Co-reporter:Shuli Zhang, Jingcong Zhuang, Guijuan Yue, Yiping Wang, Mingyu Liu, Bing Zhang, Zhenxia Du, Qun Ma
Journal of Chromatography B 2017 Volume 1060(Volume 1060) pp:
Publication Date(Web):15 August 2017
DOI:10.1016/j.jchromb.2017.06.037
•UPLC-Q-TOF/MS combined with statistical analysis approach was developed to investigate the pharmacologic mechanisms of ginkgo folium in the treatment of hyperuricemia rat model.•13 lipid metabolites significantly reversed after intervened by ginkgo folium treatment, which mainly involved in glycerophospholipid metabolism.•Ginkgo filum might inhibit the activity of PLA2 to lower uric acid.Hyperuricemia caused by purine metabolic abnormalities is reported to have close correlation with lipid metabolic disorders. Ginkgo folium, a frequently-used lipid-lowering medicine, has significant anti-hyperuricemia effects. However, it is poorly known about the interaction between lowering uric acid and regulation of lipid metabolic disorders. In this study, hyperuricemic rat model was induced by orally administration with fructose. Ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with pattern recognition approaches were used to determine different lipid metabolites in serum of control group, model group, and different doses of ginkgo folium groups. Principal component analysis (PCA) was applied to analyze the MS data to assess the establishment of model, partial least squares-discriminate analysis (PLS-DA) and independent samples T-test were performed to indicate the differences between different groups of rats and to find biomarkers. Metabolomics pathway analysis (MetPA) was introduced to reveal the pharmacologic mechanisms of ginkgo folium. 19 potential biomarkers associated with hyperuricemia were found. After intervened by ginkgo folium, these biomarkers were returning to normal level. Among these biomarkers, 13 lipid biomarkers were significantly reversed. Ginkgo filum can lower uric acid via adjusting back the level of PCs and LPCs, which suggested that its treatment mechanisms may be related to reducing the activity of PLA2. In sum, the lipidomics analysis in the system level have enhanced our understanding to pathogenesis of hyperuricemia and the results suggested that ginkgo folium could alleviate the abnormal metabolic status of hyperuricemia. These results demonstrated a new mechanism for lowering uric acid, which was helpful to the early treatment for hyperuricemia.
Co-reporter:Jianfeng Wang;Xiaojing Fan;Yan Liu;Yuechao Feng;Li Jia;Jinghua Zhang
Analytical Methods (2009-Present) 2017 vol. 9(Issue 8) pp:1282-1289
Publication Date(Web):2017/02/23
DOI:10.1039/C6AY03444F
A method employing a type of filtered solid phase extraction based on the PRiME hydrophilic lipophilic balance (HLB) was developed for extracting cephalosporin compounds (cephalexin monohydrate, cefradine, cefazolin, cefotaxime, cefmenoxime, cefoperazone sodium, cefadroxil, cefpirome sulfate, cefquinome sulfate, cefaclor, ceftizoxime, cephalonium, cephalothin sodium, cefamandole lithium, cefathiamidine, cefetamet pivoxyl) from milk samples. Compared to conventional HLB extraction, the PRiME HLB SPE process consists of only one step without activation, elution. It shows the advantage of a faster and better purifying capacity. Ultra-high pressure liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was used for detection. In order to obtain high recoveries of the analytes, several parameters were optimized, such as variation of the extraction solvents, and the volume of the extraction solvent and dripping washing solution. With an optimized sample preparation, the limit of detection (LOD) and limit of quantification (LOQ) for the multi-reaction-monitoring (MRM) mode of the method varied from 0.02 to 5 μg kg−1, and 0.02 to 10 μg kg−1, respectively. Due to the different sensitivities of the analytes, the calibration curves were linear with R2 ≥ 0.991 in their linear ranges. The relative recoveries from the milk samples were between 56% and 93% with relative standard deviations lower than 15%.
Co-reporter:Yun Zhang, Shuqi Sun, Xuebin Xing, Zhenxia Du, Qiaozhen Guo, and Wenlian Yu
Analytical Chemistry 2016 Volume 88(Issue 13) pp:6749
Publication Date(Web):June 3, 2016
DOI:10.1021/acs.analchem.6b01027
The direct contact of plastic parts with the medical products raises the possibility that plastic-related contaminants (leachables) may be present in the finished medical product. The leachable components from plastic materials may impact the safety and efficacy of the final medical product, so identification and determination of the leachables are essential for the safety assessment of medical products. A method to identify main leachables-polymer additives in medical products was developed by ultraperformance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UPLC-QTOF MS) and a self-built library. The library contains 174 additives and the information on their names, formulas, structures, retention times, fragments, classifications, origin, and corresponding MSE and MSMS spectra. The reliability of the construction process of the library was guaranteed by the system stability and suitability test. Identification parameters of library application, such as mass error, retention times, fragments, and isotope pattern, were evaluated. Leachables in real vaccine and the intermediates were identified using automatic library searching. In vaccine, the peak m/z 239.0887 that could not be assigned by the library was identified as dimethyl 2-hydroxy-1,3-cyclohexanedicarboxylate using a series of elucidation tools. As a result, the concentrations of leachables in vaccine and the intermediates ranged from 0.85 to 21.91 μg/L.
