固相萃取/高效液相色谱-串联质谱法同时检测环境水样中24种农药残留

建立了一种固相萃取/高效液相色谱-串联质谱(SPE/HPLC-MS/MS)同时检测水体中24种农药的分析方法。样品用乙腈提取后,经固相萃取小柱富集净化。以乙腈-0.1%(体积分数)甲酸水溶液为流动相梯度洗脱,在电喷雾离子源正离子模式下(ESI+)采用多反应监测(MRM)模式检测。结果显示,24种农药在1~200μg/L范围内具有良好的线性关系,相关系数(r2)均不小于0.998,水样中3个添加水平(5、20、100μg/L)下的回收率为65.9%~127.8%,相对标准偏差(RSD)为0.7%~14.2%;方法检出限为0.05~0.71 ng/L。采用该方法对大连地区10个河流入海口及2个水库的水样进行了检测,12个站位的样品中共检出10种农药,质量浓度为0.2~558.3 ng/L。结果表明,所建立的SPE/HPLC-MS/MS方法高效、灵敏、可靠,可用于实际水体中多种农药的同时检测。

Simultaneous Determination of 24 Pesticide Residues in Environmental Water Using Solid-phase Extraction and High Performance Liquid Chromatography-Tandem Mass Spectrometry

A method of solid-phase extraction (SPE) and high performance liquid chromatography-tandem mass spectrometry(SPE/HPLC-MS/MS) was developed for the simultaneous determination of 24 pesticides in water.The samples were extracted with acetonitrile,then enriched and purified with solid-phase extraction cartridges.Acetonitrile and 0.1％ (by volume) formic acid aqueous solution were used as mobile phases.Target pesticides were analyzed by HPLC-MS/MS in positive electrospray ionization(ESI +) under multiple reaction monitoring(MRM) mode.Results showed that 24 pesticides were separated in 25 rain with excellent linear relationships(r2 ≥0.998).The recoveries at spiked levels of 5,20,100 μg/L in water samples ranged from 65.9％-127.8％ with relative standard deviations(RSDs) of 0.7％-14.2％.The limits of detection were in the range of 0.05-0.71 ng/L.This method was applied in the detection of the water samples from 10 estuaries and 2 reservoirs in Dalian,and 10 pesticides were detected in the concentration range of 0.2-558.3 ng/ L.The proposed SPE/HPLC-MS/MS method is efficient and sensitive,and is suitable for the determination of various pesticides in actual water samples.