Pesticides in wines from two major production regions in the North of Spain

Abstract

The occurrence of fungicides and insecticides in wines from two reputed production regions in the North of Spain (Galicia and La Rioja) was assessed by liquid chromatography tandem mass spectrometry, including achiral and chiral analysis of more than four hundred wines, elaborated in four consecutive vintages. Fungicides presented a higher prevalence than insecticides in all samples, particularly those employed for the treatment of mildew infections. Individual compounds showed different distribution patterns in wines from both geographic regions, likely related to the different pressure of diseases affecting their vineyards. Total residue varied significantly among wines from the five denominations of origin in Galicia, with higher levels in those closest to the Atlantic coast. Temporal trends point out to a slight reduction in total residues of pesticides in wine. On the other hand, chiral analysis reflected that metalaxyl, the top concentration pesticide in most of the processed wines, was applied to vines as a mixture of active and non-active enantiomers. Thus, a potential reduction in the residues of this fungicide in wine are expected after the future phase-out of racemic formulations. Maximum concentrations of pesticides in wine remained below 10 % of maximum residues authorized in vinification grapes. Moreover, independently of the production area, the moderate consumption of wine contributes less than 1 % to the acceptable daily intake of most often detected pesticides.