丁虫腈在环境中的降解特性

采用室内模拟试验研究丁虫腈在水体中的光解、水解及其在3种不同类型土壤中的降解特性。结果表明，丁虫腈在酸性和中性条件下比较稳定，不易水解，而在碱性条件下水解较快，在50℃、pH值为9．0的缓冲溶液中降解半衰期为26．7d。通过对水解产物的鉴定，推断丁虫腈的水解机理为碱催化水解。在光]照度为2500lx、紫外强度为25I．LW·cm-2的人工光源氙灯条件下，丁虫腈的降解半衰期为1．5h，主要降解产物为氟虫腈。丁虫腈在太湖水稻土、江西红壤和陕西潮土中培养180d后均未发生明显降解，表明该农药在土壤中较难降解。

Degradation of Flufiprole in the Environment.

Degradation of flufiprole in water via various mechanisms, hydrolysis and photolysis, and in 3 different types of soils was investigated under laboratory conditions. Resuhs show that flufiprole is rather stable and not easy to break down in acid and neutral solutions, but easily gets hydrolyzed in alkaline solution with half-life being 26. 7 d in solution 9.0 in pH and 50 ~C in temperature. Through identification of its hydrolytic products, it could be inferred that the hydrolysis of flufiprole in water is alkali-catalyzed one. Under the artificial light of a Xe lamp, 2 500 lx in light intensity and 25 IxW ~ cm-2, flufiprole has a half-life of 1.5 hour, and its photolytic product was mainly fipronil. But in the paddy soil of Taihu, red soil of Jiangxi and fluo-aquic soil of Shaanxi, flufiprole was found almost unchanged after 180 days of incubation, sug- gesting that flufiprole is hard to break down in soil.