羧基化多壁碳纳米管分散固相萃取-三重四极杆气质联用法测定茶叶中16种农药残留量

Determination of 16 Pesticides in Tea by Gas Chromatography-triple Quadrupole Mass Spectrometry Using Carboxylated Multi-walled Carbon Nanotubes as Dispersive Solid-phase Extraction Sorbent

基于羧基化多壁碳纳米管(MWCNTs-COOH)分散固相萃取净化,结合三重四极杆气质联用仪,建立了茶叶中16种农药残留量的快速分析检测方法。茶叶经乙酸乙酯提取,以羧基化多壁碳纳米管和乙二胺-N-丙基硅烷化硅胶(PSA)吸附提取液中的杂质,离心过滤后经三重四极杆气质联用仪测定,基质匹配外标法定量。结果表明,目标物质在各自线性范围内的线性关系良好,相关系数(r)均大于0.99。空白茶叶样品平均加标回收率在71.2%~128.2%之间,相对标准偏差(n=6)为2.3%~9.2%;方法的定量限为0.5~10.0μg/kg。建立的方法在回收率、检测限、准确度和灵敏度等方面均能满足农药残留分析的要求,适合于茶叶中相关农药残留的快速检测。

Based on the dispersive solid-phase extraction purification of carboxylated multi-walled carbon nanotubes(MWCNTs-COOH),combined with triple quadrupole gas chromatography-mass spectrometry,a rapid analytical method for 16 pesticide residues in tea was established.Pesticide residues in teas were extracted with ethyl acetate,and cleaned up by carboxylated multi-walled carbon nanotubes(MWCNTs)and primary-secondary amine(PSA)as dispersive solid-phase extraction sorbent.After centrifugation and filtration,the target compounds were analyzed by gas chromatographytriple quadrupole mass spectrometry,and quantified by matrix matching external standard method.The results show that the linear relationships of target substances were good in their respective linear ranges with correlation coefficient(r)above 0.99.The average recovery of blank tea samples were in the range of 71.2%~128.2%,with relative standard deviations(RSDs,n=6)of 2.3%~9.2%,The limits of quantitation were in the range of 0.5~10μg/kg.The recoveries,detection limits,accuracy and sensitivity of the method could meet the requirements for pesticide residue analysis,and suitable for rapid detection of pesticide residues in tea.