Co-reporter:Jiazhi Xu, Yuan Gao, Haijun Zhang, Faqiang Zhan, and Jiping Chen
Environmental Science & Technology December 6, 2016 Volume 50(Issue 23) pp:
Publication Date(Web):November 2, 2016
DOI:10.1021/acs.est.6b03595
Chlorinated paraffin (CP) production is one important emission source for short- and medium-chain CPs (SCCPs and MCCPs) in the environment. In this study, 48 CP congener groups were measured in the surface soils and coniferous leaves collected from the inner and surrounding environment of a CP production plant that has been in operation for more than 30 years to investigate the dispersion and deposition behavior of SCCPs and MCCPs. The average concentrations of the sum of SCCPs and MCCPs in the in-plant coniferous leaves and surface soils were 4548.7 ng g–1 dry weight (dw) and 3481.8 ng g–1 dw, which were 2-fold and 10-fold higher than those in the surrounding environment, respectively. The Gaussian air pollution model explained the spatial distribution of CPs in the coniferous leaves, whereas the dispersion of CPs to the surrounding surface soils fits the Boltzmann equation well. Significant fractionation effect was observed for the atmospheric dispersion of CPs from the production plant. CP congener groups with higher octanol–air partitioning coefficients (KOA) were more predominant in the in-plant environment, whereas the ones with lower KOA values had the elevated proportion in the surrounding environment. A radius of approximately 4 km from the CP production plant was influenced by the atmospheric dispersion and deposition of CPs.
Co-reporter:Yun Fan;Haijun Zhang;Dan Wang;Meihui Ren;Xueping Zhang;Longxing Wang
Analytical Methods (2009-Present) 2017 vol. 9(Issue 35) pp:5198-5203
Publication Date(Web):2017/09/14
DOI:10.1039/C7AY01545C
Chlorinated aromatic hydrocarbons (CAHs) have received increasing attention because of their environmental persistence, bioaccumulation potential and high toxicity. In this study, an analytical methodology based on high-resolution gas chromatography/high-resolution mass spectrometry for the simultaneous determination of four typical kinds of CAHs including polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs) and chlorinated polycyclic aromatic hydrocarbons (ClPAHs) in fly ash was developed. Highly effective cleanup and separation procedures combined with optimum instrumental conditions provided a reliable method for the detection and quantification of CAHs. Meanwhile, the spike of 13C-labeled standards and deuterated phenanthrene achieved more accurate measurement. The method detection limits were determined to be in the ranges of 0.1–13.4 pg g−1 for tetra- to octa-CDD/F congeners, 0.04–11.1 pg g−1 for tri- to hepta-CB congeners, 0.2–48.5 pg g−1 for mono- to octa-CN congeners and 3.5–9.5 pg g−1 for mono- and di-chlorinated aromatic hydrocarbons. Good recoveries of CAHs (62–136%) were achieved, except for PCN-2 and PCN-6. The developed analytical methodology was validated and then used to determine the levels of CAHs in fly ashes collected from industrial thermal processes. All the target compounds were detected and the CAH congener concentrations showed a wide variation in different fly ashes.
Co-reporter:Chaonan Huang, Yun Li, Jiajia Yang, Junyu Peng, Jing Jin, Dhanjai, Jincheng Wang, Jiping Chen
Journal of Chromatography A 2017 Volume 1521(Volume 1521) pp:
Publication Date(Web):27 October 2017
DOI:10.1016/j.chroma.2017.09.021
•A novel reversed-phase/anion-exchange mixed-mode sorbent prepared based on Pickering emulsion polymerization particles.•A successful two-step quaternization enhancing ion exchange capacity.•Ultraclean efficiency achieved for wastewater compared to HLB.•Isolation of acidic pharmaceuticals from basic and neutral interferences realized.The present work represents a simple and effective preparation of a novel mixed-mode anion-exchange (MAX) sorbent based on porous poly[2-(diethylamino)ethyl methacrylate-divinylbenzene] (poly(DEAEMA-DVB)) spherical particles synthesized by one-step Pickering emulsion polymerization. The poly(DEAEMA-DVB) particles were quaternized with 1,4-butanediol diglycidyl ether (BDDE) followed by triethylamine (TEA) via epoxy-amine reaction to offer strong anion exchange properties. The synthesized MAX sorbent was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, nitrogen adsorption-desorption measurements and elemental analysis. The MAX sorbent possessed regular spherical shape and narrow diameter distribution (15–35 μm), a high IEC of 0.54 meq/g, with carbon and nitrogen contents of 80.3% and 1.62%, respectively. Compared to poly(DEAEMA-DVB), the MAX sorbent exhibited decreased SBET (390.5 vs. 515.3 m2 g−1), pore volume (0.74 vs. 0.85 cm3 g−1) and pore size (16.8 vs. 17.3 nm). Moreover, changes of N content for producing the MAX sorbent reveal a successful two-step quaternization, which can be highly related to such a high IEC. Finally, the MAX sorbent was successfully evaluated for selective isolation and purification of some selected acidic pharmaceuticals (ketoprofen, KEP; naproxen, NAP; and ibuprofen, IBP) from neutral (hydrocortisone, HYC), basic (carbamazepine, CAZ; amitriptyline, AMT) pharmaceuticals and other interferences in water samples using solid phase extraction (SPE). An efficient analytical method based on the MAX-based mixed-mode SPE coupled with HPLC-UV was developed for highly selective extraction and cleanup of acidic KEP, NAP and IBP in spiked wastewater samples. The developed method exhibited good sensitivity (0.009–0.085 μg L−1 limit of detection), satisfactory recoveries (82.1%–105.5%) and repeatabilities (relative standard deviation < 7.9%, n = 3).
Co-reporter:Yun Li, Chaonan Huang, Jiajia Yang, Junyu Peng, Jing Jin, Huilian Ma, Jiping Chen
Journal of Chromatography A 2017 Volume 1527(Volume 1527) pp:
Publication Date(Web):8 December 2017
DOI:10.1016/j.chroma.2017.10.051
•A novel reversed-phase/anion exchange mixed-mode sorbent based on multifunctional mesoporous silica SBA-15 was prepared.•The multifunctional phase is characterized by a high density of multifunctionalities in a branched structure.•High carbon and nitrogen contents of 28.30% and 2.84%, respectively.•Efficient clean-ups and extractions of NSAIDs from 500 mL of environmental water samples.A mesoporous silica Santa Barbara Amorphous-15 (SBA-15) has been first functionalized with 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane (a silane with three amines) and then reacted with an excess of phenyl glycidyl ether to generate a mixed-mode anion-exchanger containing both anion-exchange (three amines) and reversed-phase (multiple ether-linked phenyls) functionalities in a single branched ligand. The resulting material has been characterized by scanning electron microscopy, transmission electron microscopy, nitrogen adsorption-desorption measurements, Fourier-transform infrared spectroscopy, and elemental analysis. The results obtained indicated a BET specific surface area (SBET) of 362.5 m2 g−1, a pore volume of 0.70 cm3 g−1 with a narrow pore size distribution centered at 6.6 nm, and carbon and nitrogen contents of 28.30% and 2.84%, respectively. The dimensions of these particles (∼5 μm diameter, ∼60 μm length), their large surface areas, their high-density functionalities and anion-exchange mixed-mode characteristics make them very attractive for highly effective solid phase extraction (SPE) of acidic nonsteroidal anti-inflammatory drugs (NSAIDs). The important parameters on extraction efficiency including sample pH, breakthrough volume, type and volume of eluent were optimized. A simple and sensitive analytical method based on mixed-mode SPE coupled to high-performance liquid chromatography with ultraviolet detection (HPLC-UV) was developed and successfully applied to the analysis of four NSAIDs (ketoprofen, naproxen, diclofenac, and ibuprofen) in spiked real water samples with satisfactory recoveries (80.6–110.9%) and repeatability (relative standard deviation <11.3%, n = 3). The limit of detections of four NSAIDs were 0.006–0.070 μg L−1 for tap water, and 0.014–0.16 μg L−1 for river water and wastewater, with the enrichment factors of 806–1109-fold.
Co-reporter:Leimeng Shi, Yuan Gao, Haijun Zhang, Ningbo Geng, Jiazhi Xu, Faqiang Zhan, Yuwen Ni, Xiaohong Hou, Jiping Chen
Chemosphere 2017 Volume 172(Volume 172) pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.chemosphere.2016.12.150
•High concentrations of SCCPs and MCCPs were detected in indoor dusts from malls.•The C13- and C14-CPs were the dominant congeners in indoor dust samples.•Toddlers have higher exposure risks of SCCPs and MCCPs than adults in the malls.•Dermal permeation was the predominated exposure pathway for the adult.•Contribution of dust ingestion to the toddler was around 77.0% in the worst case.Levels and distribution of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) were measured in indoor dusts from malls in China. The concentrations of SCCPs and MCCPs in dustfalls from a building material mall ranged from 6.0 to 361.4 μg g−1 and from 5.0 to 285.9 μg g−1, respectively. Much heavier contamination was found in central air conditioner filter (CACF) dusts from a newly opened shopping mall, with SCCP concentrations of 114.7–707.0 μg g−1 and MCCP concentrations of 89.0–1082.9 μg g−1. The C13- and C14-CPs were the dominant congeners, while the Cl7 and Cl8 groups were the major chlorine congeners in both kinds of dust samples. Significant correlation relationships (p ≤ 0.05) were found between ∑SCCPs and ∑MCCPs in CACF dusts and dustfalls. Varied exposure pathways including dust ingestion and dermal permeation have been evaluated. The average daily exposure doses of SCCPs and MCCPs for the adult in CACF dusts and dustfalls were estimated to be 0.394 and 0.150 μg kg−1 day−1, respectively. The toddler had higher exposure risks with 5.918 and 2.658 μg kg−1 day−1 in the shopping and building material malls, respectively. Dermal permeation was the predominated exposure pathway for the adult, while dust ingestion was suggested to be more important for the toddler due to hand-to-mouth contact.
Co-reporter:Pengjun Xu, Bu Tao, Zhiguang Zhou, Shuang Fan, Ting Zhang, Aimin Liu, Shuping Dong, Jingli Yuan, Hong Li, Jiping Chen, Yeru Huang
Environmental Pollution 2017 Volume 228(Volume 228) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.envpol.2017.05.024
•Levels of PBDEs, some NBFRs, DP and PBDD/Fs in Guiyu soils are relatively high.•Levels of FRs in EW disposal area soils are PBDEs > DBDPE > DP ≈ BTBPE > HBB > BB153 > PBEB.•Technical Penta- and Deca-BDE mixtures are the major PBDE sources in Guiyu soils.•PBDD/Fs are derived from the processing, pyrolysis and combustion of BFRs.•Thermal disposal of EW incline to release more highly brominated compounds.Guiyu, China, is well-known for the crude disposal of electronic waste (EW) and severe persistent organic pollutants (POPs). Therefore, in this study, the occurrence, composition, and source of polybrominated diphenyl ethers (PBDEs), 2,2′,4,4′,5,5’-hexabromobiphenyl (BB153), some novel brominated flame retardants (NBFRs), Dechlorane Plus (DP) and polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) in farmland soils covering Guiyu were studied. In EW disposal area soils, PBDEs were the most abundant FRs, with concentrations of 13–1014 ng g−1. The primary PBDE sources were technical Penta- and Deca-BDE mixtures in northern and southern Guiyu, respectively. The levels of BB153 were relatively low, possibly because it has been banned in the 1970s. The concentrations of hexabromobenzene (HBB) were 0.048–3.3 ng g−1, while pentabromoethylbenzene (PBEB) was almost not detected in the soils. Two alternatives to commercial PBDEs, decabromodiphenyl ethane (DBDPE) and 1,2-bis(2,4,6-tribromophenoxy) ethane (BTBPE), were the primary NBFRs, with concentrations of 1.8–153 ng g−1 and 0.43–15 ng g−1, respectively. DP was another primary FR, with concentrations of 0.57–146 ng g−1. Moreover, syn-DP and anti-DP isomers were not stereoselectively decomposed during the EW disposal process and were therefore present in their original fractions in the soils. The levels of PBDD/Fs in EW disposal area soils were 2.5–17 pg TEQ g−1. 1,2,3,4,6,7,8-HpBDF and OBDF were the dominant congeners, mainly derived from processing, pyrolysis and combustion of BFRs. The regional distribution of pollutants was shown to be related to the disposal manner of EW, with their open thermal disposal tending to release more highly brominated compounds such as BDE209, DBDPE, and 1,2,3,4,6,7,8-HpBDF. Additionally, some riverbank sites were heavily polluted because of nearby point sources, downwind Simapu (SMP) town without EW disposal activity was also contaminated by these pollutants.Download high-res image (525KB)Download full-size image
Co-reporter:Xiuhua Zhu;Hao Bai;Yuan Gao
Environmental Science and Pollution Research 2017 Volume 24( Issue 26) pp:21203-21212
Publication Date(Web):22 July 2017
DOI:10.1007/s11356-017-9775-x
The concentrations of short-chain polychlorinated paraffins (SCCPs) in the urban air of Dalian, China, were monitored from March to October 2010 and from September to October 2016 with active high-volume sampler. The total concentration of SCCPs (particulate phase + gas phase) ranged from 15.12 to 66.44 ng m−3, with an average of 30.26 ng m−3 in 2010, and 65.30 to 91.00 ng m−3, with an average of 78.15 ng m−3 in 2016. Hexa-chlorinated dodecane and hexa-chlorinated undecane are the predominant components in the gas phase, while octa-chlorinated undecane and hepta-chlorinated tridecane are dominant in the particulate phase. In 2010, 82.57–97.16% of the total SCCPs were found in the gas phase, except that in winter, where 63.11% of the total SCCPs were in the particulate phase; the air concentrations of SCCPs in gas phase were summer > autumn > spring > winter, which was positively correlated with the change of the average ambient temperature, while it was the contrary in particulate phase. In autumn, the gas phase and the total air concentration of SCCPs in 2016 were 2.57 times more than that in 2010, while the congener group patterns of SCCPs were similar. Spearman’s rank correlation analysis between the concentrations of SCCPs with meteorological parameters was conducted. The gas-particle distribution was examined through the relationship of the logarithm of the gas-particle partition coefficient with that of the subcooled vapor pressure and the octanol-air partitioning coefficient of SCCPs. Results indicated that the absorption mechanisms contributed more to the partitioning process. The exposure risk of SCCPs was evaluated, which illustrated that the estimated exposure of SCCPs via the outdoor environment in Dalian did not exceed the health concern threshold of the European risk assessment.
