摘要
[目的]通过对三甲苯草酮光解特性的研究,探讨其降解机理并对环境影响作出评价。[方法]实验室条件下,以300 W汞灯为光源,高效液相色谱法测定三甲苯草酮在不同介质中的残留量。[结果]三甲苯草酮的光解特性符合一级动力学方程,300 W汞灯照射下,三甲苯草酮在p H值为4、7、9的缓冲溶液中的半衰期分别为135.9、123.8、65.4 min;正己烷、丙酮、甲苯和乙酸乙酯中的半衰期分别为7.1、113.6、46.2、39.4 min;Cu2+、K+、Mg2+和Fe3+存在的溶液中,三甲苯草酮的半衰期分别为38.1、38.3、29.8、15.5 min;蒸馏水、自来水、稻田水和伊通河水中的半衰期分别为1.9、1.7、1.0、1.4 h。[结论]偏碱时对三甲苯草酮的光解有促进作用,偏酸时有一定抑制作用;丙酮对三甲苯草酮表现为光猝灭作用,正己烷表现为光敏化作用;溶液中存在Fe3+会促进三甲苯草酮的光解;由于自来水、稻田水和伊通河水中存在的金属离子、有机质、微生物及水体p H的影响,导致了三甲苯草酮的加速降解。
[Aims] The aims were to investigate the degradation mechanism and to evaluate the environmental impact of tralkoxydim by researching the photolysis characteristics. [Methods] Tralkoxydim degraded in different mediums under the 300 W mercury lamp as light source in the laboratory, and the residues were determined by high performance liquid chromatography （HPLC）. [Results] The photolysis dynamics of tralkoxydim was accorded with the one-level kinetics equation. Under the 300 W mercury lamp irradiation, the half-lives of tralkoxydim in buffer solution with the pH of 4, 7 and 9 were 135.9, 123.8, 65.4 min, respectively; the half-lives of tralkoxydim in n-hexane, acetone, toluene and ethyl acetate solutions were 7.1, 113.6, 46.2, 39.4 min, respectively; the half-lives of tralkoxydim in solution of Cu^2＋, K^＋, Mg^2＋ and Fe^3＋ were 38.1, 38.3, 29.8, 15.5 min, respectively; the half-lives of tralkoxydim in distilled water, tap water, paddy field water and Yitong river were 1.9, 1.7, 1.0, 1.4 h, respectively. [Conclusions] The photolysis of tralkoxydim was restrained under lower pH but was promoted under higher pH; the optical quenching effect and photosensitization effect were shown in acetone and n-hexane, respectively; the photolysis of tralkoxydim was promoted sinced Fe^3＋ existed in the solution; the degradation of tralkoxydim was accelerated because of the influences of metal ions, organic matter, microorganisms and pH in tap water, paddy field water and Yitong river.
出处
《农药》
CAS
CSCD
北大核心
2015年第6期407-410,共4页
Agrochemicals
基金
农业部农药残留项目(2013NCJ001)
