微波辅助水蒸气萃取结合液液分散微萃取法萃取西红柿中三嗪类农药残留

Rapid extraction of triazine pesticides from tomatoes by microwave-assisted steam diffusion method

中文关键词:  三嗪类农药  液相色谱-串联质谱法  西红柿  农药残留

英文关键词:Triazine pesticides  high performance liquid chromatography-tandem mass spectrometry  tomatoe samples  residues

中文摘要:

      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300 μL乙腈的水蒸气, 样品与石英砂比例为1:2, 收集液体积为18 mL; 分散液液微萃取中的萃取剂为350 μL的氯仿, 分散剂为600 μL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500 μg/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2 μg/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。

英文摘要:

      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 ?L acetonitrile, the proportion of the sample and quartz sand was 1:2, and the collected volume was 18 mL; and the extractant was 350 ?L chloroform, the dispersion agent was 600 ?L acetone, and added 0.2 g NaCl for disperse liquid-liquid microextraction. The recoveries were ranged from 62.1% to 108.1% for the 6 kinds of triazine pesticides with 3 spiked levels of 1, 50 and 500 μg/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 μg/kg. Conclusion The proposed method is fast, accurate and sensitive, which is suitable for triazine pesticides detection in tomato samples.