The effect of clarifying substances on organophosphorous insecticide residues in wine

The influence of six clarifying agents (bentonite, charcoal, potassium caseinate, gelatine, polyvinylpolypyrrolidone and colloidal silicon dioxide) on pesticide residues in wine was studied. Thirteen pesticides belonging to the class of organophosphorous insecticides were studied at two different doses. Almost all clarifying agents showed no or limited ability in reducing pesticide residues. The only exception was charcoal which allowed complete or almost complete elimination of pesticide residues, especially when they were at lower doses. Charcoal activity usually decreased on increasing pesticide water solubility. Therefore, pesticides that are highly soluble in water, such as dichlorvos and dimethoate, showed no sensible decrease.