Pirimiphos-methyl Residues on/in Some Field-grown Vegetables and its Removal Using Various Washing Solutions and Kitchen Processing

ABSTRACT Pirimiphos-methyl (Actellic 50% EC), was sprayed on field-grown pepper and eggplant at the recommended rate of 0.89 kg a.c ha -1 . Fruit samples were collected at 1h to 14 days after application and analysed to determine the content and dissipation rate of pirimiphos-methyl. The effect of different washing solutions and some kitchen processing on the removal of such residues from treated vegetables were also investigated. Pirimiphos-methyl residues were quantified by using gas chromatography. The results showed that the consumable safety time were 7 days on sweet pepper, 10 days on hot pepper and 14 days on eggplant fruits. The initial disappearance of pirimiphos-methyl appeared to follow first order kinetics with different rates of reaction i.e. 0.31, 0.40 and 0.37 day -1 for hot pepper, sweet pepper and eggplant, respectively. The corresponding halflives ( t 1/2 ) were 2.20, 1.72 and 1.88 days. Results further indicated that acetic acid, potassium permenganate, sodium chloride and sodium hyroxide solution gave greater removal of pirimiphos-methyl residues from sweet pepper and eggplant fruits, while 70.16-76.61% removal was shown in hot pepper fruit after washing with soap and acetic acid solution, respectively. In general, all tested washing solutions gave higher removal of pirimiphos-methyl residues from eggplant fruit than the two other pepper fruits. Blanching and frying of pepper and eggplant fruits resulted in almost completely removed (~ 100%) of the deposited pirimiphos-methyl. In addition, pickling process removed 86.29 and 92.34% from hot pepper fruit after one week and after two weeks, respectively