Analysis of multi-pesticide residues in the foods of animal origin by GC-MS coupled with accelerated solvent extraction and gel permeation chromatography cleanup

A new analytical method was developed to simultaneously determine residues of 109 pesticides (including isomers) in the foods of animal origin. Acetonitrile was selected for accelerated solvent extraction (ASE) for effectively extracting the pesticides from the fatty samples. The cleanup was performed with an automated gel permeation chromatography (GPC) cleanup system. The prepared samples were analysed with GC-MS in the selected ion monitoring mode (SIM) using one target and two qualitative ions for each analyte. Chlorpyrifos-d(10) was used as an internal standard. The lowest limit of detection was 0.3 mu g kg(-1) for some pesticides. The recoveries and relative standard deviations (RSDs) were checked by spiking untreated samples with pesticides at 0.05, 0.1 and 0.2 mg kg(-1). The average recoveries of most pesticides were from 62.6% to 107.8%. The precision values expressed as RSD were all <= 20.5% (n = 6). Good linearity (r >= 0.99) was observed between 0.05 and 1.5 mu g mL(-1). (C) 2010 Elsevier Ltd. All rights reserved.