液相色谱质谱法直接进样测定饮用水中6种常用农药残留

Determination of 6 Pesticides Simultaneously in Drinking Water by Liquid Chromatography-Mass Spectrometry

目的建立同时测定生活饮用水中毒死蜱、丁草胺、乙草胺、敌敌畏、莠去津和多菌灵6种常用农药的超高效液相色谱串联质谱（UPLC-MS/MS）分析方法。方法采用Waters公司Acquity UPLC BEH C18柱（2.1 mm×50 mm）,以乙腈/甲醇和0.1%甲酸水溶液为流动相,进行梯度洗脱分离。经正离子电喷雾（ESI＋）电离及多反应监测（MRM）模式检测。结果毒死蜱和敌敌畏的质量浓度在2.5~100μg/L,丁草胺和乙草胺的质量浓度在0.5~20μg/L,莠去津的质量浓度在0.125~5μg/L,多菌灵的质量浓度在0.05~2μg/L范围时,线性相关系数r≥0.999;毒死蜱、丁草胺、乙草胺、敌敌畏、莠去津和多菌灵的最低检测质量浓度分别为7,21,10,5和1 ng/L。平均回收率为84.7%~105.0%,相对标准偏差为1.5%~6.1%。用该分析方法检测了7个地下水样品,都检出了莠去津残留,浓度在0.01~0.03μg/L。结论该方法具有操作简便、灵敏度高、抗干扰能力强、样品分析时间短等特点,可用于饮用水中6种农药残留水平和残留动态的日常监测。

Objectives An ultra-performance liquid chromatography-tandem mass spectrometric method（ UPLC-MS / MS） was established for the simultaneous determination of chlorpyrifos,butachlor,acetochlor,dichlorvos,atrazine and carbendazim residues in drinking water. Methods Water samples were separated by a Acquity UPLC BEH（ 2. 1mm × 50 mm） C18 column with a gradient elution of acetonitrile / methanol and 0. 1% formic acid,and detected by UPLC-MS / MS. The identification was achieved by eletrospray ionization（ ESI＋） in multiple reactions monitoring（ MRM） mode. Results There was a good linear relationship while the levels of chlorpyrifos and dichlorvos were 2. 5 ~ 100 μg / L,the levels of butachlor and acetochlor were 0. 5 ~ 20 μg / L,the levels of atrazine were0. 125 ~ 5 μg / L and that of carbendazim were 0. 05 ~ 2 μg / L in tested samples; the correlation coefficients were not less than 0. 999. The detection limits were 7,21,10,5 and 1 ng / L for chlorpyrifos,butachlor,acetochlor,dichlorvos,atrazine and carbendazim,respectively. The recoveries were in the ranged of 84. 7% ~ 105. 0% with relative standard deviations of 1. 5% ~ 6. 1%. The results indicated that the method was easy,rapid,efficient,and suitable for simultaneous determination of six pesticide residues in drinking water. Atrazine was detected in all7 underground water samples by the method,and the concentration was 0. 01 ~ 0. 03μg / L. Conclusions The method was simple and rapid with good accuracy and high sensitivity. The method could meet the needs for the determination of these 6 pesticides in drinking water.