作　　者： ; ; ; ; ;

机构地区： 河北科技大学理学院

出　　处： 《环境科学与技术》 2011年第5期121-123,139,共4页

摘　　要： 文章以汞灯为光源,在对映体水平上考察了六种典型手性农药的光化学降解。丙溴磷、马拉硫磷、稻丰散、三唑酮和甲氰菊酯等五种农药含有1个手性中心,存在两个对映体,对各对映体分别进行光解,结果表明光解速率基本一致,且几种手性农药是手性稳定的,未发现对映体转化现象,几种农药中有机磷农药降解较快,而甲氰菊酯降解最慢,半衰期长达280h。氯氰菊酯含有3个手性中心,存在4个可在非手性硅胶柱上得到拆分的异构体,每个异构体又存在两个对映体,因此共8个对映体。进一步对氯氰菊酯的一个反式异构体所含的一个单一对映体进行光解,结果发现存在一定的异构体转化,氯氰菊酯的另外3个异构体均有生成,按氯氰菊酯各异构体总量计算的光解半衰期为66.7h。 6 chiral pesticides were investigated in the study related to their photolysis characteristics by using mercury lamp as light source.Profenophos,malathion,phenthoate,triadimefon and fenpropathrin each has one chiral center and thus exists as two enantiomers.The photolysis of individual enantiomers from one chiral pesticide showed similar dissipation rates of the two enantiomers.No enantiomerization was observed for 5 chiral pesticides.3 organophosphorus insecticides were photolyzed very rapidly,whereas fenpropathrin had the slowest photolysis rate with a half-life time of 280 h.Cypermethrin has 3 chiral centers and consists of 8 enantiomers which constitute 4 diastereoisomers that could be separated on a chiral silica-gel column.Further photolysis was performed for a single enantiomer from diastereoisomer Ⅳβ-trans-2.Results indicated that certain amounts of diastereoisomers Ⅰ,Ⅱand Ⅲ were produced,suggesting isomerization took place along with photolysis process.By summing the concentrations of 4 diastereoisomers the total half-life was calculated to be 66.7 h.

关 键 词： 手性农药 光解 异构体 对映体 半衰期

领　　域： [环境科学与工程]