气相色谱-三重四极杆串联质谱法测定白芍中99种农药残留

采用固相萃取技术(SPE)结合气相色谱-三重四极杆质谱(GC-MS/MS)建立了白芍中99种农药同时检测的分析方法。试样用乙酸乙酯提取,采用氨基固相萃取柱净化后,在GC-MS/MS多反应监测(MRM)模式下进行检测,基质匹配标准曲线内标法定量。结果表明,99种农药在0.001~0.25 mg/L范围内线性关系良好,相关系数(r²)大于0.99,方法定量限为0.001~0.050 mg/kg。加标水平为0.05、0.10和0.20 mg/kg时,99种农药的平均回收率为66.7%~128.0%,相对标准偏差(RSD, n=6)小于18.3%。对市售的13批样品进行测定,其中4批样品中检出微量的毒死蜱和p,p'-滴滴伊。实验证明,建立的SPE净化和GC-QqQ-MS相结合的检测方法具有准确可靠、灵敏度高等优点,适用于白芍中多农药残留的同时筛查测定。

Determination of 99 pesticide residues in Paeoniae Radix Alba by gas chromatography-triple quadrupole tandem mass spectrometry

A method was established for the simultaneous determination of 99 pesticide residues with combination of solid-phase extraction technique (SPE) and gas chromatography-triple quadrupole tandem mass spectrometry (GC-QqQ-MS). The sample was extracted with ethyl acetate, and cleaned-up by an amino SPE column. The extract was determined by GC-MS/MS in multi-reaction monitoring (MRM) mode, and matrix-matched internal standard method was applied to quantify the pesticides. The results of all the 99 pesticides showed good linearity in the range of 0.001-0.25 mg/L, with correlation coefficients (r²) > 0.99. The limits of quantification (LOQs) were between 0.001-0.050 mg/kg. The recoveries were between 66.7% and 128.0% with RSD values typically lower than 18.3% at three spiked levels of 0.05, 0.10 and 0.20 mg/kg. This method has been applied to determine thirteen batches of commercially available samples, chlorpyriphos-ethyl and p,p'-DDE were detected in four batches of Paeoniae Radix Alba. The method is highly accurate, reliable and sensitive for monitoring the 99 pesticide residues in Paeoniae Radix Alba.