Residues of Dimethoate and Profenofos in Tomato and Cucumber, and Dissipation During the Removal within Home Processing Method

The persistence patterns of dimethoate and profenofos in fruits of tomato and cucumber and elimination of their residues through washing or home processing methods were studied. Residues were determined by gas liquid chromatography. Results showed that, the consumable safety time was found to be 10, and 14 days after application on tomato and cucumber. This was found to be enough to reduce the residues to below the maximum residue limits (MRLs). However, dimethoate and profenofos appeared to have relatively longer persistence on cucumber fruits with t1/2 of 1.92 and 1.82 days than on tomato fruits with 1.69 and 1.73 days, respectively. Results indicated that potassium permanganate, tap water and acetic acid solution gave high removal percentage of dimethoate from tomato fruits, while no detectable residues were found in cucumber. In addition, all tested washing solutions gave moderate to higher percent removal of dimethoate and profenofos residues from vegetable fruits. Tomato paste removed ≈100% of insecticide residues, while pickling of cucumber removed 97.50 and 98.69% of insecticide after one week and ≈100% after two weeks, respectively.