微波辅助液液微萃取-气相色谱-质谱分析蔬菜、水果中的多种拟除虫菊酯残留

将微波辅助萃取同液液微萃取技术相结合，利用气相色谱-质谱分析技术，结合时间编程-选择离子检测模式，开发了一种简捷、实用、回收率高的蔬菜、水果中多种拟除虫菊酯残留的检测技术。该技术同当前执行的国标方法相比，有机溶剂用量少，操作简便，提取液无须严格净化便可进行GC／MS分析，大大提高了分析速度。经基体标准加入回收实验，除联苯菊酯外，其他9种菊酯的10ng／g的加样回收率均在75％以上，且在国标要求的最大残留限量附近有良好的线性关系，能满足当前蔬菜、水果中拟除虫菊酯残留的检测要求。

Determination of Pyrethroid Insecticide Resdues in Vegetable and Fruit by Microwave-assisted Liquid-Liquid Microextraction and Gas Chromatography-Mass Spectrometry

A simple, rapid and reproducible multiresidue analytical method for the determination of pyre-throids at low nanogram levels in vegetable and fruit is described. Preconcentration was achieved by treating the sample with microwave-assisted extraction (MAE) and liquid-liquid microextraction (LLME) using n-hex-ane. Pyrethroid quantification was achieved by gas chromatography (GC) with mass spectrometry (MS) de-tection in electron impact (EI) and time program-selected ion monitoring mode (EI/SIM). The recovery effi-ciencies of the tested pesticides yield vary from 75% to 110% at a fortification level of 10 ng/g. And their relative standard deviations (RSD) vary between 4.5% and 10.7%. Detection limit of each compound varies between 0.01 and 0.1 ng/g without any additional clean-up, with linear ranges from 0.5 to 2500 ng/g.