Abstract: A multi-residue method for the simultaneous determination of 62 pesticide residues in chicken eggs was developed using gas chromatography-tandem mass spectrometry (GC-MS/MS) after clean-up by enhanced matrix removal of lipids (EMR-Lipid). The sample was extracted with a mixture of 10 mL of 1% acetic acid-acetonitrile and 5 mL of H2O and then salted out by adding sodium chlorid. Finally, 5 mL of the extracted organic phase was transferred to an EMR-Lipid tube for cleanup and high-speed centrifugation, and the analytes were detected by GC-MS/MS and quantified by the external standard method. Good linearity was shown for the 62 analytes with correlation coefficients exceeding 0.95. The limit of detection (LOD) and the limit of quantitation (LOQ) for 59 of the pesticides in eggs were 0.5–5.0 μg/kg and 1.0–20.0 μg/kg, respectively. The recoveries and repeatability for the 62 pesticides in eggs obtained using EMR-Lipid were both better than those obtained directly using a solid-phase extraction tube. The average recoveries at a spiked level of 100 μg/kg were 70.7%–117.2% for 61 of the pesticides, with relative standard deviations (RSD) between 0.3% and 10.9%. Only 20 of the pesticides showed weak matrix effects, and the test results for them should be corrected using matrix standard solutions. This method has been applied to actual sample analysis successfully.

Key words: gas chromatography-tandem mass spectrometry; enhanced matrix removal of lipids; chicken egg; pesticide multi-residues