摘要
马拉硫磷和丙溴磷是2种常用的有机磷杀虫剂,均有一个手性中心存在2个对映体。采用室内避光培养的方法,在对映体水平上研究了马拉硫磷和丙溴磷在2种土壤中的降解情况。结果表明,2种农药在土壤中的降解均较快,马拉硫磷和丙溴磷的降解半衰期分别为:黄土中3.5h和21.5h,红土中4.3h和29.4h。进一步的手性测定表明2种农药的降解均存在一定的对映体差异,丙溴磷对映体的选择性明显高于马拉硫磷,在2种土壤中马拉硫磷的左旋对映体降解快于右旋对映体,丙溴磷的右旋体降解快于左旋体。研究有助于深入认识2种有机磷农药在环境中的归趋,并对其生态风险性进行更合理的评估。
Malathion and profenophos are widely used as organophosphorous insecticides. Either of the two insecticides has one chiral center in stereostructure, and therefore they exist as two enantiomers respectively. In this paper, the enantioselective degradation of malathion and profenophos in two typical soils were studied in details. Our results showed that the two pesticides were degraded fast in the two soils. The half-lives of malathion and profenophos were 3.5 and 21.5 h in huabei yellow soil, and 4.3 and 29.4 h in hubei red soil, respectively. Further chiral analysis demonstrated their enantioselectivities during the degradation of the two pesticides. It was further observed obviously that the enantiosclectivity of profenophos was much higher than that of malathion. Moreover, the （-）-enantiomer of malathion was degraded faster than the （＋）-enantiomer in the two soils. As for profenophos, the （＋）-enantiomer was degraded faster than its corresponding （-）-enantiomer in the two soils. The study results are useful for better understanding the environmental profiles of malathion and profenophos as well as further ecological risk evaluation of the two pesticides.
出处
《生态环境学报》
CSCD
北大核心
2009年第4期1247-1250,共4页
Ecology and Environmental Sciences
基金
国家自然科学基金青年基金项目(20707005)
