Multi-residue analysis of pesticide residues in fruits and vegetables using gas and liquid chromatography with mass spectrometric detection

This article summarizes the results of the validation studies of a multi-residue method for the determination of pesticide residues in fruits and vegetables. The results of the monitoring control programs carried out in Cyprus during 2016 are also presented. In total, 314 samples of fruits and vegetables were analyzed for residues of, in total, 243 different pesticides. Gas chromatography and liquid chromatography coupled with mass spectrometry (GC-MS/MS and LC-MS/MS) were used to assess the levels of pesticide residues. For the extraction of the compounds the ethyl acetate extraction method with Ultra Turrax (Christodoulou et al. in J Wine Res 26:81-98, 2015a, Int J Environ Anal Chem 95:894-910, 2015b) was modified so that a quick and efficient extraction method could be applied. For the validation of the method blank samples were spiked with a solution of 203 and 101 pesticides for the LC-MS/MS and GC-MS/MS analyses, respectively, at two levels. The validation study was in accordance with DG SANTE guidelines (European Commission, Safety of the Food Chain Pesticides and biocides SANTE/11813/2017 (21-22 November 2017 Rev.0), 2017). The scope of validation included recovery, linearity, limit of quantification and precision. The measurement uncertainty was calculated using the results of proficiency tests. Out of a total of 314 analyzed samples 196 (62.4 %) were found contaminated with pesticide residues, whereas 38.5 % of the samples contained more than one pesticide. 6.7 % of the samples exceeded the MRLs of the regulation EU 396/2005. The most frequently found pesticides were cypermethrin, boscalid, imidacloprid and tebuconazole.