Co-reporter:Xianbo Lu, Xue Wang, Lidong Wu, Lingxia Wu, Dhanjai, Lei Fu, Yuan Gao, and Jiping Chen
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 25) pp:16533-16539
Publication Date(Web):June 9, 2016
DOI:10.1021/acsami.6b05008
Bisphenols (BPs), which have more than ten kinds of structural analogues, are emerging as the most important endocrine disrupting chemicals that adversely affect human health and aquatic life. A tyrosinase nanosensor based on metal–organic frameworks (MOFs) and chitosan was developed to investigate the electrochemical response characteristics and mechanisms of nine kinds of BPs for the first time. The developed tyrosinase nanosensor showed a sensitive response to bisphenol A, bisphenol F, bisphenol E, bisphenol B, and bisphenol Z, and the responsive sensitivities were highly dependent on their respective log Kow values. However, the nanosensor showed no response to bisphenol S (BPS), bisphenol AP (BPAP), bisphenol AF (BPAF), or tetrabromobisphenol A, although BPS, BPAP, and BPAF have structures similar to those of the responsive BPs. The obtained results reveal that the electrochemical response of different BPs is affected not only by the molecular structure, especially the available ortho positions of phenolic hydroxyl groups, but also by the substituent group properties (electron acceptor or electron donor) on the bisphenol framework. The electronic cloud distribution of the phenolic hydroxyl groups, which is affected by the substituent group, determines whether the available ortho positions of phenolic hydroxyl groups can be oxidized by the tyrosinase biosensor. These response mechanisms are very significant as they can be used for predicting the response characteristics of many BPs and their various derivatives and metabolites on biosensors. The unexpected anti-interference ability of the biosensor to nine heavy metal ions was also discovered and discussed. The MOF-chitosan nanocomposite proves to be a promising sensing platform for the construction of diverse biosensors for selective detection of targets even in the presence of a high concentration of heavy metal ions.
Co-reporter:Yuan Gao, Haijun Zhang, Lili Zou, Ping Wu, Zhengkun Yu, Xianbo Lu, and Jiping Chen
Environmental Science & Technology 2016 Volume 50(Issue 7) pp:3746-3753
Publication Date(Web):March 3, 2016
DOI:10.1021/acs.est.5b05115
Analysis of short-chain chlorinated paraffins (SCCPs) is extremely difficult because of their complex compositions with thousands of isomers and homologues. A novel analytical method, deuterodechlorination combined with high resolution gas chromatography–high resolution mass spectrometry (HRGC–HRMS), was developed. A protocol is applied in the deuterodechlorination of SCCPs with LiAlD4, and the formed deuterated n-alkanes of different alkane chains can be distinguished readily from each other on the basis of their retention time and fragment mass ([M]+) by HRGC–HRMS. An internal standard quantification of individual SCCP congeners was achieved, in which branched C10-CPs and branched C12-CPs were used as the extraction and reaction internal standards, respectively. A maximum factor of 1.26 of the target SCCP concentrations were determined by this method, and the relative standard deviations for quantification of total SCCPs were within 10%. This method was applied to determine the congener compositions of SCCPs in commercial chlorinated paraffins and environmental and biota samples after method validation. Low-chlorinated SCCP congeners (Cl1–4) were found to account for 32.4%–62.4% of the total SCCPs. The present method provides an attractive perspective for further studies on the toxicological and environmental characteristics of SCCPs.
Co-reporter:Feidi Wang, Haijun Zhang, Ningbo Geng, Baoqin Zhang, Xiaoqian Ren, and Jiping Chen
Environmental Science & Technology 2016 Volume 50(Issue 6) pp:3145-3153
Publication Date(Web):February 13, 2016
DOI:10.1021/acs.est.5b03678
The toxic effects of hexabromocyclododecane (HBCD) are complex, and the underlying toxicological mechanisms are still not completely understood. In this study, a pseudotargeted metabolomic approach based on the UHPLC/Q-Trap MS system was developed to assess the HBCD-intervention-related metabolic alteration in HepG2 cells. In addition, some physiologic indicators and relevant enzyme activities were measured. HBCD exposure obviously impaired metabolic homeostasis and induced oxidative stress, even at an environmentally relevant dose (0.05 mg/L). Metabolic profiling and multivariate analysis indicated that the main metabolic pathways perturbed by HBCD included amino acid metabolism, protein biosynthesis, fatty acid metabolism, and phospholipid metabolism. HBCD suppressed the cell uptake of amino acids, mainly through inhibition of the activity of membrane transport protein Na+/K+-ATPase. HBCD down-regulated glycolysis and β-oxidation of long-chain fatty acids, causing a large decrease of ATP production. As a result, the across-membrane transport of amino acids was further inhibited. Meanwhile, HBCD induced a significant increase of total phospholipids, mainly through the remodeling of phospholipids from the increased free fatty acids. The obtained metabolomic results also provided some new evidence and clues regarding the toxicological mechanisms of HBCD that contribute to obesity, diabetes, nervous system damage, and developmental disorders.
Co-reporter:Fang Li, Jing Jin, Dongqin Tan, Jiazhi Xu, Dhanjai, Yuwen Ni, Haijun Zhang, Jiping Chen
Journal of Chromatography A 2016 Volume 1448() pp:1-8
Publication Date(Web):27 May 2016
DOI:10.1016/j.chroma.2016.04.037
•An SPE cleanup method of PCNs and dl-PCBs in complex samples was developed.•MgO microspheres and basic alumina were used as SPE adsorbents.•The method showed excellent efficiency to remove various interferences.•The ASE/SPE/GC–MS/MS method was used to analyze PCNs and dl-PCBs in samples.•The analytical method was simple, rapid, and environmentally friendly.A solid-phase extraction (SPE) cleanup method was developed to purify the sample extracts for the analysis of polychlorinated naphthalenes (PCNs) and dioxin-like polychlorinated biphenyls (dl-PCBs). Monodisperse magnesium oxide (MgO) microspheres and basic alumina were used as SPE adsorbents. Important parameters of the SPE procedure were optimized, including the amount of basic alumina and the type and volume of the washing and elution solvents. The optimized SPE cleanup method exhibited excellent purification performance for the removal of organochlorinated compounds, lipid compounds, sulfur, and pigments. Additionally, it was found that the retention activities of congeners differed with the number and position of the chlorine substituents in PCNs. In this study, an analytical method based on a combination of accelerated solvent extraction (ASE) coupled with SPE cleanup and gas chromatography-triple quadrupole mass spectrometry (GC–MS/MS) is proposed for the analysis of PCNs and dl-PCBs in complex samples (sediment, pine needle, and scallop samples). The analytical method demonstrates good linearity, acceptable recovery (63–148%) and precision (relative standard deviations less than 26%). The limits of detection (LODs) of PCN and dl-PCB congeners were in the range of 0.6–19.1 pg g−1 and 0.4–8.6 pg g−1, respectively. The PCNs and dl-PCBs levels in these samples ranged from 0.16 to 3.07 ng g−1 dry weight (dw) and from undetectable to 0.07 ng g−1 dw, respectively.
Co-reporter:Hao Sun;Yun Li;Jiajia Yang;Xiaoli Sun;Chaonan Huang;Xiangdong Zhang
Journal of Separation Science 2016 Volume 39( Issue 11) pp:2188-2195
Publication Date(Web):
DOI:10.1002/jssc.201501305
The dummy molecularly imprinted polymers were prepared by Pickering emulsion polymerization. 4,4′-(1-Phenylethylidene) bisphenol was selected as the dummy template to avoid the leakage of the target bisphenols. The microsphere particles were characterized by scanning electron microscopy and nitrogen adsorption–desorption measurements, demonstrating that the regular-shaped and medium-sized particles (40–70 μm) were obtained with a specific surface area of 355.759 m2/g and a total pore volume of 0.561 cm3/g. The molecular imprinting properties of the particles were evaluated by static adsorption and chromatographic evaluation experiments. The association constant and maximum adsorption amount of bisphenol A were 0.115 mmol/L and 3.327 μmol/g using Scatchard analysis. The microsphere particles were then used as a solid-phase extraction sorbent for selective extraction of seven bisphenols. The method of dummy molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography and diode array detection was successfully established for the extraction and determination of seven bisphenols from environmental sediment samples with method detection limits of 0.6–1.1 ng/g. Good recoveries (75.5–105.2%) for sediment samples at two spiking levels (500 and 250 ng/g) and reproducibility (RSDs < 7.7%, n = 3) were obtained.
Co-reporter:Ningbo Geng, Haijun Zhang, Baoqin Zhang, Ping Wu, Feidi Wang, Zhengkun Yu, and Jiping Chen
Environmental Science & Technology 2015 Volume 49(Issue 5) pp:3076-3083
Publication Date(Web):February 7, 2015
DOI:10.1021/es505802x
Short-chain chlorinated paraffins (SCCPs) have attracted considerable attention for their characteristic of persistent organic pollutants. However, very limited information is available for their toxic effects at environmentally relevant doses, limiting the evaluation of their health risks. In this study, cell viability assay and targeted metabolomic approach was used to evaluate the environmental dose (<100 μg/L) effect of SCCPs on HepG2 cells. Cell viability was found to be decreased with increases in exposure dose of SCCPs. Exposure for 48 h to C10-CPs resulted in a significant reduction in cell viability compared with 24 h, even at 1 μg/L. SCCPs exposure altered the intracellular redox status and caused significant metabolic disruptions. As a kind of peroxisome proliferator, SCCPs specifically stimulated the β-oxidation of unsaturated fatty acids and long-chain fatty acids. Meanwhile, SCCPs exposure disturbed glycolysis and amino acid metabolism, and led to the up-regulation of glutamate metabolism and urea cycle. The toxic effects of SCCPs might mainly involve the perturbation of energy production, protein biosynthesis, fatty acid metabolism, and ammonia recycling.
Co-reporter:Jiajia Yang, Yun Li, Jincheng Wang, Xiaoli Sun, Syed Mazhar Shah, Rong Cao, Jiping Chen
Analytica Chimica Acta 2015 Volume 853() pp:311-319
Publication Date(Web):1 January 2015
DOI:10.1016/j.aca.2014.09.051
•Novel sponge-like molecularly imprinted mesoporous silica was synthesized.•Extraordinarily large specific surface area and highly interconnected 3-D porous network.•High specific adsorption capacity and fast adsorption kinetics for BPA.•Good class-selectivity and clean-up effect for bisphenols in sediment under SPE mode.•Good recoveries and sensitivity for bisphenols using the MISMS–SPE coupled with HPLC–DAD method.Bisphenol A (BPA) imprinted sponge mesoporous silica was synthesized using a combination of semi-covalent molecular imprinting and simple self-assembly process. The molecularly imprinted sponge mesoporous silica (MISMS) material obtained was characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption measurements. The results show that the MISMS possessed a large specific surface area (850.55 m2 g−1) and a highly interconnected 3-D porous network. As a result, the MISMS demonstrated a superior specific adsorption capacity of 169.22 μmol g−1 and fast adsorption kinetics (reaching equilibrium within 3 min) for BPA. Good class selectivity for BPA and its analogues (bisphenol F, bisphenol B, bisphenol E and bisphenol AF) was also demonstrated by the sorption experiment. The MISMS as solid-phase extraction (SPE) material was then evaluated for isolation and clean-up of these bisphenols (BPs) from sediment samples. An accurate and sensitive analytical method based on the MISMS–SPE coupled with HPLC–DAD has been successfully established for simultaneous determination of five BPs in river sediments with detection limits of 0.43–0.71 ng g−1 dry weight (dw). The recoveries of BPs for lyophilizated sediment samples at two spiking levels (50 and 500 ng g−1 dw for each BP) were in the range of 75.5–105.5% with RSD values below 7.5%.
