QuEChERS-超高效液相色谱-串联质谱法测定香菇中56种农药残留

Determination of 56 pesticides in Lentinus edodes using QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry

建立了香菇中多菌灵、啶虫脒、氟虫腈等56种农药残留的超高效液相色谱-串联质谱（UPLC-MS/MS）检测方法。样品以酸化乙腈为提取剂,涡旋提取,N-丙基乙二胺（PSA）和十八烷基键合硅胶（C_（18））粉末分散固相萃取净化,经BEH-C_（18）超高效液相色谱柱分离后,在电喷雾正离子（ESI^＋）模式下,通过多反应监测（MRM）模式测定。结果表明：56种农药在一定的浓度范围内线性关系良好,决定系数（R^2）均大于0.99;56种农药的平均回收率在71%～121%之间,相对标准偏差为0.6%～9.2%,符合农药多残留分析的要求。考察了溶剂和滤膜对检测结果的影响。结果发现,当定容溶剂含有高比例的水相时,哒螨灵等化合物在过聚四氟乙烯（PTFE）或尼龙材质的滤膜时有明显损失。基质效应测定结果显示,灭多威等40种化合物表现为弱基质效应,甲胺磷等16种化合物表现为中等强度基质效应。研究表明,建立的QuEChERS-超高效液相色谱-串联质谱法能够对香菇中56种农药残留进行快速、准确的测定。

A simple and fast multi-residue method was established to simultaneously determine 56 pesticide residues, such as carbendazim, acetamiprid, and fipronil, in Lentinus edodes using ultra performance liquid chromatography tandem mass spectrometry（UPLC-MS/MS）. Samples were extracted with acidic acetonitrile and then cleaned up with a mixture of sorbents（PSA and C_（18））.Compounds were ionized using the electrospray ionization（ESI~＋） and operated in positive mode.Results showed that good linearity was achieved with a determination coefficient of 0.99. Recoveries ranged from 71% to 121% with relative standard deviation（RSD） of 0.6% to 9.2%, which were good enough for the routine analysis of the pesticide residues. The effect of solvents and filter membranes on the detection of L. edodes were also investigated. When the solvent contains a high proportion of water phase, pyridaben and other compounds have a significant loss when filtered through the PTFE or nylon filter. The results of matrix effect study showed that 40 pesticides, such as methomyl, exhibited weak matrix effect. And 16 pesticides, such as methamidophos, showed moderate medium matrix effect. The method can be used as routine analysis method in multi-residual pesticide monitoring of L. edodes.