe = 0.5 ng mL−1) for DMSe and DMDSe, respectively. The proposed method was applied for the analysis of DMSe and DMDSe in biological samples (garlic, onion and their juice) and a good agreement was obtained between the analytical results obtained by standard addition and external calibration methods.
Co-reporter:Fei Zheng and Bin Hu
Journal of Analytical Atomic Spectrometry 2009 vol. 24(Issue 8) pp:1051-1061
Publication Date(Web):04 Jun 2009
DOI:10.1039/B900057G
In this work, a novel method of dual silica monolithic capillary microextraction (CME) on-line hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the sequential determination of inorganic As(III)/As(V) and Se(IV)/Se(VI) in natural waters. The dual CME column was composed of a 3-mercaptopropyltrimethoxysilane (MPTS) modified silica monolithic capillary (C1) and a N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS) modified silica monolithic capillary (C2), which were both prepared by sol–gel technology. Various experimental parameters affecting separation/preconcentration of As(III)/As(V) and Se(IV)/Se(VI) by C1 and C2 were studied in detail and it was found that under pH 3.0, As(III) and Se(IV) were completely adsorbed by C1 while As(V) and Se(VI) could not be retained on C1 and directly passed through C1. As(V) and Se(IV) in the effluent of C1 could be quantitatively retained on C2 under the same operation conditions as C1. With the aid of valve-switching, As(III), Se(IV) and As(V), Se(VI) retained on C1 and C2 were sequentially desorbed by 100 µL of appropriate eluents for subsequent on-line ICP-MS determination. Due to their simultaneous separation from the matrix and quantitative retention on dual silica CME system, the four species of As(III)/As(V) and Se(IV)/Se(VI) could be accurately determined without oxidation/reduction or subtraction, respectively, and the polyatomic mass interference of 40Ar35Cl on 75As in quadrupole (Q) ICP-MS could be avoided. With a consumption of 5 mL sample solution and 100 µL eluents under the optimized conditions, the detection limits (3σ) were found to be 10.9 ng L−1 for As(III), 6.2 ng L−1 for As(V), 31.1 ng L−1 for Se(IV) and 11.6 ng L−1 for Se(VI), and the enrichment factors were 34.3, 36.1, 37.5 and 39.0 for As(III), As(V), Se(IV) and Se(VI), respectively. The relative standard deviations (RSDs) of the four target species were less than 6.5% (C = 1 µg L−1, n = 7), and the sample throughput was 8 h−1. Two certified reference materials of environmental water samples, GSBZ50004-88 and GSBZ50027-94, were analyzed to validate the proposed method, and the determined values were in good agreement with the certified values. The method was also applied for the speciation analysis of inorganic As(III)/As(V) and Se(IV)/Se(VI) in natural waters, and recoveries for the spiked samples were in the range of 88–108%.
Co-reporter:Xuli Pu, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2009 Volume 64(Issue 7) pp:679-684
Publication Date(Web):July 2009
DOI:10.1016/j.sab.2009.06.001
A new method of solvent bar microextraction (SBME) combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the speciation of As(III) and As(V) in water samples was developed. The method is based on the chelation of As(III) and ammonium pyrrolidine dithiocarbamate (APDC) under the selected conditions, and the As(III)-PDC complex could be extracted into the organic phase, while As(V) remained in aqueous solution. The post-extraction organic phase was directly injected into ETV-ICP-MS for determination of As(III) with the use of iridium as permanent chemical modifier. As(V) was reduced to As(III) by L-cysteine and was then subjected to SBME prior to total As determination. The assay of As(V) was based on subtracting As(III) from total As. The factors affecting on the SBME, such as organic solvent, sample pH, chelating reagent concentration, stirring rate and extraction time, and chemical modification of iridium in ETV-ICP-MS have been studied. Under the optimized conditions, the enrichment factor of 220-fold could be achieved in 15 min extraction, the limit of detection (LOD) for As(III) was 0.32 pg mL− 1, and the relative standard deviation (RSD) was 8.8% (0.1 ng mL− 1, n = 9). Compared with hollow fiber liquid phase microextraction (HF-LPME), SBME has a higher enrichment factor and faster extraction kinetics. In order to validate the accuracy of the method, a Certified Reference Material of GSBZ50004-88 (No. 200420) water sample was analyzed and the results obtained were in good agreement with the certified values. The developed method was also applied to the speciation of inorganic As in environmental waters with satisfactory results.
Co-reporter:Jibrin Sabo Suleiman, Bin Hu, Hanyong Peng, Chaozhang Huang
Talanta 2009 Volume 77(Issue 5) pp:1579-1583
Publication Date(Web):15 March 2009
DOI:10.1016/j.talanta.2008.09.049
A new method for separation/preconcentration of trace amounts of Cr, Cu and Pb in environmental samples by magnetic solid-phase extraction (SPE) with Bismuthiol-II-immobilized magnetic nanoparticles and their determination by ICP-OES has been developed. The separation of the target analytes from the aqueous solution containing the target analytes and Bismuthiol-II-immobilized magnetic nanoparticles was simply achieved by applying external magnetic field. Optimal experimental conditions including pH, sample volume, eluent concentration and volume and co-existing ions have been studied and established. Under the optimal experimental conditions, the detection limits for Cr, Cu and Pb with enrichment factors of 96, 95 and 87 were found to be 0.043, 0.058 and 0.085 ng mL−1 and their relative standard deviations (R.S.D.s) were 3.5%, 4.6% and 3.7% (n = 5, C = 2 ng mL−1), respectively. The method was validated with certified reference material (GBW50009-88) of environmental water sample and the analytical results coincided well with the certified values. Furthermore, the method was successfully applied to the determination of target analytes in river and lake water samples. Compared with established methods, the proposed method is characterized with high enrichment factor, fast separation and low detection limits.
Co-reporter:Jiankun Duan, Bin Hu
Talanta 2009 Volume 79(Issue 3) pp:734-738
Publication Date(Web):15 August 2009
DOI:10.1016/j.talanta.2009.04.063
A flow injection online speciation procedure by using micro-column packed with Cu(II) loaded nanometer-sized Al2O3 coupled to inductively coupled plasma mass spectrometry (ICP-MS) for the separation and determination of selenomethionine (SeMet) and selenocystine (SeCys2) has been developed. The main factors affecting the separation and preconcentration of SeMet and SeCys2 including pH value, sample flow rate, eluent concentration, eluent volume and flow rate, and interfering ions have been investigated. It was found that SeCys2 could be selectively retained by micro-column packed with Cu(II) loaded nanometer-sized Al2O3 at pH 4.0, and the retained SeCys2 could be eluted by 1.0 mol L−1 HNO3, while SeMet was not retained and passed through the micro-column directly at this pH. Both SeMet and SeCys2 could be quantitatively adsorbed by the micro-column at pH 9.0, and the retained SeMet and SeCys2 could be easily eluted with 1.0 mol L−1 HNO3. The content of SeMet was obtained by subtracting the SeCys2 from the total content of seleno amino acids. With the enrichment factor of 7.8 and 7.7, the limits of detection (LODs) for SeMet and SeCys2 were found to be 24 pg Se mL−1 and 21 pg Se mL−1, respectively. The relative standard deviations (RSDs) for SeCys2 and SeMet with seven replicate determinations of 1.0 ng mL−1 SeMet and SeCys2, were 2.1% and 1.6%, respectively, the sampling frequency of 8 h−1 was obtained. The proposed method was applied to the speciation of SeMet and SeCys2 in selenized yeast, human urine and serum with satisfactory results.
Co-reporter:Dahui Chen, Bin Hu, Chaozhang Huang
Talanta 2009 Volume 78(Issue 2) pp:491-497
Publication Date(Web):30 April 2009
DOI:10.1016/j.talanta.2008.11.046
A novel adsorbent of chitosan chemically modified ordered mesoporous silica was synthesized and employed as a solid phase extraction (SPE) material for flow injection (FI) micro-column preconcentration on-line coupled with inductively coupled plasma optical emission spectrometry (ICP-OES) determination of trace heavy metals V, Cu, Pb, Cd and Hg in environmental water samples. The factors affecting separation and preconcentration of target heavy metals such as pH, sample flow rate and volume, eluent concentration and volume, interfering ions were investigated. Under the optimized experimental conditions, an enrichment factor of 20 and sampling frequency of 10 h−1 were obtained. The detection limits of the method for V, Cu, Pb, Cd and Hg were 0.33, 0.30, 0.96, 0.05 and 0.93 ng mL−1, and the relative standard deviations (RSDs) were 2.8%, 6.7%, 1.8%, 4.0% and 5.3% (n = 7, C = 10 ng mL−1), respectively. The adsorption capacities of chitosan modified ordered mesoporous silica for V, Cu, Pb, Cd, and Hg were found to be 16.3, 21.7, 22.9, 12.2 and 13.5 mg g−1, respectively. In order to validate the developed method, a certified reference material of GSBZ50009-88 environmental water sample was analyzed and the determined values were in good agreement with the certified values. The proposed method has also been applied to the determination of trace heavy metals in natural water samples with satisfactory results.
Co-reporter:Yunli Wu, ;Yanli Hou
Journal of Separation Science 2008 Volume 31( Issue 21) pp:3772-3781
Publication Date(Web):
DOI:10.1002/jssc.200800365
Abstract
Two methods based on headspace single drop microextraction (HS-SDME) and headspace hollow fiber liquid phase microextraction (HS-HF-LPME) were developed and critically compared with HPLC-UV determination of phenols (including phenol (Ph), 2-chlorophenol (CP), 2,4-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP)) in this paper. The significant parameters affecting the extraction efficiency of the target analytes in both extraction modes were studied and the optimal extraction conditions were established. Under the optimal conditions, the detection limits (S/N = 3) for Ph, CP, DCP and TCP obtained by HS-SDME-HPLC-UV and HS-HF-LPME-HPLC-UV were 2.1, 0.2, 0.8,1.1 ng/mL and 4.2, 0.4, 0.4, 0.4 ng/mL with enrichment factors of 15.8, 198.9, 159.7, 194.8 and 9.2, 149.9, 301.9, 411.1, respectively. The RSDs obtained by HS-SDME-HPLC-UV and HS-HF-LPME-HPLC-UV were 3.7, 4.0, 9.8, 6.7% and 6.3, 3.6, 3.1, 4.8% for Ph, CP, DCP and TCP, respectively. Both extraction modes have a comparable analytical performance, but HS-HF-LPME was more robust than HS-SDME, while HS-SDME was simpler than HS-HF-LPME. The two headspace microextraction modes were applied for HPLC-UV determination of target phenols in water, honey and toner samples, and the determined values obtained by both techniques were in good agreement with each other.
Co-reporter:Chaozhang Huang
Journal of Separation Science 2008 Volume 31( Issue 4) pp:760-767
Publication Date(Web):
DOI:10.1002/jssc.200700405
Abstract
A new method was developed for the speciation of inorganic tellurium species in seawater by inductively coupled plasma-MS (ICP-MS) following selective magnetic SPE (MSPE) separation. Within the pH range of 2–9, tellurite (Te(IV)) could be quantitatively adsorbed on γ-mercaptopropyltrimethoxysilane (γ-MPTMS) modified silica-coated magnetic nanoparticles (MNPs), while the tellurate (Te(VI)) was not retained and remained in solution. Without filtration or centrifugation, these tellurite-loaded MNPs could be separated easily from the aqueous solution by simply applying external magnetic field. The Te(IV) adsorbed on the MNPs could be recovered quantitatively using a solution containing 2 mol/L HCl and 0.03 mol/L K2Cr2O7. Te(VI) was reduced to Te(IV) by L-cysteine prior to the determination of total tellurium, and its assay was based on subtracting Te(IV) from total tellurium. The parameters affecting the separation were investigated systematically and the optimal separation conditions were established. Under the optimal conditions, the LOD obtained for Te(IV) was 0.079 ng/L, while the precision was 7.0% (C = 10 ng/L, n = 7). The proposed method was successfully applied to the speciation of inorganic tellurium in seawater.
