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Zhang J.-M.,Zhejiang Academy of Agricultural Sciences | Wu Y.-L.,Ningbo Academy of Agricultural science | Lu Y.-B.,Zhejiang Academy of Agricultural Sciences
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2013

A simple, sensitive and reliable analytical method was developed for the simultaneous determination of 22 carbamate insecticides and 17 mycotoxins in cereals by ultra high performance liquid chromatography electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS). Carbamates and mycotoxins were extracted from cereal samples using a QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) procedure without any further clean-up step. The extract was diluted with water containing 0.1% formic acid and 5.0mM ammonium acetate, and analyzed by LC-MS/MS on a Waters Acquity BEH C18 column with water (0.1% formic acid, 0.50mM ammonium acetate)/methanol as mobile phase with gradient elution. Matrix-matched calibration was used for quantification. Blank samples (rice, wheat and corn) were fortified at 5, 10 and 50μg/kg except for five zearalenonic compounds at 25, 50 and 250μg/kg, and recoveries were in the range of 70-120%. Relative standard deviations were lower than 20% in all cases. The LOQ values were in the range of 0.20-29.7μg/kg. The method is suitable for the simultaneous determination of carbamate insecticides and mycotoxins in cereals. The total time required for the analysis of one sample, including sample preparation, was about 35min. © 2013. Source


Zhang M.-X.,Hebei University of Engineering | Li C.,Hebei University of Engineering | Li C.,Tianjin Agricultural University | Wu Y.-L.,Ningbo Academy of Agricultural science
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2012

A simple, sensitive and reliable analytical method was developed for the determination of a new beta-agonist phenylethanolamine A in animal hair, tissues and animal feeds by ultra high performance liquid chromatography-positive electrospray ionization tandem mass spectrometry (UHPLC-ESI-MS/MS) with QuEChERS. Samples were extracted with acetonitrile/water (80:20, v/v). The extract was purified through QuEChERS method, then was dried with nitrogen and residues were redissolved in mobile phase for hair sample or directly diluted with 0.1% formic acid in water for other samples, and analyzed by LC-MS/MS on a Waters Acquity BEH C 18 column with 0.1% formic acid in water/methanol as mobile phase with gradient elution. The samples were quantified using phenylethanolamine A-D 3 as internal standards. The proposed method was validated according to the European Commission Decision 2002/657/EC determining specificity, decision limit (CCα), detection capability (CCβ), recovery, precision, linearity, robustness and stability. The CCα values ranged from 0.10 to 0.26μg/kg. The CCβ values ranged from 0.20 to 0.37μg/kg. The mean recoveries of 95.4-108.9% with intra-day CVs of 2.2-5.6% and inter-day CVs of 3.1-6.2% were obtained. The method is demonstrated to be suitable for the determination of phenylethanolamine A in animal hair, tissues and animal feeds. The total time required for the analysis of one sample except animal hair sample, including sample preparation, was about 25min. © 2012 Elsevier B.V.. Source


Yang Q.-F.,National Animal Husbandry Services | Wu Y.-L.,Ningbo Academy of Agricultural science
Chromatographia | Year: 2012

A fast analytical method for the simultaneous determination of fumonisin B1 (FB 1) and fumonisin B 2 (FB 2) in corn using a novel QuEChERS method and LC-MS-MS was developed and validated. Samples were extracted with methanol-water (3:1 v/v) by means of ultrasonic extraction. The extract was purified with a novel modified QuEChERS method. Firstly, FB 1 and FB2 in the extract were retained with primary secondary amine (PSA). Then, FB1 and FB 2 were released from PSA with 1.0 % formic acid in methanol. The final eluate was diluted with water, and analyzed by LC-MS-MS on a Waters Acquity BEH C 18 column with 0.1 % formic acid in water/methanol as mobile phase with gradient elution. Mean recoveries of 83.5-102.4 % with CVs of 3.6-10.5 % were obtained at fortification levels of 2, 50 and 1,000 μg kg -1. The limit of quantification was 2.0 μg kg -1. © 2012 Springer-Verlag. Source


Hou X.-L.,China Agricultural University | Wu Y.-L.,Ningbo Academy of Agricultural science | Yang T.,Ningbo Academy of Agricultural science | Du X.-D.,Henan Agricultural University
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2013

A simple and cost-effective pre-treatment procedure was developed for 18 sulfonamides in pork using dispersive solid phase extraction (dSPE) with multi-walled carbon nanotubes (MWCNTs). The sample was analysed after purification by ultra high-performance liquid chromatography-positive electrospray ionisation tandem mass spectrometry (UHPLC-ESI-MS/MS). After extraction with phosphate buffer (pH 6.0), a dSPE procedure was conducted with MWCNTs. The pH value of the extract, extraction time with MWCNTs, type and amount of MWCNTs and type of eluent were optimised to increase the sample throughput and sensitivity. The samples were quantified using sulfamethazine-13C6 as an internal standard. The recoveries of the target compounds from the pork samples were most efficient when 150mg of MWCNTs with an outer diameter of less than 8nm and a length of 0.5-2μm was used. A mixture of acetonitrile/50mM ammonium acetate (95:5, v/v) was shown to be the most suitable solvent for desorbing the compounds from the MWCNTs. The proposed method was validated according to the European Commission Decision 2002/657/EC, which determines linearity, specificity, decision limit (CCα), detection capability (CCβ), recovery, precision and stability. © 2013 Elsevier B.V. Source


Chen X.-B.,Shanghai JiaoTong University | Wu Y.-L.,Ningbo Academy of Agricultural science | Yang T.,Ningbo Academy of Agricultural science
Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences | Year: 2011

A simple and sensitive analytical method was developed for the simultaneous determination of clenbuterol, chloramphenicol and diethylstilbestrol in bovine milk by isotope dilution ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Samples were directly purified through HLB cartridge. The organic phase was dried under nitrogen and residues were redissolved in mobile phase. Samples were analyzed by UPLC-MS/MS on an Acquity UPLC® BEH C18 column with gradient elution. The samples were quantified using clenbuterol-D9, chloramphenicol-D5 and diethylstilbestrol-D8 as internal standards. The proposed method was validated according to the European Union regulation 2002/657/EC determining specificity, decision limit (CCα), detection capability (CCβ), trueness, precision, linearity and stability. The method is demonstrated to be suitable for the determination of clenbuterol, chloramphenicol and diethylstilbestrol in bovine milk. The total time required for the analysis of one sample was about 50min. © 2011 Elsevier B.V. Source

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