唑啉草酯的水解及光解特性  

Hydrolysis and photolysis characteristics of pinoxaden

作　　者：欧将 刘开林[3] 滕玉婷 曾利红 张贵群[1,2] 聂春林 欧晓明[1,2] OU Jiang;LIU Kailin;TENG Yuting;ZENG Lihong;ZHANG Guiqun;NIE Chunlin;OU Xiaoming(National Engineering Research Center for Agrochemicals/Hunan Province Key Laboratory for Agrochemicals,Hunan Research Institute of Chemical Industry,Changsha 410014,China;Hunan Research Institute of Chemical Industry Testing Technology Co.,Ltd.,Changsha 410014,China;College of Plant Protection,Hunan Agricultural University,Changsha 410128,China)

机构地区：[1]湖南化工研究院国家农药创制工程技术研究中心/湖南省农用化学品重点实验室,长沙410014 [2]湖南化研院检测技术有限公司,长沙410014 [3]湖南农业大学植物保护学院,长沙410128

出　　处：《农药学学报》2022年第3期649-654,共6页Chinese Journal of Pesticide Science

基　　金：湖南省自然科学基金项目(2019JJ50270).

摘　　要：在实验室条件下,采用高效液相色谱和高效液相色谱-串联质谱研究了唑啉草酯在不同条件下的水解和光解特性。结果表明:在pH值分别为4.0、7.0和9.0的缓冲溶液中,25℃时唑啉草酯的半衰期分别为347、40.8和1.08 h,50℃时则分别为57.8、11.6和0.498 h,均为易水解;唑啉草酯在碱性条件下易水解,酸性条件下水解较慢;其水解速率随温度升高而升高,温度效应系数为2.18~6.00。在模拟太阳光氙灯辐射下,唑啉草酯在缓冲溶液中的光解速率随其pH值的升高而加快,在pH值为8.0时最短,为10.0 h;唑啉草酯在自然水体中的光解速率依次为池塘水>稻田水>河水>纯水,4种条件下的半衰期分别为5.17、7.79、8.56和38.5 h。唑啉草酯水解的主要产物是M2(8-(2,6-二乙基-4-甲基苯基)-9-羟基-1,2,4,5-四氢吡唑[1,2-d][1,4,5]噁二氮杂卓-7-酮),其降解机理主要是酯水解反应,M2在光照条件下进一步降解,表明光解为唑啉草酯降解的一个重要途径。研究结果可为唑啉草酯在水体中的环境行为及其环境安全性评价提供参考。The hydrolytic and photolytic characteristics of pinoxaden under different conditions were investigated by high performance liquid chromatography(HPLC)and high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)in laboratory conditions.The results showed that in the buffer solutions of pH 4.0,7.0 and 9.0,the hydrolysis half-lives of pinoxaden were 347,40.8 and 1.08 h at 25℃,and were 57.8,11.6 and 0.498 h at 50℃,respectively,which classified it as easily hydrolysis type.The hydrolysis of pinoxaden was rapid under alkaline conditions,but slowly under acidic conditions.The hydrolytic rate of pinoxaden increased with the increase of temperature,and the temperature effect coefficients ranged from 2.18 to 6.00.Under the irradiation of xenon simulated sunlight,the photo-degradation half-lives of pinoxaden in the buffer solutions were decreased with the increase of pH value,and the shortest was 10.0 h at pH of 8.0.The photolytic rates of pinoxaden in different natural water showed the following sequence:pond water>paddy water>river water>pure water,and the half-lives were 5.17,7.79,8.56 and 38.5 h,respectively.The main hydrolysis product of pinoxaden was M2(8-(2,6-diethyl-4-methyl-phenyl)-9-hydroxy-1,2,4,5-tetrahydro-pyrazolo[1,2-d][1,4,5]oxadiazepin-7-one),and the main degradation mechanism was the hydrolyzation of the ester group.M2 was further degraded under light conditions,indicating that photolysis was an important degradation way of pinoxaden.The results provided a scientific reference for the environmental behavior and safety assessment of pinoxaden in water environment.

关 键 词：唑啉草酯 水解 光解 半衰期 

分 类 号：O657.63[理学—分析化学] TQ457.2[理学—化学]