Co-reporter:Fei Zheng, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2008 Volume 63(Issue 1) pp:9-18
Publication Date(Web):January 2008
DOI:10.1016/j.sab.2007.10.034
A novel bimodal porous N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS)-silica monolithic capillary was prepared by sol–gel technology, and used as capillary microextraction (CME) column for aluminum fractionation by electrothermal vaporization inductively coupled plasma mass spectrometry (ETV)–ICP–MS with the use of polytetrafluoroethylene (PTFE) slurry as fluorinating agent. The extraction behaviors of different Al species were studied and it was found that in the pH range of 4–7, labile monomeric Al (free Al3+, Al–OH and Al–F) could be retained quantitatively on the monolithic capillary, while non-labile monomeric Al (Al–Cit and Al–EDTA) passed through the capillary directly. The labile monomeric Al retained on monolithic capillary was eluted with 10 μL 1 mol L− 1 HCl and the elution was introduced into the ETV for fluorination assisted ETV–ICP–MS determination. The total monomeric Al fraction was also determined by AAPTS-silica monolithic CME–fluorination-assisted electrothermal vaporization (FETV)–ICP–MS after the sample solution was adjusted to pH 8.8. Non-labile monomeric Al was obtained by subtracting labile monomeric Al from the total monomeric Al. Under the optimized conditions, the relative standard deviation (R.S.D) was 6.2% (C = 1 μg L− 1, n = 7; sample volume, 5 mL), and the limit of detection was 1.6 ng L− 1 for Al with an enrichment factor of 436 fold and a sampling frequency of 9 h− 1. The prepared AAPTS-silica monolithic capillary showed an excellent pH tolerance and solvent stability and could be used for more than 250 times without decreasing adsorption efficiency. The developed method was applied to the fraction of Al in rainwater and fruit juice, and the results demonstrated that the established system had advantages over the existing 8-hydroxyquinoline (8-HQ) chelating system for Al fractionation such as wider pH range, higher tolerance of interference and better regeneration.
Co-reporter:Chaozhang Huang, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy 2008 Volume 63(Issue 3) pp:437-444
Publication Date(Web):March 2008
DOI:10.1016/j.sab.2007.12.010
We report here the synthesis of a new sorbent comprising silica-coated magnetic nanoparticles (SCMNPs) modified with γ-mercaptopropyltrimethoxysilane (γ-MPTMS) for solid phase extraction of trace amounts of Cd, Cu, Hg, and Pb from biological and environmental samples. The prepared nanoparticles were characterized by infrared spectroscopy, transmission electron microscopy, and static adsorption-desorption experiments. These magnetic nanoparticles carrying the target metals could be easily separated from the aqueous solution simply by applying an external magnetic field; no filtration or centrifugation was necessary. Using this novel magnetic material, we have developed an efficient and cost-effective two-step method for detecting trace amounts of Cd, Cu, Hg, and Pb in environmental and biological samples. The first step of the method is a separation/preconcentration step, in which metals are adsorbed onto γ-MPTMS-SCMNPs. In the second step, inductively coupled plasma mass spectrometry is used to study the adsorbed metals. The effects of pH, sample volume, eluent, and interfering ions have been investigated. Under the optimized conditions, the limits of detection for Cd, Cu, Hg, and Pb were as low as 24, 92, 107, and 56 pg L− 1, respectively. Relative standard deviations (RSDs, C = 2 ng L− 1, n = 7) were 6.7%, 9.6%, 8.3%, and 3.7%, respectively.The proposed method has been validated using three certified reference materials, and it has been applied successfully in the determination of trace metals in biological and environmental samples.
Co-reporter:Linbo Xia, Xuan Li, Yunli Wu, Bin Hu, Rui Chen
Spectrochimica Acta Part B: Atomic Spectroscopy 2008 Volume 63(Issue 11) pp:1290-1296
Publication Date(Web):November 2008
DOI:10.1016/j.sab.2008.09.018
A new method of ionic liquids based cycle flow single drop microextraction combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) was proposed for the determination of trace Co, Hg and Pb with 1-(2-pyridylazo)-2-naphthol (PAN) as both extractant and chemical modifier and 1-butyl-3-methylimidazolium hexafluorophosphate as the extraction solvent. Several factors that influence the microextraction efficiency, such as sample pH, sample flow rate, microdrop volume and extraction time, were investigated and the optimized microextraction conditions were established. Co, Hg and Pb in the post-extraction ionic liquids phase were directly determined by ETV-ICP-MS with the use of PAN as chemical modifier. The chemical modification of PAN in ETV-ICP-MS was studied and the factors affecting the vaporization behaviors of target analytes were investigated. Under the optimized conditions, the detection limits of the method were 1.5, 9.8 and 6.7 pg/mL for Co, Hg and Pb, with the relative standard deviations for 0.5 ng/mL (n = 7) of Co, Hg and Pb were 7.7%, 5.2% and 12.0%, respectively. After 10 min of extraction, the enrichment factors were 350 (Co), 50 (Hg) and 60 (Pb). The proposed method was successfully applied to the determination of trace Co, Hg and Pb in human serum and environmental water samples. In order to validate the developed method, a certified reference material of human hair (GBW07601) was analyzed and the determined values were in good agreement with the certified values.
Co-reporter:Yunli Wu, Linbo Xia, Rui Chen, Bin Hu
Talanta 2008 Volume 74(Issue 4) pp:470-477
Publication Date(Web):15 January 2008
DOI:10.1016/j.talanta.2007.05.057
A new method by combining headspace single drop microextraction (HS-SDME) with HPLC fluorescence detection for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental samples was developed. Aqueous solution of saturated β-cyclodextrin was used as extraction solvent and five PAHs were employed as target analytes. The factors affecting the extraction efficiency were studied in detail and the optimal extraction conditions were established. β-cyclodextrin was found to play two important roles, one is the improvement of extraction efficiency of target analytes and the other is the enhancement of their fluorescence intensities in HPLC fluorescence detection. The detection limits for the target analytes were found to be in the range of 0.004–0.247 ng/ml and the relative standard deviations (R.S.D.s) of 5.1–7.1% were obtained. The proposed method was applied to the analysis of trace PAHs in environmental samples with satisfactory results.
Co-reporter:Chaozhang Huang, Bin Hu, Zucheng Jiang, Nan Zhang
Talanta 2008 Volume 74(Issue 5) pp:1699
Publication Date(Web):15 February 2008
DOI:10.1016/j.talanta.2007.06.002
Co-reporter:Hongmei Jiang, Yongchao Qin, Bin Hu
Talanta 2008 Volume 74(Issue 5) pp:1160-1165
Publication Date(Web):15 February 2008
DOI:10.1016/j.talanta.2007.08.022
A new method of dispersive liquid phase microextraction (DLPME) combined with graphite furnace atomic absorption spectrometry (GFAAS) was proposed for the determination of trace Co and Ni using 1-(2-pyridylazo) 2-naphthol (PAN) as chelating reagent. Several factors influencing the microextraction efficiency of Co and Ni and their subsequent determinations, such as pH, extraction and disperser solvent type and their volume, concentration of the chelating agent, extraction time and ashing temperature and atomization temperature were studied, and the optimized experimental conditions were established. After extraction, the enrichment factors were 101 and 200 for Co and Ni, respectively. The detection limits of the method were 21 and 33 pg/mL for Co and Ni, and the relative standard deviations (R.S.Ds.) for five determinations of 0.5 ng/mL Co and Ni were 7.5% and 8.2%, respectively. The results for the determination of Co and Ni in East Lake water, Yangtse River water, Dongbei rice and spiked samples have demonstrated the accuracy, recovery and applicability of the proposed method. To validate the proposed method, two certified reference materials of Environment Water (GSBZ50009-88) and NIES No.10-b rice flour were analyzed, and the determined values were in good agreement with the certified values.
Co-reporter:Nan Zhang, Jibrin Sabo Suleiman, Man He, Bin Hu
Talanta 2008 Volume 75(Issue 2) pp:536-543
Publication Date(Web):15 April 2008
DOI:10.1016/j.talanta.2007.11.059
A new chromium(III)-imprinted 3-(2-aminoethylamino) propyltrimethoxysilane (AAPTS)-functionalized silica gel sorbent was synthesized by a surface imprinting technique and was employed as a selective solid-phase extraction material for speciation analysis of chromium in environmental water samples prior to its determination by inductively coupled plasma mass spectrometry (ICP-MS). The prepared Cr(III)-imprinted silica gel shows the selectivity coefficient of more than 700 for Cr(III) in the presence of Mn(II). The static adsorption capacity of the ion-imprinted and non-imprinted sorbent for Cr(III) were 30.5 mg g−1 and 13.4 mg g−1. It was also found that Cr(VI) could be adsorbed at low pH by the prepared imprinted silica gel, and this finding makes it feasible to enrich and determine Cr(VI) at low pH without adding reducing reagents. The imprinted silica gel sorbent offered a fast kinetics for the adsorption and desorption of both chromium species. Under the optimized conditions, the detection limits of 4.43 pg mL−1 and 8.30 pg mL−1 with the relative standard deviations (R.S.D.s) of 4.44% and 4.41% (C = 0.5 ng mL−1, n = 7) for Cr(III) and Cr(VI) were obtained, respectively. The proposed method was successfully applied to the speciation of trace chromium in environmental water samples. To validate the proposed method, two certified reference materials were analyzed and the determined values were in a good agreement with the certified values. The developed method is rapid, selective, sensitive and applicable for the speciation of trace chromium in environmental water samples.
Co-reporter:Chaomei Xiong, Man He, Bin Hu
Talanta 2008 Volume 76(Issue 4) pp:772-779
Publication Date(Web):15 August 2008
DOI:10.1016/j.talanta.2008.04.031
A new, simple, and selective method has been presented for the separation and preconcentration of inorganic arsenic (As(III)/As(V)) and selenium (Se(IV)/Se(VI)) species by a microcolumn on-line coupled with inductively coupled plasma-optical emission spectrometry (ICP-OES). Trace amounts of As(V) and Se(VI) species were separated and preconcentrated from total As and Se at desired pH values by a conical microcolumn packed with cetyltrimethylammonium bromide (CTAB)-modified alkyl silica sorbent in the absence of chelating reagent. The species adsorbed by CTAB-modified alkyl silica sorbent were quantitatively desorbed with 0.10 ml of 1.0 mol l−1 HNO3. Total inorganic arsenic and selenium were similarly extracted after oxidation of As(III) and Se(IV) to As(V) and Se(VI) with KMnO4 (50.0 μmol l−1). The assay of As(III) and Se(IV) were based on subtracting As(V) and Se(VI) from total As and total Se, respectively. All parameters affecting the separation/preconcentration of As(V) and Se(VI) including pH, sample flow rate and volume, eluent solution and volume have been studied. With a sample volume of 3.0 ml, the sample throughput was 24 h−1 and the enrichment factors for As(V) and Se(VI) were 26.7 and 27.6, respectively. The limits of detection (LODs) were 0.15 μg l−1 for As(V) and 0.10 μg l−1 for Se(VI). The relative standard deviations (RSDs) for nine replicate determinations at 5.0 μg l−1 level of As(V) and Se(VI) were 4.0% and 3.6%, respectively. The calibration graphs of the method for As(V) and Se(VI) were linear in the range of 0.5–1000.0 μg l−1 with a correlation coefficient of 0.9936 and 0.9992, respectively. The developed method was successfully applied to the speciation analysis of inorganic arsenic and selenium in natural water samples with satisfactory results.
Co-reporter:Hongmei Jiang
Microchimica Acta 2008 Volume 161( Issue 1-2) pp:101-107
Publication Date(Web):2008 April
DOI:10.1007/s00604-007-0785-0
A new method of direct single-drop microextraction combined with electrothermal atomic absorption spectrometry (ETAAS) is presented for the determination of trace Cd and Pb with dithizone (H2DZ) as chelating reagent. Factors influencing the microextraction efficiency and determination, such as pH, microdrop volume, stirring rate, extraction time were evaluated. Under the optimized experimental conditions, the detection limits of the method are 2 and 90 pg mL−1 for Cd and Pb, and the relative standards deviations for 0.5 ng mL−1 Cd and 10 ng mL−1 Pb are 11 and 12.8%. After 10 min of extraction, the enrichment factors for Cd and Pb are 118 and 90, respectively. The results for the determination of Cd and Pb in tap water, spring water, river water, pond water, lake water and spiked water samples demonstrate the accuracy, recovery and applicability of the method. An environmental water certified reference material (GSBZ 50009-88) was analyzed, and the determined values are in a good agreement with the certified values.