Co-reporter:Jinheng Pan, Yu Ji, Zhenxia Du, Jianwen Zhang
Journal of Chromatography A 2016 Volume 1465() pp:190-196
Publication Date(Web):23 September 2016
DOI:10.1016/j.chroma.2016.08.051
•Novel and efficient UHPSFC-QTOF-MS method was developed to characterize the polysorbate 80.•UHPSFC-QTOF-MS could distinguish n-mer from (n − 1)-mer and (n + 1)-mer, which provided the high separation resolution needed for quantifying each oligomer in the same series.•The characteristic ion fragments were found in MS/MS experiment and used to identify different series.•The relationship between molecular structure of different oligomers and retention behavior in supercritical fluid chromatography were investigated.Polysorbate 80, as a nonionic surfactant, is widely used in the food, personal care, and pharmaceutical industries due to the advantages of high surface activity, low toxicity, etc. In fact, the products of polysorbate 80 are complex mixtures of oligomers. In this work, a novel and fast method was developed to characterize the commercial polysorbate 80 by ultra-high performance supercritical fluid chromatography (UHPSFC) combined with quadrupole time-of-flight mass spectrometry (QTOF-MS). Some crucial parameters, such as temperature, back pressure and flow rate were optimized. UHPSFC could distinguish n-mer from (n − 1)-mer and (n + 1)-mer in the same series, which provided the high separation resolution needed for quantitative determination of each oligomer in same series. It was not achieved in previous studies. Furthermore, the characteristic ion fragments were found in MS/MS experiment and used to identify different series. The results revealed that main components of this nonionic surfactant comprise polyethylene oxide (PEO), PEO-monooleate, PEO-isosorbide, PEO-isosorbide monooleate, PEO-isosorbide dioleate, PEO-sorbitan, PEO-sorbitan monooleate, PEO-sorbitan dioleate and PEO-sorbitan trioleate, etc. The separation was performed using BEH stationary phase, so the relationship between molecular structure of these oligomers and chromatographic retention behavior in supercritical fluid chromatography were also investigated for first time. The whole analytical process only takes 8 min for one sample. Therefore, UHPSFC-QTOF-MS is a simple, novel and efficient tool to analyze polysorbate 80.
Co-reporter:Yun Zhang;Zhiyong Xiao;Surong Lv;Xiaoxia Liu
Journal of Separation Science 2016 Volume 39( Issue 5) pp:993-999
Publication Date(Web):
DOI:10.1002/jssc.201500823
A new fast and effective analysis method has been developed to simultaneously determine 16 polycyclic aromatic hydrocarbons in reclaimed water samples by ultra-performance convergence chromatography with photodiode array detection and solid-phase extraction. The parameters of ultra-performance convergence chromatography on the separation behaviors and the crucial condition of solid-phase extraction were investigated systematically. Under optimal conditions, the 16 polycyclic aromatic hydrocarbons could be separated within 4 min. The limits of detection and quantification were in the range of 0.4–4 and 1–10 μg/L in water, respectively. This approach has been applied to a real industrial wastewater treatment plant successfully. The results showed that polycyclic aromatic hydrocarbons were dramatically decreased after chemical treatment procedure, and the oxidation procedure was effective to remove trace polycyclic aromatic hydrocarbons.
Co-reporter:Anqi Tu, Zhenxia Du and Shuping Qu
Analytical Methods 2016 vol. 8(Issue 21) pp:4226-4238
Publication Date(Web):26 Apr 2016
DOI:10.1039/C6AY00970K
Triacylglycerol (TAG) as the major ingredient of oil is a key indicator for the identification of oil adulteration due to its characteristic distributions in different oils. In this research, a high-throughput method for rapidly detecting acylglycerols in various edible oils was established by applying supercritical fluid chromatography (SFC) coupled with quadruple time-of-flight mass spectrometry (Q-TOF-MS), without any sample pretreatment procedure. The retention mechanism of TAGs on different columns were comprehensively evaluated including the previous work on an ODS column, as well as our study on HSS C18SB, BEH and BEH 2-EP columns. Distinctive retention of our method allows the separation of certain pairs of TAGs which remains difficult by traditional methods, and the analysis time is greatly reduced. SFC-MS data were subsequently analysed by principal component analysis (PCA) to make a clear classification between six different kinds of vegetable oils, showing its potential in differentiating the fakes quickly. Considering the high-price of olive oil, further quantification of olive oil adulteration was studied by estimating known and unknown compositions of blend oils according to the curves of areas of selected TAG markers versus adulterant concentrations. Good consistencies with the labeled content of olive oil in commercial blend oils demonstrated the reliability of the quantitative method, and these blend oils were differentiated distinctly from pure olive oils in the score plot of a PCA model. To the best of our knowledge, it was the first time that the retention of TAGs using different stationary phases in a SFC system was discussed, and that SFC was applied to quantify oil adulteration. This fast and effective method is of great advantage to authenticate edible oils.
