溴虫腈在不同溶剂中的光化学降解  

Study on photochemical degradation of chlorfenapyr in different solvents

作　　者：孙晓燕[1] 赵百萍[1] 王鸣华[1] 

机构地区：[1]南京农业大学植物保护学院农药科学系,南京210095

出　　处：《农药学学报》2013年第4期469-474,共6页Chinese Journal of Pesticide Science

基　　金：国家公益性行业(农业)科研专项经费项目(201203022)

摘　　要：研究了高压汞灯光源下溴虫腈在不同溶剂中的光化学降解特性及其影响因素。在室内模拟条件下,初始质量浓度为2 mg/L的溴虫腈在纯水中的光解半衰期为25.86 min,在1～10 mg/L范围内,其光解速率随初始浓度的增大而降低;溴虫腈在pH值为5、7和9的缓冲溶液中的光解半衰期分别为42.52、24.49和32.39 min,即其在中性条件下光解最快;不同形态含氮离子(NO2-、NO3-、NH4+)对溴虫腈的光解均表现为抑制作用,且在离子质量浓度<20 mg/L时,NO3-、NO2-的抑制作用较强,≥20 mg/L时则NH4+的抑制作用较强;溴虫腈在不同有机溶剂中的光解速率从大到小依次为:正己烷>甲醇>乙酸乙酯>丙酮,其光解速率与有机溶剂的极性大小无关。研究结果可为溴虫腈的环境风险评价提供参考。The photochemical degradation characteristics of chlorfenapyr and its influencing factors were investigated in different solvents under high-pressure mercury lamp （HPML）. Under simulated experiment in laboratory, the half-life of chlorfenapyr in pure water was 25.86 rain at 2 mg/L, the photolytic rate negatively correlated with the increasing concentration of chlorfenapyr in pure water at a range from 1 mg/L to 10 mg/L. The photolysis half-lives of chlorfenapyr were 42.52,24.49 and 32. 39 rain in buffer solution of pH 5,7 and 9, respectively. The result indicated that the degradation velocity of chlorfenapyr was the fastest in the buffer solution of pH 7. The photochemical degradations of chlorfenapyr were inhibited in water solutions that contained NO2^-, NO3^- or NH4. The inhibition of NO2^- and NO3 were stronger at the concentrations less than 20 mg/L, the inhibition of NH4 was stronger at the concentration greater than or equal to 20 mg/L. The photolytic rates of chlorfenapyr in different organic solvents showed the following sequence： n-hexane 〉 methanol 〉 ethyl acetate 〉 acetone. The photodegradation rate had no correlation with organic solvent polarity. The results provided a scientific basic for environmental risk assessment of chlorfenapyr.

关 键 词：溴虫腈 有机溶剂 光解 氮 

分 类 号：TQ450.263[化学工程—农药化工] O657.71[理学—分析化学]