Co-reporter:Nan Zhang, Bin Hu, Chaozhang Huang
Analytica Chimica Acta 2007 Volume 597(Issue 1) pp:12-18
Publication Date(Web):30 July 2007
DOI:10.1016/j.aca.2007.06.045
Dysprosium(III)-imprinted thenoyltrifluoroacetone (TTA) modified silica gel sorbent was synthesized by surface imprinting technique and was employed as a selective solid-phase extraction material for flow injection solid-phase extraction on-line coupled with inductively coupled plasma-atomic emission spectrometry (ICP-AES) determination of Dy(III). The largest selectivity coefficient for Dy(III) in the presence of competitive ions such as La(III), Nd(III) and Gd(III) was above 350. The static adsorption capacity and selectivity coefficient of the imprinted sorbent are higher than those of the non-imprinted sorbent and the imprinted TTA modified silica gel sorbent offered a fast kinetics for the adsorption and desorption of Dy(III). With a sample loading flow rate of 2.5 mL min−1 for 48 s preconcentration and elution flow rate of 1.5 mL min−1 for 8 s elution, an enrichment factor of 10 and the sample frequency of 40 sample h−1 were obtained. Detection limits (3σ) based on three times standard deviations of the blanks by eight replicates was 0.2 ng mL−1 and the precisions (R.S.D.s) was 1.5% (n = 8, c = 40 ng mL−1). To validate the proposed method, two certified reference materials of GBW07401 soil and GBW07301a sediment were analyzed and the determined values were in a good agreement with the certified values. The method is rapid, selective, sensitive and applicable to the determination of trace Dy(III) in environmental samples with complicated matrix.
Co-reporter:Fei Zheng, Bin Hu
Analytica Chimica Acta 2007 Volume 605(Issue 1) pp:1-10
Publication Date(Web):12 December 2007
DOI:10.1016/j.aca.2007.10.018
In this work, a novel sol–gel coating of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS)-silica was prepared for capillary microextraction (CME) of trace Cu, Zn, Ni, Hg and Cd followed by on-line ICP-MS detection. This organic–inorganic hybrid coating was in situ created on the inner walls of fused silica capillary using a sol solution containing tetramethoxysilane (TMOS) as a precursor, AAPTS as a co-precursor, ethanol as the solvent and cetyltrimethylammonium bromide (CTAB) as the template. The structure of the capillary coating was characterized by IR, SEM and TEM. Various experimental parameters affecting capillary microextraction of the target analytes have been investigated carefully, and the optimized extraction conditions were established. It was found that the AAPTS-silica coating with a terminal functional group of –NH–CH2–CH2–NH2 exhibited a high selectivity towards the selected metal ions. With a consumption of 1.0 mL sample solution and 80 μL eluent, the detection limits (3σ) were found to be 1.8, 11.8, 1.1, 3.3 and 1.4 pg mL−1 for Cu, Zn, Ni, Hg and Cd, respectively. A sampling frequency of 14 h−1 and an enrichment factor of 12.5 were obtained under the optimized experimental conditions. The relative standard deviations (RSDs) for the target analytes were less than 3.6% (C = 1 ng mL−1, n = 7, sample volume = 1 mL). Two certified reference materials of NIES No.10-c rice flour and BCR-CRM 278 mussel flesh were analyzed to validate the proposed method, and the determined values were in good agreement with the certified values. The developed method had also been applied to the determination of trace target elements in human hair, serum and urine, and the recoveries for the spiked samples were in the range of 89.2–101.8%. The AAPTS-silica coated capillary showed an excellent pH resistance and could be used for more than 120 times without decreasing adsorption efficiency.
Co-reporter:Chaomei Xiong and Bin Hu
Journal of Agricultural and Food Chemistry 2007 Volume 55(Issue 25) pp:10129-10134
Publication Date(Web):November 22, 2007
DOI:10.1021/jf071979b
A simple and effective method for the determination of trace amounts of methylmercury (MeHg+) and inorganic mercury (Hg2+) in seafood was developed by online microcolumn separation/preconcentration combined with inductively coupled plasma optical emission spectrometry (ICP-OES). It was found that Hg2+ could be quantitatively adsorbed by YPA4 resin from pH 7.0 to strong acidic medium (6 mol L−1 HCl) and that MeHg+ was retained by the YPA4 microcolumn only at pH 1.0−7.0. Therefore, a strong acidic medium (about 5 mol L−1 HCl), which could liberate mercury species from biological samples, was used to directly separate inorganic Hg2+ from total Hg, and MeHg+ in effluent was retained by YPA4 column after the effluent was adjusted to pH 1.5. The effects of acidity, sample flow rate and volume, elution solution, and interfering ions on recovery of the two mercury species have been systematically investigated. Under optimal conditions, the limits of detection (LODs) were 72 and 44 ng L−1 for Hg2+ and MeHg+ (as Hg) with online concentration factors of 12.5 and 12.1, respectively. The relative standard deviations (RSDs) for nine replicate determinations at 5 ng mL−1 levels of mercury species were 2.7 and 2.0% for Hg2+ and MeHg+, respectively. The calibration graphs were linear with a correlation coefficient of 0.9902 in the range of 0.5−100 ng mL−1 for Hg2+ and 0.9976 in the range of 0.1−100 ng mL−1 for MeHg+, respectively. The developed method was successfully applied to the direct determination of MeHg+ and Hg2+ in seafood samples, and the recoveries for the spiked samples were in the range of 89.9−102.4% (MeHg+) and 87.0−104.6% (Hg2+), respectively. The method was validated by analyzing a certified reference material DORM-2 (dogfish muscle), and the determined values were in good agreement with certified values.
Co-reporter:Chaozhang Hang, Bin Hu, Zucheng Jiang, Nan Zhang
Talanta 2007 Volume 71(Issue 3) pp:1239-1245
Publication Date(Web):28 February 2007
DOI:10.1016/j.talanta.2006.06.033
A novel organic reagent 3-(8-quinolinylazo)-4-hydroxybenzoic acid (QAHBA) was synthesized for chemically modified nanometer-sized alumina, and it was characterized with infrared spectrum and 1H NMR spectra. By using modified nanometer-sized alumina as micro-column packing material, a new method of flow injection (FI) on-line preconcentration coupled to ICP-OES was developed for simultaneous determination of trace metals (Ag, Pd, Au, Ga, In and Nb) in geological and environmental samples. The effects of pH, sample flow rate, sample volume, elution and interfering ions on the recovery of the analytes have been investigated. Under the optimized operating conditions, the adsorption capacity of the modified nanometer-sized alumina for Ag, Pd, Au, Ga, In and Nb were found to be 5.1, 7.6, 17.7, 15.6, 8.1 and 12.3 mg g−1, respectively. With 4 min preconcentration time and 24 s elution time, the enrichment factor was 10 and the sample frequency was 10 h−1. The detection limits of this method for Ag, Pd, Au, Ga, In and Nb were 0.12, 0.44, 0.27, 0.19, 0.54 and 0.18 μg l−1, respectively, while the R.S.D.s were 1.6, 2.3, 4.5, 1.6, 1.9 and 1.7% (n = 7, c = 50 ng ml−1), respectively. The proposed method has been applied to the determination of these trace metals in geological-certified reference materials and natural water samples with satisfactory results.
Co-reporter:Li Li, Bin Hu
Talanta 2007 Volume 72(Issue 2) pp:472-479
Publication Date(Web):30 April 2007
DOI:10.1016/j.talanta.2006.11.005
For separation and determination of vanadium(IV/V) species, a fast and sensitive method by combining hollow-fibre liquid phase microextraction (HF-LPME) with electrothermal vaporization (ETV)-ICP-OES has been developed. Two vanadium species (V(IV) and V(V)) were separated by HF-LPME with the use of ammonium pyrrolidinecarbodithioate (APDC) as chelating agent for complexing with different V species and carbon tetrachloride as the extraction solvent, and the vanadium in the post-extraction organic phase was injected into the graphite furnace for ETV-ICP-OES detection, in which APDC was acted as the chemical modifier. At pH 5.0, both V(IV)-APDC and V(V)-APDC were extracted quantitatively into CCl4 for determination of total V. For speciation studies, 1,2-cyclohexanediaminetetraacetic acid (CDTA) was added to the sample for masking V(IV), so that only V(V)-APDC was extracted and determined. The concentration of V(IV) was calculated by subtracting the V(V) concentration from the total concentration of V. Under the optimized experimental conditions, the enrichment factor was 74 and the detection limits for V(IV) and V(V) were 86 pg mL−1 and 71 pg mL−1, respectively. The proposed method has been applied to the speciation of V in environmental water samples, and the recovery was in the range of 94%–107%. The results show that V(V) is the dominant existence form in oxygenic water and V(IV) could not been detected. In order to validate the developed procedure, a NIES No.8 vehicle exhaust particulates certified reference material was analyzed, and the results obtained for total vanadium are in good agreement with the certified values. The proposed method is simple, rapid, selective, and sensitive and no oxidation/reduction is required, it is applicable to the speciation of vanadium in environmental samples with the complicated matrix.
Co-reporter:Fei Zheng, Bin Hu
Talanta 2007 Volume 73(Issue 2) pp:372-379
Publication Date(Web):15 September 2007
DOI:10.1016/j.talanta.2007.03.060
A novel sol–gel 3-mercaptopropyltrimethoxysilane (MPTS) modified silica coating was developed for capillary microextraction (CME) of trace Cu, Hg and Pb prior to their on line determination by inductively coupled plasma–atomic emission spectrometry (ICP–AES). This organic–inorganic hybrid coating was in situ created on the inner walls of fused silica capillary using a sol solution containing TMOS (tetramethoxysilane) as a precursor, MPTS as a co-precursor, ethanol as the solvent and hydrochloric acid as a catalyst. The structure of the capillary coating was characterized by FT-IR spectroscopy, Raman spectroscopy, SEM and TEM. The factors affecting on the capillary microextraction of analytes such as pH, sample flow rate and volume, elution solution and interfering ions had been investigated, and the optimized experimental parameters were obtained. Under the optimized conditions, the absorption capacity of MPTS-silica coated capillary was found to be 1.17, 1.96 and 1.19 μg m−1 for Cu, Hg and Pb, and the limits of detection were as low as 0.17 0.22 and 0.52 ng mL−1, respectively. With a sampling frequency of 12 h−1, the relative standard deviations (R.S.D.s) were 4.2, 2.6 and 3.8% (C=4 ng mL−1, n = 7, sample volume = 1 mL) for Cu, Hg and Pb, respectively. The proposed method had been successfully applied to the determination of Cu, Hg and Pb in human urine, human serum and preserved egg. To validate the proposed method, certified reference materials of BCR151 milk powder, GBW07601 (GSH-1) human hair, GSBZ 50016-90 and GSB 07-1183-2000 water samples were analyzed and the determined values were in a good agreement with the certified values.
Co-reporter:Chaozhang Huang, Zucheng Jiang, Bin Hu
Talanta 2007 Volume 73(Issue 2) pp:274-281
Publication Date(Web):15 September 2007
DOI:10.1016/j.talanta.2007.03.046
Mesoporous titanium dioxide as a novel solid-phase extraction material for flow injection micro-column preconcentration on-line coupled with ICP-OES determination of trace metals (Co, Cd, Cr, Cu, Mn, Ni, V, Ce, Dy, Eu, La and Yb) in environmental samples was described. Possessing a high adsorption capacity towards the metal ions, mesoporous titanium dioxide has found to be of great potential as an adsorbent for the preconcentration of trace metal ions in samples with complicated matrix. The experimental parameters including pH, sample flow rate, volume, elution and interfering ions on the recovery of the target analytes were investigated, and the optimal experimental conditions were established. Under the optimized operating conditions, a preconcentration time of 90 s and elution time of 18 s with enrichment factor of 10 and sampling frequency of 20 h−1 were obtained. The detection limits of this method for the target elements were between 0.03 and 0.36 μg L−1, and the relative standard deviations (R.S.D.s) were found to be less than 6.0% (n =7, c =5 ng mL−1). The proposed method was validated using a certified reference material, and has been successfully applied for the determination of the afore mentioned trace metals in natural water samples and coal fly ash with satisfactory results.
