Publications (10)10.86 Total impact
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Article: A sensitive and specific ELISA for determining a residue marker of three quinoxaline antibiotics in swine liver.
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ABSTRACT: Methyl-3-quinoxaline-2-carboxylic acid (MQCA) is a possible residue marker for three quinoxaline veterinary medicines (olaquindox, mequindox, and quinocetone). The wide application of mequindox/quinocetone or the illegal use of olaquindox leads to MQCA residue in animal's original food, thereby threatening the safety of human food. The indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) with a specific coating antigen and monoclonal antibody (MAB) was established and optimized for detecting MQCA in swine liver. Samples were acidified with 2 mol l(-1) hydrochloric acid, extracted with ethyl acetate-hexane-isopropanol (8 + 1 + 1, v/v/v) and then detected by IC-ELISA. The logarithm correlation of standards to OD values ranged from 0.2 to 200 μg l(-1), with IC(50) of 6.46 μg l(-1). Negligible cross-reactivity happened to five quinoxaline antibiotics (olaquindox, mequindox, quinocetone, carbadox, and cyadox) and the metabolite of carbadox and cyadox (quinoxaline-2-carboxylic acid). When spiked with 1 to 100 μg kg(-1) of MQCA, the recoveries ranged from 85.44 to 100.02 %, with the intra-assay coefficient of variation (CV) of 6.64-10.57 % and inter-assay CV of 7.29-10.88 %. The limit of detection for MQCA was 1.0 μg kg(-1) in swine liver. Furthermore, incurred samples were detected by the IC-ELISA and then conformed by a reported LC/MS/MS method, it shown that there was good correlation between the two methods. All these results indicated that the IC-ELISA method is appropriate for surveillance MQCA residue in animal tissues.Analytical and Bioanalytical Chemistry 01/2013; · 3.78 Impact Factor -
Article: Fluorescence polarization immunoassay for salinomycin based on monoclonal antibodies
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ABSTRACT: A fluorescence polarization immunoassay (FPIA) for the determination of salinomycin (SAL) was developed by using anti-SAL monoclonal antibodies (mAb). Fluorescein labeled SAL (tracer) was synthesized by the N-hydroxysuccinimide active ester method and purified using thin layer chromatography (TLC). The developed FPIA for SAL had a dynamic range from 0.60 to 2193 ng/mL with an IC50 value of 33.2 ng/mL and a detection limit (LOD) of 0.08 ng/mL. No significant cross-reactivities were observed with other drugs but 67.6% with narasin. Keywordssalinomycin-tracer-fluorescence polarization immunoassay-monoclonal antibodyScience China-Chemistry 04/2012; 53(3):553-555. · 1.02 Impact Factor -
Article: GC–MS Method for Simultaneous Determination of Four Sedative Hypnotic Residues in Swine Tissues
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ABSTRACT: A robust, reliable and sensitive method is described for the simultaneous determination of diazepam, methaqualone, chlorpromazine and promethazine in swine muscle and liver tissues by GC–MS. The analytes were extracted with ethyl acetate and further clean-up performed with MCX solid-phase extraction cartridges. LODs and LOQs in the two tissues ranged from 0.2 to 0.3μgkg−1 and 0.5 to 1μgkg−1, respectively. Mean recoveries for the analytes ranged between 87.6 and 106.8%.Chromatographia 04/2012; 71(1):155-158. · 1.20 Impact Factor -
Article: [Determination of 3-methyl-quinoxaline-2-carboxylic acid in animal and aquatic products by ultra performance liquid chromatography-tandem mass spectrometry].
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ABSTRACT: An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/ MS) method was established for the determination of 3-methyl-quinoxaline-2-carboxylic acid (MQCA) in animal tissues and aquatic products. The analyte was extracted with 0.2 mol/L hydrochloric acid. The extract was cleaned up on a Bond Elut C18 cartridge. Then the eluate was collected and evaporated to dryness under nitrogen gas at 35 degrees C. The residue was redissolved in acetonitrile containing 0.1% (v/v) formic acid. The identification was performed by multiple reaction monitoring in positive electrospray ionization. The quantification was done by external standard method. The calibration curves showed good linearity within the range of 2-500 microg/L with the correlation coefficients (r2) greater than 0.990. The limits of detection (LODs) of MQCA in pork, swine liver, pig kidney, fish, prawn, and crab were 0.90, 1.51, 0.94, 1.04, 1.62 and 1.80 microg/kg, respectively; and the limits of quantification (LOQs) were 3.00, 5.02, 3.13, 3.46, 5.40 and 6.00 microg/kg, correspondingly. The recoveries of MQCA in animal tissues and aquatic products were 73.6%-89.0% at the spiked levels of 3-100 microg/kg. The intra-day relative standard deviations (RSDs, n = 5) were less than 15%, and inter-day RSDs (n = 3) were less than 20%. The results demonstrated that the sensitivity, accuracy, and precision were fit for the requirements of veterinary drug residue analysis.Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 01/2012; 30(1):45-50. -
Article: Metabolism profile of quinocetone in swine by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry.
