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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 establish a method for the simultaneous determination of 75 pesticide residues in Gynostemma by solid-phase extraction-gas chromatography-tandem mass spectrometry. Methods The constituents of Gynostemma pentaphyllum were extracted by acetonitrile homogenization, purified with Pro Elut GPR extraction column, eluted with acetonitrile - toluene (1: 1, V / V) and eluted with 2 ml ~ 10 ml effluent. Gas chromatography - Tandem mass spectrometry multiple reaction monitoring (MRM) mode determination, external standard quantitative. Results When the concentration of 75 pesticides was between 50μg / L and 1 000μg / L, the linear relationship was good with the correlation coefficients (r)> 0.99. The relative standard deviations (RSDs) were less than 10%. Three spiked recoveries of spiked samples (10 μg / kg, 25 μg / kg and 100 μg / kg) were obtained respectively. The average recoveries were 60.2% -135.9% The detection limit (LOD) was 0.06μg / kg ~ 14.9μg / kg according to the S / N ratio of 10. Conclusion The method has low background interference, high sensitivity and low detection limit. It is suitable for simultaneous determination of multi-pesticide residues in Gynostemma pentaphyllum.