Co-reporter:Jiajia Yang, Yun Li, Jincheng Wang, Xiaoli Sun, Rong Cao, Hao Sun, Chaonan Huang, Jiping Chen
Analytica Chimica Acta 2015 Volume 872() pp:35-45
Publication Date(Web):4 May 2015
DOI:10.1016/j.aca.2015.02.058
•BPA imprinted polymer microspheres were prepared by Pickering emulsion polymerization.•Regular spherical shape and narrow diameter distribution.•Good specific adsorption capacity for BPA.•Good class-selectivity and clean-up efficiency for bisphenols in human urine under SPE mode.•Good recoveries and sensitivity for bisphenols using the MIPMS-SPE coupled with HPLC-DAD method.The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption–desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30–60 μm), a specific surface area (SBET) of 281.26 m2 g−1 and a total pore volume (Vt) of 0.459 cm3 g−1. Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2–2.2 ng mL−1. The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL−1 for each BP) were in the range of 81.3–106.7% with RSD values below 8.3%.
Co-reporter:Yun Li, Jiajia Yang, Chaonan Huang, Longxing Wang, Jincheng Wang, Jiping Chen
Journal of Chromatography A 2015 Volume 1392() pp:28-36
Publication Date(Web):1 May 2015
DOI:10.1016/j.chroma.2015.03.003
•Novel dendrimer-functionalized large pore 3D cubic mesoporous KIT-6 sorbent.•DF-KIT-6 sorbent as a mixed-mode anion-exchanger for SPE of acidic drugs.•High extraction efficiency from mixed-mode retention and high adsorption capacity.•Good recoveries and sensitivity using the DF-KIT-6 based SPE/RPLC-UV method.•Highly efficient clean-up of NSAIDs in human urine compared to C18.A new dendrimer-functionalized mesoporous silica material based on large-pore 3D cubic Korea Advanced Institute of Science and Technology-6 (KIT-6) was synthesized by the growing of dendritic branches inside the mesopores of aminopropyl functionalized KIT-6. Detailed physical characterizations using transmission electron microscopy, nitrogen adsorption–desorption measurements, Fourier transform infrared (FTIR) spectroscopy, and elemental analysis reveal that the multifunctional dendrimers have been grown successfully within the confined spaces of mesopores. Although the 3D ordered mesoporous architecture of KIT-6 was well preserved, there was a significant and continuous decrease in pore size, specific surface area (SBET) and pore volume when increasing dendrimer generation up to six. In order to get a compromise between the SBET, pore size and density of functionalities, the dendrimer-functionalized KIT-6 (DF-KIT-6) for generation 2 (SBET, 314.2 m2 g−1; pore size, 7.9 nm; carbon and nitrogen contents, 19.80% and 1.92%) was selected for solid phase extraction (SPE) applications. The DF-KIT-6 was then evaluated as a reversed-phase/anion-exchange mixed-mode sorbent for extraction of the selected acidic drugs (ketoprofen, KEP; naproxen, NAP; and ibuprofen, IBU), since the dendrimers contained both hydrocarbonaceous and amine functionalities. The effective parameters on extraction efficiency such as sample pH and volume, type and volume of eluent and wash solvents were optimized. Under the optimized experimental conditions, the DF-KIT-6 based SPE coupled with HPLC-UV method demonstrated good sensitivity (0.4–4.6 ng mL−1 detection of limits) and linearity (R2 > 0.990 for 10–2000 ng mL−1 of KEP and IBU, and 1–200 ng mL−1 of NAP). The potential use of DF-KIT-6 sorbent for preconcentration and cleanup of acid drugs in human urine samples was also demonstrated. Satisfactory recoveries at two spiking levels (30 and 300 ng mL−1 for KEP and IBU, 3 and 30 ng mL−1 for NAP) were obtained in the range of 85.7–113.9% with RSD values below 9.3% (n = 3).
Co-reporter:Lidong Wu, Xianbo Lu, Xue Wang, Yi Song and Jiping Chen
Analytical Methods 2015 vol. 7(Issue 8) pp:3347-3352
Publication Date(Web):02 Feb 2015
DOI:10.1039/C5AY00020C
A sensitive electrochemical biosensor based on double-stranded deoxyribonucleic acid (DNA) has been proposed for rapid screening of chemicals genotoxicity potential. A DNA probe from the clone RP3-402G11 gene of the human DNA sequence and electroactive methylene blue (MB) have been used as a biorecognition element and signal amplification molecules respectively for evaluating the genotoxic potential of target analytes with high sensitivity. The biosensing mechanism of genotoxicity screening is based on the damage of targets for the DNA double helix, which results in the subsequent distinct change of the electrochemical signal. More than 10 kinds of genotoxic chemicals have been used as testing analytes including highly toxic dioxins (polychlorinated dibenzodioxins, polychlorinated dibenzofurans) and polychlorinated biphenyls (PCBs). Dioxins and dioxin-like chemicals have been identified as highly genotoxic chemicals by the proposed DNA biosensor, which is consistent with the conclusion from International Agency for Research on Cancer. The results obtained demonstrated that the signal response of the biosensor for dioxins and PCBs correlated well with their toxic equivalent factor (TEF) values and concentrations of tested targets. The biosensor proved to be a promising in vitro screening tool for rapid estimation of chemicals genotoxicity potential.
Co-reporter:Xue Wang, Xianbo Lu, Lidong Wu, Jiping Chen
Biosensors and Bioelectronics 2015 Volume 65() pp:295-301
Publication Date(Web):15 March 2015
DOI:10.1016/j.bios.2014.10.010
•Cu-MOF was synthesized and explored to construct a tyrosinase biosensor.•The Cu-MOF possesses >1000 m2 g−1 surface area and 3D interconnected channels.•The biosensor displayed ultrasensitive, rapid and selective response for Bisphenol A.•The biosensor method was successfully applied to determine BPA in plastic products.•MOFs-based 3D structures show great prospect as a robust biosensing platform.As is well known, bisphenol A (BPA), usually exists in daily plastic products, is one of the most important endocrine disrupting chemicals. In this work, copper-centered metal-organic framework (Cu-MOF) was synthesized, which was characterized by SEM, TEM, XRD, FTIR and electrochemical method. The resultant Cu-MOF was explored as a robust electrochemical biosensing platform by choosing tyrosinase (Tyr) as a model enzyme for ultrasensitive and rapid detection of BPA. The Cu-MOF provided a 3D structure with a large specific surface area, which was beneficial for enzyme and BPA absorption, and thus improved the sensitivity of the biosensor. Furthermore, Cu-MOF as a novel sorbent could increase the available BPA concentration to react with tyrosinase through π–π stacking interactions between BPA and Cu-MOF. The Tyr biosensor exhibited a high sensitivity of 0.2242 A M−1 for BPA, a wide linear range from 5.0×10−8 to 3.0×10−6 mol l−1, and a low detection limit of 13 nmol l−1. The response time for detection of BPA is less than 11 s. The proposed method was successfully applied to rapid and selective detection of BPA in plastic products with satisfactory results. The recoveries are in the range of 94.0–101.6% for practical applications. With those remarkable advantages, MOFs-based 3D structures show great prospect as robust biosensing platform for ultrasensitive and rapid detection of BPA.
Co-reporter:Xindong Ma, Haijun Zhang, Zhen Wang, Ziwei Yao, Jingwen Chen, and Jiping Chen
Environmental Science & Technology 2014 Volume 48(Issue 10) pp:5964-5971
Publication Date(Web):April 18, 2014
DOI:10.1021/es500940p
Short chain chlorinated paraffins (SCCPs) are under the evaluation for inclusion into the Stockholm Convention on persistent organic pollutants. However, information on their bioconcentration and biomagnification in marine ecosystems is unavailable, limiting the evaluation of their ecological risks. In this study, seawater, sediment, zooplankton, invertebrates, and fishes collected from Liaodong Bay, Bohai Sea, North China were analyzed to investigate the residual level, congener group profile, bioaccumulation, and trophic transfer of SCCPs in a marine food web. The total concentrations of SCCPs ranged from 4.1 to 13.1 ng L–1 in seawater, 65 to 541 ng g–1 (dw) in sediment, and 86 to 4400 ng g–1 (ww) in organisms. Correspondence analysis indicated the relative enrichment of C10Cl5 and C11Cl5 formula groups in most aquatic organisms. Both the logarithm bioaccumulation factors (log BAFs: 4.1–6.7) and biota–sediment accumulation factors (BSAFs: 0.1–7.3) of individual congeners implied the bioaccumulation of SCCPs. The trophic magnification factor (TMF) of ∑SCCPs was determined to be 2.38 in the zooplankton–shrimp–fish food web, indicating biomagnification potential of SCCPs in the marine ecosystem. The TMF values of individual congener groups significantly correlated with their log KOW values.
Co-reporter:Xueli Wang, Haijun Zhang, Yuwen Ni, Qinqin Du, Xueping Zhang, and Jiping Chen
Environmental Science & Technology 2014 Volume 48(Issue 8) pp:4361-4367
Publication Date(Web):March 25, 2014
DOI:10.1021/es404347h
Chlorine bleaching is still practiced by most of nonwood pulp and paper mills, resulting in a considerable amount of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) formation and emission. In this study, the effects of primary chlorination conditions on the formation of PCDD/Fs from nonwood pulp bleaching with elemental chlorine were investigated. It was found that low-chlorinated PCDD/Fs were usually formed and then underwent further chlorination to form highly chlorinated PCDD/Fs with increasing chlorination time. Higher available chlorine dosages and lower system pH values greatly accelerated dioxin formation, and pH 3 was the threshold for the formation of tetra- to octa-CDD/Fs. Higher temperatures promoted the formation of lower-chlorinated PCDD/Fs, while caused significant reduction of tetra- to hepta-CDDs and penta- to octa-OCDFs. PCDFs were formed much faster than PCDDs. A first-order kinetic model showed a good fit to the data for tetra- to oct-CDFs formation under different chlorination conditions, indicating that chlorine substitution was the rate determining step for their formation. Finally, the optimum chlorination conditions for minimizing and eliminating the formation of 2,3,7,8-TCDD/TCDF in nonwood pulp bleaching with elemental chlorine were established.
Co-reporter:Yun Li, Jiajia Yang, Jing Jin, Xiaoli Sun, Longxing Wang, Jiping Chen
Journal of Chromatography A 2014 Volume 1337() pp:133-139
Publication Date(Web):11 April 2014
DOI:10.1016/j.chroma.2014.02.044
•A novel dendritic polymer-modified silica stationary phase was synthesized.•Multiple retention mechanisms imparted by the unique dendritic structure.•Reversed phase, anion-exchange and hydrophilic interaction mechanisms.•Separation of basic, neutral and acidic compounds under RP/AEX mixed mode.•Effective separation of nucleobases and nucleosides under HILIC mode.A novel dendritic polymer-modified silica (DPS) stationary phase was prepared by a divergent synthesis scheme starting from propylamine on silica by consecutive amine-epoxy reactions with 1,4-butanedioldiglycidyl ether and aniline. Both elemental analysis and infrared spectra data shows the successful growth of dendritic polymer on silica particles. The carbon and nitrogen contents increased with an increasing number of reaction cycles and achieved 25.2% and 2.1% (w/w) after 11 reaction cycles. The combination of a phenyl ring with a quaternary ammonium, or a tertiary amine at the branch point along with embedded polar functionalities (including ether and hydroxyl groups) in the branch, generated hydrophobic, electrostatic, as well as hydrophilic interactive domains. Depending on solute structure and mobile phase composition, the DPS stationary phase provided multiple retention mechanisms, including reversed phase (RP), anion-exchange (AEX), and hydrophilic interactions. The RP capability achieved separation of polycyclic aromatic hydrocarbons. Basic, neutral and acidic molecules were well separated under RP/AEX mixed mode. Effective separation of small polar compounds (such as nucleobases and nucleosides) was also obtained under hydrophilic interaction liquid chromatography (HILIC) mode.