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ABSTRACT: With the profile of ultra-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC/ESI-QTOF-MS), the metabolites of quinocetone (QCT) in swine were identified and investigated. On the basis of finding, the biodistribution and elimination characters of them were revealed. Through data-dependent acquisition ways, both MS and MS/MS scans of metabolites were simultaneously acquired on the same sample injection. The metabolites were reliably characterized by their accurate MS/MS spectra and their different fragmentation pathways. A total of 42 metabolites were found in swine, 11 (Q32-Q42) of them were identified to be novel in vivo. The results demonstrated that QCT was extensively metabolized and distributed in vivo, especially in gastrointestinal tract. The reductions of the N → O group, carbonyl, double-bond in QCT were the main metabolic pathways observed in swine. Elimination of the four major metabolites (Q1, Q2, Q7, Q39) of QCT suggest that QCT was mainly metabolized at 12 h in swine, then excreted gradually together with its main metabolites after that. QCT and its major metabolites are excreted more and more rapidly in swine liver, kidney and muscle, respectively. It afforded prima research of QCT metabolism in vivo of swine and given an important basis for further study of its toxicological safety evaluation and marker residue finding.European Journal of Drug Metabolism and Pharmacokinetics 09/2011; 37(2):141-54. · 0.36 Impact Factor -
Article: Hapten-antibody recognition studies in competitive immunoassay of α-zearalanol analogs by computational chemistry and Pearson Correlation analysis.
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ABSTRACT: The molecular recognition of hapten-antibody is a fundamental event in competitive immunoassay, which guarantees the sensitivity and specificity of immunoassay for the detection of haptens. The aim of this study is to investigate the correlation between binding ability of one monoclonal antibody, 1H9B4, recognizing and the molecular aspects of α-zearalanol analogs. The mouse-derived monoclonal antibody was produced by using α-zearalanol conjugated to bovine serum albumin as an immunogen. The antibody recognition abilities, expressed as IC(50) values, were determined by a competitive ELISA. All of the hapten molecules were optimized by Density Function Theory (DFT) at B3LYP/ 6-31G* level and the conformation and electrostatic molecular isosurface were employed to explain the molecular recognition between α-zearalanol analogs and antibody 1H9B4. Pearson Correlation analysis between molecular descriptors and IC(50) values was qualitatively undertaken and the results showed that one molecular descriptor, surface of the hapten molecule, clearly demonstrated linear relationship with antibody recognition ability, where the relationship coefficient was 0.88 and the correlation was significant at p < 0.05 level. The study shows that computational chemistry and Pearson Correlation analysis can be used as tool to help the immunochemistries better understand the processing of antibody recognition of hapten molecules in competitive immunoassay.Journal of Molecular Recognition 08/2011; 24(5):815-23. · 3.31 Impact Factor -
Article: [Determination of 5 polyether antibiotics in chicken tissues by liquid chromatography-electrospray ionization tandem mass spectrometry].
