FATE OF SOME INSECTICIDES FROM VINE TO WINE

The fate of residues of five insecticides (chlorpyrifos methyl, fenthion, methidathion, parathion methyl, and quinalphos) from the treatment on vine to the production of wine was studied. The influence of clarifying agents (bentonite, charcoal, potassium caseinate, gelatin, polyvinylpolypyrrolidone, and colloidal silicon dioxide) on residue concentrations in wine was also studied. The insecticide residues on grapes showed high decay rates after treatment, with first-order kinetics and half-lives ranging from 0.97 to 3.27 days. Grape processing into wine caused considerable residue reduction (>80%) for chlorpyrifos methyl, parathion methyl, and quinalphos, moderate reduction (ca. 50%) for methidathion, and almost no reduction for fenthion. The wine-making technique (with or without maceration) had the same influence on the residue concentrations in wine. The clarifying agents tested showed no or moderate influence on the residue contents in wine with the exception of charcoal, which allowed complete or almost complete elimination of insecticide residues.