Multiresidue method for the control of pesticide residues in tomatoes and derived products
A new multiresidue method, intended for the routine analysis of 60 multi-class pesticides in tomatoes and derived products, has been developed. The method uses gas chromatography, with a large volume injection system and tandem mass spectrometry detection (LVI-GC-MS-MS). The pretreatment of the samples is fast and simple, as the pesticide residues are extracted from the sample with ethyl acetate in presence of NaHCO3 and anhydrous Na2SO4, without additional clean-up steps and, consequently, with cost and time saving benefits. The method presents appropriate selectivity and good sensitivity with limits of quantification (LOQs) between 0.5 and 20 μg kg−1, which are lower than the maximum residue levels established by several regulatory legislation. Average recoveries between 70 and 115%, with a relative standard deviation lower than 20% in all cases, and good linearity were obtained in the studied concentration range. For the routine analysis, a quality control system was applied to avoid false positive and false negative results.