分散固相萃取净化-气相色谱-质谱联用法测定茶叶中7种杀螨杀虫类农药残留

摘要

目的 建立茶叶中7种农药残留的快速检测方法.方法 采用分散固相萃取净化,气相色谱-质谱法(gas chromatography-mass spectrometry,GC-MS)测定茶叶中噻螨酮、噻嗪酮、哒螨灵、喹瞒醚、苯醚甲环唑、联苯菊酯和氟氰戊菊酯7种农药的残留.结果 7种农药在0.05~5.00 mg/kg范围有良好的线性关系,相关系数均大于或等于0.9995.3个浓度的平均加标回收率为70%~115%,相对标准偏差为5.0%~13.2%;方法检出限(limit of detection,LOD)为0.005~0.05 mg/kg,定量限(limit of quantitation,LOQ)为0.015~0.15 mg/kg.采用此方法抽检了我国不同地区市场上的110批次的茶叶样品,其中有15批次样品检出联苯菊酯,含量在24~1640μg/kg之间;有4批次样品中检出噻嗪酮,含量在35~150μg/kg之间;3批次样品检出哒螨灵,含量在70~200μg/kg之间.结论 本方法符合农药残留分析标准的要求,可用于茶叶中7种农药残留的快速检测和确证分析.%Objective To establish a rapid detection method for 7 pesticide residues in tea. Methods The residues of hexythiazox, buprofezin, pyridaben, fenazaquin, difenoconazole, bifenthrin and flucythrinate in tea were detected by dispersion solid phase extraction purification combined with gas chromatography-mass spectrometry (GC-MS). Results The 7 pesticides had good linear relationships in the range of 0.05~5.00 mg/kg, and the correlation coefficients were larger than or equal to 0.9995. The recoveries of 7 pesticides of 3 different spiked levels were 70%~115%, with the relative standard deviations of 5.0%~13.2%. The limits of detection for 7 pesticides were 0.005~0.05 mg/kg, and limits of quantitation, were 0.015~0.15 mg/kg. The results of application of the established method in the detection of 110 batches of tea samples in different regions of China showed that, flucythrinate was detected in 15 batches of samples, and the content was 24~1640 μg/kg, buprofezin was detected in 4 batches of samples, and the content was 35~150 μg/kg, and pyridaben was detected in 3 batches of samples, and the content was 70~200 μg/kg. Conclusion The established method meets the requirements of pesticide residue analysis standard, which is suitable for the rapid detection and corroboration analysis of 7 pesticide residues in tea.