Pesticide residues in grapes and during vinification process

Pesticide residues in vinification process of two white and two red grapevine varieties were monitored during the 2007 vintage. Crushed grapes, cake, must, lees and wine were sampled during the vinification process. Additionally, grapes were sampled during the ripening process. All samples were taken in triplicate and analyzed for the presence of 117 pesticides. The pesticide residues were determined by three validated internal analytical methods: the multi-residual GC-MS method (71 pesticides), the multi-residual LC-MS-MS method (45 pesticides) and GC-MS method for the determination of dithiocarbamates (the sum of their concentrations is given as a concentration of carbon disulfide). Boscalid and phosalone were the most persistent pesticides in grapes during ripening. The concentrations of pesticide residues in must and wine were significantly diminished through separations during the solid and liquid phases of the vinification process, particularly the pressing of crushed grapes and wine racking after alcoholic fermentation. The pesticides detected throughout the vinification process were boscalid, cyprodinil, dimethomorph, fenhexamid, metalaxyl and procymidone and their concentrations in the wines were 0.01–0.02, 0.04, 0.01–0.08, 0.12–0.13, 0.09–0.11 and 0.07–0.13 mg L−1 respectively.