【摘要】 目的建立一种基于微波辅助水蒸气萃取结合液液分散微萃取用于西红柿中三嗪类农药残留的绿色萃取方法。方法西红柿样品经微波辅助水蒸气萃取后,用液液微萃取法对萃取液进行净化和富集,采用液相色谱-串联质谱法(LC-MS/MS)对三嗪类农药进行定性和定量分析。结果微波辅助水蒸气萃取结合液液微萃取法的最佳萃取条件为:微波功率为200 W,萃取剂为添加300μL乙腈的水蒸气,样品与石英砂比例为1:2,收集液体积为18mL;分散液液微萃取中的萃取剂为350μL的氯仿,分散剂为600μL的丙酮,并加入0.2 g NaCl以增加三嗪类农药的回收率。在最佳的萃取条件下,6种三嗪类农药在1、50和500μg/kg添加水平的回收率为62.1%~108.1%;日内和日间精密度分别在1.6%~6.7%和4.8%~10.3%之间(n=6),方法定量限为2μg/kg。结论该方法快速、准确、灵敏,适合测定西红柿中三嗪类农药残留。更多还原

【Abstract】 Objective To extract triazine pesticides in tomato samples by microwave-assisted steam diffusion combined with disperse liquid-liquid microextraction.Methods Tomato samples were extracted by microwave-assisted steam diffusion method,and then obtained extract was purified and enriched by disperse liquid-liquid microextraction.The triazine pesticides were detected using liquid chromatography-tandem mass spectrometry(LC-MS/MS) with multiple reactions monitoring(MRM).Results The results of optimized extraction conditions were as follows:microwave forward power was 200 W,the extractant was water vapor with 300 μL acetonitrile,the proportion of the sample and quartz sand was 1:2,and the collected volume was18 mL;and the extractant was 350 μL chloroform,the dispersion agent was 600 μL acetone,and added 0.2 g NaCl for disperse liquid-liquid microextraction.The recoveries were ranged from 62.1%to 108.1%for the 6kinds of triazine pesticides with 3 spiked levels of 1,50 and 500 ug/kg.The intra- and inter-day relative standard deviation(RSDs) were 1.6%~6.7%and 4.8%~10.3%(n=6),and the limit of quantitation(LOQ) for the 6 kinds of triazine pesticides was 2 υg/kg.Conclusion The proposed method is fast,accurate and sensitive,which is suitable for triazine pesticides detection in tomato samples.更多还原