Co-reporter:Qin Xiao;Jiankun Duan;Man He
Journal of The American Society for Mass Spectrometry 2007 Volume 18( Issue 10) pp:1740-1748
Publication Date(Web):2007 October
DOI:10.1016/j.jasms.2007.07.006
A novel method for the analysis of four polybrominated diphenyl ethers (PBDEs) in environmental and human serum samples based on hollow fiber-liquid phase microextraction (HF-LPME) followed by gas chromatography-inductively coupled plasma mass spectrometric (GC-ICP-MS) detection has been developed. The organic solvent in the porous hollow fiber was first dipped into the sample for extraction at a given time, and the retracted organic phase was introduced into the GC-ICP-MS for analysis. The addition of methanol has a strong effect on the HF-LPME extraction efficiency. Other significant parameters affecting the extraction efficiency of HF-LPME were also studied. HF-LPME was effective to isolate the analytes from the complex matrix. Under the optimized conditions, the detection limits of the proposed method varied from 15.2 to 40.5 ng/L. In general, the relative standard deviations (RSDs) were less than 10%. Good linearity was obtained with the correlation coefficients all better than 0.999. The proposed method is simple, quick, few microliters of organic solvent required, and is especially suitable for the analysis of the real sample with small amount available. The overall process of HF-LPME with GC-ICP-MS was applied successfully for the determination of polybrominated diphenyl ethers (PBDEs) in environmental and spiked human serum samples, and the results were satisfactory.
Co-reporter:Chaomei Xiong, Zucheng Jiang, Bin Hu
Analytica Chimica Acta 2006 Volume 559(Issue 1) pp:113-119
Publication Date(Web):10 February 2006
DOI:10.1016/j.aca.2005.11.051
A novel solid phase extraction technique for the speciation of trace dissolved Fe(II) and Fe(III) in environmental water samples was developed by coupling micro-column packed with N-benzoyl-N-phenylhydroxylamine (BPHA) loaded on microcrystalline naphthalene to electrothermal vaporization inductively coupled plasma-optical emission spectrometry (ETV-ICP-OES). Various influencing factors on the separation and preconcentration of Fe(II) and Fe(III), such as the acidity of the aqueous solution, sample flow rate and volume, have been investigated systematically, and the optimized operation conditions were established. At pH 3.0 Fe(III) could be selectively retained by micro-column (20 mm × 1.4 mm, i.d.) packed with BPHA immobilized on microcrystalline naphthalene, and Fe(II) passed through the micro-column. Both Fe(II) and Fe(III) could be adsorbed by the micro-column at pH 6.5. Thus, the total Fe could be determined without the need for preoxidation of Fe(II) to Fe(III). The retained Fe(III) or the Fe(II) and Fe(III) was subsequently eluted by 0.1 ml of 1 mol l−1 HCl. The adsorption capacity of the solid phase adsorption material was found to be 45.0 mg g−1 for Fe(III) at pH 3.0 and 65.3 mg g−1 for Fe(II) at pH 6.5, respectively. The detection limit (3σ) of 0.053 μg l−1 was obtained with a practical enrichment factor of 156 at a sample volume of 17 ml. The relative standard deviations of 4.2% and 4.6% (CFe(III) = CFe(II) = 10 μg l−1, n = 7) for Fe(III) and total iron were found, respectively. The method was successfully applied to the determination of trace Fe(II) and Fe(III) in environmental water samples (East Lake water, local tap water and mineral water). In order to validate the method, the developed method was applied to the determination of total iron in certified materials of NIES NO.10-b rice flour and GBW07605 tea leaves, and the results obtained were in good agreement with the certified values.
Co-reporter:Wenling Hu, Bin Hu, Zucheng Jiang
Analytica Chimica Acta 2006 Volume 572(Issue 1) pp:55-62
Publication Date(Web):14 July 2006
DOI:10.1016/j.aca.2006.05.024
In this paper, an ordered mesoporous alumina coating was prepared and applied to capillary microextraction (CME) of trace Co, Ni and Cd for the first time. The coated capillary was used for on-line coupling CME with inductively plasma mass spectrometry (ICP-MS) for the determination of trace metals of Co, Ni and Cd. The porous structure of Al2O3 coating was examined by SEM and TEM. The effects of the extraction parameters including pH, sample flow rate and volume, elution solution and interfering ions on the recovery of analytes have been investigated and optimized. Under the optimized conditions, the limits of detection were 0.33, 1.5 and 1.4 ng L−1 for Co, Ni and Cd, respectively, with a preconcentration factor of 10 times. The precisions for all investigated elements were 2.7, 4.1 and 2.5% (c = 0.05 ng L−1, n = 7), for Co, Ni and Cd, respectively, and the sample frequency was 8 h−1.The proposed method was successfully applied for the analysis of trace metals in water, rice and urine samples with the recovery of 94–105%. In order to validate the proposed method, two certified reference materials of GBW 0913 human urine and NIES No.10-b rice flour were analyzed, and the determination values are in good agreement with the certified values. The ordered mesoporous Al2O3 coated capillary can be used more than 20 times without decreasing the extraction efficiency.
Co-reporter:Yingjie Li, Bin Hu, Zucheng Jiang
Analytica Chimica Acta 2006 Volume 576(Issue 2) pp:207-214
Publication Date(Web):25 August 2006
DOI:10.1016/j.aca.2006.06.018
A new method for the determination of inorganic Sb species by on-line cloud point extraction combined with electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES) is presented and evaluated. The method is based on the complexation of Sb(III) with pyrrolidine dithiocarbamate (PDC) which form an hydrophobic complex at pH 5.5 and subsequently enter surfactant-rich phase at pH 5.5, whereas Sb(V) remained in aqueous solutions. The preconcentration step is mediated by micelles of the non-ionic surfactant Triton X-114 with ammonium pyrrolidine dithiocarbamate (APDC). The micellar system containing the complex was loaded into the FIA manifold at a flow rate of 2.5 mL min−1, and the surfactant-rich phase was retained in a microcolumn packed with absorbent cotton, at pH 5.5. After the surfactant-rich phase was eluted with 100 μL acetonitrile, it was determined by ETV-ICP-AES. Sb(V) is reduced to Sb(III) by l-cysteine prior to determined total Sb, and its assay is based on subtracting Sb(III) from total antimony. The main factors affecting separation/preconcentration and the vaporization behavior of analyte in graphite tube were investigated in detail. Under the optimized conditions, the precision relative standard deviation (R.S.D.) for eight replicate measurements of 0.2 μg mL−1 Sb(III) was 4.3%. The apparent concentration factor, which is defined as the concentration ratio of the analyte in the final diluted surfactant-rich extract ready for ETV-ICP-AES detection and in the initial solution, was 872 for Sb(III). The limit of detection (LOD) for Sb(III) was 0.09 μg L−1. The proposed method was successfully applied for the speciation of inorganic antimony in different water samples and urine sample with satisfactory results.
Co-reporter:Linbo Xia, Bin Hu, Zucheng Jiang, Yunli Wu, Rui Chen and Li Li
Journal of Analytical Atomic Spectrometry 2006 vol. 21(Issue 3) pp:362-365
Publication Date(Web):13 Jan 2006
DOI:10.1039/B514623B
A novel method for the speciation of Se(IV) and Se(VI) in environmental water samples based on liquid-phase microextraction (LPME) methods in conjunction with electrothermal vaporization (ETV) ICP-MS has been developed. Two modes of LPME: single drop microextraction (SDME) and hollow fiber liquid phase microextraction (HF-LPME) were studied comparatively. The organic chelating reagent ammonium pyrrolidine dithiocarbamate (APDC) was used as both the extractant for microextraction and the chemical modifier for ETV-ICP-MS determination. Under the optimal conditions, enrichment factors of 75 and 410 could be achieved for SDME and HF-LPME, respectively. The detection limit of Se in HF-LPME-ETV-ICP-MS and SDME-ETV-ICP-MS were 0.50, 0.56 pg mL−1 and 2.7, 3.0 pg mL−1 for Se(IV) and Se(VI), respectively. HF-LPME was finally selected for the analysis of Se(IV) and Se(VI) in lake water, river water and pool water samples due to its good analytical features and robustness. The proposed method was validated by the determination of total Se with PN-ICP-MS.
Co-reporter:Qin Xiao, Bin Hu, Chunhe Yu, Linbo Xia, Zucheng Jiang
Talanta 2006 Volume 69(Issue 4) pp:848-855
Publication Date(Web):15 June 2006
DOI:10.1016/j.talanta.2005.11.024
A single-drop microextraction (SDME) procedure was developed for the analysis of organophosphorus pesticides (OPPs) in water and fruit juice by gas chromatography (GC) with flame photometric detection (GC-FPD). The significant parameters affecting the SDME performance such as selection of microextraction solvent, solvent volume, extraction time, stirring rate, sample pH and temperature, and ionic strength were studied and optimized. Two types of SDME mode, static and cycle-flow SDME, were evaluated. The static SDME procedure provided more sensitive analysis of the target analytes. Therefore, static SDME with tributyl phosphate (TBP) as internal standard was selected for the real sample analysis. The limits of detection (LODs) in water for the six studied compounds were between 0.21 and 0.56 ng/mL with the relative standard deviations ranging from 1.7 to 10.0%. Linear response data was obtained in the concentration range of 0.5–50 ng/mL (except for dichlorvos 1.0–50 ng/mL) with correlation coefficients from 0.9995 to 0.9999. Environmental water sample collected from East Lake and fruit juice samples were successfully analyzed using the proposed method, but none of the analytes in both lake water and fruit juice were detected. The recoveries for the spiked water and juice samples were from 77.7 to 113.6%. Compared with the conventional methods, the proposed method enabled a rapid and simple determination of organophosphorus pesticides in water and fruit juice with minimal solvent consumption and a higher concentration capability.
Co-reporter:Man He, Bin Hu, Zucheng Jiang
Analytica Chimica Acta 2005 Volume 530(Issue 1) pp:105-112
Publication Date(Web):7 February 2005
DOI:10.1016/j.aca.2004.08.074
A method of electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of trace lanthanides and yttrium in soil samples with a polytetrafluorethylene (PTFE) emulsion as chemical modifier to promote the vaporization of the analytes from the graphite furnace was developed in this paper. The analytical characteristics, spectral interference and matrix effect of the analytical method were evaluated and critically compared with those of pneumatic nebulization inductively coupled plasma mass spectrometry (PN-ICP-MS). Under the optimized operation conditions, the relative detection limits of lanthanides (La–Lu) and yttrium for ETV-ICP-MS and PN-ICP-MS were 0.4–20 ng l−1 and 1.0–21 ng l−1, respectively, the absolute detection limits for ETV-ICP-MS were 4–200 fg, which were improved by 1–2 orders of magnitude compared with PN-ICP-MS. While the analytical precision of ETV-ICP-MS is worse than that of PN-ICP-MS, with the R.S.D.s (%) of 4.1–10% for the former and 2.9–7.8% for the latter. Regarding to the matrix effect, both conventional method and stepwise dilution method were employed to observe the effect of matrix and the very similar results were obtained. It was found that the highest tolerance concentration of the matrix is 1000 mg l−1 and 800 mg l−1 for ETV-ICP-MS and PN-ICP-MS, respectively. To assess the accuracy, the proposed method was applied to the determination of trace lanthanides and yttrium in three different soil standard reference materials and one soil sample, and the determined values are in good agreement with the certified values or reference values.
