PERSISTENCE AND FATE OF FENTHION IN OLIVES AND OLIVE PRODUCTS

Two field experiments were carried out-with three and five treatments, respectively-to study the persistence and metabolism of fenthion in olives. Fenthion showed a low degradation rate, with a half-life of ca. 38 days. This accounts for a noteworthy effect of the number of treatments on the residue amounts at harvest time. Besides the active ingredient, five metabolites were detected in olives; among these, fenthion sulfoxide and fenoxon sulfoxide were quantitatively the most important. Olives were also processed into oil, and the partitioning of fenthion among oil, cake, and vegetation water was evaluated. Fenthion residues in oil were ca. 3 times higher than in olives, while its metabolites showed analogous residues in olives and oil or were totally absent.