利用固相萃取-气相色谱-负化学离子源质谱技术快速分析茶叶中3种杀螨剂和八氯二丙醚农药残留

Rapid Determination of 3 Acaricides and Octachloro-Dipropyl-Ether(S-421) Pesticide Residues in Tea by GasChromatography-Negative Chemical Ionization Mass Spectrometry

  • 摘要: 建立了茶叶中3种杀螨剂及八氯二丙醚农药残留快速分析的固相萃取-气相色谱-负化学离子源质谱检测(GC-NCI-MSD)方法,并应用于出口欧盟茶叶中农残检测及基地监管.样品经正己烷-丙酮(1∶1,V∶V)提取后,用固相萃取柱(Agela)除去茶叶中干扰物质,以环氧七氯为内标物,经气相色谱-负化学离子源质谱分时段选择离子监测技术进行测定.结果显示,在5~80 μg/kg之间的3个添加水平下,平均回收率在80%~110%之间,RSD≤5.5%;该法对三氯杀螨砜的检出限为0.1 μg/kg,三氯杀螨醇的检出限为0.4 μg/kg,哒螨灵的检出限为1.0 μg/kg,八氯二丙醚的检出限为2.0 μg/kg.其中,三氯杀螨砜检出限最低,八氯二丙醚检出限最高.

     

    Abstract: A solid phase extraction(SPE)-gas chromatography(GC)-negative chemical ionization mass spectrometry(NCI/MS) method has been set up for the analysis of 3 acaricides and octachloro-dipropyl-ether pesticides in tea, and has been applied to the detection and base regulation of pesticide residues in tea for EU exports. Pesticide residues were extracted from tea samples with hexane-acetone(1∶1,by vol) and cleaned-up by active carbon and Florisil SPE column to remove co-extractives, and with heptachlor-epoxide as the internal standard. Analytical screening was determined by the technique of gas chromatography-negative chemical ionization mass spectrometry-selected ion monitoring. The recoveries of all pesticides were in the range of 80%~110%at three spiked level(5~80 μg/kg) and relative standard deviations were below 5.5%.The detection limits of tetradifon, dicofol, pyridaben, and S-421 are 0.1 μg/kg, 0.4 μg/kg, 1.0 μg/kg and 2.0 μg/kg respectively.The method showed excellent sensitivity and selectivity for 3 acaricides and octachloro-dipropyl-ether pesticides.

     

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