Co-reporter:Linbo Xia, Bin Hu, Zucheng Jiang, Yuli Wu, Li Li and Rui Chen
Journal of Analytical Atomic Spectrometry 2005 vol. 20(Issue 5) pp:441-446
Publication Date(Web):15 Mar 2005
DOI:10.1039/B416938G
A new method of cycle-flow single drop microextraction (SDME) combined with electrothermal vaporization (ETV)-ICP-MS was proposed for the fractionation of aluminium with 8-hydroxyquinoline (8-HQ) as extractant. Several factors affecting the separation of aluminium species, such as sample flow rate, microdrop volume, pH and extraction time were investigated, and the optimized microextraction conditions were established. The experimental results indicated that in a pH range of 5.0–7.5 labile monomeric Al species (free Al (Al3+, AlOH2+, and Al(OH)2+)) could be extracted by the 8-HQ–chloroform microdrop while non-labile monomeric Al species (Al–citrate, Al–SO4, Al–F, Al–EDTA, Al–humic) directly passed through the microdrop. Labile aluminium in the post-extraction organic phase was directly determined by ETV-ICP-MS. The total Al was determined using pneumatic nebulization (PN)-ICP-MS. The non-labile aluminium was obtained by subtraction of labile aluminium from the total aluminium. Under the optimized conditions, the detection limit of the method was 3.3 pg mL−1 and the relative standard deviation for 1 ng mL−1 of Al was 10%. After 8 min of extraction, the enrichment factor was 210. The proposed method has been successfully applied to the determination of Al species in natural water, coffee and tea infusions. The results were comparable with that obtained by the 8-HQ loaded silanized silica gel microcolumn system and conventional liquid–liquid extraction system.
Co-reporter:Yiwei Wu, Zucheng Jiang, Bin Hu
Talanta 2005 Volume 67(Issue 4) pp:854-861
Publication Date(Web):15 October 2005
DOI:10.1016/j.talanta.2005.04.014
A simple and selective method of flow injection (FI) using a micro-column packed with quinine modified resin as solid phase extractant has been developed for preconcentration and separation of trace amount of vanadium(V) and vanadium(IV) in water samples, followed by determination with fluorination assisted electrothermal vaporization (FETV)–inductively coupled plasma optical emission spectrometry (ICP-OES). At pH 3 ∼ 3.8, the modified resin is selective towards V(V) and almost not towards V(IV), while, V(IV) could be quantitatively adsorbed by the modified resin at pH 5 ∼ 7. The two vanadium species adsorbed by modified resin could be readily desorbed quantitatively with 0.3 ml of 0.5 mol l−1 HCl. Both vanadium species in elution were then determined by ETV–ICP-OES with the use of polytetrafluoroethylene (PTFE) as chemical modifier. Effects of acidity, sample flow rate, concentration of elution solution and interfering ions on the recovery of the analytes have been systematically investigated. Under the optimal conditions, the adsorption capacities of the quinine modified resin for V(V) and V(IV) are 7.6 and 8.0 mg g−1, respectively. The detection limit (3σ) of V is 0.072 ng ml−1 for FETV–ICP-OES and 0.56 pg ml−1 for FETV–ICP-MS with enrichment factor of 62.5, and the relative standard deviation (R.S.D.) is 4.9% (n = 9, C = 0.2 μg ml−1) and 3.8% (n = 9, C = 1.0 ng ml−1), respectively. The proposed method has been applied to the determination of trace V(V) and V(IV) in different water samples, and the recoveries of V(V) and V(IV) are 100 ± 10%. In order to further verify the accuracy of the developed method, FETV–ICP-MS was employed to analyze the vanadium species in water samples after separation/preconcentration, and analytical results are in good agreement with that obtained by the proposed method. The developed method was also applied to the analysis of the total V in GBW07401 soil certified reference material and in GBW07605 tea leaves certified reference material, and the determined values coincided with the certified values very well.
Co-reporter:Yiwei Wu, Zucheng Jiang, Bin Hu, Jiankun Duan
Talanta 2004 Volume 63(Issue 3) pp:585-592
Publication Date(Web):17 June 2004
DOI:10.1016/j.talanta.2003.11.042
A new method for determination of trace gold (Au), palladium (Pd), and platinum (Pt) in environmental and geological samples by electrothermal vaporization (ETV)–inductively coupled plasma atomic emission spectrometry (ICP-AES) with the use of chelating resin YPA4 as both solid phase extractant and chemical modifier has been developed. The resin loaded with analytes was prepared to slurry and directly introduced into the graphite furnace without any pretreatment. The factors affecting the vaporization behaviors of Au, Pd, and Pt were investigated in detail. It was found that, in the presence of YPA4, Au and Pd could be quantitatively vaporized at lower vaporization temperature of 1900 °C. Compared with the conventional electrothermal vaporization, the vaporization temperature was decreased by 700 °C, and the detection limits for Au and Pd was decreased by a three-fold. However, a little effect of YPA4 on the ETV–ICP-AES determination of Pt was found. Under the optimized conditions, the detection limits (3σ) of Au, Pd, and Pt for this method are 75, 60, and 217 pg, respectively; and their relative standard deviations (R.S.D.) are 4.4, 5.6, and 3.7%, respectively (n=9, C=0.2 μg ml−1). The proposed method has been applied to the determination of trace Pd and Pt in sewage sludge, and the results well agreed with the recommended values. In order to further verify the accuracy of the developed method, a GBW07293 certified geological reference material and an auto catalyst NIST SRM 2557 reference material were analyzed, and the determined values coincided with the certified values very well.
Co-reporter:Yingliang Wu, Bin Hu, Zucheng Jiang and Shizhong Chen
Journal of Analytical Atomic Spectrometry 2002 vol. 17(Issue 2) pp:121-124
Publication Date(Web):20 Dec 2001
DOI:10.1039/B106359F
A low temperature electrothermal vaporization inductively coupled plasma atomic emission spectrometry (ETV-ICP-AES) method for the determination of palladium, by using sample introduction of gaseous palladium oxinate, was developed. The thermally stable palladium oxinate was formed and vaporized at a temperature of 900°C from the graphite furnace. The main factors affecting the vaporization behavior of the analyte were investigated in detail. The detection limit of palladium for this method was 50 pg, and the relative standard deviation (RSD) for 0.2 µg ml−1 palladium was 4.7%
(n = 8). Compared with conventional ETV-ICP-AES, the analytical sensitivity of this method was improved by one order of magnitude. The proposed method was applied to the determination of trace palladium in geological samples with satisfactory results.
Co-reporter:Pei Liang, Bin Hu, Zucheng Jiang, Yongchao Qin and Tianyou Peng
Journal of Analytical Atomic Spectrometry 2001 vol. 16(Issue 8) pp:863-866
Publication Date(Web):19 Jul 2001
DOI:10.1039/B104050M
A new method using a micro-column packed with nanometer sized TiO2 as a sorbent has been developed for the on-line preconcentration of trace amounts of rare earth elements (La, Y, Yb, Eu and Dy) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The effects of pH, sample flow rate and volume, elution solution and interfering ions on the separation of analytes have been investigated. The adsorption capacity of nanometer TiO2 for La, Y, Yb, Eu and Dy was found to be 7.0, 6.1, 9.8, 8.3 and 8.8 mg g−1, respectively. The method has been successfully applied for the determination of trace rare earth elements in some environmental samples.
Co-reporter:Bing Cai, Bin Hu, Hongchun Xiong, Zhenhuan Liao, Lesen Mao, Zucheng Jiang
Talanta 2001 Volume 55(Issue 1) pp:85-91
Publication Date(Web):3 August 2001
DOI:10.1016/S0039-9140(01)00394-0
A sensitive and rapid method for the determination of lanthanum, europium and ytterbium by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solid–liquid extraction with microcrystalline naphthalene was developed. Analytes could be quantitatively adsorbed on tribromoarsenazo–cetylpyridinium bromide–naphthalene (TBA–CPB–naphthalene) packed in a column and determined by ICP-AES after desorption with 3 mol l−1 HCl. The effect of various experimental parameters, such as pH, reagent amounts, naphthalene concentrations and diverse ions, on the determination of interesting elements were investigated in detail. Under the optimized experimental conditions, the detection limits of this method for La3+, Eu3+ and Yb3+ were 1.3–8.6 ng ml−1, and the relative standard deviations obtained for nine replicate determinations at a concentration of 0.5 μg ml−1 were 1.4–2.2%. The proposed method has been applied in the analysis of NIES CRM No. 8 vehicle exhaust particulates and GBW 07602 GSV-1 bush branches and leaves for La, Eu and Yb, and La in NIST SRM 1752 citrus leaves samples; the analytical results were in good agreement with reference values.
Co-reporter:Bin Yang, Yuan Zhang, Beibei Chen, Man He, Bin Hu
Talanta (15 May 2017) Volume 167() pp:499-505
Publication Date(Web):15 May 2017
DOI:10.1016/j.talanta.2017.02.063
Co-reporter:Xiangju Mao, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A (11 November 2016) Volume 1472() pp:27-34
Publication Date(Web):11 November 2016
DOI:10.1016/j.chroma.2016.10.051
•A novel membrane protected SBSE(MPSBSE) was proposed to filter out large molecules.•Environmental water samples were subjected to MPSBSE without filtration.•The membrane protected stir bar avoided the frictional damage and matrix interference.By wrapping a porous membrane around the coated stir bar, a novel membrane protected stir bar sorptive extraction (MPSBSE) was proposed to filter out the high molecular weight interferences (such as humic acid), resulting in the analysis of real environmental water samples without filtration or centrifugation. Hydrophilic and hydrophobic membranes were compared and hydrophobic polytetrafluoroethylene (PTFE) membrane impregnated with methanol was employed to protect the C18 coated stir bar. The impregnated methanol improves the transfer of target analytes from sample solution to the pores and lumen of the membrane, and then to the coated stir bar inside. By combining C18-MPSBSE with HPLC-UV, a method was proposed for the direct determination of two common non-steroidal anti-inflammatory drugs, Ketoprofen (KEP) and Naproxen (NAP) in complex water samples. Under the optimized conditions, the limit of detections of KEP and NAP are 7.89, 9.52 μg L−1 in the waste water and 7.69, 6.90 μg L−1 in the pure water, respectively, with the enrichment factors of 32.0–49.1-fold. Besides, the lifetime of the prepared C18 stir bar protected by PTFE membrane (50 times) is longer than that of C18 stir bar without membrane protection (20 times), indicating that the friction damage of SBSE coating during extraction was effectively avoided. The developed method was successfully applied to the analysis of KEP and NAP in domestic sewage and campus lake water samples.
Co-reporter:Xiangju Mao, Man He, Beibei Chen, Bin Hu
Journal of Chromatography A (11 November 2016) Volume 1472() pp:27-34
Publication Date(Web):11 November 2016
DOI:10.1016/j.chroma.2016.10.051
Co-reporter:Xiaolan Liu, Man He, Beibei Chen, Bin Hu
Spectrochimica Acta Part B: Atomic Spectroscopy (1 November 2014) Volume 101() pp:254-260
Publication Date(Web):1 November 2014
DOI:10.1016/j.sab.2014.09.008
•An on-line CME-ICP-MS method was developed for Au and Pd analysis in human fluids.•Poly(GMA-EDMA-SH) monolith exhibited good selectivity for Au/Pd and acid-resistance.•The method is rapid, simple, and sensitive with low sample/reagents consumption.A novel method based on on-line polymer monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace Au and Pd in biological samples. For this purpose, poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was prepared and functionalized with mercapto groups. The prepared monolith exhibited good selectivity to Au and Pd, and good resistance to strong acid with a long life span. Factors affecting the extraction efficiency of CME, such as sample acidity, sample flow rate, eluent conditions and coexisting ion interference were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) were 5.9 ng L− 1 for Au and 8.3 ng L− 1 for Pd, and the relative standard deviations (RSDs, c = 50 ng L −1, n = 7) were 6.5% for Au and 1.1% for Pd, respectively. The developed method was successfully applied to the determination of Au and Pd in human urine and serum samples with the recovery in the range of 84–118% for spiked samples. The developed on-line polymer monolithic CME-ICP-MS method has the advantages of rapidity, simplicity, low sample/reagent consumption, high sensitivity and is suitable for the determination of trace Au and Pd in biological samples with limited amount available and complex matrix.
