Development and full validation of a multiresidue method for the analysis of a wide range of pesticides in processed fruit by UHPLC-MS/MS.

A reliable 16-min analytical method for the simultaneous determination of 250 pesticides in processed fruit using ultra-performance liquid chromatography, coupled to tandem mass spectrometry (UHPLC-MS/MS), was developed and validated according to SANTE 11813/2017 guidelines and accredited successfully based on ISO 17025. Extraction was achieved using a modified QuEChERS method, without any clean-up, including a dilution to obtain good peak shapes and to reduce matrix effects. Pesticides were quantified using matrix-matched calibration, and the method was validated in terms of relative retention time window, linearity (6-167 µg kg and 0.6-16.7 µg kg, coefficient R ≥ 0.98), trueness (recovery of 70-120%), selectivity, precision (RSD ≤ 20%), limits of quantification (LOQs = 0.6-6.0 µg kg) and uncertainty. Finally, the method was applied to the routine analysis of 103 samples of processed fruits, detecting the presence of several pesticide residues, such as fluopyram, spinosad or cyprodinil (0.006-0.22 mg kg).