固相萃取-气相色谱/质谱法分析水果和蔬菜中残留的嘧菌酯

Determination of Azoxystrobin Residues in Fruits and Vegetables by Gas Chromatography/Mass Spectrometry with Solid-Phase Extraction

建立了多种水果和蔬菜中嘧菌酯残留的气相色谱／质谱分析方法。首先用乙酸乙酯一环己烷（体积比为1：1）对样品中的嘧菌酯进行超声波提取，经硅胶固相萃取小柱对样品提取液进行净化、富集，采用气相色谱／质谱法以选择离子监测模式（m／z344，372，388，403定性，m／z344定量）进行检测。实验结果表明，嘧菌酯在0．01～1．0mg／kg浓度范围内呈线性，其相关系数r〉0．99。在低、中、高3个添加水平，嘧菌酯的回收率为85．2％-98．2％，相对标准偏差为5．8％～21．5％。方法的检测限不大于0．01mg／kg，定量限不大于0．05mg／kg。

A method was developed for the determination of azoxystrobin residues in fruits and vegetables by gas chromatography/mass spectrometry （GC/MS）. Azoxystrobin residues were extracted with ethyl acetate-cyclohexane （1：1, v/v） by ultrasonication and then they were cleaned up on a silica solid-phase extraction （ SPE ） column to obtain an extract suitable for analysis by GC/MS in the selective ion monitoring （SIM） mode （ the selected ion： m/z 344, 372, 388 and 403）. The calibration curves were linear between area and concentration of azoxystrobin from 0.01 to 1.0 mg/kg with the correlation coefficient greater than 0.99. The average recoveries from spiked fruit and vegetable matrixes at three concentrations of 0.01, 0. 1, 1.0 mg/kg ranged from 85.2% to 98.2% with relative standard deviation less than 21.5%. The limit of detection was 0.01 mg/kg and the limit of quantity was 0.05 mg/kg in fruit and vegetable matrixes, respectively.