Evaluation of gas chromatography–tandem quadrupole mass spectrometry for the determination of organochlorine pesticides in fats and oils

A gas chromatography–tandem quadrupole mass spectrometry multi-residue method for the analysis of 19 organochlorine pesticides in fats and oils has been developed. Gel permeation chromatography was employed to remove lipid material prior to GC–MS/MS analysis. Average recoveries of the pesticides spiked at 10 and 50 μg kg−1 into fish oil, pork fat, olive oil and hydrogenated vegetable oil were typically in the range 70–110% with relative standard deviations generally less than 10%. Calculated limits of detection are between 0.1 and 2.0 μg kg−1 and results obtained for the analysis of proficiency test materials are in good agreement with assigned values. The higher selectivity of the GC–MS/MS compared to electron capture detection and GC–MS in selective ion monitoring mode allowed unambiguous identification and confirmation of all the target pesticides at low μg kg−1 levels in fats and oils in a single analysis.