Co-reporter:Xiaoli Sun, Jincheng Wang, Yun Li, Jing Jin, Baoqin Zhang, Syed Mazhar Shah, Xueli Wang, Jiping Chen
Journal of Chromatography A 2014 Volume 1343() pp:33-41
Publication Date(Web):23 May 2014
DOI:10.1016/j.chroma.2014.03.063
•Dummy template selection via an HPLC column packed with the non-imprinted polymer.•Highly class-selectivity for BPs of BPS-DMIP.•Simultaneous analysis of five BPs in water using the developed DMISPE–HPLC method.•Highly selective and sensitive method with good recovery and reproducibility.A simple and fast method for both dummy template selection and polymer composition optimization is proposed here. A series of dummy templates for bisphenols imprinting were screened by running them on a non-imprinted polymer (NIP) column with porogen solvent as mobile phase. The tested dummy templates mainly involved bisphenol S (BPS), bromobisphenol A (TBBPA), bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB), bisphenol AF (BPAF), 2,2′,6,6′-tetramethyl-4,4′-sulfonyldiphenol (BS-TM) and 4,4′-diaminodiphenylmethane (DADPM). Different monomers and porogens were also investigated for BPS and DADPM using the same method. BPS dummy template was finally selected with acetonitrile and 4-VP as porogen and monomer. The resulting dummy molecularly imprinted polymer (DMIP) achieved superior affinities for BPF, BPE, BPA, BPB and BPAF with imprinting factors 14.5, 13.8, 8.7, 5.7 and 4.2, respectively. An efficient method based on BPS-DMIP-SPE coupled with HPLC-UV was developed for selective extraction of BPF, BPE, BPA, BPB and BPAF in water samples. The method showed excellent recoveries (89.4–102.0%) and precision (RSD 0.3–4.8%, n = 5) for tap and river water samples spiked at three concentration levels each (40, 200 and 1000 ng L−1). The detection limits ranged between 2.2 and 3.8 ng L−1 with a sample volume of 500 mL. The result demonstrated the superiority of the optimized method for selective extraction of BPs in water samples at the ng L−1 level.
Co-reporter:Huilian Ma, Yun Li, Haijun Zhang, Syed Mazhar Shah, Jiping Chen
Journal of Chromatography A 2014 Volume 1358() pp:14-19
Publication Date(Web):5 September 2014
DOI:10.1016/j.chroma.2014.06.021
•A novel dispersant solvent-free MADLLME method was reported.•The dispersion of extractant in aqueous sample was performed only by salt addition.•Quantification of HANs was performed by PTV-GC–MS.•Preservation and occurrence study for MIAN was performed for the first time.•Six target HANs detected in different drinking waters.We report here a new analytical method for the simultaneous determination of seven haloacetonitriles (HANs) in drinking water by coupling salt-assisted dispersive liquid–liquid microextraction (SADLLME) with programmed temperature vaporizer-gas chromatography–mass spectrometry (PTV-GC–MS). The newly developed method involves the dispersion of the extractant in aqueous sample by addition of a few grams of salt and no dispersion liquid was required as compared to the traditional DLLME methods. The extractant (CH2Cl2, 50 μL) and the salt (Na2SO4, 2.4 g) were successively added to water (8 mL) in a conical centrifuge tube that was shaken for 1 min and centrifuged (3500 rpm, 3 min). The aliquot of sedimented phase (4 μL) was then directly injected into the PTV-GC–MS system. The limits of detection and quantification for the HANs were 0.4–13.2 ng L−1 and 1.2–43.9 ng L−1, respectively. The calibration curves showed good linearity (r2 ≥ 0.9904) over 3 orders of magnitude. The repeatability of the method was investigated by evaluating the intra- and inter-day precisions. The relative standard deviations (RSDs) obtained were lower than 10.2% and 7.8% at low and high concentration levels. The relative recoveries ranged from 79.3% to 105.1%. The developed methodology was applied for the analysis of seven HANs in several drinking water samples in coastal and inland cities of China. It was demonstrated to be a simple, sensible, reproducible and environment friendly method for the determination of trace HANs in drinking water samples.
Co-reporter:Xiaoli Sun, Jincheng Wang, Yun Li, Jiajia Yang, Jing Jin, Syed Mazhar Shah, Jiping Chen
Journal of Chromatography A 2014 Volume 1359() pp:1-7
Publication Date(Web):12 September 2014
DOI:10.1016/j.chroma.2014.07.007
•Highly class-selective DMIPs for FQs prepared by using daidzein as a non-poisonous dummy template.•Simultaneous determination of eight FQs from fish samples using the developed DMI-MSPD-HPLC-FLD method.•Highly selective and sensitive method with good recovery and precision.A series of novel dummy molecularly imprinted polymers (DMIPs) were prepared as highly class-selective sorbents for fluoroquinolones. A non-poisonous dummy template, daidzein, was used for the first time to create specific molecular recognition sites for fluoroquinolones in the synthesized polymers. The influence of porogen polarity on dummy molecular imprinting effect was studied. The DMIP prepared using dimethylsulfoxide−acetonitrile (1:1.8, v/v) as porogen achieved the highest imprinting factors (IF) for fluoroquinolones over a range of IF 13.4–84.0. This DMIP was then used for selective extraction of eight fluoroquinolones (fleroxacin, ofloxacin, norfloxacin, pefloxacin, ciprofloxacin, lomefloxacin, enrofloxacin and gatifloxacin) from fish samples based on dummy molecularly imprinted matrix solid-phase dispersion (DMI-MSPD). The extracted fluoroquinolones were subsequently analyzed by high-performance liquid chromatography (HPLC) equipped with a fluorescence detector (FLD). The developed method had acceptable recoveries (64.4−102.7%) and precision (RSDs: 1.7−8.5%, n = 5) for determination of fluoroquinolones in fish samples fortified at levels of 10 and 100 ng g−1. The limits of detection (LODs) for identification of eight fluoroquinolones ranged between 0.06 and 0.22 ng g−1. The results demonstrated great potential of the optimized method for sample preparation in routine analysis of trace fluoroquinolones in fish samples.
Co-reporter:Xianbo Lu, Xue Wang, Jing Jin, Qing Zhang, Jiping Chen
Biosensors and Bioelectronics 2014 Volume 62() pp:134-139
Publication Date(Web):15 December 2014
DOI:10.1016/j.bios.2014.06.036
•A non-covalent method was developed for preparing water-soluble graphene.•Results confirmed the water-soluble graphene retained excellent electronic conductivity.•The graphene dispersions enable the use of conventional solution-phase processing techniques.•A robust biosensing platform was developed based on amino acid ionic liquid functionalized graphene.•The biosensing platform displayed excellent performance for biosensor application.In this study, a facile non-covalent method was developed for preparing water-soluble graphene with excellent electronic conductivity. Room temperature ionic liquids (ILs) with high ionic conductivity were used for the non-covalent surface functionalization of graphene through π–π stacking interactions. Compared to other ILs used, amino acid ionic liquids (AAILs) were found to be the most effective for improving the dispersion of graphene in water phase. Electrochemical and spectroscopic results confirmed that the obtained AAIL functionalized GR can retain the excellent electronic conductivity of pristine graphene without damaging the graphene lattice. The obtained water-soluble graphene (GR-AAIL) was exemplified to fabricate an electrochemical biosensor using tyrosinase as a model enzyme, and the sensitivity (12,600 mA cm−2 M−1) of GR-AAIL based biosensor was about 17 times higher than that of graphene oxide and other nanomaterial based biosensor, displaying its unprecedented high sensitivity for biosensing. The detection limit for catechol (one important environmental pollutant) reached as low as 8 nM with a response time of 3 s and a linear range from 25 nM to 11,100 nM. The AAIL-GR based biosensor also demonstrated good reproducibility, repeatability, selectivity, long-term stability and high recovery for catechol detection. Amino acid ionic liquid functionalized graphene proves to be a robust and versatile electrochemical biosensing platform for fabricating biosensors with excellent performance.
Co-reporter:Xiaoli Sun, Jincheng Wang, Yun Li, Jing Jin, Jiajia Yang, Fang Li, Syed Mazhar Shah, Jiping Chen
Journal of Chromatography A 2014 1360() pp: 9-16
Publication Date(Web):
DOI:10.1016/j.chroma.2014.07.055
Co-reporter:Xue Wang, Xianbo Lu, Jiping Chen
Trends in Environmental Analytical Chemistry 2014 Volume 2() pp:25-32
Publication Date(Web):May 2014
DOI:10.1016/j.teac.2014.04.001
•A comprehensive survey of the biosensors developed for environmental contaminants is presented.•This review includes definition, classification and detection principle of biosensors.•Details of the recent works are given from four aspects of recognition elements.•We discuss the future trends, limitations and challenges of biosensors for environmental applications.Recent developments of biosensor technologies for environmental applications are reviewed in this article. Biosensors offer simple, rapid, sensitive and selective detection method for analysis of environmental contaminants mainly including phenols, heavy metals, toxins, pesticides and other organic pollutants. Biosensors, which are usually classified according to the biorecognition elements, e.g., enzyme, DNA, antibody and whole-cell, are discussed respectively. Several examples of their applications for determination of environmental contaminants are reviewed. Special attention will be paid to novel biosensing systems based on new sensing elements and transduction principles. In addition, we present the beneficial use of nanomaterials in constructing biosensors. Finally, a general overview is provided about the future trends, the limitations and challenges in this field.
Co-reporter:Huilian Ma;Haijun Zhang;Longxing Wang
Environmental Monitoring and Assessment 2014 Volume 186( Issue 5) pp:2813-2821
Publication Date(Web):2014 May
DOI:10.1007/s10661-013-3582-8
An analytical strategy for comprehensive screening of target and non-target volatile organic compounds (VOCs) in surface water was developed, and it was applied to the analysis of VOCs in water samples from Daliao River. The target VOCs were quantified using purge and trap-gas chromatography-mass spectrometry (P&T-GC/MS). Among 20 water samples, 34 VOCs were detected at least once. For the screening of non-target VOCs, the double distillation apparatus was used for the pre-concentration of VOCs prior to P&T-GC/MS analysis. Subsequently, deconvolution software and NIST mass spectral library were applied for the identification of the non-target compounds. A total of 17 non-target VOCs were identified. The most frequently detected VOCs (detection frequencies >80 %) included toluene, benzene, naphthalene, 1,2-dichloroethane, 1,1,2-trichloroethane, and methyl tert-butyl ether. The distribution of VOCs obviously varied according to the sampling sites. The total concentrations of VOCs in water samples collected from the heavily industrialized cities (Anshan and Liaoyang) and the busy port city (Yingkou) were relatively high. The top ten priority VOCs, including naphthalene, 1,2-dichloroethane, o-xylene, 1,3-dichlorobenzene, tetrachloroethene, 1,2-dichlorobenzene, 1,2,4-trichlorobenzene, ethylbenzene, m-xylene, and p-xylene, were obtained by the ranking of the detected VOCs according to their occurrence and ecological effects. These compounds should be given more attention in monitoring and drainage control strategies.
Co-reporter:Fengmei Tang, Yuwen Ni, Haijun Zhang, Yun Li, Jing Jin, Longxing Wang, Jiping Chen
Analytica Chimica Acta 2012 Volume 729() pp:73-79
Publication Date(Web):4 June 2012
DOI:10.1016/j.aca.2012.04.004
A new cleanup method was developed and validated for the determination of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in sediment. The sample extract was first treated with sulfuric acid and then cleaned up by a large volume injection gas chromatography online coupled with liquid chromatography (LVI-GC-LC) system. PCDD/Fs in the extract were separated by a GC column (DB-5), selected cut, cool trapped and transferred to a LC column (alumina). The fraction of PCDD/Fs eluted from the alumina column was collected and concentrated for the instrumental analysis. Under the optimized conditions, LVI-GC-LC method achieved the recoveries of 57–102% for 2,3,7,8-substituted PCDD/Fs, which met the requirements of US Environmental Protection Agency (EPA) Method 1613 and were better than those obtained using the conventional multistep column cleanup method. Meanwhile, compared with the conventional method, the limit of detection (LOD) values of 2,3,7,8-substituted PCDD/Fs cleaned up by LVI-GC-LC method were decreased due to the high-efficiency removal of interferents. These results suggested that the LVI-GC-LC cleanup method was a promising alternative to the multistep cleanup procedure for the determination of dioxins in environmental samples.Graphical abstractThe sample extract could be purified by the LVI-GC-LC cleanup method, and satisfying cleanup efficiency was obtained.Highlights► A new cleanup method for the determination of dioxins in sediment was developed. ► The new method is simpler, less labor-intensive, and more economical. ► The new method showed satisfactory precision, accuracy and cleanup efficiency. ► The new method can be amenable to automation.
