Determination of captan, folpet, and captafol in fruits and vegetables, using two multiresidue methods

Two multiresidue methods, the Mills method and the Luke et al. method, are widely used for the determination of pesticides in foods. These methods were evaluated for the determination of the fungicides captan, folpet, and captafol in selected fruits and vegetables. The analytical behavior of standards through these methods was investigated first. Recoveries from apples, strawberries, lettuce, and tomatoes fortified with these compounds at levels of 0.2-5.9 ppm were then obtained. The analytes were quantitated by gas chromatography with electron capture detection, using a column of 5% SP-2401 on 100-120 mesh Supelcoport. Recoveries of captan, folpet, and captafol from fortified crops ranged from 69 to 78, 90 to 93, and 67 to 83%, respectively, by the Mills procedure and from 87 to 102, 81 to 106, and 91 to 109%, respectively, by the Luke et al. method modified to include additional solvent elution of the optional Florisil column.