Co-reporter:Yun Zhang, Zhenxia Du, Xueming Xia, Qiaozhen Guo, Huijie Wu, Wenlian Yu
Polymer Testing 2016 Volume 53() pp:276-282
Publication Date(Web):August 2016
DOI:10.1016/j.polymertesting.2016.06.008
UV-ink photoinitiators (PIs), which are used to initiate polymerization reaction for the curing of inks and lacquers, have become a kind of contaminant residues in printing plastic food packaging. The residual PIs in packaging may pose a potential threat to customers. In this work, migration behaviors of 13 PIs from a polyethylene (PE) packaging to food simulants according to regulation EU No 10/2011 were studied by supercritical fluid chromatography combined with photodiode array detector and tandem mass spectrometry (SFC-PDA-MS/MS). The method simultaneously analyzed 13 PIs within 4.5 min and was sensitively with low limits of detection of 0.02–2.16 μg/L, which could meet high throughput analysis for control the quality of food packaging. The migration results revealed that Irgacure 819, Darocure 1173 and TPO, which had low migration rates, should be preferably selected by plastic food packaging manufacture for food safety.
Co-reporter:Jingcong Zhuang, Xiaohu Tang, Zhenxia Du, Ming Yang, Ying Zhou
Talanta 2016 Volume 160() pp:636-644
Publication Date(Web):1 November 2016
DOI:10.1016/j.talanta.2016.08.007
•Biomarkers were found out to indicate what kind of lung cancer patients who is suitable for treating with gefitinib.•19 biomarkers were statistically significant predictors of PFS.•Cox regression analysis was employed to get rid of the influences of individual differencesLung carcinoma is one of the most frequently diagnosed malignancy and threats human life and health. In clinical practice, gefitinib, one of the most well-known epidermal growth factor receptor tyrosine kinase inhibitors, was frequently used in the treatment of non-small cell lung carcinoma. However, this drug is not useful for all non-small cell patients. In this study, the biomarkers were found out to predict the therapeutic effects of gefitinib for lung carcinoma patients. Serum samples were collected from patients with advanced lung adenocarcinoma. The ultra-high performance liquid chromatography (UHPLC)-quadrupole-time of flight mass spectrometry (Q-TOF MS) was conducted to obtain the metabolic data for each patient. Partial least squares-discriminate analysis (PLS-DA) was performed to indicate the differences between metabolites of patients, and Cox proportional hazards regression analysis was used to eliminate the interference of the patient’s gender, age, smoking history and disease stage. Thus, differential biomarkers were found. The combination of these biomarkers was statistically significant predictors based on progression-free survival. If these biomarkers can be further confirmed by the clinic, it could suggest the proper therapeutic schedule, and help to reduce patients’ economic burden and medication side effects.
Co-reporter:Yiping Wang, Zhenxia Du, Yun Zhang, Lili Zhou and Wenlian Yu
Analytical Methods 2015 vol. 7(Issue 23) pp:9861-9866
Publication Date(Web):26 Oct 2015
DOI:10.1039/C5AY02077H
A rapid, effective and eco-friendly method for determination of eight organophosphate esters in plastic samples from car interiors by microwave assisted extraction followed by ultra-high performance liquid chromatography combined with tandem mass spectrometry was established. Acetone/ethyl acetate (3/1, v/v) was used as extractant. Response surface methodology was applied as the experimental design strategy to screen and optimize the extraction variables which affected the extraction efficiency, such as the volume of the extraction solvent, the time for extraction, and the temperature of extraction. Baseline separation of eight OPEs was achieved in 4.5 minutes. The method showed excellent linearity 1–250 μg L−1 for TBEP, TCP, and DPOP; 2–500 μg L−1 for TPhP; 5–1250 μg L−1 for TEP; 10–2500 μg L−1 for TPrP and TCPP; 15–3750 μg L−1 for TCEP (R > 0.9907). For the eight OPEs, the LODs ranged between 0.25 μg L−1 and 5 μg L−1 and the LOQs ranged between 0.5 μg L−1 and 15 μg L−1.
Co-reporter:Shuping Qu, Zhenxia Du, Yun Zhang
Food Chemistry 2015 170() pp: 463-469
Publication Date(Web):
DOI:10.1016/j.foodchem.2014.08.043
Co-reporter:Yu Ji, Zhenxia Du, Haojie Zhang and Yun Zhang
Analytical Methods 2014 vol. 6(Issue 18) pp:7294-7304
Publication Date(Web):30 Jun 2014
DOI:10.1039/C4AY01305K
A novel rapid analytical method for the determination of four non-steroidal anti-inflammatory drugs (NSAIDs) – nabumetone, ibuprofen, naproxen and diclofenac – in tap water and drinks is presented. The method is based on ultrasound-assisted ionic liquid dispersive liquid–liquid microextraction (US-IL-DLLME) followed by ultra-high performance supercritical fluid chromatography (UHPSFC) coupled to a photo-diode array detector (PDA). The ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MIM][PF6]) and methanol were used as the extraction and dispersion solvents for the DLLME procedure other than using a toxic chlorinated solvent. Plackett–Burman and Box–Behnken designs were applied as the experimental design strategies to screen and optimize the experimental variables such as the volume of the ionic liquid, the volume of the disperser solvent, sample pH, ionic strength, ultrasonication time and centrifugation time which affected the extraction efficiency. Separation conditions of UHPSFC, such as column screening, modifiers, column temperature, back pressure and flow rate, were also optimized in this study. 4 NSAIDs were simultaneously separated and determined in 2.1 minutes. The optimized US-IL-DLLME-UHPSFC-PDA method showed good enrichment factors (126–132) and recoveries (81.37–107.47%) for the rapid extraction of nabumetone, ibuprofen, naproxen and diclofenac in tap water and drinks. The method's limits of detection for nabumetone, ibuprofen, naproxen and diclofenac were 1.56, 7.69, 0.62, and 7.37 ng mL−1 with excellent linearity (R > 0.9957).
