液相色谱-串联质谱法测定黄芪中119种农药残留

HPLC-MS/MS determination of 119 pesticides in Astragali Radix

目的:建立液相色谱串联质谱法(LC-MS/MS)测定黄芪中119种农药多残留。方法:样品用乙腈提取,经PSA、C18、GCB净化后用HPLC分离。色谱柱:ZORBAX Eclipse plus C18(2.1 mm×100 mm,1.8μm);柱温:40℃;流动相:乙腈(含5%水,0.1%甲酸,5 mmol.L-1甲酸铵)-水(含0.1%甲酸,5 mmol.L-1甲酸铵)梯度洗脱;流速:0.4 mL.min-1;进样量:5μL;离子源:ESI;扫描模式:正离子;在动态MRM模式下,以保留时间和质荷比对分离的组分给予定性,外标法峰面积定量。结果:119种农药在0.012～0.75 ng的范围内线性关系良好(r>0.9930),样品最低检测限为0.003～22μg.kg-1,多数农药的加标回收率为70%～120%。结论:本方法简便准确,可用于黄芪中多种农药残留的检测。

Objective： To establish method for the determination of 119 pesticides in Astragali Radix by LC-MS/MS.Methods： The sample was extracted by acetonitrile,cleaned by PSA,C18 and graphitized carbon and separated by HPLC.Chromatographic separation was performed on ZORBAX Eclipse plus C18 column（2.1 mm×100 mm,1.8 μm）using a gradient elution of acetonitrile（contain 5% water,0.1% formic acid,5 mmol·L-1 ammonium formate）-water（contain 0.1% formic acid,5 mmol·L-1 ammonium formate）at a flow rate of 0.4 mL·min-1.The column temperature was 40 ℃ and the sample size was 5 μL.The analytes were detected by an electrospray ionization tandem mass spectrometry with dynamic MRM.Qualitation of the pesticides based on the retention time and mass charge ratio and the quantitation based on the peak area of fragment ion.Results： The calibration curve of 119 pesticides was good linear in the range of 0.012-0.75 ng（r 0.9930）,and the average recovery of largely analytes were in the range of 70%-120%.The LODs of this method were between 0.003–22 μg·kg-1.Conclusion：This method is accurate and repeatable.It can be applied to screening and detection of these pesticides in Astragali Radix.