A study on the persistence of trifluralin, chlorpyrifos, decamethrm, cypermethrin and dichlorvos in rice and beans after cooking in a commercial microwave oven

摘要

The objective of this research was to evaluate the persistence of trifluralin, chlorpyrifos, decamethrin, cypermethrin and dichlorvos in rice and beans after cooking in a commercial microwave oven. The rice and beans, spiked with pesticides at levelsof 1.0 mg/kg, were cooked at powers of 500 W and 800 W for 15 and 45 minutes, respectively. The pesticides were quantified by gas chromatography using electron capture (Ni~(63)) and flame photometric detectors. After cooking, the residual levels of trifluralin, chlorpyrifos, decamethrin, cypermethrin and dichlorvos in the rice and beans were respectively, on average, 0.03, 0.04, 0.02, 0.05 and 0.01 mg/kg for rice and 0.01, 0.02, 0.05, 0.08 and 0.01 mg/kg for beans. Thus, from 92 percent to 99 percent of pesticides were eliminated. We conclude that cooking in a microwave oven causes a decrease in the residue levels of these pesticides.