Reduction of Pesticide Residues in Field-Sprayed Leafy Vegetables by Washing and Boiling

The reduction rate of pesticide residues on spinach(bifenthrin, metalaxyl, procymidone), chard(bifenthrin, imidacloprid) and mallow(bifenthrin, chlorpyrifos, imidacloprid) were tested on each step of washing and boiling(spinach: 1, 3, 5min., chard: 3, 6, 9min., mallow: 10, 20, 30min.). The reduction rates of bifenthrin and procymidone by washing were and 82%, and these were not changed significantly after boiling. In case of imidacloprid, the rates showed 43% on chard and 12% on mallow by washing, and these were highly increased to 94% after boiling. And the reduction rate of metalaxyl and chloropyrifos were 69% and 11% by washing, and and by boiling. Specifically we monitored the pesticide residues on both boiled vegetable and its water because there are used to cook as soup in Korea. The total residual amounts of imidacloprid and chloropyrifos were effectively removed on both boiled mallow and its water (, ), however, the other tested pesticides were not changed on pesticide residues when calculated with total amounts on boiled vegetable and its water. These explained the other pesticides were just moved vegetable to water by boiling.