Removal efficiencies of ten pesticide residues from cucumber by five processing methods

The removal efficiencies of ten pesticide residues (carbendazim, imidacloprid, acetamiprid, diethofencarb, propamocarb, profenofos, cypermethrin, triazophos, dichlorvos and pyrimethanil) from cucumber by five different processing methods (washing, boiling, stir-frying, peeling and salting) were investigated under laboratory simulation using LC-MS/MS and GC-MS/MS. The results showed that peeling was the most effective pesticide removal method among these processing methods. Especially, in the cases of  profenofos and cypermethrin, the processing factors by peeling were both 0.04. The pesticide removal abilities of other investigated processing methods were in the following order: boiling > stir-frying, washing, and salting. Meanwhile, it was found that the effects of processing methods were directly related to the log K_ow of each pesticide. The smaller the log K_ow of pesticides, the easier to remove them by washing and boiling. Moreover, we also investigated the time effect of pesticide residue removal with washing, boiling and stir-frying within 10 min. The results showed a decreasing trend of pesticide residue amounts with the increase of treatment time. For all investigated pesticide residues, the processing factors for washing, boiling and stir-frying varied in the region of 1.00-0.62, 0.86-0.37 and 1.13-0.52, respectively, after 10 min treatments.