提出了测定茶叶中克螨特、哒螨酮残留的气相色谱方法.试样经丙酮提取,正己烷反萃取,弗罗里硅土柱进行净化,用不同极性的淋洗剂分段收集.以气相色谱-电子捕获检测器(GC-ECD)方式测定哒螨酮,气相色谱-火焰光度检测器(硫滤光片)[GC-FPD(S)]方式测定克螨特,外标法定量.试验表明:试样中加入0.25~10 mg·kg-1浓度水平的克螨特,回收率为84%~102%,方法的测定下限为0.25 mg·kg-1,同一样品中6次测定克螨特残留量的相对标准偏差小于5%.试样中加入0.01~0.5 mg·kg-1浓度水平的哒螨酮,回收率为90%~103%,方法测定下限为0.01 mg·kg-1,同一样品中6次测定哒螨酮残留量的相对标准偏差小于5%.

Gas chromatography was applied to the determination of residual propargite and pyridaben in tea.Propargite and pyridaben in tea sample were extracted with acetone and back-extracted with n-hexane.The hexane extract was passed through a purifying column packed with florisil.Propargite was eluted from the column with eluant A [n-hexane mixed with ethyl ether in the ratio of 8 to 2] and determined by FPD.And then pyridaben was eluted with eluant B [n-bexane and ethyl ether mixed in the ratio of 5 to 5] and determined by ECD.External standard curve method was used in the determination.Values of recovery for propargite obtained were in the range of 84%-102%,when tested with addition of standard propargite in the concentration levels between 0.5-10 mg·kg-1,and values of RSD′s (n=6) found were less than 5%.The detection limit of this method was 0.5 mg·kg-1.Values of recovery for pyridaben tested with addition of standard pyridaben in the concentration levels between 0.01-0.5 mg·kg-1,were found to be from 90% to 103%,and values of RSD′s (n=6) found also less than 5%.The detection limit of this method was 0.01 mg·kg-1.