Multiresidue analysis of organochlorine and organophosphorus pesticides in muscle of chicken, pork and lamb by gas chromatography-triple quadrupole mass spectrometry

A method was optimized and validated for the simultaneous determination of residues of organochlorine (OCPs) and organophosphorus (OPPs) pesticides in meat samples from chicken, pork and lamb. The method is based in the extraction of homogenized meat mixed with sodium sulphate and ethyl acetate in polytron, although both Soxhlet and accelerated solvent extraction (ASE) were also tested. Then, a clean-up step by gel permeation chromatography (GPC) was applied, before the final determination by gas chromatography (GC) coupled to a triple quadrupole (QqQ) mass spectrometry (MS) detection system. Confirmation criteria of the pesticides were based in the 2002/657/EC European Commission Decision that establishes at least three identification points (IPs) for organic residues in live animals and animal products. The analytical process was validated in each matrix by the analysis of spiked blank samples. Performance characteristics, such as linearity, detection limit (LOD), quantitation limit (LOQ), precision and recovery were studied. Recoveries and precision values were 70.0-90.0% and 15%, respectively, for the bulk majority of pesticides. LOD < 2.0 and LOQ < 5.0 mu g/kg were obtained for all the target compounds, except for acephate. The proposed analytical methodology was applied to the analysis of the pesticides in 30 samples, 10 from chicken, 10 from pork and 10 from lamb. Only three OCPs, endosulfan alpha, endosulfan sulfate and dichloran were detected in three different lamb samples, while endosulfan a was detected in only one pork sample, at concentration levels lower than the LOQ values. However, pesticide residues were not found in any of the other 10 chicken samples analyzed. (c) 2005 Elsevier B.V. All rights reserved.