液相色谱-串联质谱法测定大蒜中40种农药残留

LC-MS/MS Determination of 40 Pesticide Residues in Garlic

摘要: 采用液相色谱-串联质谱法同时测定大蒜中40种农药的残留量。样品经磷酸酸化的乙腈提取后,采用QuEChERS方法净化,净化液采用Waters HSS T3 C18色谱柱分离,以甲酸-氨水-水(0.01+0.05+99.94)混合溶液和甲醇的混合液为流动相进行梯度洗脱,质谱中选择电喷雾电离源和多反应监测模式。40种农药的质量浓度均在5.0~400 μg·L-1范围内与峰面积呈线性关系,测定下限(10S/N)在0.1~5 μg·kg-1之间。加标回收率在70.1%~129%之间,测定值的相对标准偏差(n=5)在0.6%~9.3%之间。

Abstract: LC-MS/MS was applied to simultaneous determination of residual amounts of 40 pesticides in garlic. The sample was extracted with H3PO4-acidified acetonitrile and then purified by QuEChERS method. The purified solution was separated on Waters HSS T3 C18 chromatographic column, using a mixture of methanol and HCOOH-NH4OH (0.01+0.05+99.94) solution as mobile phase in the gradient elution. ESI and MRM were adopted in MS. Linear relationships were found between values of peak areas and mass concentrations of the 40 pesticides in the same range of 5.0-400 μg·L-1, with lower limits of determinaiton (10S/N) in the range of 0.1-5 μg·kg-1. Values of recovery obtained by standard addition method were in the range of 70.1%-129%, and RSDs found (n=5) were in the range of 0.6%-9.3%.