Multiresidue analysis of 74 pesticides in fruits and vegetables by liquid chromatography–electrospray–tandem mass spectrometry

A multiresidue method is described for the determination of 74 pesticides commonly used in crop protection including mainly carbamate, conazole, benzimidazole and pyrimidine fungicides and insecticides. Pesticides residues are extracted from the samples with ethyl acetate. No additional clean-up steps are necessary. Analysis is performed by liquid chromatography–electrospray ionization–tandem mass spectrometry. The method has been validated for various fruits and vegetables matrices. Good sensitivity and selectivity of the method are obtained with limits of quantification of 0.01 mg/kg in almost all cases. Recoveries, RSD and accuracy values of the method fulfilled the criteria of validation commonly admitted. The method was applied very satisfactorily to routine analysis as a complement to traditional GC method. More than 2500 fruits and vegetables samples have been controlled, as a part of the pesticide monitoring program of the “Service de Protection de la Consommation” in Geneva. Quality control systems applied during the assays have demonstrated very good performances and stability with time.