固相萃取分离-高效液相色谱法测定陈皮中噻菌灵残留量

HPLC Determination of Residual Amount of Thiabendazole in Dried Tangerine After Separation by SPE and Ion-exchange

试样于磷酸（1＋999）溶液中浸泡2h，超声振荡20min，加水定容为50mL离心3min，分取上层澄清液5．0mL，通过ENVI^TM C18固相萃取柱纯化。用由0．1mol·L^-1磷酸二氢钾溶液（pH3．0）与乙腈以70比30的体积比组成的混合液（此溶液也用作流动相）作为淋洗液，将被测定物质从固相萃取柱上洗脱，所得淋出液供高效液相色谱（HPLC）测定。HPLC分析中，LC-SCX离子交换柱用作色谱柱，上述的混合溶液作为流动相，荧光检测的激发波长为307nm，发射波长为359nm。噻菌灵的质量浓度在0．5-100．0ug·L^-1范围内与其相应的峰面积值之间呈线性关系，在3个浓度水平上对回收率作了试验，测得回收率在88．0％～95．0％之间，相对标准偏差（n=6）在3．1%～5．0%之间。

Sample was soaked with dil. H3 PO4 （1 ＋ 999） solution for 2 h, agitated for 20 rain ultrasonically and centrifuged for 3 rain after diluting to 50 mL. Am aliquot of the supernatant solution was taken for purification by passing through the ENVITM Cls SPE column. A mixed solution, containing 0. 1 mol · L^-1 KH2PO4 of pH 3. 0 and acetonitrile mixed in the ratio of 70 to 30 by volume （which was also used as mobile phase） was used as eluant to elute the analyte from the SPE column, and the eluate obtained was used for HPLC determination. The LC-SCX column was used as ion-exchange chromatographic column and the mixed solution mentioned above was used as mobile phase in the HPLC analysis with fluorescence detection at the wavelengths of 307 nm （λex） and 359 nm （λem）. Range of linearity was found in the concentration range of 0. 5 - 100. 0 ug · L^-1 of thiabendazole against values of relative peak area. Test for recovery was performed at 3 concentration levels, giving values of av. recovery in the range of 88. 0%-95.0% and RSD＇s （n=6） in the range 3.1%-5. 0%.