Co-reporter:Xueli Wang, Yuwen Ni, Haijun Zhang, Xueping Zhang, and Jiping Chen
Environmental Science & Technology 2012 Volume 46(Issue 21) pp:12234-12240
Publication Date(Web):October 15, 2012
DOI:10.1021/es303373b
Chlorine bleaching is still practiced by non-wood pulp and paper mills in China, resulting in considerable formation and emission of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs). We investigate the distribution of PCDD/Fs in different papermaking processes and dioxin emissions at six typical Chinese non-wood pulp and paper mills. Raw materials for papermaking included reed, wheat straw, bamboo, and sugar cane bagasse. The formation and emission of PCDD/Fs varied strikingly according to bleaching processes and raw materials. Elemental chlorine bleaching promoted the formation of tetra- to octa-CDDs and 2,3,7,8-TCDF, while hypochlorite bleaching only gave rise to a significant increase of 2,3,7,8-TCDF. Bleaching with elemental chlorine and hypochlorite increased 2,3,7,8-TCDF 0.9–42.5 and 0.3–4.1 times, respectively. Most of the 2,3,7,8-TCDF formed at hypochlorite bleaching stage was partitioned into the effluent, which indicated that hypochlorite bleaching was also an important emission source of dioxins. The removal of PCDD/Fs occurred visibly during alkaline digestion, alkaline extraction, and hydrogen peroxide bleaching. Furthermore, the annual emission of PCDD/Fs from Chinese non-wood pulp and paper mills was evaluated.
Co-reporter:Yuan Gao, Haijun Zhang, Fan Su, Yuzeng Tian, and Jiping Chen
Environmental Science & Technology 2012 Volume 46(Issue 7) pp:3771-3778
Publication Date(Web):March 8, 2012
DOI:10.1021/es2041256
Chlorinated paraffins (CPs) are industrially produced in large quantities in the Liaohe River Basin. Their discharge inevitably causes environmental contamination. However, very limited information is available on their environmental levels and distributions in this typical industrial region. In this study, short chain CPs (SCCPs) were analyzed in sediments, paddy soils, and upland soils from the Liaohe River Basin, with concentrations ranging from 39.8 to 480.3 ng/g dry weight. A decreasing trend in SCCP concentrations was found with increasing distance from the cities, suggesting that local industrial activity was the major source of SCCP contamination. A preliminary sediment inventory of SCCPs indicated approximately 30.82 tonnes of SCCPs residual in the sediments from the Liaohe River. The average discharge of SCCPs was estimated to be about 74.4 mg/tonne industrial wastewater. The congener group profiles showed that the relative abundances of shorter chain and lower chlorinated CP congeners (C10–CPs with 5 or 6 chlorine atoms) in soils in rural areas were higher than in sites near cities, which demonstrated that long-range atmospheric transportation could be the major transport pathway. Environmental degradation of SCCPs might occur, where higher chlorinated congeners could dechlorinate to form the lower chlorinated congeners.
Co-reporter:Lidong Wu;Xianbo Lu;Haijun Zhang
ChemSusChem 2012 Volume 5( Issue 10) pp:1918-1925
Publication Date(Web):
DOI:10.1002/cssc.201200274
Abstract
A novel nanocomposite based on ordered graphitized mesoporous carbon (GMC) and amino acid ionic liquids (AAIL) is obtained through controlled surface modification of GMC with hydrophilic AAILs (1-ethyl-3-methylimidazolium alanine, EMIM[Ala]), which is used as a platform for a tyrosinase biosensor to detect phenol. The GMC–AAIL nanocomposite possesses a better biocompatibility and improved aqueous-phase dispersion than hydrophobic GMC alone, owing to the introduction of hydrophilic and biocompatible AAILs. Comparative studies revealed that the catalytic activity of tyrosinase for phenol in phosphate buffer solution (PBS) containing EMIM[Ala] was about ten times higher than that in pure PBS. By entrapping tyrosinase molecules into the mesopores of GMC, making use of the synergy effect of GMC and AAIL (the “interspace confinement effect”, the anti-fouling ability, and the biocompatible microenvironment), the GMC–AAIL-based biosensors display superior analytical performance to GMC-based ones in terms of signal-to-noise ratio, stability, repeatability, and working life. After 21-day storage, the electrode retained more than 90% of its initial response, indicating that surface modification of GMC with hydrophilic and biocompatible AAILs could significantly prolong the life of tyrosinase in vitro. The GMC10–EMIM[Ala]-based biosensor demonstrates a linear response for phenol concentrations from 0.1 to 10 µmol L−1 with a low detection limit of 20 nmol L−1 and sensitivity of 1385 mA cm−2 M−1. The GMC–AAIL nanocomposite proves to be a promising platform for enzyme-based biosensors and biocatalysis.
Co-reporter:Lidong Wu, Dehui Deng, Jing Jin, Xianbo Lu, Jiping Chen
Biosensors and Bioelectronics 2012 Volume 35(Issue 1) pp:193-199
Publication Date(Web):15 May 2012
DOI:10.1016/j.bios.2012.02.045
Hydrophilic nanographene (NGP) prepared by ball milling of graphite was used as the support to construct a novel tyrosinase biosensor for determination of bisphenol A (BPA). The performances of the nanographene-based tyrosinase biosensor were systematically compared with those of multiwall carbon nanotubes (MWNTs) modified tyrosinase biosensors. The results indicated that the nanographene-based tyrosinase biosensor provided significant advantages over MWNTs-based tyrosinase biosensor in term of response, repeatability, background current and limit of detection (LOD), which could be attributed to its larger specific surface area and unique hierarchical tyrosinase-NGP nanostructures. The nanographene-based tyrosinase biosensor displayed superior analytical performance over a linear range from 100 nmol L−1 to 2000 nmol L−1, with LOD of 33 nmol L−1 and sensitivity of 3108.4 mA cm−2 M−1. The biosensor was further used for detecting BPA (leaching from different vessels) in tap water, and the accuracy of the results was validated by high performance liquid chromatography (HPLC). The nanographene-based tyrosinase biosensor proved to be a promising and reliable tool for rapid detection of BPA leached from polycarbonate plastic products and for on-site rapid analysis of emergency pollution affairs of BPA.Highlights► Hydrophilic nanographene was prepared in a controllable nanometer size by a simple ball milling method of graphite materials. ► The nanographene was explored to construct a novel tyrosinase biosensor for rapid, sensitive and selective determination of bisphenol A. ► Comparative studies revealed the significant advantages of nanographene over MWNTs in the performance of fabricated tyrosinase biosensors. ► The biosensor was used for detecting BPA in water samples, and the obtained results were validated by high performance liquid chromatography. ► The nanographene based tyrosinase biosensor proved to be a promising and reliable tool for rapid detection of BPA.
Co-reporter:Yun Li, Milton L. Lee, Jing Jin, Jiping Chen
Talanta 2012 Volume 99() pp:91-98
Publication Date(Web):15 September 2012
DOI:10.1016/j.talanta.2012.04.066
A novel porous poly(ethylene glycol) methacrylate-based monolithic column for normal phase liquid chromatography was prepared by thermally initiated polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and ethylene dimethacrylate (EDMA) in the presence of selected porogens. The monolith was macroscopically homogeneous, had low flow resistance, and did not swell or shrink significantly in solvents of different polarities. Inverse size-exclusion data indicate that the monolith had a total porosity of 79.2%, including an external porosity of 69.3% and an internal porosity of 9.9%. Due to its mild polarity (hydrophilicity), the PEG-functionalized monolith could perform traditional normal phase chromatography using non-polar solvents The van Deemter plot demonstrated that the column efficiency of 33,600–34,320 theoretical plates/m could be achieved at a linear flow velocity of 0.9–1.5 mm/s. The dual retention capability (both weak hydrophilic and hydrophobic interactions) investigated in this paper explains well why the PEG-functionalized monolith could operate in various chromatographic modes.Highlights► A porous hydrophilic poly(ethylene glycol) methacrylate-based monolithic column was prepared and characterized. ► The PEG-functionalized monolith as a novel stationary phase for normal phase liquid chromatography. ► Comparable retentivity to silica-based media or comparable efficiency to other polymer monolithic media. ► Its dual retention capability makes the various chromatographic modes possible.
Co-reporter:Jing Jin, Zhiping Zhang, Yun Li, Xianbo Lu, Lidong Wu, Jiping Chen
Analytica Chimica Acta 2011 Volume 693(1–2) pp:54-61
Publication Date(Web):5 May 2011
DOI:10.1016/j.aca.2011.03.015
A new solid-phase extraction sorbent, octadecyl modified magnesium oxide (C18-MgO) microspheres, was successfully prepared in the present work. Its composition, morphology and structure were studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), N2 adsorption–desorption technique, and solid-state nuclear magnetic resonance (NMR). The as-synthesized C18-MgO was employed as a solid-phase extraction sorbent for the enrichment of polycyclic aromatic hydrocarbons (PAHs) in aqueous solutions. Several factors affecting the extraction efficiency of PAHs, including the type and concentration of organic modifiers, flow rate, sample volume, and the types of rinsing solvents and eluting solvents, were investigated systematically. The results demonstrated that C18-MgO was superior to MgO in terms of large volume in loading samples. In comparison with MgO and Sep-Pak C18, C18-MgO exhibited excellent extraction efficiency (>91% except for naphthalene) in respect of high recoveries under the optimized conditions. The limits of detection varied from 0.001 to 0.603 ng mL−1 for 15 PAHs using high-performance liquid chromatography coupled with a fluorescence detector, indicating that the analytical method was highly sensitive. The proposed method was applied to enrich PAHs in tap water and acceptable recoveries (18–96%) were obtained.
Co-reporter:Yuan Gao, Haijun Zhang, Jiping Chen, Qing Zhang, Yuzeng Tian, Peipei Qi, Zhengkun Yu
Analytica Chimica Acta 2011 Volume 703(Issue 2) pp:187-193
Publication Date(Web):10 October 2011
DOI:10.1016/j.aca.2011.07.041
The performances of three adsorbents, i.e. silica gel, neutral and basic alumina, in the separation of short chain polychlorinated n-alkanes (sPCAs) from potential interfering substances such as polychlorinated biphenyls (PCBs) and organochlorine pesticides were evaluated. To increase the cleanup efficiency, a two-step cleanup method using silica gel column and subsequent basic alumina column was developed. All the PCB and organochlorine pesticides could be removed by this cleanup method. The very satisfying cleanup efficiency of sPCAs has been achieved and the recovery in the cleanup method reached 92.7%. The method detection limit (MDL) for sPCAs in sediments was determined to be 14 ng g−1. Relative standard deviation (R.S.D.) of 5.3% was obtained for the mass fraction of sPCAs by analyzing four replicates of a spiked sediment sample. High resolution gas chromatography/electron capture negative ion–low resolution mass spectrometry (HRGC/ECNI–LRMS) was used for sPCAs quantification by monitoring [M−HCl]− ions. When applied to the sediment samples from the mouth of the Daliao River, the optimized cleanup method in conjunction with HRGC/ECNI–LRMS allowed for highly selective identifications for sPCAs. The sPCAs levels in sediment samples are reported to range from 53.6 ng g−1 to 289.3 ng g−1. C10- and C11-PCAs are the dominant residue in most of investigated sediment samples.Graphical abstractThe sediment sample could be purified by the optimized cleanup method, and satisfying cleanup efficiency was obtained.Highlights► The elution characters of sPCAs and interfering substances were evaluated on three adsorbents. ► An optimized cleanup method was developed for sPCAs with satisfying cleanup efficiency. ► The cleanup method combined with HRGC/ECNI–LRMS was applied for sPCAs analysis. ► The sPCAs levels range from 53.6 ng g−1 to 289.3 ng g−1 in tested sediment samples.
Co-reporter:Yun Li, Xin Xie, Milton L. Lee, Jiping Chen
Journal of Chromatography A 2011 Volume 1218(Issue 48) pp:8608-8616
Publication Date(Web):2 December 2011
DOI:10.1016/j.chroma.2011.09.070
Hydrophilic C18 monolithic polymer sorbents were synthesized for use in solid phase extraction (SPE) and in capillary liquid chromatography (LC). The approach involved incorporating both hydrophobic and hydrophilic monomers into a monolithic material, by copolymerization of stearyl methacrylate (SMA), poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and ethylene dimethacrylate (EDMA) in the presence of selected porogens, to produce translucent mesoporous monolithic materials in bulk (SPE) or white macroporous monoliths inside fused silica capillary columns (capillary LC). A capillary column containing one of the hydrophilic C18 monoliths (i.e. poly(SMA-co-PEGMEMA-co-EDMA) with 15% (w/w) PEGMEMA) demonstrated nearly 35% reduction in retention of polycyclic aromatic compounds and greater than 40% increase in retention of phenols compared to a hydrophobic C18 monolithic column. In addition, the hydrophilic monolith demonstrated significantly improved resolution of phenols. Similar monolithic materials prepared in bulk were ground and sieved to obtain 45–65 μm particles with desired rigidity for SPE. To achieve optimum extraction performance for phenols, several parameters, including sample pH and volume, and eluent type and volume, were investigated. Under optimized experimental conditions, the method demonstrated good sensitivity (1.6 ng/mL LOD) and linearity (R2 > 0.97 for 10–200 ng/mL). Again, incorporation of 15% (w/w) PEGMEMA in the monolith increased the extraction efficiency of phenols in water from approximately 20% to 67–92% compared to a hydrophobic C18 monolithic material. Increased wettability of the sorbent by the aqueous sample matrix and the presence of hydrogen-bonding interactions are responsible for the improved retention of polar compounds.Highlights► A novel hydrophilic polymeric C18 monolith for capillary LC of phenols. ► Increased retention and resolution of polar phenols than conventional C18. ► The hydrophilic C18 polymeric sorbents for enhanced extraction of phenols from water sample. ► Increased wettability in aqueous solutions and additional hydrogen bonding interactions are responsible.