Co-reporter:Ying Zhou, Zhenxia Du, Yun Zhang
Talanta 2014 Volume 127() pp:108-115
Publication Date(Web):1 September 2014
DOI:10.1016/j.talanta.2014.03.055
•Validation of a UHPSFC–MS/MS method to analyze 17 allergenic and prohibited disperse dyes in textile.•Four stationary phases, BEH, BEH 2-ethyl-pyridine, HSS C18 SB, and CSH fluorophenyl, to select the well-suited one.•Analytical conditions (modifier percentage, backpressure and temperature) were studied to improve the separation.A simple, highly sensitive and fast procedure for the control of 17 allergenic and prohibited disperse dyes in textile products was optimized. The method was based on ultrasound assisted extraction of textile samples with 10 mL of methanol under controlled conditions (30 min, 70 °C). The extracts were analyzed by the ultra-high performance supercritical fluid chromatography (UHPSFC) system coupled with triple quadrupole tandem mass spectrometry (MS/MS). Four stationary phases (BEH, BEH 2-ethyl-pyridine, HSS C18 SB and CSH fluorophenyl) were screened as well as analytical conditions (modifier percentage, backpressure and column temperature) were investigated to improve the separation. All 17 disperse dyes were simultaneously separated and determined by UHPSFC–MS/MS in 5 min. The dyes were monitored via the ESI+ ionization method and quantified by 3-channel multiple reaction monitoring (MRM). The calibrations were performed and good linear relationship (R≥0.99) was observed within the concentration range of 2–50 μg mL−1. Satisfactory recoveries (70.55–103.03%) of all the disperse dyes spiked with standards at different levels were demonstrated. This is the first report on the simultaneous analysis of disperse dyes using UHPSFC–MS/MS.
Co-reporter:Wenjun Sun, Shuping Qu, Zhenxia Du
Journal of Chromatography B 2014 Volumes 951–952() pp:157-163
Publication Date(Web):1 March 2014
DOI:10.1016/j.jchromb.2014.01.029
•Buprenorphine, norbuprenorphine and naloxone were quantified in plasma by UPLC–MS/MS.•This is the first extraction of these analytes from human plasma by HF–LPME (PVDF).•All the extraction conditions of HF–LPME were optimized carefully.•This method was compared with SPE method to prove the reliability.•This method is contributed to pharmacokinetic studies of BP, NBP and NLX.A hollow fiber liquid phase microextraction (HF–LPME) combined with ultra-high performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method was developed for the extraction and determination of naloxone (NLX), buprenorphine (BP) and its major metabolite norbuprenorphine (NBP) in human plasma. The optimum extraction conditions of HF–LPME were: the porous of polyvinylidene fluoride (PVDF) hollow fiber was full of component solvent (1-octanol/chloroform/toluene, 2/4/4), the pH of donor phase was 8.7, the extraction time was 30 min and stirring speed was 1000 revolutions per minute (rpm). The UHPLC–MS/MS method was performed with Waters ACQUITY UPLCTM BEH C18, 50 mm × 2.1 mm, 1.7 μm, using methanol–0.2%formic acid as mobile phase with a gradient elution at a flow rate of 0.25 mL/min. The target compounds were detected under a tandem quadrupole mass spectrometer in positive electrospray ionization (ESI) mode, then analyzed in multiple reaction monitoring (MRM) mode and the isotope internal standard method was used for quantification. The results showed that linearities were in the range of 0.1–25 ng/mL (R > 0.996). The limits of detection (LOD) of BP/NBP/NLX were 0.05/0.05/0.025 ng/mL and the limits of quantitation (LOQ) of BP/NBP/NLX were 0.1/0.1/0.05 ng/mL, respectively. The spiked recoveries were in the range of 92.1–106.0% with relative standard deviation (RSD) values were less than 15%. This method was simple, inexpensive, sensitive and has been successfully used to quantify plasma samples from patients included in a clinical pharmacogenetic study.
