固相萃取-气相色谱-串联质谱法检测丽江玛咖中41种有机氯和菊酯类农药残留

Simultaneous Determination of 41 Organochlorine and Pyrethroid Pesticide Residues in Lijiang-Grown Maca by Solid Phase Extraction-Gas Chromatography-Tandem Mass Spectrometry

建立气相色谱-串联质谱法同时快速检测丽江玛咖中41种有机氯和菊酯类农药残留量的方法。样品经粉碎后,在超声波辅助作用下用乙腈-氯化钠饱和溶液(5∶4,V/V)提取;提取液用石墨化碳/氨基复合型小柱萃取净化,以乙腈-甲苯(3∶1,V/V)混合溶剂洗脱,使用中等极性固定相(50%苯基-甲基聚硅氧烷)毛细管柱分离,质谱全扫模式定性,多反应监测模式联合外标法定量。结果表明,待测物质在0.02~10μg/mL或0.04~20μg/mL范围内线性关系良好,相关系数(R^2)均大于0.99,检出限为0.01~2.38μg/kg,样品平均加标回收率为90.2%~108.8%,相对标准偏差为2.1%~10.9%。该方法简捷、快速、准确、灵敏、经济,适用于大批量玛咖样品中有机氯和菊酯类农药残留量的快速筛查和定量检测。

A method of gas chromatography-tandem mass spectrometry was established for simultaneous detection of 41 organochlorine and pyrethroid pesticide residues in Lijiang-grown maca.Pesticide residues were extracted from the crushed samples with acetonitrile-sodium chloride saturated aqueous solution(5:4,V/V)with the aid of ultrasonic stirring.Then the extracts were purified with a graphitized carbon/amino composite column and eluted with a mixed solvent of acetonitrile and toluene(3:1,V/V).The purified extracts were separated with a medium-polar stationary phase(50%phenylmethylpolysiloxane)capillary column.Finally,the analytes were detected by triple quadrupole mass spectrometry in the full scan mode,and quantified in the multiple reaction monitoring mode by an external standard method.The results showed that good linearity was observed for all analytes in the concentration range of 0.02–10μg/mL or 0.04–20μg/mL with a correlation coefficient(R^2)over 0.99.The limits of detection(LODs)ranged from 0.01 to 2.38μg/kg,and the average recovery rates of spiked samples varied from 90.2%to 108.8%with relative standard deviation between 2.1%and 10.9%.In summary,the proposed method proved to be simple,rapid,accurate,sensitive,economical and suitable for the screening and quantitative detection of organochlorine and pyrethroid pesticide residues in large batches of maca samples.