Co-reporter:Jing Jin, Yun Li, Zhiping Zhang, Fan Su, Peipei Qi, Xianbo Lu, Jiping Chen
Journal of Chromatography A 2011 Volume 1218(Issue 51) pp:9149-9154
Publication Date(Web):23 December 2011
DOI:10.1016/j.chroma.2011.10.085
A new method for the selective cleanup of complex matrices and simultaneous separation of benzo[a]pyrene (BaP) was developed in this study. This method was based on solid-phase extraction (SPE) using magnesium oxide microspheres as sorbents, and it eliminated interferences from various impurities, such as lipids, sulphur, pigments, halobenzenes, polychlorodibenzo-p-dioxins and polychlorodibenzofurans. Several parameters, including the volume of rinsing and eluting solvents, the type of loading solvents and SPE sorbents, were optimized systematically. The capability for impurity removal was verified by gel permeation chromatography, gas chromatography, and liquid chromatography. Compared to commercial sorbents (silica gel, florisil and alumina), MgO microspheres exhibited excellent performance in the selective isolation of BaP and removal of impurities. The proposed method was applied to detect BaP in complex samples (sediments, soils, fish, and porcine liver). The limit of quantification (LOQ) was 1.04 ng L−1, and the resulting regression coefficient (r2) was greater than 0.999 over a broad concentration range (9.5–7600 ng L−1). In contrast to traditional methods, the proposed method can give rise to higher recovery (85.1–100.8%) and better selectivity with simpler operation and less consumption of organic solvents (20–40 mL).Highlights► Developing a simple method for the selective cleanup of complex matrices. ► Eliminating interferences from various impurities with high cleanup capability. ► Exhibiting excellent performance in the simultaneous separation of BaP. ► With higher extraction efficiency and less consumption of organic solvents.
Co-reporter:Peipei Qi;Jincheng Wang;Yun Li;Fan Su;Jing Jin
Journal of Separation Science 2011 Volume 34( Issue 19) pp:2712-2718
Publication Date(Web):
DOI:10.1002/jssc.201100264
Abstract
A molecularly imprinted polymer (MIP) was prepared using monobutyl phthalate as template. The synthesis was optimized by using different porogens and functional monomers. The MIP was used as a selective sorbent in molecularly imprinted solid-phase extraction (MIP-SPE) for pre-concentration and determination of monobutyl phthalate (mBP) from the bottled water. The difference in recognition selectivity of the polymer columns was observed in HPLC system, and the effect of the mobile phase on the performance of MIP columns was also investigated. Control of the MIP-SPE process is seen as important in helping to facilitate the selective extraction of mBP from water samples. Thereafter, the choice of washing solvent, eluting solvent amount, pH of loading sample, flow rate of loading solution and the loading sample volume was presented. The optimized procedure was described as follows: 25 mL spiked aqueous solution was percolated through the MIP-SPE cartridge at the flow rate of 1.5 mL/min. After rinsing with acetonitrile/methanol mixture (1:1, v/v), the bound analyte was desorbed with 3 mL methanol. The developed MIP-SPE method was demonstrated to be applicable for the analysis of mBP in the bottled water.
Co-reporter:Lidong Wu, Xianbo Lu, Jing Jin, Haijun Zhang, Jiping Chen
Biosensors and Bioelectronics 2011 Volume 26(Issue 10) pp:4040-4045
Publication Date(Web):15 June 2011
DOI:10.1016/j.bios.2011.03.027
In this work, an electrochemical DNA biosensor based on double-stranded DNA modified Au electrode (dsDNA/Au) was proposed for the rapid screening and detection of chlorinated benzenes pollutants, in which redox-active methylene blue (MB) was used to amplify the interaction between dsDNA and the target analyte. Using hexachlorobenzene (HCB) as a model analyte of chlorinated benzenes, the biosensor demonstrated a linear response with the logarithm of HCB concentrations from 100 pmol L−1 to 100 nmol L−1. The obtained detection limit was 30 pmol L−1, which was remarkably superior to other biosensors. The interaction mechanism of the biosensor with HCB was proposed based on systematical characterization by cyclic voltammetry (CV), differential pulse voltammetry (DPV), UV–vis spectrometry and electrochemical quartz crystal microbalance (EQCM). Further studies revealed that the biosensor could screen chlorinated benzenes in the presence of 100 fold amount of other co-existing chemicals (ethyl acetate and sodium oxalate, etc.), and the response signal of the biosensors for different chlorinated benzenes was correlative to their respective toxicity. The proposed biosensor proved to be a promising “alarm” tool for rapid screening of chlorinated benzenes in real water samples.
Co-reporter:Jixiu Zhang, Xiumei Sun, Zhiping Zhang, Yuwen Ni, Qing Zhang, Xinmiao Liang, Hongbin Xiao, Jiping Chen, James G. Tokuhisa
Phytochemistry 2011 Volume 72(14–15) pp:1767-1778
Publication Date(Web):October 2011
DOI:10.1016/j.phytochem.2011.06.002
In order to determine how plant uptake of a sulfur-rich secondary metabolite, sinalbin, affects the metabolic profile of sulfur-deficient plants, gas chromatography time-of-flight mass spectrometry (GC–TOF-MS), in combination with liquid chromatography–mass spectrometry (LC–MS), was used to survey the metabolome of Arabidopsis seedlings grown in nutrient media under different sulfur conditions. The growth media had either sufficient inorganic sulfur for normal plant growth or insufficient inorganic sulfur in the presence or absence of supplementation with organic sulfur in the form of sinalbin (p-hydroxybenzylglucosinolate). A total of 90 metabolites were identified by GC–TOF-MS and their levels were compared across the three treatments. Of the identified compounds, 21 showed similar responses in plants that were either sulfur deficient or sinalbin supplemented compared to sulfur-sufficient plants, while 12 metabolites differed in abundance only in sulfur-deficient plants. Twelve metabolites accumulated to higher levels in sinalbin-supplemented than in the sulfur-sufficient plants. Secondary metabolites such as flavonol conjugates, sinapinic acid esters and glucosinolates, were identified by LC–MS and their corresponding mass fragmentation patterns were determined. Under sinalbin-supplemented conditions, sinalbin was taken up by Arabidopsis and contributed to the endogenous formation of glucosinolates. Additionally, levels of flavonol glycosides and sinapinic acid esters increased while levels of flavonol diglycosides with glucose attached to the 3-position were reduced. The exogenously administered sinalbin resulted in inhibition of root and hypocotyl growth and markedly influenced metabolite profiles, compared to control and sulfur-deficient plants. These results indicate that, under sulfur deficient conditions, glucosinolates can be a sulfur source for plants. This investigation defines an opportunity to elucidate the mechanism of glucosinolate degradation in vivo.Graphical abstractGas chromatography time-of-flight mass spectrometry (GC–TOF-MS) in combination with liquid chromatography–mass spectrometry (LC–MS) was used to survey the metabolome of Arabidopsis seedlings in response to sulfur deficiency and sinalbin supplements.Highlights► Metabolite profiling of Arabidopsis seedlings in response to sulfur deficiency and sinalbin supplement. ► Identification and quantification of metabolites by GC–TOF-MS and LC–MS. ► Investigation of mass fragmentation patterns of flavonol conjugates, sinapinic acid esters and glucosinolates. ► Comparison of metabolite profiles by principal component analysis. ► Interpretation of metabolite differences via metabolic pathways.
Co-reporter:Jing Jin, Zhiping Zhang, Yun Li, Peipei Qi, Xianbo Lu, Jincheng Wang, Jiping Chen, Fan Su
Analytica Chimica Acta 2010 Volume 678(Issue 2) pp:183-188
Publication Date(Web):30 September 2010
DOI:10.1016/j.aca.2010.08.028
The enrichment of polycyclic aromatic hydrocarbons (PAHs) in water samples with magnesium oxide (MgO) microspheres was evaluated, and four 3–5-ring PAHs were used as probes to validate the adsorption capacity of the material. Factors affecting the recovery of PAHs were investigated in detail, including the type and concentration of organic modifiers, elution solvents, particle size of the adsorbent, volume and flow rate of the samples, and the lifetime of MgO cartridges. The recoveries of four PAHs extracted from 20 mL of seawater spiked with standard PAHs ranged from 85.8% to 102.0% under the optimised conditions. The limits of detection varied from 1.83 ng L−1 to 16.03 ng L−1, indicating that the analytical method was highly sensitive. Additionally, the proposed method was successfully used to enrich PAHs in seawater. Compared to conventional methods, the proposed method consumed less organic modifier (5% acetone), and cheaper sorbents with comparable extraction efficiency were employed.
Co-reporter:Haijun Zhang, Sufang Zhao, Ying Yu, Yuwen Ni, Xianbo Lu, Yuzeng Tian and Jiping Chen
Environmental Science & Technology 2010 Volume 44(Issue 10) pp:3677
Publication Date(Web):April 19, 2010
DOI:10.1021/es9034705
To achieve a higher efficiency of thermal remediation of soil contaminated with organic compounds, the retention mechanisms of organic compounds on thermally treated soil need to be understood adequately. In this study, a soil-column gas chromatography approach was developed to determine the soil-air partition coefficients (KSA) at 300 °C for a diverse set of nonionic organic compounds bearing many different functional groups; and the retention mechanisms of these organic compounds on two typical soils, isohumisols and ferralisols, were characterized using a polyparameter linear free energy relationship (pp-LFER). The KSA values (mL g−1) of typical volatile organic compounds (VOCs) with lower boiling points were <1.5 and in some cases even below 1.0, suggesting the rapid removal of VOCs from soils at 300 °C. Moreover, the KSA values were found to be a strong function of the soil-column temperature T (K), and be almost independent of the carrier-gas flow rate. Significant differences in molecular interactions were noted among various soil-solute pairs. The relative contributions of nonspecific van der Waals forces to the retention of test polar solutes were higher on isohumisols than on ferralisols. In contrast to the reported pp-LFER models for natural soils and soil components at normal environmental temperatures, our results suggest that elevated temperature remarkably reduces H-bond interactions between polar organic compounds and the soil matrix, thus allowing accelerated desorption of polar organic compounds from soils during thermal treatment.
Co-reporter:Yun Fan, Xianbo Lu, Yuwen Ni, Haijun Zhang, Liang Zhao, Jiping Chen and Chenglin Sun
Environmental Science & Technology 2010 Volume 44(Issue 8) pp:3079-3084
Publication Date(Web):March 24, 2010
DOI:10.1021/es9031437
Destruction of polychlorinated aromatic compounds was carried out over spinel-type catalysts XY2O4 (where X = Mg, Ca, Cu, Ni, Zn, and Y = Al, Fe). The catalysts were characterized by XRD, nitrogen adsorption−desorption isotherms and FTIR. The performance of these catalysts toward the decomposition of hexachlorobenzene (HCB) and octachlorodibenzo-p-dioxin (OCDD) was evaluated in a closed system. The spinel-type catalyst with mesoporous structure demonstrated high catalytic activity for the hydrodechlorination of polychlorinated aromatic compounds. Among them, the copper−aluminum spinel (CuAl2O4), specifically calcined at 600 °C, exhibited the best activity. More than 85% dechlorination efficiency of HCB and 99% decomposition of polychlorinated dibenzodioxin (PCDD) were achieved at 250 °C for 30 min over the above catalyst which was more effective than the corresponding metallic copper and copper oxide catalysts during the thermal degradation of polychlorinated aromatic compounds. The correlation of catalytic performance to structural characteristics is discussed based on the detailed characterization. The simple preparation procedure and reasonable cost of the spinel-type catalysts present a good potential for the thermal treatment of polychlorinated aromatic pollutants at lower temperatures.
