残留的五种有机磷农药在菜豆烹饪过程中的降解

采用气相色谱法检测了久效磷、毒死蜱、马拉硫磷、对硫磷、敌敌畏5种有机磷农药在菜豆烹饪过程中残留量的变化。结果表明:菜豆经油炸后,除久效磷未降解外,其余农药降解率在37.6%~85.1%之间。油炸时间的长短对敌敌畏降解影响较大,炸5 min时降解率为37.6%,7 min 时降解率为65.2%;油炸时间长短对其余农药的降解均无显著影响。炒的过程中5种农药的降解率在7.6%~56.5%之间;蒸的过程中降解率为23.0%~63.4%;未盖锅盖煮的条件下降解率为39.5%~81.7%,盖锅盖煮后降解率为42.0%~86.4%。在加盖煮10 min后的汤中,各种农药的残留量在0.03~0.50 mg/L 之间。炒过的菜豆再经微波加热2 min后, 5种农药残留量比炒过之后又降解了21.0%~41.5%。

Degradation of Five Organophosphate Pesticides in French Bean during Cooking Processes

The effects of cooking on the residue levels of monocrotophs,chlorpyrifos,malathion,parathion and dichlorvos in samples of French bean were determined by gas chromatography.The results showed that the residues of pesticides were decreased except monocrotophs during frying.The degradation rate ranged from 37.6 % to 85.1%.The frying time was more impacting to dichlorvos degradation than those of other pesticides.The degradation rate of dichlorvos was 37.6% after 5 min frying,and 65.2% after 7 min frying,while no significant changes of degradation rate were observed on other four pesticides.Losses of the residues due to processing were as following: stir-frying,7.6%~56.5%;steaming,23.0%~63.4%;boiling in a uncovered utensil,39.5%~81.7%;boiling in a covered utensil,42.0%~86.4%.When boiling the French bean for 10 min in a covered utensil,the residues in the soup was ranged from 0.03 to 0.50 mg/L.After 2 min heating by microwave,the degradation rates of five pesticides in French bean which have been stir-fried were 21.0%~41.5%.