摘要
采用液相色谱-三重四极杆串联质谱,建立了测定昆虫对茚虫威活化代谢（N-脱甲氧羰基反应,产物为DCJW）活性的新方法.按本方法制备样品后30 h内,产物DCJW的化学稳定性较好,5次重复测定的相对标准偏差（RSD）为2.1％.本方法的检出限为0.01 pg,定量限为0.1 pg;DCJW纯乙腈溶液、小菜蛾酶促反应样品连续进样、5次独立酶促反应样品分别进样,3组样品独立测定的RSD分别为0.7％,1.1％,2.7％;3种DCJW添加水平（440,880和2200 pg）的回收率为96.1％～102.9％,RSD为4.8％～9.4％;DCJW在46～2310 pg范围内线性关系良好.本方法灵敏度高,操作方便,适用于昆虫代谢酶系对茚虫威的活化代谢活性分析.应用本方法比较了小菜蛾阿维菌素抗性品系与敏感品系对茚虫威N-脱甲氧羰基代谢活性差异,结果表明,小菜蛾抗性品系对茚虫威N-脱甲氧羰基活性是敏感品系的3.43倍,初步推断小菜蛾对杀虫剂阿维菌素和茚虫威可能存在负交互抗性.
Abstract A new method for measuring indoxacarb N-decarbomethoxyllation activity catalyzed by insect crude enzymes, was developed by triple-quadrupole LC-MS/MS. The metabolite, N-decarbomethoxyllated indoxacarb （DCJW）, was determined using electrospray isozation in positive ion mode. The quantitative and qualitative analyses were performed in MRM. The relative standard deviation （RSD） （n = 5 ） of DCJW was 2, 1%, indicating the metabolite had a good chemical stability in 30 h after the sample preparation. Five injections of DCJW standard solution in acetonitrile, five injections of the same sample in one incubation （ substrates plus enzyme samples）, and five injections of 5 separate metabolic reactions with the whole body of a susceptible strain of Plutella xylostella （ L. ） were individually injected into LC/MS system, and the RSD was 0.7%, 1.1% and 2.7%, respectively. The average recoveries of 440, 880 and 2200 pg DCJW added to incubation mixtures were 96. 1% - 102. 9% , and the RSD of recoveries of three added levels ranged 4.8% -9.4%. The limits of quantification and detection were 0. 1 pg and 0.01 pg, respectively. A good linearity was achieved in the range of 46-2310 pg （R2 =0. 9996）. This method with high sensitivity and simplicity was applied to the assay of indoxacarb N-deearbomethoxyllation activity of insect metabolic enzymes. A comparison of indoxacarb N-decarbomethoxyllation activity of an avermectin-resistant strain and a susceptible strain of Plutella xylostella （L.） was carried out using this novel LC-MS/MS method. The indoxacarb N-decarbomethoxyllation activity in the resistant strain was 3. 43-fold of that in the susceptible strain, implicating that negative cross-resistance might exist between indoxacarb and avermectin in Plutella xylostella （L.）.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
2014年第4期463-468,共6页
Chinese Journal of Analytical Chemistry
基金
国家重点基础研究发展计划项目(973计划)(No.201203038)资助~~
关键词
液相色谱-三重四极杆串联质谱
茚虫威
活化代谢
小菜蛾
Keywords Liquid chromatoraphy-triple quadrupole mass spectrometry
Indoxacarb
Activation metabolism
Plutella xylostella （ L. ）
