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Du J.,Wuhan Polytechnic University | Lu B.,China Center for Food Safety Risk Assessment | Zhu P.,China Center for Food Safety Risk Assessment | Miao H.,China Center for Food Safety Risk Assessment | Wu Y.,Wuhan Polytechnic University
Se pu = Chinese journal of chromatography / Zhongguo hua xue hui

A new analytical method was developed for the determination of 30 organochlorine pesticides (OCPs) in animal-originated food, including pork, chicken, fish and shrimp. The combined purification by gel permeation chromatography (GPC) and solid-phase extraction (SPE) were established by optimizing different fraction collection times. The detection conditions can be achieved by gas chromatography-mass spectrometry (GC-MS) using selective ion monitoring (SIM). Isotopic internal standards were used for the quantitative determination of the 30 OCPs. The sample pretreatment procedure was based on acetonitrile extraction and combined purification of GPC and Florisil SPE cartridge. The experimental results showed that the linear ranges for 30 OCPs were 5.0 - 500.0 microg/L, the correlation coefficients were better than 0.996, and the method detection limits (MDLs) of the 30 OCPs were 0.2 - 2.7 microg/kg. The spiked recoveries at three levels of 5.0, 10.0 and 20.0 microg/kg using pork, chicken, fish and shrimp samples as blank matrices were in the range of 55.0% - 119.1%, the relative standard deviations (RSDs) were in the range of 0.4% - 15.0%. The method has the advantages of wide linear range, high sensitivity and efficient clean-up procedure, and consistent with the demand of pesticide routine analysis. Source

Fan S.,Institute of Nutrition and Food Hygiene | Zou J.H.,Chinese Peoples Liberation Army | Miao H.,China Center for Food Safety Risk Assessment | Zhao Y.F.,China Center for Food Safety Risk Assessment | And 4 more authors.
Food Additives and Contaminants - Part A Chemistry, Analysis, Control, Exposure and Risk Assessment

A liquid chromatography-linear ion-trap spectrometry (LC-MS3) method using β-receptor molecular-imprinted polymer (MIP) solid-phase extraction (SPE) as clean-up was developed to determine simultaneously and confirmatively residues of 25 β2-agonists and 21 β-blockers in urine samples. Urine samples were subjected to enzymatic hydrolysis by β-glucoronidase/arylsulphatase, and then extracted with perchloric acid. Sample clean-up was performed using β-receptor MIP SPE. A Supelco Ascentis® express Rp-Amide column was used to separate the analytes, and MS3 detection used an electrospray ionisation source in positive-ion mode. Recovery studies were carried out using blank urine samples fortified with the 46 analytes at the levels of 0.5, 1.0 and 2.0 μg l-1. Recoveries were obtained ranging from 60.1% to 109.9% with relative standard deviations (RSDs, n = 7) from 0.5% to 19.4%. The limits of detection (LODs) and limits of quantitation (LOQs) of the 46 analytes in urine were 0.02-0.18 and 0.05-0.60 μg l-1, respectively. As a result of the selective clean-up by MIP SPE and MS3 detection of the target drugs, the sensitivity and accuracy of the present method was high enough for monitoring β2-agonist and β-blocker residues in urine samples. Satisfactory results were obtained in the process of the determination of positive urine samples. © 2013 Taylor & Francis. Source

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