蔬菜中阔草清等8种农药残留量的高效液相色谱-质谱分析

Simultaneous determination of eight pesticide residues in vegetables by liquid chromatography-mass spectrometry

建立了固相萃取-高效液相色谱-电喷雾质谱法同时测定蔬菜中的阔草清、西玛津、硫双威、绿麦隆、扑草净、仲丁威、马拉硫磷和二嗪农等8种农药的分析方法.蔬菜用乙腈超声波提取,经过ODS-C18固相萃取小柱富集纯化.采用C18柱分离,以体积分数0.03%甲酸乙腈-体积分数0.03%甲酸水溶液为流动相,线性梯度洗脱,以保留时间和质荷比对分离出的组分进行定性,用峰面积进行定量.结果表明,8种农药的质量浓度与其峰面积在一定的范围内呈良好的线性关系,检出限为0.1～5.0 μg/L,相关系数为0.9939～0.9998,样品的加标平均回收率为83%～106%,相对标准偏差为3.1%～9.8%.方法适用于蔬菜中阔草清等8种农药残留量的分析.

A solid phase extraction-liquid chromatography-eleetrospray mass spectrometric （SPE-LC-ES-MS） method for the determination of flumetsulam, simazine, thiodicard, chlortolurm, prometryn, fenobucarb, malathion and diazinon in vegetables has been developed. The samples were extracted with acetonitrile using ultrasotmd-assisted extraction, then enriched and cleaned up by ODS-C18 solid phase extraction column. The analytes were separated by using a C18 column （5 p.m, 150 mm×2.1 mm i. d. ） and 0.03% formic acid in acetonitrile - 0.03% formic acid aqueous solution as the mobile phase with linear gradient elution. The eight pesticides were identified by retention time and m/z and quantified by peak areas. The results demonstrated that the linear ranges were 10.0- 1000.0 μg/L, 20.0 1000.0μg/L, 10.0 - 1000.0μg/L, 2.0 - 500.0μg/L, 1.0 - 500.0μg/L, 8.0 - 1000.0μg/L, 12.0 - 1000.0μg/ L, 0.5 - 50.0μg/L with a detection limit of 3.0, 5.0, 2.5, 0.4, 0.2, 2.0, 3.0, 0.1μg/L for flumetsulam, simazine, thiodicard, chlortolum, prometryn, fenobucarb, malathion and diazinon, respectively. The average recoveries for all eight analytes ranged from 83% to 106% and the relative standard deviations were 3.1% - 9.8% （ n = 6）. The method is accurate and suitable for the identification and quantification of these pesticides in vegetables.