Application of full scan gas chromatography high resolution mass spectrometry data to quantify targeted-pesticide residues and to screen for additional substances of concern in fresh-food commodities.

A novel application, which combines targeted and non-targeted approaches, using gas chromatography high-resolution mass spectrometry (GCHRMS) for multiresidue analysis of pesticides in fruits and vegetables is proposed; the aim is to add information to that obtained from targeted methods to be used in pesticide residues monitoring laboratories. Extract from fruit samples obtained with QuEChERS method are analysed with two different approaches: a first step in targeted mode in full scan, and a second step in non-targeted mode with HRMS deconvolution. The targeted method was validated for 191 pesticides, in banana, watermelon, pear and strawberry, with recoveries within 70-120%, precision-RSD <20%, linearity between 1-100 µg/kg (5-100 µg/kg in strawberry) and quantification limits (LOQs) of 5 µg/kg. For targeted method, 12 different pesticides in 14 samples were detected. The non-targeted approach allowed the corroboration of all the results obtained through targeted method, in addition other compounds were tentatively identified.