Multiresidue analysis of 184 pesticides in high-fat fish feed using a new generic extraction method coupled with gas and liquid chromatography-tandem mass spectrometry

Abstract

Animal feed is typically plant-based and can contain pesticide residues. Methods for testing food and feed samples, such as the Quick Easy Cheap Effective Rugged Safe (QuEChERS) method or the Swedish Ethyl Acetate (SweEt) method, successfully extract many pesticide residues. However, nonpolar pesticides, such as organochlorine pesticides, show poor recovery when extracted from lipid-rich samples. The previously developed water-acetonitrile-heptane-solid-phase-extraction (WAHSPE) method shows better recoveries for the nonpolar pesticides but requires two injections per sample and per instrument. Here, we present a modified version of the WAHSPE method for pesticides in fish feed using one injection per sample and per instrument. Of the 184 pesticides tested, 179 met the European Union Legislation’s validation criteria at a spike level of 50 μg/kg, showing recoveries between 70 and 120% and a relative standard deviation (RSD) below 20%. Organochlorine pesticides accounted for 14 of the tested compounds.