Co-reporter:Qiaozhen Guo;Yun Zhang;Xiaoyu Lu;Jinhua Wang;Wenlian Yu
Journal of Separation Science 2013 Volume 36( Issue 4) pp:677-683
Publication Date(Web):
DOI:10.1002/jssc.201200730
Simultaneous determination of bisphenol A, tetrabromobisphenol A, and perfluorooctanoic acid in small household electronics appliances by accelerated solvent extraction-ultra-performance liquid chromatography-tandem mass spectrometry was established. Samples, heated for 5 min, were extracted by toluene/methanol (10:1, v/v) under the pressure 1500 psi at 100°C, and were extracted 3 static cycles with 20 min per cycle. And then 15 mL extractant solvent was used to wash the samples, and at last the sample was purged by nitrogen for 100 s. The partial extractant (10 mL) was concentrated by nitrogen and re-dissolved with 1 mL methanol/water (1:1, v/v). The three compounds were separated by BEH C18 column effectively in 3 min and detected by electrospray ionization mode mass spectrometry. The linear ranges for bisphenol A, perfluorooctanoic acid, and tetrabromobisphenol A were 1–100, 10–1000 ng/mL, and 0.1–10 μg/mL, respectively. The correlation coefficient was greater than 0.996. The LOD and limit of quantitation for three compounds were 0.1, 10, 1 ng/mL, and 0.5, 50, 5 ng/mL, respectively. And the recoveries were 84–92, 76–82, and 72–74%, respectively, with RSD < 5%. The method was successfully used in determining the real samples. The method and the result were confirmed by liquid chromatography-ion trap-time of flight mass spectrometry.
Co-reporter:Jianfeng Wang, Zhongxia Zhang, Zhenxia Du and Wenjun Sun
Analytical Methods 2013 vol. 5(Issue 23) pp:6592-6597
Publication Date(Web):05 Sep 2013
DOI:10.1039/C3AY40667A
A novel method based on hollow fibre liquid phase microextraction coupled with a hand-held ion mobility spectrometer was developed for determination of seven pesticides in cucumber samples. The hollow fibre liquid phase microextraction (LPME) sample preparation method is used to preconcentrate pesticide residues present in cucumber samples. The extracted pesticide residues are detected by IMS under optimized operating conditions. During the tests, the instrument is operated in the positive mode at ambient pressure using 63Ni as the ionization source, with dry, clean air as the drift gas which circulates in a closed loop system. The IMS detection limits for propoxur, carbofuran, atrazine, cyanatryn, metolachlor, prometryn and tebuconazole were 5, 5, 1, 5, 5, 10 and 50 ng respectively. The analysis via IMS takes less than 10 s. The mean recoveries were in the range of 60–89% with an acceptable reproducibility (RSD < 12%). The results obtained reveal that the method is of great potentiality for rapid screening and detection of seven pesticide residues contained in agricultural products.
Co-reporter:Yun Zhang, Zhenxia Du, Ailin Li, Anqi Tu, Wenlian Yu and Jixin Zou
Analytical Methods 2013 vol. 5(Issue 19) pp:5112-5120
Publication Date(Web):22 Jul 2013
DOI:10.1039/C3AY40806J
A rapid method for the qualitative and semi-quantitative determination of polymer additives was developed to determine a set of eight polymer additives used in plastic samples by accelerated solvent extraction–electrospray ionization-triple quadrupole mass spectrometry (ASE–ESI-MS/MS). The eight additives were Tinuvin 328, Tinuvin 770, Cyasorb 2908, Cyasorb 3853, Irgafos 168, Antioxidant 405, Irganox 565, Irganox MD 1024. In order to enable the fast identification of additives, an ESI-MS library for 100 additives was built. By using a molecular weight search of the library, and comparing the MS/MS spectra, additives in polymers can be easily identified. Moreover the additives can be quantified by ESI-MS/MS without a column separation step. ASE was used for sample preparation. Three static extraction cycles were carried out for 20 min per cycle at 1500 psi and 100 °C, using trichloromethane/acetone (1/1, v/v) as the extraction solvent, then the samples were washed with a 20% volume of the maximum bottle (66 mL) of extraction solvent. Finally the samples were purged with nitrogen for 100 s and re-dissolved in 1 mL methanol, diluted 100 times and 5 μL directly injected into the instrument for analysis. Limits of detection for the multi-reaction-monitoring mode of the ESI-MS/MS analysis varied from 0.1 to 10 ng mL−1. The calibration curves were linear with R ≥ 0.993. The relative recoveries were between 84.0% and 120% with relative standard deviations (RSD, n = 6) lower than 20%. This quantification method was successfully used in the determination of additives in real samples. The method was confirmed by UPLC–MS/MS and the results were in excellent accordance.