Co-reporter:Jing Jin;Zhiping Zhang;Jincheng Wang;Peipei Qi
Journal of Separation Science 2010 Volume 33( Issue 12) pp:1836-1841
Publication Date(Web):
DOI:10.1002/jssc.200900786
Abstract
Magnesium oxide microspheres were developed as a novel SPE sorbent for the determination of benzo[a]pyrene (BaP), one of the most potent carcinogenic agents, in environmental water samples. The parameters controlling the extraction efficiency, such as elution volume, flow rate, pH values, and breakthrough volume, were investigated in detail. Considering the facile preparation and satisfying recovery, a corresponding analytical method has been developed to determine the concentration of BaP in real tap water, river water, and seawater. The recoveries for the spiked BaP were excellent (94–101%).
Co-reporter:Hai-Yan ZHU, Xian-Bo LU, Yu-Zeng TIAN, Ji-Ping CHEN
Chinese Journal of Analytical Chemistry 2010 Volume 38(Issue 7) pp:1003-1006
Publication Date(Web):July 2010
DOI:10.1016/S1872-2040(09)60056-6
Co-reporter:Peipei Qi, Jincheng Wang, Liandi Wang, Yun Li, Jing Jin, Fan Su, Yuzeng Tian, Jiping Chen
Polymer 2010 Volume 51(Issue 23) pp:5417-5423
Publication Date(Web):29 October 2010
DOI:10.1016/j.polymer.2010.09.037
Semi-covalent imprinting with carbonyl group as sacrificial spacer was employed to synthesize molecularly imprinted polymer (MIP) for phenols. A series of semi-covalently imprinted polymers were prepared by varying the templates and porogens. The MIP with 4-chlorophenyl (4-vinyl)phenyl carbonate as template was proved to be the best one, with ethylene glycol dimethacrylate (EGDMA) as cross-linker, 2,2-azobisisobutyronitrile(AIBN), and chloroform as initiator and porogen, respectively. Under such conditions, the corresponding non-covalently imprinted polymer was fabricated with 4-chlorophenol (4-CP) as template and 4-vinylpyridine (4-VP) as functional monomer. The polymer prepared by semi-covalent imprinting displayed superior selectivity to the non-covalently imprinted polymer for phenols. The peak broadening and tailing had been largely reduced on the column packed with semi-covalently imprinted polymer. Meanwhile, the constant retention for these phenols and the good linearity for phenol and 4-CP augured that the semi-covalently imprinted polymer had the potential application as stationary phase for quantitative determination of phenols.
Co-reporter:Peipei Qi, Jincheng Wang, Jing Jin, Fan Su, Jiping Chen
Talanta 2010 Volume 81(4–5) pp:1630-1635
Publication Date(Web):15 June 2010
DOI:10.1016/j.talanta.2010.03.015
A molecularly imprinted polymer (MIP) was prepared using 2,4-dimethylphenol (2,4-DMP) as template. The synthesis is optimized by using three different porogens, chloroform, acetonitrile and toluene. The MIP was used as a class-selective sorbent in molecularly imprinted solid-phase extraction (MIP-SPE) for pre-concentration and determination of phenolic compounds from the environmental water. The difference in recognition selectivity of the polymer columns was observed in HPLC system. The variables affecting the extraction efficiency of MIP-SPE procedure were systematically investigated to facilitate the class-selective extraction of phenols from spiked water samples. The spiked aqueous solution was adjusted to pH 6.0 before being percolated through the MIP-SPE cartridge at the flow rate of 0.5 mL min−1. After rinsing with dichloromethane, the bound phenolic compounds were desorbed with acetonitrile containing 5% aqueous ammonia. The developed MIP-SPE method was demonstrated to be applicable to the analysis of phenolic compounds in the environmental water.
Co-reporter:Xianbo Lu, Yi Xiao, Zhibin Lei, Jiping Chen, Haijun Zhang, Yuwen Ni and Qing Zhang
Journal of Materials Chemistry A 2009 vol. 19(Issue 27) pp:4707-4714
Publication Date(Web):20 May 2009
DOI:10.1039/B903179K
Three dimensional ordered graphitized mesoporous carbon GMC-6 (pore diameter ∼6 nm) and GMC-13 (pore diameter ∼13 nm), prepared by a nickel-catalyzed template-assisted method, were explored systematically for the construction of enzyme-based electrochemical biosensors. Comparative studies revealed that GMC-6 offer significant advantages over GMC-13 and graphitized multiwalled carbon nanotubes (CNTs) in facilitating the direct electron transfer of entrapped hemoglobin and improving the performance of fabricated biosensors. The possible factors that affect the biosensing performance of these carbon materials were evaluated comprehensively and comparatively based on the characterization of their physical parameters. The biosensor based on GMC-6 displayed excellent analytical performance over a wide linear range along with good stability and selectivity for the detection of hydrogen peroxide. The “entrapment” immobilization mode and “interspace confinement effect” (by restraining the unfolding or conformational change of enzyme molecules from inactivation) provided by GMC can result in pore-size-dependent enzymatic stability and bioactivity, which might be a crucial factor for the superior biosensing performance of GMC-6 to that of CNTs and GMC-13. Graphitized ordered mesoporous carbons with good pore size matching for enzymes proved to be a promising electrochemical biosensing platform.
Co-reporter:Jing Jin, Zhiping Zhang, Huilian Ma, Xianbo Lu, Jiping Chen, Qing Zhang, Haijun Zhang, Yuwen Ni
Materials Letters 2009 Volume 63(Issue 17) pp:1514-1516
Publication Date(Web):15 July 2009
DOI:10.1016/j.matlet.2009.04.003
The surface of spherical magnesium oxide has been modified with ethylene glycol in the presence of basic aqueous solution. Fourier transform infrared spectra have shown the presence of the graft group ethylene glycol on the surface of spherical magnesium oxide. In addition, this conclusion can also be drawn from appearance of new diffraction peak in X-ray diffraction pattern. Although magnesium oxide microspheres can directly react with ethylene glycol in 373 K for 24 h, owing to Lewis acid and alkali interaction, product derived is colloidal and difficult to filter so that their morphology is easy to be destroyed. However, in the presence of basic aqueous solution, their morphology still retains. The modified magnesium oxide illustrates a specific surface area of 55.9 m2/g and a narrow pore size distribution centered at 8.96 nm.
Co-reporter:Xianbo Lu, Yi Xiao, Zhibin Lei, Jiping Chen
Biosensors and Bioelectronics 2009 Volume 25(Issue 1) pp:244-247
Publication Date(Web):15 September 2009
DOI:10.1016/j.bios.2009.06.018
A novel graphitized ordered macroporous carbon (GMC, pore size ∼380 nm) with hierarchical mesopores (2–30 nm) and high graphitization degree was prepared by nickel-catalyzed graphitization of polystyrene arrays. The obtained GMC possessed high specific surface area, large pore volume, and good electrical conductivity, which was explored for the enzyme entrapment and biosensor fabrication by a facile method. With advantages of novel nanostructure and good electrical conductivity, direct electrochemistry of hemoglobin (a model protein) was observed on the GMC-based biocomposite with a formal potential of −0.36 V (vs. Ag/AgCl) and an apparent heterogeneous electron transfer rate constant (ks) of 1.2 s−1 in pH 7.0 buffer. Comparative studies revealed that GMC offered significant advantages over carbon nanotubes (CNTs) in facilitating direct electron transfer of entrapped Hb. The fabricated biosensor exhibited good sensitivity (101.6 mA cm−2 M−1) and reproducibility, wide linear range (1–267 μM), low detection limit (0.1 μM), and good long-term stability for H2O2 detection. GMC proved to be a promising matrix for enzyme entrapment and biosensor fabrication, and may find wide potential applications in biomedical detection and environmental analyses.
Co-reporter:Xiumei Sun;Jixiu Zhang;Haijun Zhang;Qing Zhang
Water, Air, & Soil Pollution 2009 Volume 200( Issue 1-4) pp:
Publication Date(Web):2009 June
DOI:10.1007/s11270-008-9897-3
The influence of cadmium on growth, cadmium accumulation, composition, and content of glucosinolates was investigated in Arabidopsis thaliana after 4 weeks of growth in hydroponics. Accumulation of 3,820 and 321 μg Cd g−1 dry weight in the roots and leaves of A. thaliana, respectively, exposed to 50 μM Cd. Cadmium treatment significantly decreased the total concentration of glucosinolates both in the leaves and roots. Cd-induced alteration of total glucosinolate content in the roots was mainly due to the decrease of indolyl-glucosinolates. In the Cd treatment leaves, significant decreases were, respectively, detected for glucoibervirin and 4-methoxyglucobrassicin (P < 0.01), while other glucosinolate levels did not decrease significantly. In response to cadmium, the three indolyl-glucosinolates all showed significant decreases in the roots. The distinctive influence of cadmium on glucosinolate profiles in Cd-sensitive A. thaliana may be of great ecological importance, decreasing the resistance to phytophage attack. Taken together, our data is discussed in relation to jasmonic acid and salicylic acid as possible molecules that modulate the alteration of glucosinolate profiles in response to cadmium. The similar effects of Cd treatment on the levels of individual glucosinolates in leaves and roots were observed at higher-concentration cadmium treatment (100 μM Cd).
Co-reporter:Feng Zhang, Jiping Chen, Haijun Zhang, Yuwen Ni, Qing Zhang, Xinmiao Liang
Separation and Purification Technology 2008 Volume 59(Issue 2) pp:164-168
Publication Date(Web):15 February 2008
DOI:10.1016/j.seppur.2007.06.016
Dechlorinations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (co-PCBs) were carried out in ethanol–water solution of NaOH in the presence of Pd/C catalyst with using of H2. The dechlorination of octachlorodibenzo-p-furan (OCDF) proceeded with Pd/C under mild conditions (atmospheric pressure and <100 °C) to give a chlorine-free product, dibenzo-p-furan (DF), in high yield. After a reaction of 3 h at 50 °C, 98.8% of OCDF was degraded and the yield of DF was 85.2%. PCDD/Fs and co-PCBs extract from fly ash of commercial solid-waste incinerator was degraded in this catalytic system at 50 °C for 6 h. Pd/C exhibited excellent reaction activity in this catalytic system. In the dechlorination of environmental sample, the concentrations of toxic congeners and TEQ decreased to a promising level.
Co-reporter:Z. Zhang;Y. Zheng;J. Chen;Q. Zhang;Y. Ni;X. Liang
Advanced Functional Materials 2007 Volume 17(Issue 14) pp:
Publication Date(Web):7 AUG 2007
DOI:10.1002/adfm.200600906
Low-cost, uniform, and monodisperse spherical particles are desirable for a variety of applications. We report the realization of uniform spherical magnesium oxide with a diameter of 10.5 μm and specific surface area of 140.9 m2 g–1 resulting from a facile seed-induced precipitation in the presence of a trace amount of phosphate species. By optimizing the experimental parameters, the results demonstrate that the morphologies of magnesium oxide precursors are very sensitive to the amount and the sequence of addition of Mg5(CO3)4(OH)2 · 4H2O seeds, as well as the amount and type of phosphate species. These particles have also been used as a packing material for high performance liquid chromatography. In comparison with the commercial spherical silica, as-synthesized spherical magnesium oxide exhibits excellent efficiency in the separation of polycyclic aromatic hydrocarbons, and has a larger retention to planar compounds in contrast to non-planar ones. It is believed that this method will provide a simple and versatile approach to large-scale production of spherical magnesium oxide via a facile seed-induced mechanism. The spherical magnesium oxide may find widespread use as a packing material in the group separation of polycylic aromatic hydrocarbons from target samples.
Co-reporter:Zhiping Zhang, Yajun Zheng, Jixiu Zhang, Jiping Chen, Xinmiao Liang
Journal of Chromatography A 2007 Volume 1165(1–2) pp:116-121
Publication Date(Web):21 September 2007
DOI:10.1016/j.chroma.2007.07.072
Uniform monodisperse magnesium oxide microspheres with a high surface area have been prepared by a facile seed-induced precipitation. By characterizing these particles with scanning electron microscopy and N2 physisorption techniques, the results demonstrate that these magnesium oxide microspheres have an average particle diameter of 9.5 μm, a specific surface area of 211.7 m2 g−1, a total pore volume of 0.76 mL g−1, and an average pore diameter of 143 Å. The chromatographic properties of these microspheres have been investigated in normal-phase mode for the separation of various basic compounds including aniline, quinoline, and pyridine derivatives. In contrast to conventional silica, the magnesium oxide particles exhibit unique selectivity and retention property for the separation of the tested basic compounds, and these microspheres are promising as an alternative new packing material for high-performance liquid chromatography.
