气相色谱-串联质谱法测定食用菌中的70种农药残留量

Analysis of 70 pesticides in edible fungi by GC-MS / MS

目的采用气相色谱-串联质谱(GC-MS/MS)分析技术,通过全扫描、子离子扫描和多反应监测(MRM)模式,确定各农药的保留时间、监测离子对以及碰撞能量等质谱参数,结合固相萃取样品前处理技术,建立食用菌中70种农药残留量的测定方法。方法样品用乙腈提取,经过滤、氯化钠盐析后,有机相过CARB/NH2固相萃取小柱净化,浓缩、定容、装进样瓶后,利用GC-MS/MS在MRM模式下进行测定,外标法定量。结果所有农药的质量浓度为0.01 mg/L^2.00 mg/L时,呈现良好的线性关系,相关系数(r)均>0.99,定量限为0.001 mg/kg^0.009 mg/kg。在0.05 mg/kg、0.10 mg/kg和1.00 mg/kg 3种添加水平下,新鲜食用菌的加标回收率为71.6%~127.6%,相对标准偏差(RSD)为3.3%~15.8%。结论本方法简便、重现性良好,可用于食用菌样品中多农药残留的确证和定量检测。

Objective A method was developed for the simultaneous determination of 70 pesticides in edible fungi based on sol- id phase extraction（SPE） with gas chromatography tandem mass spectrometry（ GC -MS/MS）. Retention time, monitoring of ion pair and collision energy were establish by full scan, ion scan and multi - reaction monitoring （MRM） modes. Methods The samples were extracted with acetonitrile, filtered and salted out by sodium chloride NaCl. Then, the organic phase was purified by SPE column of CARB/NH2, concentrated, quantified and filled into bottles. The targeted compounds was analyzed and iden- tiffed by GC - MS/MS system under the mode of MRM, and quantified by the external standard method. Results There was a good linearity when the concentration of each pesticide was among 0.01 mg/L -2.00 mg/L, and the linear correlation coeffi- cients （ r ） was greater than 0.99. The limits of quantization （LOQ） were among 0.001 μg/kg - 0. 009 μg/kg. The recovery ra- tio of fresh edible fungus at levels of 0. 05 mg/kg, 0. 10 mg/kg and 1.00 mg/kg were found to be in the range of 71.6% - 127.6%, with the relative standard deviations（RSD） of 3.3% - 15.8%. Conclusion This method was suitable for the screening and quantification of multi - pesticides in edible fungi due to its simplicity and good sensitivity.