Co-reporter:Haojie Zhang, Zhenxia Du, Yu Ji, Mei Mei
Talanta 2013 Volume 109() pp:177-184
Publication Date(Web):15 May 2013
DOI:10.1016/j.talanta.2013.02.048
In this study, a two-phase hollow fiber liquid-phase microextraction (HF-LPME) coupling with ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed for determination of four non-steroidal anti-inflammatory (NSAIDs)—salicylic acid, ibuprofen, naproxen and diclofenac in real water samples. The influencing parameters of HF-LPME sample preparation method, such as organic solvents (acceptor phase), pH of sample solution (donor phase), extraction time, stirring speed, extraction temperature and ionic strength were systematically optimized. Through the developed determination method, high enrichment factors (195–346) were achieved for the four drugs. The instrumental calibration curves of salicylic acid, naproxen, diclofenac, and ibuprofen show good linear relations (R>0.998) in the concentration range of 1–500, 5–2500, 10–5000 and 5–2500 μg L−1, respectively. The average recoveries of the four drugs in the low, medium and high spiked concentration levels (20–200, 50–500 and 100–1000 μg L−1) were between 98–115% with relative standard deviation (RSD) values were less than 12% (n=6). Limits of detection (LOD) of salicylic acid, naproxen, diclofenac, and ibuprofen in water were 0.5, 0.5, 1.0, and 1.25 μg L−1, respectively. The determination method has been applied for the real samples (purified water, tap water, juice, soda and energy drinks), and the results show that salicylic acid was detected in tap water and soda, the concentrations were 2.85 μg L−1 and 61.22 μg L−1 separately, the RSD values were less than 9% (n=6). Salicylic acid and diclofenac were detected in energy drink, the concentrations were 44.62 μg L−1 and 8.31 μg L−1, the RSD values were less than 11% (n=6).Highlights► A two-phase HF-LPME procedure is optimized prior to UPLC-MS/MS analysis. ► 1-octanol was placed in the pores and lumen of hollow fiber as extractant. ► Determination of four NSAIDs in purified water, tap water, soda, juice, and energy drink.
Co-reporter:Jianfeng Wang, Zhenxia Du, Wenlian Yu, Shuping Qu
Journal of Chromatography A 2012 Volume 1247() pp:10-17
Publication Date(Web):20 July 2012
DOI:10.1016/j.chroma.2012.05.040
A liquid-phase microextraction (LPME) methodology based on the use of porous polyvinylidene fluoride (PVDF) hollow fibres was developed for extracting seven pesticides from cucumbers. The seven pesticides include propoxur, carbofuran, atrazine, cyanatryn, metolachlor, prometryn and tebuconazole. The PVDF hollow fibre provides higher extraction efficiency due to its higher porosity and better solvent compatibility. A new desorption methodology was developed since some pesticides were absorbed by the wall pore of the PVDF. Ultra-high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC–MS/MS) was used for pesticide analysis. In order to obtain high recoveries and enrichment factors of the analytes, several parameters such as method of sealing, acceptor phase (organic solvents), stirring speed, extraction time, salting out effect, desorption mode and time were optimized. A fast, simple method for closing fibre ends was practiced by using mechanical crimping. Pesticides were extracted from the sample to the organic solvent and then desorbed in a mixture of methanol:water (1:1 v/v) prior to chromatographic analysis. Limits of detection (LOD) for the multi-reaction-monitoring (MRM) mode of the method varies from 0.01 to 0.31 μg/kg with optimized sample preparation. Calibration curves are linear with R2 ≥ 0.991. Enrichment factor of the hollow fibre LPME ranges from 100 to 147. Matrix effect has been considered and is in the range of 76–122%. The relative recoveries from cucumber samples are between 63% and 119% with the relative standard deviation (RSD, n = 6) lower than 20%.Highlights► A porous PVDF hollow fibre LPME was used for extracting pesticides from cucumbers. ► A fast, simple method of the fibre seal was practiced by using insulated terminal. ► Desorption mode changed and pesticides in fibre were desorbed after extraction. ► The fibre with large membrane porosity can be applied to pesticide extraction.
Co-reporter:Wenhan Yang, Jinhua Wang, Xiaolin Li, Zhenxia Du
Journal of Chromatography A 2011 Volume 1218(Issue 11) pp:1423-1428
Publication Date(Web):18 March 2011
DOI:10.1016/j.chroma.2010.12.121
Crocin yellow was determined in soft drinks, sausages and sauces by ultra performance liquid chromatography coupled with ultraviolet detector and analyzed within 5 min using a short analytical column ACQUITY UPLC HSS T3 2.1 × 100 mm 1.8 μm) with gradient elution. An innovative pretreatment method based on homemade macroporous resin solid-phase extraction (SPE) column was established. The SPE column packed with macroporous resins could simplify the sample preparation of multi-matrices and be reused by regeneration steps. The recoveries of crocin yellow added to soft drinks, sausages and sauces at three levels ranged from 81.3% to 106.2%, and relative standard deviations (RSDs) were within 8.8%. The limits of quantitation of soft drinks, sausages and sauces were 0.5 mg/kg, 5 mg/kg and 5 mg/kg, respectively.