Co-reporter:Yu Wanying, Zhang Hua, Huang Weidong, Chen Jiping, Liang Xinmiao
Talanta 2005 Volume 65(Issue 1) pp:172-178
Publication Date(Web):15 January 2005
DOI:10.1016/j.talanta.2004.06.016
The confirmation and identification of the impurities in metolachlor (a herbicde) by using gas chromatography-orthogonal acceleration time of flight mass spectrometry (GC-oaTOFMS) and gas chromatography-quadrupole mass spectrometry (GC-qMS) are described. For the accurate mass measurement can be carried by GC-oaTOFMS, the elemental compositions of molecular and fragment ions in the spectra are suggested. In the experiment the average of mass deviations between the measured and theoretical values was below 2.5 mDa. Finally ten impurities were confirmed and identified. They accounted for 94% of the total impurities by weight.
Co-reporter:Shengye Jin, Zhaochao Xu, Jiping Chen, Xinmiao Liang, Yongning Wu, Xuhong Qian
Analytica Chimica Acta 2004 Volume 523(Issue 1) pp:117-123
Publication Date(Web):4 October 2004
DOI:10.1016/j.aca.2004.05.030
A flow injection system for the determination of organophosphate and carbamate pesticides is described. A sensitive fluorescence probe was synthesized and used as the pH indicator to detect the inhibition of the enzyme acetylcholinesterase (AChE). The percentage inhibition of enzyme activity is correlated to the pesticide concentration. Several parameters influencing the performance of the system are discussed. The detection limits of 3.5, 50, 12 and 25 μg/l for carbofuran, carbaryl, paraoxon and dichlorvos, in pure water, respectively were achieved with an incubation time of 10 min. A complete cycle of analysis, including incubation time, took 14 min. The detection system has been applied to the determination of carbofuran in spiked vegetable juices (Chinese cabbage and cole), achieving recovery values between 93.2 and 107% for Chinese cabbage juice and 108 and 118% for cole juice at the different concentration levels assayed.
Co-reporter:Fang Li, Jing Jin, Dongqin Tan, Longxing Wang, ... Jiping Chen
Journal of Environmental Sciences (October 2016) Volume 48() pp:209-217
Publication Date(Web):1 October 2016
DOI:10.1016/j.jes.2016.03.018
Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are two kinds of brominated flame retardants and widely present in the environment and biota. The levels, spatial distributions and mass inventories of HBCD and TBBPA were investigated in sediments and paddy soils from the Liaohe River Basin in northeast China. The concentrations of ΣHBCD and TBBPA were in the range of not detected (nd) to 4.02 ng/g dry weight (dw) and 0.03 to 4.06 ng/g dw, respectively. γ-HBCD was dominated in sediments, while the abundance of α-HBCD was relatively high in paddy soils. The spatial distributions of HBCD and TBBPA in surface sediments and paddy soils indicated that the local point-input was their major source. The significant correlation between total organic carbon (TOC) contents and the HBCD levels suggested that TOC content also exerted an influence on the distribution of HBCD in sediments. Meanwhile, it was found that the irrigation with river water was not the major transportation pathway of HBCD and TBBPA in paddy soils. Based on the study, it was estimated that there were about 1.67 tons HBCD and 2.20 tons TBBPA deposited into sediments of the Liaohe River system every year. The total mass inventories of HBCD and TBBPA in sediments were far higher than that in paddy soils.Download high-res image (189KB)Download full-size image
Co-reporter:Pengjun Xu, Bu Tao, Zhiqiang Ye, Hu Zhao, ... Jiping Chen
Journal of Environmental Sciences (October 2016) Volume 48() pp:102-111
Publication Date(Web):1 October 2016
DOI:10.1016/j.jes.2015.11.035
The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) were measured in 23 farmland soil samples and 10 riverine sediment samples from Guiyu, China, and the carcinogenic risks associated with PAHs in the samples were evaluated. Guiyu is the largest electronic waste (EW) dismantling area globally, and has been well known for the primitive and crude manner in which EWs are disposed, such as by open burning and roasting. The total PAH concentrations were 56–567 ng/g in the soils and 181–3034 ng/g in the sediments. The Shanglian and Huamei districts were found to be more contaminated with PAHs than the north of Guiyu. The soils were relatively weakly contaminated but the sediments were more contaminated, and sediments in some river sections might cause carcinogenic risks to the groundwater system. The PAHs in the soils were derived from combustion sources, but the PAHs in the sediments were derived from both combustion and petroleum sources.Download high-res image (565KB)Download full-size image
Co-reporter:Hongcai Gao, Yuwen Ni, Haijun Zhang, Liang Zhao, Ning Zhang, Xueping Zhang, Qing Zhang, Jiping Chen
Chemosphere (October 2009) Volume 77(Issue 5) pp:634-639
Publication Date(Web):1 October 2009
DOI:10.1016/j.chemosphere.2009.08.017
Stack gas samples from 14 domestic-made hospital waste incinerators (HWIs) in China were collected and analyzed for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The waste burning capacities of the investigated HWIs ranged from 5 to 25 ton d−1. The stack gas emissions of PCDD/Fs from HWIs exhibited a large variation (0.08–31.60 ng I-TEQ N m−3). Nine incinerators had the emission levels below the current emission standard in China (0.5 ng I-TEQ N m−3), while only two facilities exhibited emission levels below the European Union directive emission limit (0.1 ng I-TEQ N m−3). For two plants, concentrations of PCDD/Fs in stack gas were above 10.0 ng I-TEQ N m−3. The emission factors of PCDD/Fs from the investigated HWIs were in the range of 0.78–473.97 μg I-TEQ ton−1 medical wastes. It was estimated that 4.87 g I-TEQ of PCDD/Fs was annually released from HWIs to the atmosphere in China in 2006. Principal component analysis and hierarchical cluster analysis were applied to analyze the congener profiles of PCDD/Fs from HWIs in China.
Co-reporter:Haijun Zhang, Yuwen Ni, Jiping Chen, Fan Su, Xianbo Lu, Liang Zhao, Qing Zhang, Xueping Zhang
Chemosphere (November 2008) Volume 73(Issue 10) pp:1640-1648
Publication Date(Web):1 November 2008
DOI:10.1016/j.chemosphere.2008.07.067
Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F) were analyzed in surface sediments and top soils collected from 30 sites in Daliao River Basin. The concentrations of PCDD/F ranged from 0.28 to 29.01 ng TEQ kg−1 dw (mean value, 7.45 ng TEQ kg−1 dw) in sediments, and from 0.31 to 53.05 ng TEQ kg−1 dw (mean value, 7.00 ng TEQ kg−1 dw) in soils. PCDD/F pollution in sediments from the mid- and downstream sections of Hun River was found to be relatively heavy, and the levels of PCDD/F contamination in paddy soils were generally higher than those of upland soils. Using multivariate statistical analysis, the PCDD/F homologue and congener profiles of all soil and sediment samples were compared with those of suspected PCDD/F sources. The results showed that, PCDD/F contamination in most sediments of Hun River should mainly originated from the production of organochlorine chemicals, while metal smelting was the important potential source of PCDD/F in the drainage area of Taizi River. PCDD/F contamination in paddy soils should be simultaneously attributed to the polluted water irrigation and the organochlorine pesticide application.
Co-reporter:Xindong Ma, Haijun Zhang, Hongqiang Zhou, Guangshui Na, Zhen Wang, Chen Chen, Jingwen Chen, Jiping Chen
Atmospheric Environment (June 2014) Volume 90() pp:10-15
Publication Date(Web):June 2014
DOI:10.1016/j.atmosenv.2014.03.021
Co-reporter:Haijun Zhang, Jiping Chen, Yuwen Ni, Qing Zhang, Liang Zhao
Chemosphere (August 2009) Volume 76(Issue 6) pp:740-746
Publication Date(Web):1 August 2009
DOI:10.1016/j.chemosphere.2009.05.030
Root uptake and subsequent translocation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in 12 agricultural crops were comparatively investigated. All crop plants were exposed hydroponically to a mixture of three kinds of dioxin congeners over 4 d. The root concentration factor (RCF) of dioxin showed a logarithmic correlation with extractable lipid content in plant root. On the assumption that the dioxin escaping via gas phase from nutrient solution in the closed container can evenly diffuse in the air and equally absorb onto the shoot tissues of the dioxin-exposed plant and their nearby blank control plant, the amount of translocated dioxin was estimated by subtracting dioxin content in the shoot tissues of the blank control plant from that of the dioxin-exposed plant, and then the transpiration stream concentration factor (TSCF) of dioxin was calculated. The TSCF values of PCDD/Fs largely varied according to the plant species, and the TSCF values of 2,4,8-TrCDF were a little higher than those for 1,3,6,8-TeCDD expect for zucchini. For 1,3,6,8-TeCDD, zucchini had the highest TSCF value of 0.0089, followed by pumpkin (0.0064) towel gourd (0.0027), and cucumber (0.0010), verifying plants of the genus Cucurbita have the higher abilities of dioxin translocation. The TSCF values of 1,3,6,8-TeCDD for wheat and sorghum were 0.0013 and 0.0012, respectively. For maize, soybean, rice, Chinese cabbage, tomato and garland chrysanthemum, translocation was an insignificant mechanism of dioxin contamination in shoot tissues.
Co-reporter:Dongqin Tan, Jing Jin, Fang Li, Xiaoli Sun, Dhanjai, Yuwen Ni, Jiping Chen
Analytica Chimica Acta (1 March 2017) Volume 956() pp:
Publication Date(Web):1 March 2017
DOI:10.1016/j.aca.2016.12.040
•Phenyltrichlorosilane modified magnesium oxide microsphere (PTS-MgO) was presented.•PTS-MgO was used for a new sorbent material in matrix solid-phase dispersion.•The sorbent showed high selectivity for DL-PAHs with satisfactory recoveries obtained.•The method was applied to the extraction of dioxin-like PAHs from soil samples.Magnesium oxide microspheres functionalized with phenyltrichlorosilane (PTS-MgO) were synthesized by surface modification through silanization reaction, which was confirmed by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetry analysis (TGA) and N2 adsorption-desorption. The result indicated that PTS-MgO not only possessed the ability of enhancing the retention with PAHs, but also weakening the interference from chlorinated compounds. As a sorbent for the matrix solid-phase dispersion (MSPD) extraction, PTS-MgO was used to selectively extract seven dioxin-like polycyclic aromatic hydrocarbons (DL-PAHs) from soil samples. Various parameters affecting the recoveries of seven DL-PAHs were investigated and optimized, such as sorbent/sample mass ratio, grinding time, rinsing and eluting conditions. Under the optimized conditions, the developed method combining MSPD with HPLC-FLD exhibited good sensitivity (0.02–0.12 ng g−1 detection of limits) and linearity (linear correlation coefficient greater than 0.9997). Satisfactory recoveries with DL-PAHs spiked at two levels (10 and 80 ng g−1) were obtained in the range of 72.2–113.1% with RSD < 9.6%, indicating that PTS-MgO had a potential in MSPD extraction of DL-PAHs in soils. Additionally, the proposed MSPD-HPLC-FLD method was also verified by detecting seven DL-PAHs in the standard reference soil. Based on the developed method, DL-PAHs in soil samples were detected with the concentration ranging from 70.08 to 555.05 ng g−1 dry weight (dw). The total toxic equivalency quotients (TEQ) of seven DL-PAHs varied from 9.93 to 143.94 ng TEQ/g dw.
Co-reporter:Xianbo Lu, Yi Xiao, Zhibin Lei, Jiping Chen, Haijun Zhang, Yuwen Ni and Qing Zhang
Journal of Materials Chemistry A 2009 - vol. 19(Issue 27) pp:NaN4714-4714
Publication Date(Web):2009/05/20
DOI:10.1039/B903179K
Three dimensional ordered graphitized mesoporous carbon GMC-6 (pore diameter ∼6 nm) and GMC-13 (pore diameter ∼13 nm), prepared by a nickel-catalyzed template-assisted method, were explored systematically for the construction of enzyme-based electrochemical biosensors. Comparative studies revealed that GMC-6 offer significant advantages over GMC-13 and graphitized multiwalled carbon nanotubes (CNTs) in facilitating the direct electron transfer of entrapped hemoglobin and improving the performance of fabricated biosensors. The possible factors that affect the biosensing performance of these carbon materials were evaluated comprehensively and comparatively based on the characterization of their physical parameters. The biosensor based on GMC-6 displayed excellent analytical performance over a wide linear range along with good stability and selectivity for the detection of hydrogen peroxide. The “entrapment” immobilization mode and “interspace confinement effect” (by restraining the unfolding or conformational change of enzyme molecules from inactivation) provided by GMC can result in pore-size-dependent enzymatic stability and bioactivity, which might be a crucial factor for the superior biosensing performance of GMC-6 to that of CNTs and GMC-13. Graphitized ordered mesoporous carbons with good pore size matching for enzymes proved to be a promising electrochemical biosensing platform.
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