Co-reporter:Han Wang, Xiaolan Liu, Kai Nan, Beibei Chen, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2017 - vol. 32(Issue 1) pp:NaN77-77
Publication Date(Web):2016/08/11
DOI:10.1039/C6JA00077K
The biochemical reactions involving trace elements depend on the nature and form of their chemical species in a biological system. Consequently, the study of the chemical speciation of a given element in biological samples has become essential for understanding their bioavailability and toxicity. Inductively coupled plasma-mass spectrometry (ICP-MS) hyphenated techniques are the most powerful and widely used for elemental speciation combining both high sensitivity and good selectivity for the determination of ultra-trace elements in biological samples. However, direct analysis of biological samples can suffer from matrix interferences, and both the low concentrations of chemical species, and in some cases, the limited amount of sample available can present analytical challenges. Therefore, there is a need to develop sample pre-treatment methods that can be used to remove the matrix and pre-concentrate the species of interest prior to analysis. This review will focus specifically on the state-of-the-art sample pre-treatment methods published in the last ten years including liquid and solid phase micro-extraction, and chip-based manifolds that can be coupled to ICP-MS hyphenated techniques. The different methods are evaluated for their ability to be deployed for the pre-treatment of actual biological samples. The development trends in this area of research are discussed, and integrated automated miniaturized systems are also reviewed.
Co-reporter:
Analytical Methods (2009-Present) 2015 - vol. 7(Issue 15) pp:NaN6189-6189
Publication Date(Web):2015/06/18
DOI:10.1039/C5AY01181G
A method based on solidification of floating organic drop microextraction (SFODME) with vortex-assisted (VA) emulsification was proposed for the preconcentration of organophosphorus pesticides (OPPs) in water samples, followed by gas chromatography (GC) with flame photometric detection (GC-FPD). A binary mixed solvent whose density is lower than water was used as an extractant to improve the extraction efficiency of the five target OPPs and avoid the employment of traditional organic solvents that are usually highly toxic and expensive. Moreover, vortex agitation accelerated the dispersion of extraction solvents in aqueous samples. The significant parameters affecting the VA-SFODME of target OPPs were studied in detail and the optimal extraction conditions were established. With the use of tributyl phosphate (TBP) as the internal standard, the limits of detection (S/N = 3) were found to be in the range of 0.12–0.56 μg L−1 for the five target OPPs, and the linear range was from 0.6 μg L−1 to 100 μg L−1. The RSDs of the proposed method were in the range of 5.4–13.9% (n = 7, c = 3 μg L−1) and the enrichment factors varied from 117 to 215-fold. The proposed method was successfully applied to the analysis of five OPPs in East Lake water, well water and rainwater samples, and the recoveries for spiked samples were in the range of 83.7–112%.
Co-reporter:Xueqin Guo, Man He, Kai Nan, He Yan, Beibei Chen and Bin Hu
Journal of Analytical Atomic Spectrometry 2016 - vol. 31(Issue 2) pp:NaN414-414
Publication Date(Web):2015/09/15
DOI:10.1039/C5JA00286A
Magnetic solid phase extraction (MSPE) was combined with hollow fiber liquid liquid liquid microextraction (HF-LLLME) for the extraction of seleno-amino acids. Graphene oxide (GO) modified magnetic nanoparticles (MNPs) were prepared and loaded with Cu2+ for the adsorption of target seleno-amino acids based on the interaction between Cu2+ and seleno-amino acids. Aqueous ethylenediamine was employed as the desorption solvent, and the desorption solution was directly employed as the donor solution in the subsequent HF-LLLME procedure for further preconcentration of target seleno-amino acids. In HF-LLLME, 1-octanol was employed as the extraction solvent, ionic liquid trioctylmethylammonium chloride ([MTOA]+[Cl]−) was employed as the carrier for the extraction of target seleno-amino acids, and aqueous NaNO3 solution was employed as the acceptor solution. The target seleno-amino acids were extracted from the donor solution into the organic phase and then back into the acceptor solution under the driving force of ion-pair formation between target seleno-amino acids and [MTOA]+[Cl]− and the gradient counter ions between the donor phase and the acceptor phase. Various factors influencing the extraction of target seleno-amino acids by MSPE and HF-LLLME were investigated thoroughly. Based on it, a method of MSPE-HF-LLLME coupled with high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) was developed and the analytical performance was evaluated under optimized conditions. After preconcentration by MSPE-HF-LLLME, the enrichment factors (EFs) for target seleno-amino acids ranged from 152 to 278-fold, and the LODs for target seleno-amino acids were in the range of 0.0075–0.013 μg L−1. A certified reference material of SELM-1 was used to validate the accuracy of the proposed method, and the determined value of SeMet was in good agreement with the certified values. The proposed method was successfully applied to the speciation of seleno-amino acids in rice and Se-enriched yeast cell samples.
Co-reporter:Jing Zhang, Beibei Chen, Han Wang, Xi Huang, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2016 - vol. 31(Issue 7) pp:NaN1399-1399
Publication Date(Web):2016/04/25
DOI:10.1039/C6JA00105J
Microfluidic devices provide a potential platform that can specialize in miniaturization, integration and automation. In this study, we prepared ethanediamine modified poly glycidyl methacrylate trimethylol propane triacrylate monolithic columns (poly (GMA-co-TRIM-NH2)) in a microfluidic chip channel and established a novel method by combining chip-based poly (GMA-co-TRIM-NH2) monolithic microextraction with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of bismuth in cell samples. Various factors affecting chip-based monolithic microextraction of bismuth were investigated. Under the optimized conditions, the limit of detection was 0.21 ng mL−1 and the relative standard deviation for bismuth was 6.0% (c = 5 ng mL−1, n = 7). The method was successfully applied to the analysis of HepG2 cells incubated with bismuth. With consumption of ∼600 cells, the average amount of bismuth was determined to be at the sub picogram level in a single cell. The prepared chip-based poly (GMA-co-TRIM-NH2) monolithic column had a high-surface area and exhibited high extraction efficiency towards bismuth. The proposed chip-based monolithic microextraction method combined with ICP-MS provides a novel strategy for the analysis of trace metals in cells.
Co-reporter:Xiangju Mao, Wenying Fan, Man He, Beibei Chen and Bin Hu
Journal of Analytical Atomic Spectrometry 2015 - vol. 30(Issue 1) pp:NaN171-171
Publication Date(Web):2014/10/22
DOI:10.1039/C4JA00294F
In this paper, a new approach of C18-coated stir bar sorptive extraction (SBSE) coupled with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) was developed for the speciation of butyltins in environmental samples. The butyltin compounds, including monobutyltin trichloride (MBT), dibutyltin dichloride (DBT) and tributyltin chloride (TBT), were first extracted with a C18-coated stir bar, and then desorbed with 40% (v/v) methanol for subsequent HPLC-ICP-MS analysis. The factors affecting C18-SBSE were systematically studied. To reduce the percentage of organic solvents in the mobile phase loaded on the plasma and to improve the separation resolution, a CN column with carboxylic acids as the mobile phase additives was used for butyltin separation. Quick separation (<8 min) was accomplished using a methanol–formic acid–water (16:8:76, v/v/v) mobile phase containing 5 mmol L−1 mercaptoacetic acid, and the mobile phase was compatible with the conventional quadrupole ICP-MS detector without addition of oxygen gas or desolvation and post-column dilution systems. Under the optimal conditions, the limits of detection for three target butyltins ranged from 15.6 to 29.4 ng L−1, with a linear range of 0.05–50 μg L−1. The enrichment factors (EFs) were 85- to 127-fold (the theoretical EF is 200-fold). The developed method is simple and rapid, with no derivatization involved, and is successfully applied to the speciation of butyltins in the Certified Reference Material of PACS-2 sediment and real water as well as sediment samples from the East Lake, Yangtze River and Bohai Sea in China.
Co-reporter:Beibei Chen, Yunli Wu, Xueqin Guo, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2015 - vol. 30(Issue 4) pp:NaN881-881
Publication Date(Web):2014/10/27
DOI:10.1039/C4JA00312H
A novel method by combining hollow fiber-liquid–liquid–liquid microextraction (HF-LLLME) with HPLC-ICP-MS was developed for the speciation of inorganic mercury (Hg2+) and organomercury including methylmercury (MeHg+), ethylmercury (EtHg+) and phenylmercury (PhHg+), in the micro-ecosystem of East Lake (Wuhan, China). The factors affecting HF-LLLME were systematically investigated. Under the optimized conditions, the limits of detection for four mercury species were in the range of 2.9–5.6 ng L−1 with the relative standard deviations (c = 0.5 μg L−1, n = 7) ranging from 5.6 to 10.6%. The developed method was validated by analyzing a certified reference material of DORM-2, and the determined values were in good agreement with the certified values. The method has been applied for the speciation of mercury in five representative samples from the micro-ecosystem of East Lake including atmospheric particles, lake water, fish, plant and sediment.
Co-reporter:Chao Cui, Hanyong Peng, Yanan Zhang, Kai Nan, Man He, Beibei Chen and Bin Hu
Journal of Analytical Atomic Spectrometry 2015 - vol. 30(Issue 6) pp:NaN1394-1394
Publication Date(Web):2015/03/23
DOI:10.1039/C5JA00035A
Ti-containing mesoporous silica was prepared and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectrometry (UV-Vis) and the N2 adsorption technique. The adsorption behaviours of Cr(III), Cu(II), Cd(II) and Pb(II) on Ti-containing mesoporous silica were studied and the adsorption mechanism was also investigated by FT-IR and X-ray photoelectron spectroscopy (XPS). With Ti-containing mesoporous silica as the adsorbent, a new method of microcolumn solid phase extraction (SPE) combined with inductively coupled plasma-mass spectrometry (ICP-MS) was established for the determination of Cr(III), Cu(II), Cd(II) and Pb(II) in environmental samples. The parameters affecting extraction and desorption of the target analytes, such as pH, sample flow rate, desorption reagent, desorption flow rate and sample volume, were investigated. Under optimized conditions, the limits of detection (LODs) of Cr(III), Cu(II), Cd(II) and Pb(II) were 19, 39, 7 and 13 pg mL−1 with a preconcentration factor of 10, respectively, and the relative standard deviations (RSDs) varied from 6.1 to 7.3% (n = 7, c = 1 ng mL−1). The developed method was applied to analyze environmental water and soil samples with recovery in the range of 85–119% for the spiked samples. In order to validate the accuracy of the method, certified reference materials of GSBZ50009-88 (environmental water), GBW07429 and GBW07425 (soil sample) were analyzed and the determined values were in good agreement with the certified values. The developed method is simple, rapid, sensitive and suitable for the analysis of trace elements in environmental samples with complex matrices.
Co-reporter:Shaowei Su, Beibei Chen, Man He, Zuowei Xiao and Bin Hu
Journal of Analytical Atomic Spectrometry 2014 - vol. 29(Issue 3) pp:NaN453-453
Publication Date(Web):2013/11/28
DOI:10.1039/C3JA50342A
In this work, Al3+ immobilized Fe3O4@SiO2@iminodiacetic acid (IDA) was prepared and its extraction performance for gold nanoparticles (AuNPs) and gold ions (Au ions) was investigated. It was found that AuNPs and Au ions could be simultaneously retained on this adsorbent and their separation was achieved by sequential elution of Au ions and AuNPs with Na2S2O3 and NH3·H2O, respectively. Based on it, a novel strategy by coupling magnetic solid phase extraction (MSPE) with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the speciation of AuNPs and Au ions in environmental water samples. Various experimental parameters affecting MSPE of AuNPs and Au ions have been investigated carefully. AuNPs in a size range of 14–140 nm and with different coatings, including citrate, 11-mercaptoundecanoic acid (MUA), polyvinylpyrrolidone (PVP) and cetyltrimethylammonium bromide (CTAB), could be quantitatively determined by the proposed method. And the size and shape of the AuNPs were found to remain unchanged during the extraction process; thus the elution solutions could be directly introduced into ICP-MS without digestion. The developed MSPE-ICP-MS method has been applied in the analysis of AuNPs in natural water, sewage water and even sea water samples and Au ions in natural water samples with satisfactory results. Compared with the established methods for metal nanoparticle analysis, the developed method is more sensitive, faster, easier-to-operate, requires no digestion, and provides more valuable information for environmental monitoring and the assessment of nanoparticles' toxicity.
