超声波提取-高效液相色谱测定茶叶中拟除虫菊酯农药残留

Determination of Pyrethroids Residues in Tea by High Performance Liquid Chromatography with Ultrasonic Extraction

建立了超声波提取-高效液相色谱同时测定茶叶中甲氰菊酯、三氟氯氰菊酯、溴氰菊酯、氰戊菊酯和氯菊酯农药残留的方法。以10mL正己烷-丙酮(30/70,V/V)超声提取、Florisil固相萃取小柱净化处理后,在220nm波长处,采用甲醇-水(78.5/21.5,V/V)作为流动相进行色谱分析。5种农药在0.5—50mg/L范围内具有良好的线性关系,检出限为0.1—0.15mg/L。分析模拟样品,回收率为71.4%—104.4%,相对标准偏差小于10.0%(n=5)。

Five pyrethroids residues in tea including fenpropathrin, lambda-cyhalothrin, deltamethrin, fenvalerate and permethrin were determined by high performance liquid chromatography with ultrasonic extraction. With extraction reagents of n-hexane/acetone （30/70,V/V） for 60min,and then cleaning up with florisil solid phase extraction,five pyrethroids were well separated and detected by using menthol/water （78. 5/21.5,V/V） as mobile phase. Under the optimum conditions,good linearities of five pyrethroids were obtained in the ranges of 0. 5-50mg/L with detection limits of 0. 1-0. 15mg/L. By analyzing of the spiked tea sample, the recoveries of tea with different level content pyrethroids were between 71.4 % and 104. 4 %, and relative standard deviation （n = 5） were less than 10.0%.