基于功能磁性材料和固相微萃取净化富集一体化的茶饮料中三唑类农药残留分析

Triazole pesticide residues analysis based on functionalized magnetic materials and solid phase microextraction collaborative technology in tea drinks

构建了固相微萃取(SPME)富集与功能磁性材料净化相结合的一体化协同提取技术,并应用于茶饮料中三唑类杀菌剂的残留分析。以磁性材料四氧化三铁-N-丙基乙二胺(Fe3O4-PSA)为净化吸附剂,采用SPME萃取针富集样品溶液中的目标农药后直接进气相色谱-质谱联用仪(GC-MS)进样口解吸附、分析,无需其他样品转移等操作,方法简便、灵敏。本研究系统优化了SPME条件(如萃取时间、萃取温度、氯化钠用量及pH值),并采用正交试验设计,探明了磁性材料用量与SPME条件的交互影响,以确定最佳试验条件。对优化的分析方法进行方法确证,结果表明:在0.002~0.2 mg/L范围内,19种三唑类农药在茶饮料中均表现出很好的线性关系,相关系数(r)均大于0.99,检出限(LOD)在0.00012~0.0089 mg/L之间,定量限(LOQ)均为0.002 mg/L。采用基质匹配标准溶液校正时,回收率在71%~98%之间,RSD不高于16%(n=3)。此方法较常规法简单、操作便捷、可靠,且环境友好,适用于茶饮料中三唑类农药残留的分析。

An integrated collaborative extraction technology of solid phase microextraction(SPME)enrichment and functional magnetic material cleanup was constructed and applied to the analysis of triazole pesticide residues in tea drink samples.The magnetite(Fe3O4)nanoparticles modified with 3-(N,N-diethylamino)propyltrimethoxysilane(Fe3O4-PSA)was selected as the cleanup adsorbents to remove the matrix interferences.The target analytes were microextracted by SPME needle and analyzed by GC-MS.In this method,SPME conditions such as extraction time,extraction temperature,salinity and pH value were optimized.Meanwhile,the amount of magnetic material and SPME conditions were optimized by orthogonal experiments.Under the optimal conditions,the 19 triazole pesticides showed good linearity in the concentration range of 0.002-0.2 mg/L,and the correlation coefficient(r)was greater than 0.99.The limits of detection(LOD)ranged from 0.00012 to 0.0089 mg/L and LOQ was 0.002 mg/L.Using the matrix matched calibration curves,the recoveries ranged from 71%to 98%with relative standard deviation(RSD)lower than 16%at three spiked concentrations.Compared with the conventional method,this method was simple,convenient,reliable and environment-friendly.It is suitable for the analysis of triazole pesticide residues in tea drinks.