【摘要】 采用V(正己烷)∶V(丙酮)=97.5∶2.5混合溶剂提取茶叶样品中的氯氰菊酯和氰戊菊酯农药残留,选用氟罗里硅土/活性炭混合柱为色谱柱和V(石油醚)/V(乙酸乙酯)=9∶1为淋洗液的方法净化待测样品.在优化的流动相配比(V(乙腈)∶V(水)=74∶26)及流速(1.2mL·min-1)条件下,用配备HypersilODS柱、二极管阵列检测器的高效液相色谱仪进行了待测组分的分离和测定.实验证明茶叶样品中氯氰菊酯和氰戊菊酯添加标准的回收率分别为71.0%和76 0%,加标回收的相对标准偏差(RSD%,n=6)分别为2.5%和2.2%.本方法具有溶剂使用量少、净化效果好、操作简便、快速等特点,可用于茶叶中氯氰菊酯和氰戊菊酯的农药残留分析.更多还原

【Abstract】 A method for rapid determination of cypermethrin and fenvalerate residues in tea sample by reversedphase high performance liquid chromatography was proposed. The pyrethroids in tea sample were first extracted at 40 ℃ by a mixture of V(hexane)∶V(acetone)=97.5∶2.5. And then, the extract was puried by a column (5 mm×70 mm) packed with 320 mg florisil and toppacked with 15 mg active carbon. V(Petroleum ether mixed)∶V(acetic ether)=9∶1 was selected as eluant. The HPLC operating conditions were Hypersil ODS column, V(acetonitrile)∶V(water)=74∶26 as mobile phase with the flow rate of 1.2 mL·min-1 and UV detection wavelength at 198 nm. The pyrethroids were analyzed by HPLC with diode assay detector under optimun conditions and quantified by external standard calibration method. Recoveries of cypermethrin and fenvalerate in tea samples are 71.0% and 76.0%, respectively. Relative standard deviation (n=6) are 2.5% for cypermethrin and 2.2% for fenvalerate.更多还原