Co-reporter:Qiaozhen Guo
Chinese Journal of Chemistry 2011 Volume 29( Issue 9) pp:1922-1926
Publication Date(Web):
DOI:10.1002/cjoc.201180334
Abstract
A simultaneous method was successfully established and validated for the separation and determination of buprenorphine (BP), its primary metabolite, nor-buprenorphine (NBP) and a proposed co-formulate, naloxone (NLX) in human plasma. The method used buprenorphine-d4 (BP-D4), nor-buprenorphine-d3 (NBP-D3), naltrexone (NTX) as internal standards (ISs). 100 μL of plasma sample fortified with the ISs was cleaned up by solid-phase extraction (SPE), and was then separated on a Waters AcquityTM BEH C18 column with gradient elution using methanol and water (containing 0.2% formic) at a flow rate of 0.25 mL·min−1. The mass spectrometer was used for detection and was operated in the positive electrospray ionization with multiple reaction monitoring (MRM) mode. The three compounds were effectively separated in 5 min. The linear ranges of the compounds were 0.1–25, 0.25–25 and 0.05–25 ng·mL−1 for BP, NBP and NLX, respectively, with r≧0.9935. The method had high sensitivity (the limits of detection were 0.02, 0.1 and 0.01 ng·mL−1 for BP, NBP and NLX, respectively) and high recoveries (≧97.6%). The result was shown to be linear and satisfactorily met current acceptance criteria for validation of bioanalytical method: intra and inter assay precisions within the required limits of ≦25% RSD. The LOQs fulfilled the LOQ requirements: precision≦25% RSD, and was fully validated according to the State Food and Drug Administration (SFDA) regulations. The results demonstrated that ultra-high performance liquid chromatography-tandem mass spectrometer (UPLC-MS/MS) with SPE was a powerful detection tool and contributed to pharmaceutical analysis in biological matrices.
Co-reporter:Mei MEI, Zhen-Xia DU, Yun CEN
Chinese Journal of Analytical Chemistry 2011 Volume 39(Issue 11) pp:1659-1664
Publication Date(Web):November 2011
DOI:10.1016/S1872-2040(10)60482-3
Co-reporter:Chuangji Liu, Hai Wang, Yanbin Jiang, Zhenxia Du
Journal of Chromatography B 2011 Volume 879(7–8) pp:533-540
Publication Date(Web):1 March 2011
DOI:10.1016/j.jchromb.2011.01.016
A rapid, sensitive, and specific method for the determination of amoxicillin (AMO), amoxicilloic acid (AMA), amoxicillin diketopiperazine-2′,5′-dione (DIKETO), penicillin G (PEN G), benzylpenicilloic acid (BPA-1), benzylpenilloic acid (BPA-2), and benzylpenillic acid (BPA-3) in bovine milk using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) was developed and validated. The method used penicillin V (PEN V) as the internal standard and ethanol for the deproteinisation of bovine milk. Chromatographic separation of the components was performed on a Waters Acquity UPLC® HSS T3 column (100 mm × 2.1 mm, 1.8 μm) using a mixture of 0.15% formic acid in water with 5 mM ammonium acetate and acetonitrile as the mobile phase. Gradient elution was performed at a flow rate of 0.25 mL min−1. The mass spectrometer was operated in the positive electrospray ionisation MS/MS mode. The method was fully validated according to EU requirements, including linearity, precision, trueness, limit of quantification, limit of detection, and specificity. The results were within the ranges specified. The established method was successfully applied in the determination of AMO, PEN G, and their major metabolites in 40 commercial bovine milk samples. The results showed that 8 samples were contaminated with BPA-1 or BPA-2. The mean levels (occurrence) of BPA-1 and BPA-2 in positive samples were 287 (50%) and 320 (100%) ng mL−1, respectively. No sample was found to be contaminated with AMO, AMA, DIKETO, PEN G, and BPA-3. These findings could play an important role in food safety, because BPA-1 and BPA-2 metabolites pose possible health risks, although they are not included in the maximum residue limit legislation.
Co-reporter:Anqi Tu, Qiang Ma, Hua Bai, Zhenxia Du
Food Chemistry (15 April 2017) Volume 221() pp:
Publication Date(Web):15 April 2017
DOI:10.1016/j.foodchem.2016.11.139
•A high efficient method for determining TAGs in milk samples was established.•Over 60 TAGs in human milk and 50 TAG in infant formula were identified.•Results showed differences between Chinese human milk and imported infant formula.•Principal component analysis (PCA) was applied for data processing.Triacylglycerols (TAGs) as the major component of milk fat are significant factors to ensure the healthy growth of infants. An efficient method for identifying TAGs in human milk (HM) and infant formula (IF) was established using supercritical fluid chromatograph (SFC) coupled with quadruple time-of-flight mass spectrometry (Q-TOF-MS). The results indicated the feasibility of this method with satisfactory recoveries (>80%) and correlation coefficients (r2 ⩾ 0.993). More than 60 TAGs in HM and 50 TAGs in IF were identified. The profiling results demonstrated that TAGs in HM were greatly affected by lactation stage. Significant differences were found between HM and IF, such as much higher medium chain TAGs and saturated TAGs in IF, indicating that the formulas developed by foreign manufacturers were not suitable for Chinese babies. This high-throughput method exhibits a huge potential for analysis of milk samples and the result may serve as an important guide for Chinese infants diet.
