Validation of Two Variations of the QuEChERS Method for the Determination of Multiclass Pesticide Residues in Cereal-Based Infant Foods by LC-MS/MS

Over the past years to ensure food safety and particular for food that intend to be consumed by infants and young children, the European Union has adopted specific legislation concerning the control of pesticide residue levels in that kind of food. In this paper, a liquid chromatography tandem quadrupole mass spectrometry (LC-MS/MS) multiresidue method for the simultaneous analysis of 23 pesticides and metabolites chosen according to the Commission Directives 2006/141/EC, 2006/125/EC, and 96 multiclass pesticides and metabolites chosen according to their physicochemical properties is presented and validated. The extraction procedure is based on three modifications of the quick, easy, cheap, effective, rugged, and safe method according to the analyte. The analytical performance was demonstrated by the analysis of extracts from cereal-based infant foods, spiked at two concentration levels for each pesticide or metabolite. Good sensitivity and selectivity of the method were obtained with limits of quantification at 10 or 3 mu g/kg, depending on the analyte. All pesticides and metabolites, except six cases, gave recoveries in the range of 60.4-125.4%, with relative standard deviations less than 29.7%, for both validation levels.