Abstract: A gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed for the analysis of organochlorine pesticides (OCP) and polychlorinated biphenyls (PCBs) in milk. Samples were?pre-processed with 30% sulfuric acid-methanol, and then extracted with n-hexane. The supernatant extract was puri?ed by a modi?ed quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction procedure, and the?purified extract was detected by GC-MS/MS and quantified by the matrix standard calibration curve method. The results showed that all the target analytes displayed good linear relationships in the range of 5–200 μg/L with correlation coefficients more than 0.99. The limits of detection (LODs) of OCPs and PCBs ranged from 0.1 to 0.3 μg/kg. The average recoveries of OCPs and PCBs from spiked samples were in the ranges of 85.5%–115.2%, with relative standard deviations (RSDs) less than 10% (n = 6). In summary, the proposed method due to its simplicity, high accuracy and ef?ciency could be used for the rapid screening and quantitative analysis of organochlorine pesticide and polychlorinated biphenyls in milk.

Key words: gas chromatography-tandem mass spectrometry (GC-MS/MS), QuEChERS, organochlorine pesticides, polychlorinated biphenyls, milk