场放大样品进样-压力辅助毛细管区带电泳测定饮用水中的百草枯

Rapid,Simple and Ultrasensitive Analysis of Paraquat in Drinking Water by Field-Amplified Sample Injection Combined with Pressure-Assisted Capillary Zone Electrophoresis

1引言 百草枯属有机杂环类季铵盐除草剂,由于它具有优良的除草效果,已广泛应用于多种作物的杂草防治。百草枯具有极强的水溶性,极易迁移至水体环境中,从而对饮用水的质量安全构成潜在威胁。目前,百草枯的残留检测方法主要有分光光度法[1]、液相色谱质谱联用法[2]、气相色谱质谱联用法[3]和毛细管电泳法（CE）[4～6]。

Field-amplified sample injection（FASI） combined with pressure-assisted capillary zone electrophoresis（CZE） was developed for the determination of paraquat in drinking water.High reproducibility in FASI-CZE process could be attained with constant pressure applied at both ends of capillary.Compared with conventional hydrodynamic injection,the enrichment factor of 1174 was achieved for paraquat by FASI.Several parameters including length of water plug,injection time and composition of sample solution were systematically optimized.Linearity,sensitivity,precision and accuracy were investigated to validate the proposed method.The result showed that the calibration curve was linear at the concentration of 1.0-100 μg/L with a correlation coefficient of 0.9975.The limit of detection was 0.039 μg/L（S/N=3）.Mean recovery of paraquat was ranged from 78.4% to 94.5% with relative standard deviation ranging from 3.0% to 10.4%.Finally,the method proposed was applied for the determination of paraquat in real drinking water.