固相萃取-超快速液相色谱-串联质谱法测定当归中135种农药及其代谢物残留

建立了超快速液相色谱-串联质谱(UFLC-MS/MS)同时测定当归药材中135种农药及其代谢物(包括有机磷类、氨基甲酸酯类、拟除虫菊酯类农药等)残留量的分析方法。以回收率为考察指标,评估了不同的提取溶剂、固相萃取小柱、洗脱溶剂及体积对当归中多农残的提取净化效果,最终确定样品经乙腈提取,PSA固相萃取柱净化处理,在电喷雾正离子扫描、依赖保留时间的多反应监测模式(scheduled MRM)下,以基质匹配校准曲线内标法定量。结果表明,135种农药及其代谢物在各自的浓度范围内线性关系良好(r>0.99); 3个添加水平(10、50、100 μg/kg)下,除了烯草酮回收率偏低(62.0%~68.2%)外,其余农药的回收率为71.3%~119.7%,相对标准偏差(RSD, n=6)不大于19.9%, 135种农药及其代谢物的定量限为1.0~10.0 μg/kg。该方法样品前处理简单、快速、灵敏,可用于当归药材中多类别农药残留量的定性、定量。

Determination of 135 pesticides and their metabolites in Angelica sinensis by ultra-fast liquid chromatography-tandem mass spectrometry coupled with solid-phase extraction

A method using solid-phase extraction (SPE) followed by ultra-fast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) has been established for simultaneously quantitative determination of 135 pesticides and their metabolites (organophosphorus pesticides, pyrethroid pesticides and carbamate pesticides, etc.) in Angelica sinensis. The pesticide residues were extracted from the samples by acetonitrile, cleaned-up with a primary secondary amine (PSA) column and then analyzed using UFLC-MS/MS in multiple reaction monitoring (MRM) mode with positive electrospray ionization. The pesticide residues were quantified by matrix matched standard solution-internal standard method. All of the pesticides had good linear responses with r>0.99. The average recoveries of the pesticides at the spiked levels of 10, 50, 100 μg/kg ranged from 71.3%-119.7% with the RSDs of 1.0%-19.9%, except for clethodim (62.0%-68.2%). The limits of quantification of the 135 pesticides and their metabolites were 1.0-10.0 μg/kg. The results demonstrated that the method is simple, fast, sensitive and can be used for the analysis of the multiclass of pesticide residues in Angelica sinensis.