Co-reporter:Hanyong Peng, Yang Jiao, Xiao Xiao, Beibei Chen, Man He, Zhengru Liu, Xing Zhang and Bin Hu
Journal of Analytical Atomic Spectrometry 2014 - vol. 29(Issue 6) pp:NaN1119-1119
Publication Date(Web):2014/03/05
DOI:10.1039/C4JA00003J
Carbohydrate biomolecules are difficult targets for analysis due to their branched structure and diverse modifications of saccharidic monomers. The variety of biochemical functions of carbohydrate biomolecules have attracted great and extensive attention, which has spurred a pressing need for rapid development of analytical methods for absolute quantification of glycoproteins in recent years. Herein a sensitive and selective method using magnetic separation coupled with inductively coupled plasma mass spectrometry (ICP-MS) detection is proposed for simultaneous determination of multiple glycoproteins. Haptoglobin (HP), hemopexin (HPX) and ovalbumin (OVA) were selected as target glycoproteins. They were firstly selected by lectin conjugated magnetic particles due to the glycol-structure, and then immunoreacted with antibodies labeled with Cd, Hg, Pb through poly(acrylic acid), respectively. The metal ions, corresponding to the concentration of glycoproteins, were released from antibody with an acid-dissolution step and subjected to subsequent ICP-MS detection. With consumption of only 50 μL sample solution, the established method presents a limit of detection of 0.032, 0.027 and 0.13 ng mL−1 for HP, HPX and OVA, with the relative standard deviation of 7.4%, 6.8% and 7.6% (c = 5 ng mL−1, n = 7), respectively. The response of magnetic immuno-ICP-MS assay for HP, HPX and OVA was linear over a dynamic range of 0.1–100 ng mL−1, 0.1–100 ng mL−1 and 0.5–100 ng mL−1, respectively. The recoveries for HP, HPX and OVA in spiked human serum samples are in the range of 97.6–105%. The developed method is demonstrated to be versatile to multiple glycoproteins quantification in complicated samples.
Co-reporter:Beibei Chen, Bin Hu, Man He, Qian Huang, Yuan Zhang and Xing Zhang
Journal of Analytical Atomic Spectrometry 2013 - vol. 28(Issue 3) pp:NaN343-343
Publication Date(Web):2012/12/18
DOI:10.1039/C2JA30280B
Elemental speciation in cells is significant for metallomics research. In this study, novel methods of (on-chip) magnetic solid phase extraction (MSPE) combined with high performance liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) were proposed for selenium speciation in selenium-enriched yeast cells. An integrated microfluidic chip consisting of reaction, mixing, and extraction units was designed and fabricated for on-chip MSPE. Sulfonated polystyrene-coated magnetic nanoparticles (Fe3O4@PSS MNPs) were prepared as adsorption material for MSPE of selenoamino acids and selenopeptide. The factors affecting the extraction performance of the target selenium species by (on-chip) MSPE-HPLC-ICP-MS were systematically investigated. The analytical performance of the (on-chip) MSPE-HPLC-ICP-MS was evaluated under individual optimal conditions. The limits of detection for five target selenium species were 0.025 μg L−1 to 0.090 μg L−1 and 0.057 μg L−1 to 0.149 μg L−1 for MSPE-HPLC-ICP-MS and on-chip MSPE-HPLC-ICP-MS, respectively. The MSPE-HPLC-ICP-MS method is sensitive, fast, easy-to-operate, and economical. The on-chip MSPE-HPLC-ICP-MS method has the unique advantages of low sample consumption and high integration; thus, it is suitable for selenium speciation in a small number (∼800) of selenium-enriched yeast cells. A Certified Reference Material of SELM-1 yeast was used to validate the accuracy of the developed (on-chip) MSPE-HPLC-ICP-MS methods. The proposed methods were successfully applied to the speciation of selenium in selenium-enriched yeast cells. Analysis of approximately 800 cells by on-chip MSPE-HPLC-ICP-MS revealed that the average amounts of selenocystine (SeCys2) and selenomethionine (SeMet) in a single selenium-enriched yeast cell are in the order of subpicograms.
Co-reporter:Beibei Chen, Hanyong Peng, Fei Zheng, Bin Hu, Man He, Wei Zhao and Daiwen Pang
Journal of Analytical Atomic Spectrometry 2010 - vol. 25(Issue 11) pp:NaN1681-1681
Publication Date(Web):2010/05/28
DOI:10.1039/C003029E
A sensitive and selective method of immunoaffinity monolithic capillary microextraction (CME) based on a sandwich immunoreaction with quantum dots (QDs) labels coupled with micro-concentric nebulizer inductively coupled plasma mass spectrometry (MCN-ICP-MS) was proposed for the determination of antigen human IgG in human serum. Aminopropyltriethoxysilane (APTES)-silica hybrid monolithic capillary which was prepared by room temperature ionic liquid (RTIL)-mediated sol–gel method was immobilized with primary goat-anti-human antibody. After a complete immunoreaction among primary antibody, IgG antigen and secondary antibody labeled with CdSe QDs in monolithic capillary, the concentration of IgG was quantified by MCN-ICP-MS simultaneous analysis of Cd and Se released from captured QDs labels with an acid-dissolution (pH 2.0) step. With consumption of only 50 μL sample solution, the established method presented a limit of detection of 0.058 μg L−1 based on the Cd signal and 0.097 μg L−1 based on the Se signal for human IgG antigen, with the relative standard deviations (RSDs) of 7.2% based on the Cd signal and 13% based on the Se signal (chumanIgGantigen = 5 μg L−1, n = 7), respectively. The response of CME-MCN-ICP-MS method for human IgG was linear over a dynamic range from 0.2 to 10 μg L−1 based on the Cd signal and from 0.5 to 10 μg L−1 based on the Se signal, respectively. The proposed method was successfully applied for the determination of IgG in real human serum with good recoveries. For validation, the same sample was also analyzed by the commonly used clinical method of immunoturbidimetry, and the analytical result obtained by the proposed method is in good agreement with that the result obtained by immunoturbidimetry. By using CdSe QDs labels, the quantification of human IgG antigen could be performed by ICP-MS determination of both Cd and Se, and the analytical results for human IgG antigen could be validated in one run. The developed method was fast, sensitive, selective, versatile and could be easily extended to other protein quantification schemes as well as in DNA analysis.
Co-reporter:Beibei Chen, Shujing Heng, Hanyong Peng, Bin Hu, Xu Yu, Zhiling Zhang, Daiwen Pang, Xin Yue and Ying Zhu
Journal of Analytical Atomic Spectrometry 2010 - vol. 25(Issue 12) pp:NaN1938-1938
Publication Date(Web):2010/10/07
DOI:10.1039/C0JA00003E
Quantitative analysis of trace levels of heavy metals in human cells is critical to environmental and toxicological research. We describe here a new strategy of determining ultratrace levels of cadmium, lead, and mercury in cultured cells. It involves the integration of cell sample introduction and magnetic nanoparticle solid phase microextraction (MSPME) on a microfluidic chip, combined with electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS) detection. γ-mercaptopropyltrimethoxysilane (γ-MPTS) modified silica-coated magnetic nanoparticles were synthesized and demonstrated for the microextraction of Cd, Pb, and Hg. Under an external magnetic field, these magnetic nanoparticles self-assembled in microchannels to form a solid phase packed column. The formation mechanism of the on-chip magnetic solid phase packed column and the main factors influencing the packing and analytical performance were investigated. Under the optimized conditions, MSPME enabled enrichment of Cd, Hg, and Pb by a factor of >40, and resulted in improved limits of detection for Cd (0.72 ng L−1), Hg (0.86 ng L−1), and Pb (1.12 ng L−1) using ETV-ICP-MS. Quantitative analyses of trace Cd, Hg and Pb in HepG2 cells were achieved by applying the microfluidic system that integrated cell rupture, mixing, magnetic extraction and elution into one device, followed by ultrasensitive detection by ETV-ICP-MS, which required only a microlitre amount of sample. Analysis of approximately 5000 cells revealed that the average amounts of Cd, Hg and Pb in a single HepG2 cell were of the order of a few femtograms, and that the cellular levels increased with increasing concentrations of these metals in cell cultures. The concentrations of Cd, Hg, and Pb detectable in HepG2 cells were several orders of magnitude lower than their IC50 values, suggesting that the technique is potentially useful for measuring these heavy metals in studies of chronic metal toxicity.
Co-reporter:Jun Yin, Bin Hu, Man He, Mingming Zheng and Yu-Qi Feng
Journal of Analytical Atomic Spectrometry 2009 - vol. 24(Issue 1) pp:NaN82-82
Publication Date(Web):2008/10/24
DOI:10.1039/B810442E
A novel method of polymer monolith microextraction (PMME) using a poly(acrylamide-vinylpyridine-N,N′-methylene bisacrylamide) (AA-VP-Bis) monolithic column combined with electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of trace Cd, Tl, and Pb with Pd as chemical modifier has been proposed. Several factors that influence the microextraction efficiency including pH value, sample flow rate, extraction time, sample volume, eluent volume, and coexisting ions, were investigated and the optimal microextraction conditions were established. The chemical modification of Pd in ETV-ICP-MS has been studied and the results indicated that the pyrolysis temperature for the target analytes could be increased up to 600 °C and the signal intensities were increased by 4.1, 2.1, and 13.8 times for Cd, Tl, and Pb, respectively. Under the optimized conditions, with a consumption of 0.4 mL sample, the limits of detection (LODs) were 1.1, 0.5, and 0.2 ng L−1 for Cd, Tl, and Pb, and the relative standard deviations (RSDs) were 10.3, 9.7, and 9.2% (C = 0.05 µg L−1, n = 5) for Cd, Tl, and Pb, respectively. The proposed method was successfully applied to the determination of trace Cd, Tl, and Pb in human serum and urine samples, and the recovery for the spiked samples were in the range of 90–110%. In order to validate the proposed method, certified reference material of GBW09103 human urine was analyzed, and the determined values were in good agreement with the certified values. The poly(AA-VP-Bis) monolith can be used more than 40 times without decrease in the extraction efficiency.
Co-reporter:Fei Zheng and Bin Hu
Journal of Analytical Atomic Spectrometry 2009 - vol. 24(Issue 8) pp:NaN1061-1061
Publication Date(Web):2009/06/04
DOI:10.1039/B900057G
In this work, a novel method of dual silica monolithic capillary microextraction (CME) on-line hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) was developed for the sequential determination of inorganic As(III)/As(V) and Se(IV)/Se(VI) in natural waters. The dual CME column was composed of a 3-mercaptopropyltrimethoxysilane (MPTS) modified silica monolithic capillary (C1) and a N-(2-aminoethyl)-3-aminopropyltrimethoxysilane (AAPTS) modified silica monolithic capillary (C2), which were both prepared by sol–gel technology. Various experimental parameters affecting separation/preconcentration of As(III)/As(V) and Se(IV)/Se(VI) by C1 and C2 were studied in detail and it was found that under pH 3.0, As(III) and Se(IV) were completely adsorbed by C1 while As(V) and Se(VI) could not be retained on C1 and directly passed through C1. As(V) and Se(IV) in the effluent of C1 could be quantitatively retained on C2 under the same operation conditions as C1. With the aid of valve-switching, As(III), Se(IV) and As(V), Se(VI) retained on C1 and C2 were sequentially desorbed by 100 µL of appropriate eluents for subsequent on-line ICP-MS determination. Due to their simultaneous separation from the matrix and quantitative retention on dual silica CME system, the four species of As(III)/As(V) and Se(IV)/Se(VI) could be accurately determined without oxidation/reduction or subtraction, respectively, and the polyatomic mass interference of 40Ar35Cl on 75As in quadrupole (Q) ICP-MS could be avoided. With a consumption of 5 mL sample solution and 100 µL eluents under the optimized conditions, the detection limits (3σ) were found to be 10.9 ng L−1 for As(III), 6.2 ng L−1 for As(V), 31.1 ng L−1 for Se(IV) and 11.6 ng L−1 for Se(VI), and the enrichment factors were 34.3, 36.1, 37.5 and 39.0 for As(III), As(V), Se(IV) and Se(VI), respectively. The relative standard deviations (RSDs) of the four target species were less than 6.5% (C = 1 µg L−1, n = 7), and the sample throughput was 8 h−1. Two certified reference materials of environmental water samples, GSBZ50004-88 and GSBZ50027-94, were analyzed to validate the proposed method, and the determined values were in good agreement with the certified values. The method was also applied for the speciation analysis of inorganic As(III)/As(V) and Se(IV)/Se(VI) in natural waters, and recoveries for the spiked samples were in the range of 88–108%.
