毛细管区带电泳场放大进样检测自来水中季铵盐类除草剂  

Analysis of Quaternary Ammonium Herbicides in Tap Water by Fieldamplified Sample Stacking of Capillary Zone Electrophoresis

作　　者：张庆庆[1] 孟品佳[1] 王燕燕 张文芳 

机构地区：[1]中国人民公安大学,北京100038 [2]法庭毒物分析公安部重点实验室,北京100192

出　　处：《刑事技术》2016年第4期265-269,共5页Forensic Science and Technology

基　　金：公安部科技强警基础工作专项项目(No.2013GABJC002)

摘　　要：本文建立了毛细管电泳场放大堆积在线富集技术检测自来水中百草枯、敌草快和燕麦枯3种季铵盐类除草剂的方法。采用p H4的200 mmol/L磷酸盐溶液（含体积分数为20%乙腈）为分离缓冲液,0.5 psi压力下引入去离子水3 s,10 k V电迁移进样30 s,＋2 5k V下分离12 min,对3种季铵盐类除草剂进行分离和测定。其中百草枯和敌草快的LOD均达到0.1 ng/m L;百草枯和敌草快线性范围0.25-10μg/m L,回归系数0.995和0.998。燕麦枯则更适用于压力进样方式,优化条件下,其自来水中检测限可以达到100 ng/m L,0.25-10μg/m L范围内线性回归系数为0.993。3种除草剂的日内精密度和日间精密度均小于8%和11%。该方法简单、快速,无需进行样品前处理,且能获得较高灵敏度,可应用于自来水中该类药物的检测。In this paper,we established a capillary zone-electrophoresis analytical method for the determination of three herbicides of paraquat, diquat and difenzoquat in tap water. Capillary electrophoresis （CE） is a popular separation technique for the charged molecules. However, because of the short optical detection length and low sample loading, it has some limitations in terms of sensitivity, thereby restricting its use into a wide range of applications. Much effort has been devoted to address this problem. Sample pretreatment and/or online pre-concentration represent some approaches to increase the sensitivity of CE. Employed the online field-amplified stacking （FASS） injection technique. No sample pretreatment was needed. In this method, a phosphate solution （pH=4.0） containing 20 % acetonitrile was used as separation buffer. After optimization of the key parameters and experimental set-ups, the best stacking efifciency was obtained under these conditions：deionized water to be introduced at ifrst at 0.5 psi pressure for 3s, followed by the introduction of sample solution at 10 kV for 30s. The separation was conducted under 25 kV and completed in 12 min, and the three herbicides were well separated. In the method validation, results demonstrated that paraquat and diquat were given linearity at concentration range of 0.25-10 μg/mL （coefifcient： 0.995 and 0.998）, with their LODs of both 0.1ng/mL based on the signal-to-noise ratio of 3：1. For the difenzoquat, the hydrodynamic injection mode was more suitable than FASS mode. Good linear relation was obtained over the scope of 0.25 -10 μg/mL with related coefifcient of r2=0.993 and its LOD of 100ng/mL. The intra-day precisions of our method for the three herbicides were all less than 7.5% and those of the inter-dayall below 10.4%. This method is simple, sensitive, able to be used in the rapid detection and determination of quaternary ammonium herbicides in tap water.

关 键 词：毛细管区带电泳 场放大样品堆积 季铵盐类除草剂 自来水 

分 类 号：DF795.1[医药卫生—法医学]