The study of changes of bromopropylate and carbendazim residues during apple processing was carried out. It was stated that bromopropylate residues on apples before and after washing stayed at similar levels (0.024 mg/kg) and then dropped by 60% during apple processing while those of carbendazim remained at the level of 0.10 mg/kg during the whole process.
Disappearance of iprodione deposits on peppers, eggplants and tomatoes grown in commercial greenhouses and in a foil tunnel were studied. lt was found that iprodione residues on ripening fruits decreased according to simple regression lines. Their initial values dropped by half and reached zero levels within 2.5-2.8 and about 5 weeks after Rovral FLO 255 SC application, respectively. lprodione deposits on pepper leaves dropped within four weeks only by 30% white on eggplant leaves in practice stayed at the same level. The chemical may be suitable for the comparative study of real disappearance of pesticides after their applications for the control of pests and diseases.
Disappearance of chlorothalonil, dichlofluanid, vinclozolin and carbendazim, as active ingredients of agrochemicals commonly used for the protection of greenhouse vegetables against fungal diseases, was studied comparatively. It was found that initial residues of chlorothalonil and dichlofluanid dropped by half within 4 and 2 weeks after treatment, respectively, while the deposits of vinclozolin and carbendazim were the most persistent and after 5 weeks still constituted 50% of their initial levels. Therefore, the obtained results indicated that iprodione, procymidone and vinclozolin should ensure the longest effective protection of greenhouse tomatoes while chlorothalonil, and especially dichlofluanid, for the shortest.
Partition coefficients, determined for the aqueous/acetone solution - dichloromethane system, ranged from 40 to 100, and indicated that the losses of the twenty two tested pesticides, potentially resulting from incomplete extraction procedure, should not exceed 1% and may well be disregarded as the possible cause of error. The recoveries of individual pesticides from spiked samples, using a single extraction with dichloromethane, were within a narrow range of 80 to 90% with Relative Standard Deviations not exceeding 5-6%.