Co-reporter:Chao Cui, Bin Hu, Beibei Chen and Man He
Journal of Analytical Atomic Spectrometry 2013 - vol. 28(Issue 7) pp:NaN1117-1117
Publication Date(Web):2013/05/03
DOI:10.1039/C3JA50108F
Ionic liquids of methyltrioctylammonium chloride modified magnetic nanoparticles were prepared, and a new method of magnetic solid phase extraction combined with inductively coupled plasma-optical emission spectrometry was established for the determination of Cu, Zn, and Cd in human hair and urine samples. The effect of pH on the extraction of Cu, Zn, and Cd was investigated. The results show that the ionic liquid played a key role in the extraction of target analytes. The magnetic nanoparticles served as the carriers of the ionic liquid and the base of the phase separation. Several parameters affecting the extraction and desorption of the target analytes were investigated including the sample volume, extraction time, eluent concentration and volume, desorption time, sedimentation time, amount of the ionic liquid and Fe3O4@Si–OH, and the optimized conditions were established. Under the optimized conditions, the detection limits of Cu, Zn, and Cd were 0.54, 0.56, and 0.33 μg L−1, respectively, and the relative standard deviations (n = 7) were 4.9% (c = 2 μg L−1), 3.7% (c = 2 μg L−1), and 5.1% (c = 1 μg L−1), respectively. To validate the accuracy of the proposed method, it was applied to analyze certified reference materials of GBW07601 human hair and GBW09103 human urine. The determined values agree with the certified values. The developed method was also employed to analyze human hair and urine, and the recoveries for the spiked samples were in the range of 89.1% to 120%. The developed method was simple, highly sensitive, solvent-free, chelate-free, and could be considered as a green analytical technique.
Co-reporter:Xueqin Guo, Beibei Chen, Man He, Bin Hu and Xiaoqing Zhou
Journal of Analytical Atomic Spectrometry 2013 - vol. 28(Issue 10) pp:NaN1647-1647
Publication Date(Web):2013/08/14
DOI:10.1039/C3JA50243K
A novel method of ionic liquid based carrier mediated hollow fiber liquid liquid liquid microextraction (IL-carrier mediated HF-LLLME) combined with high performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed for the speciation of five phenylarsenic compounds and arsenate in chicken and feed samples. The target arsenic species were extracted from 6 mL aqueous samples (pH = 10.2) into an organic phase (20% (v/v) [MTOA]+[Cl]− in toluene) impregnated in the pores of a hollow fiber, then back extracted into a 10 μL acceptor phase of 0.3 mol L−1 NaBr in the lumen of the hollow fiber. The main driving force for the extraction was the gradient concentration of the counter ion from the donor phase to the acceptor phase. Factors affecting the extraction of the target arsenic species were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) for five target phenylarsenic compounds and arsenate were in the range of 1.4–16.0 ng L−1 with the relative standard deviations (CAs(V),4-OH,3-NHPAA,PA,4-NPAA = 0.05 μg L−1, Cp-ASA = 0.10 μg L−1, n = 7) ranging from 3.6 to 10.0%, and the enrichment factors were varied from 86 to 372-fold. The proposed method of IL-carrier mediated HF-LLLME-HPLC-ICP-MS was successfully applied to the determination of five phenylarsenic compounds and arsenate in chicken and feed samples with the recoveries of 79.2–105.4% and 81.1–117.8% for the spiked chicken and spiked feed samples, respectively.
Co-reporter:Han Wang, Zhekuan Wu, Yuan Zhang, Beibei Chen, Man He and Bin Hu
Journal of Analytical Atomic Spectrometry 2013 - vol. 28(Issue 10) pp:NaN1665-1665
Publication Date(Web):2013/07/29
DOI:10.1039/C3JA50223F
Metal determination in precious biological samples is critical to metallomics research. Microfluidic chips provide an excellent platform for the miniaturization of extraction. In this work, a chip-based liquid phase microextraction (chip-based LPME) device was fabricated and combined with electrothermal vaporization-inductively coupled plasma mass spectrometry (ETV-ICP-MS) for the determination of trace Cu, Zn, Cd, Hg, Pb and Bi in cell samples and human serum samples. With sodium diethyldithiocarbamate (DDTC) as both the chemical modifier for low-temperature ETV-ICP-MS and the extracting reagent for the chip-based LPME, the chip parameters influencing the extraction efficiency including central channel width, branch channel ratio and central channel length were optimized by orthogonal design experiments. Under the optimized conditions, the limits of detection (LODs) are in the range of 6.6–89.3 pg mL−1 with the RSDs ranging from 4.23–8.15% (n = 7, c = 1 ng mL−1) for the target metal ions. The linear range covers three magnitudes with correlation coefficients higher than 0.99. The proposed method was validated by analyzing the target metal ions in certified reference materials of GBW07605 human hair and GBW09152 human serum, and metal determination in HepG2 cells, Jurkat T cells and a human serum sample were achieved with the recoveries in the range of 86.6–119%. The developed method is fast, has a low sample and reagent consumption and is highly sensitive, thus it is quite suitable for the analysis of precious biological samples such as cells.
Co-reporter:Fei Zheng, Nan Zhang and Bin Hu
Journal of Analytical Atomic Spectrometry 2011 - vol. 26(Issue 7) pp:NaN1525-1525
Publication Date(Web):2011/02/24
DOI:10.1039/C1JA10025D
Mn(II) imprinted 3-mercaptopropyltrimethoxysilane (MPTS)-silica coated capillary was synthesized by sol–gel technique combining with a double-imprinting concept. The prepared capillary was employed for capillary microextraction (CME) of trace Mn(II) followed by on-line inductively coupled plasma mass spectrometry (ICP-MS) detection. This coating was in situ created on the inner wall of tetramethoxysilane (TMOS) coated silica capillary using a sol solution containing MPTS as the functional precursor, ethanol as the solvent and both Mn(II) and surfactant micelles (cetyltrimethylammonium bromide, CTAB) as the templates. The factors affecting on the CME of Mn(II) such as sample pH, sample flow rate and volume, elution solution and interfering ions have been investigated. Under the optimized conditions, the adsorption capacities of non-imprinted and imprinted capillary were found to be 1.24 and 2.38 μg m−1, respectively. With a sampling frequency of 9 h−1, an enrichment factor of 16.7 was obtained for Mn(II). The detection limit (3σ) based on three times the standard deviations of the blanks by seven replicates was 10.3 ng L −1 and the relative standard deviation (RSD) was 4.3% (c = 0.1 μg L−1, n = 7). The proposed method was successfully applied for the determination of trace Mn(II) in serum samples and validated by two certified reference materials. The method is rapid, selective, sensitive and applicable for the analysis of trace Mn(II) in biological samples with limited sample volume.
Co-reporter:Lijin Huang, Man He, Beibei Chen and Bin Hu
Journal of Materials Chemistry A 2016 - vol. 4(Issue 14) pp:NaN5166-5166
Publication Date(Web):2016/03/08
DOI:10.1039/C6TA00343E
A facile preparation of magnetic MOF composites with flexible mercapto group pendants in their pores is realized through solvent-assisted ligand exchange (SALE) under mild conditions in water, and terephthalate in UIO-66 is replaced with mercaptoacetic acid (MAA). After the SALE processing, the crystallinity, porosity, and superparamagnetism of the mercapto functionalized magnetic Zr-MOF (MFC-S) are well maintained, and the obtained MFC-S exhibits a higher adsorption capacity (282 mg g−1) for Hg2+ than that of the magnetic Zr-MOF (MFC-O). Furthermore, the prepared MFC-S can be regenerated easily by liquid desorption after adsorption of metal ions and be reused more than 5 times without obvious decrease in removal performance. The proposed SALE method for the preparation of mercapto functionalized magnetic MOF composites (MFCs) is easy-to-operate and low cost, providing not only a reliable porous MFC platform for the removal of metal ions, but also a simple and efficient synthesis route for the preparation of functionalized MFCs which cannot be achieved through conventional approaches.
Co-reporter:Jiankun Duan, Xuan Li, Chunhe Yu and Bin Hu
Journal of Analytical Atomic Spectrometry 2009 - vol. 24(Issue 3) pp:NaN303-303
Publication Date(Web):2009/01/23
DOI:10.1039/B813182A
A new method for the determination of volatile organo seleno compounds (dimethylselenide (DMSe) and dimethyldiselenide (DMDSe)) has been developed using a headspace sorptive extraction combined with capillary gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS). The DMSe and DMDSe retained on the sorptive bar were desorbed by methanol and introduced into GC-ICP-MS for separation and determination. The extraction performance of various sorptive bar coatings, including poly(dimethylsiloxane) (PDMS), PDMS-poly(vinyl alcohol) (PVA), carbowax (CW)-PDMS-PVA, PDMS-β-cyclodextrin (β-CD) has been studied, and the best extraction efficiencies for DMSe and DMDSe were obtained by PDMS-PVA sorptive bar coating. The factors affecting extraction and desorption of DMSe and DMDSe were studied and the optimized operation conditions were established. The limits of detection were 33 and 7.1 ng L−1 for DMSe and DMDSe, respectively, and the correlation coefficients of 0.9986 for DMSe and 0.9998 for DMDSe were obtained in the concentration range 0.5–500 ng mL−1 and 0.025–50 ng mL−1, respectively. Repeatability, based on seven replicate determinations, expressed as relative standard deviations (RSDs), were 8.0% (CDMSe = 5 ng mL−1) and 6.1% (CDMDSe = 0.5 ng mL−1) for DMSe and DMDSe, respectively. The proposed method was applied for the analysis of DMSe and DMDSe in biological samples (garlic, onion and their juice) and a good agreement was obtained between the analytical results obtained by standard addition and external calibration methods.
Co-reporter:Lijin Huang, Man He, Beibei Chen and Bin Hu
Journal of Materials Chemistry A 2015 - vol. 3(Issue 21) pp:NaN11595-11595
Publication Date(Web):2015/04/21
DOI:10.1039/C5TA01484K
A magnetic MOF composite was successfully prepared by a novel and green strategy through reasonable design. The nano Fe3O4@SiO2 core was first coated by a shell of Cu(OH)2 as the self-template, followed by a conversion of Cu(OH)2 into HKUST-1 at room temperature in a water–ethanol mixture solvent, and Fe3O4@SiO2@HKUST-1 core–shell nanostructures were obtained successfully. Based on this, a Bi-I-functionalized-magnetic HKUST-1 composite was prepared through a flexible coordination-based post-synthetic strategy. Powder X-ray diffraction spectrometry, N2 sorption–desorption isotherms and Fourier transform infrared spectroscopy were used for the characterization of the magnetic MOF composites. The core–shell morphology was confirmed by transmission electron microscope images and the result of thermogravimetric analysis showed that the magnetic composites had excellent thermal stability. Besides, the adsorption of Hg2+ on Fe3O4@SiO2, Fe3O4@SiO2@HKUST-1 and Bi-I-functionalized magnetic MOF composites was investigated, and a good adsorption selectivity of Bi-I-functionalized magnetic MOF composites towards Hg2+ was demonstrated, with high adsorption capacity (264 mg g−1) and fast adsorption dynamics. The Bi-I-functionalized magnetic HKUST-1 composite was then successfully employed for the selective removal of Hg2+ from water, demonstrating great potential application of the prepared magnetic MOF composite as a fascinating adsorbent in environmental monitoring.
Co-reporter:Ling Li, Xiao Lan Liu, Hong Yun Geng, Bin Hu, Gong Wu Song and Zu Shun Xu
Journal of Materials Chemistry A 2013 - vol. 1(Issue 35) pp:NaN10299-10299
Publication Date(Web):2013/06/21
DOI:10.1039/C3TA11478C
The adsorption of methylene blue (MB) from aqueous solution on a HKUST-1/GO (MOFs:HKUST-1) composite was studied in view of the adsorption isotherm, kinetics and regeneration of the sorbent. The adsorption isotherms of methylene blue (MB) on the HKUST-1/GO composite followed both the Freundlich isotherm and the Langmuir isotherm. Adsorption kinetics and thermodynamic parameters were determined from the experimental data. The used HKUST-1/GO could be regenerated by acetone, so it can be recycled for reuse. The high adsorption capacity and excellent reusability make HKUST-1/GO attractive for the removal of MB from aqueous solution.
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