固相萃取-气相色谱-串联质谱法测定绞股蓝中75种农药残留

Determination of 75 pesticides in gynostemma pentaphylla using solid-phase extraction and gas chromatography-tandem mass spectrometry

目的建立固相萃取-气相色谱-串联质谱法同时测定绞股蓝中75种农药残留的方法。方法采用乙腈匀浆提取绞股蓝中待测组分,Pro Elut GPR萃取柱净化,乙腈-甲苯(1∶1,V/V)淋洗净化柱,收集2 ml^10 ml流出物,气相色谱-串联质谱多反应监测(MRM)模式测定,外标法定量。结果 75种农药的质量浓度为50μg/L^1 000μg/L时,线性关系良好,相关系数(r)均>0.99。方法的相对标准偏差(RSD)<10%,分别对绞股蓝样品进行3个水平(10μg/kg、25μg/kg和100μg/kg)的加标回收试验,平均加标回收率为60.2%~135.9%,按信噪比(S/N)为10计,方法检出限(LOD)为0.06μg/kg^14.9μg/kg。结论该分析方法背景干扰低,灵敏度高,检出限低,适合绞股蓝中多农药残留的同时测定。

Objective To develop a method for the simultaneous determination of 75 kinds of pesticides in gynostemma pentaphylla by solid phase extraction（ SPE）-gas chromatography/tandem mass spectrometry（ GC-MS/MS）. Methods The target pesticides in gynostemma pentaphylla were extracted with acetonitrile,cleaned-up by SPE on a Pro Elut GPR cartridge,rinsed purification column by acetonitrile-toluene（ 1 ∶1,V/V）,and 2 ml-10 ml effluent was collected. The detection was carried out by GC-MS/MS in the multiple reaction monitoring（ MRM） mode,and quantification analysis was performed by external standard method. Results The linear relation was good when the concentration range was within 50 μg/L-1 000 μg/L,and the correlation coefficients（ r） were above 0. 99. The relevant standard deviation（ RSD） of this method was less than 10%.The average recoveries of 75 pesticides spiked in gynostemma pentaphylla at the levels of 10 μg/kg,25 μg/kg and 100 μg/kg were within 60. 2%-135. 9%. The limits of detection（ S/N = 10） were within 0. 06 μg/kg-14. 9 μg/kg. Conclusion The method possesses low background,high sensitivity,and low determination limits. It can be applied to the simultaneous analysis of 75 pesticedes in gynostemma pentaphylla.