茶叶中吡虫啉农药残留的液相色谱检测方法

摘要

A method for the analysis of imidacloprid residue in tea by high performance liquid chromatography (HPLC) with UV detector was established. Through the comparation of extract efficiencies of several solvent and the clean-up capacities of different SPE cartridges, the results show that after soaked with water, extracted by acetonitrile, cleaned up with the Envi-Carb/PSA cartridge, imidacloprid was eluted with 6 mL acetonitrile solution from the cartridge and detected with HPLC, the samples was spiked at the level of 0.025-0.250 mg/kg, and the recovery of Imidacloprid range from 92.0%~97.6% with RSD less than 3.8%. Practical determination limit was 0.025 mg/kg. It meet with the analytical requirements to imidacloprid residue in exported tea. The pretreatment method was simple, sensitive and less organic solvent consumption.%建立了茶叶中吡虫啉农药残留的液相检测方法.对比了几种常用溶剂和提取方式的提取率以及固相萃取材料对茶叶样品中干扰基质的净化效果.研究结果表明,茶叶经水浸泡,乙腈高速匀浆提取,Envi-Carb/PSA固相萃取柱净化,乙腈6 mL洗脱后,经反相高效液相色谱紫外检测器检测茶叶中吡虫啉农药的残留量,吡虫啉的添加质量分数为0.025～0.250 mg/kg,其回收率为92.0％～97.6％,相对标准偏差(RSD)≤3.8％,方法的定量限为0.025 mg/kg,符合出口茶叶吡虫啉农药残留分析要求.前处理方法简单快捷,有机溶剂用量少.