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ABSTRACT: A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI MS/MS) method for the determination of 5 polyether antibiotics (lasalocid, salinomycin, monensin, narasin and maduramicin) in chicken tissues was developed. The polyether antibiotics were extracted from chicken tissues with methanol. The extract was evaporated to dry, and redissolved in hexane, then cleaned up on a Sep-Pak Silica solid-phase extraction cartridge. The target drugs were eluted with 6 mL methylene chloride-methanol (90:10, v/v), and the eluate was collected and dried under a gentle stream of nitrogen gas, then the residue was dissolved with 1 mL acetonitrile (containing 0.1% formic acid) and analyzed by LC-MS/MS. The LC separation was performed on a Symmetry Shield reversed phase C18 bonded silica column with acetonitrile (containing 0.1% formic acid)-0.1% formic acid (97:3, v/v) as mobile phase. The quantification was carried out by positive electrospray ionization and multiple reaction monitoring (MRM) mode. The validation was carried out on spiked chicken muscle (spiked at 0.1 -1500 microg/kg) and chicken liver (spiked at 0.2-4500 microg/kg), the average recoveries of target drugs ranged from 71.6%-99.1% with intra-day relative standard deviations (RSDs) of 3.2%-10.7% and inter-day RSDs of 4.6%-14.7%. The limits of quantification (LOQs) in chicken muscle and liver were 0.1-1.0 kg/kg. The results demonstrated that the sensitivity, accuracy and precision of this method meet the requirements of veterinary drug residue analysis. The method is applicable to detect 5 polyether antibiotics in chicken muscle and liver.Se pu = Chinese journal of chromatography / Zhongguo hua xue hui 11/2009; 27(6):815-9. -
Article: Simultaneous determination and confirmation of chloramphenicol, thiamphenicol, florfenicol and florfenicol amine in chicken muscle by liquid chromatography–tandem mass spectrometry
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ABSTRACT: A reliable and sensitive liquid chromatography–electrospray ionization-tandem mass spectrometry (LC–ESI-MS/MS) confirmation method has been developed for the simultaneous determination of chloramphenicol (CAP), thiamphenicol (TAP), florfenicol (FF), and florfenicol amine (FFA) in chicken muscle. Samples were extracted with basic ethyl acetate, defatted with hexane, and cleaned up on Oasis MCX cartridges. LC separation was achieved on a XTerra C18 column with gradient elution using a mobile phase composed of acetonitrile and water at a flow rate of 0.20 mL/min. The analysis was carried out on a triple–quadrupole tandem mass spectrometer in the multiple reaction monitoring (MRM) mode via electrospray interface operated in the positive and negative ionization modes, with deuterated chloramphenicol-d5 (d5-CAP) as the internal standard. The method validation was performed according to the criteria of Commission Decision 2002/657/EC. Four identification points were obtained for each analyte with one precursor ion and two product ions. Limits of detection (LODs) were 0.1 μg/kg for CAP, 0.2 μg/kg for FF and 1 μg/kg for TAP and FFA in chicken muscle. Linear calibration curves were obtained over concentration ranges of 0.3–20 μg/kg for CAP, 0.5–20 μg/kg for FF and 3–100 μg/kg for TAP and FFA in tissues. Mean recoveries of the 4 analytes ranged from 95.1% to 107.3%, with the corresponding intra- and inter-day variation (relative standard deviation, R.S.D.) less than 10.9% and 10.6%, respectively. The decision limit (CCα) and detection capability (CCβ) of the method were also reported.Journal of Chromatography B. -
Article: Three Dimensional Quantitative Structure-Activity Relationships of Sulfonamides Binding Monoclonal Antibody by Comparative Molecular Field Analysis
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ABSTRACT: The three-dimensional quantitative structure-activity relationship (3D-QSAR) model of sulfonamide analogs binding a monoclonal antibody (MabSMR) produced against sulfamerazine, was carried out by comparative molecular field analysis (CoMFA). The affinities of MabSMR, expressed as Log10IC50, for 17 sulfonamide analogs were determined by competitive fluorescence polarization immunoassay (FPIA). Removal of two outliers from the initial set of 17 sulfonamide analogs improved the predictability of the models. The 3D-QSAR model of 15 sulfonamides resulted in q2cv values of 0.600, and r2 values of 0.995, respectively. This novel study combining FPIA with CoMFA demonstrates that multidisciplinary research can be used as a useful tool to investigate antigen-antibody interactions and provide information required for design of novel haptens, which may result in new antibodies with properties already optimized by an antibody-based immunoassay.Nature Precedings. -
Article: Simultaneous determination of florfenicol and florfenicol amine in fish, shrimp, and swine muscle by gas chromatography with a microcell electron capture detector.
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ABSTRACT: A rapid and sensitive gas chromatography method was developed for the simultaneous determination of florfenicol (FF) and its metabolite florfenicol amine (FFA) in fish, shrimp, and swine muscle. The extracted samples were defatted with hexane and cleaned up by solid-phase extraction using Oasis MCX cartridges. The eluate was evaporated to dryness, and residues were derivatized and determined by gas chromatography with a microcell electron capture detector. Overall average recoveries ranged from 81.7 to 109.7% for fish, 94.1 to 103.4% for shrimp, and 71.5 to 91.4% for swine muscle. The detection limit was 0.5 ng/g for FF and 1 ng/g for FFA, respectively. The method was validated for the determination of incurred swine muscle samples in an actual residue study.Journal of AOAC International 89(5):1437-41. · 1.20 Impact Factor
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Institutions
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2009–2013
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China Agricultural University
- College of Veterinary Medicine
Beijing, Beijing Shi, China
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