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Analytical Methods (2009-Present) 2015 - vol. 7(Issue 23) pp:NaN9866-9866
Publication Date(Web):2015/10/26
DOI:10.1039/C5AY02077H
A rapid, effective and eco-friendly method for determination of eight organophosphate esters in plastic samples from car interiors by microwave assisted extraction followed by ultra-high performance liquid chromatography combined with tandem mass spectrometry was established. Acetone/ethyl acetate (3/1, v/v) was used as extractant. Response surface methodology was applied as the experimental design strategy to screen and optimize the extraction variables which affected the extraction efficiency, such as the volume of the extraction solvent, the time for extraction, and the temperature of extraction. Baseline separation of eight OPEs was achieved in 4.5 minutes. The method showed excellent linearity 1–250 μg L−1 for TBEP, TCP, and DPOP; 2–500 μg L−1 for TPhP; 5–1250 μg L−1 for TEP; 10–2500 μg L−1 for TPrP and TCPP; 15–3750 μg L−1 for TCEP (R > 0.9907). For the eight OPEs, the LODs ranged between 0.25 μg L−1 and 5 μg L−1 and the LOQs ranged between 0.5 μg L−1 and 15 μg L−1.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 18) pp:
Publication Date(Web):
DOI:10.1039/C4AY01305K
A novel rapid analytical method for the determination of four non-steroidal anti-inflammatory drugs (NSAIDs) – nabumetone, ibuprofen, naproxen and diclofenac – in tap water and drinks is presented. The method is based on ultrasound-assisted ionic liquid dispersive liquid–liquid microextraction (US-IL-DLLME) followed by ultra-high performance supercritical fluid chromatography (UHPSFC) coupled to a photo-diode array detector (PDA). The ionic liquid 1-octyl-3-methylimidazolium hexafluorophosphate ([C8MIM][PF6]) and methanol were used as the extraction and dispersion solvents for the DLLME procedure other than using a toxic chlorinated solvent. Plackett–Burman and Box–Behnken designs were applied as the experimental design strategies to screen and optimize the experimental variables such as the volume of the ionic liquid, the volume of the disperser solvent, sample pH, ionic strength, ultrasonication time and centrifugation time which affected the extraction efficiency. Separation conditions of UHPSFC, such as column screening, modifiers, column temperature, back pressure and flow rate, were also optimized in this study. 4 NSAIDs were simultaneously separated and determined in 2.1 minutes. The optimized US-IL-DLLME-UHPSFC-PDA method showed good enrichment factors (126–132) and recoveries (81.37–107.47%) for the rapid extraction of nabumetone, ibuprofen, naproxen and diclofenac in tap water and drinks. The method's limits of detection for nabumetone, ibuprofen, naproxen and diclofenac were 1.56, 7.69, 0.62, and 7.37 ng mL−1 with excellent linearity (R > 0.9957).
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Analytical Methods (2009-Present) 2013 - vol. 5(Issue 19) pp:
Publication Date(Web):
DOI:10.1039/C3AY40806J
A rapid method for the qualitative and semi-quantitative determination of polymer additives was developed to determine a set of eight polymer additives used in plastic samples by accelerated solvent extraction–electrospray ionization-triple quadrupole mass spectrometry (ASE–ESI-MS/MS). The eight additives were Tinuvin 328, Tinuvin 770, Cyasorb 2908, Cyasorb 3853, Irgafos 168, Antioxidant 405, Irganox 565, Irganox MD 1024. In order to enable the fast identification of additives, an ESI-MS library for 100 additives was built. By using a molecular weight search of the library, and comparing the MS/MS spectra, additives in polymers can be easily identified. Moreover the additives can be quantified by ESI-MS/MS without a column separation step. ASE was used for sample preparation. Three static extraction cycles were carried out for 20 min per cycle at 1500 psi and 100 °C, using trichloromethane/acetone (1/1, v/v) as the extraction solvent, then the samples were washed with a 20% volume of the maximum bottle (66 mL) of extraction solvent. Finally the samples were purged with nitrogen for 100 s and re-dissolved in 1 mL methanol, diluted 100 times and 5 μL directly injected into the instrument for analysis. Limits of detection for the multi-reaction-monitoring mode of the ESI-MS/MS analysis varied from 0.1 to 10 ng mL−1. The calibration curves were linear with R ≥ 0.993. The relative recoveries were between 84.0% and 120% with relative standard deviations (RSD, n = 6) lower than 20%. This quantification method was successfully used in the determination of additives in real samples. The method was confirmed by UPLC–MS/MS and the results were in excellent accordance.
Co-reporter:
Analytical Methods (2009-Present) 2013 - vol. 5(Issue 23) pp:
Publication Date(Web):
DOI:10.1039/C3AY40667A
A novel method based on hollow fibre liquid phase microextraction coupled with a hand-held ion mobility spectrometer was developed for determination of seven pesticides in cucumber samples. The hollow fibre liquid phase microextraction (LPME) sample preparation method is used to preconcentrate pesticide residues present in cucumber samples. The extracted pesticide residues are detected by IMS under optimized operating conditions. During the tests, the instrument is operated in the positive mode at ambient pressure using 63Ni as the ionization source, with dry, clean air as the drift gas which circulates in a closed loop system. The IMS detection limits for propoxur, carbofuran, atrazine, cyanatryn, metolachlor, prometryn and tebuconazole were 5, 5, 1, 5, 5, 10 and 50 ng respectively. The analysis via IMS takes less than 10 s. The mean recoveries were in the range of 60–89% with an acceptable reproducibility (RSD < 12%). The results obtained reveal that the method is of great potentiality for rapid screening and detection of seven pesticide residues contained in agricultural products.