A method by combining liquid chromatography with tandem mass spectrometry was developed to determine the residues of 20 pesticides in edible fungi.Samples were extracted using acetonitrile containing 0.1%acetic acid cleaned-up with anhydrous magnesium sulfate and primary secondary amine (PSA).Measurement on the residues was conducted on the extracts under the modes of electrospray positive ionization (ESI +)and multiple reaction monitoring (MRM),using external standards.The calibration curves of the pesticides had a linear relationship with a correlation coefficients greater than 0.99 in the range of 0.005 to 0.10 mg·kg-1 .The optimized testing conditions included a lower limits of quantitation (LOQs,S/N>10)at 0.005 mg·kg-1 .A test for recovery was performed by adding 0.05 mg·kg-1 standard pesticides to the mushrooms and white fungi.It was found that the recovery rates ranged from 65.1% to 96.0%,with a relative standard deviations of 2.5% - 9.0%.It was concluded that the newly developed methodology was rapid and accurate,and could be applied for the determination of the 20 pesticide residues in edible fungi.%本研究建立了食用菌中20种农药残留同时检测的液相色谱-串联质谱(LC-MS/MS)检测方法。样品经含0.1%乙酸的乙腈提取,经无水硫酸镁、N-丙基乙二胺(PSA)净化,以电喷雾电离正离子(ESI+)、多反应检测模式(MRM)进行检测,外标法定量。20种农药在0.005~0.10 mg·kg-1范围内线性关系良好,相关系数大于0.99。该分析方法快速、准确,通过优化前处理和上机条件,在最优条件下进行测试,方法定量下限(S/N>10)为0.005 mg·kg-1,在香菇和白木耳中进行0.05 mg·kg-1加标水平测试,其回收率为65.1%~96.0%,RSD 为2.5%~9.0%。该方法适用于食用菌中20种农药测定。
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