采用二维气相色谱及毛细管色谱柱分析汽油中苯和甲苯的含量

Determination of benzene and toluene in gasoline by two-dimensional gas chromatography and capillary column

采用微板流路控制技术(Deans Switch)和常见的商品毛细管柱HP-5(30m×0.32mm×0.25μm)和Rtx-TCEP(30m×0.25mm×0.4μm),建立了一种全新的分析车用汽油中苯和甲苯含量的二维气相色谱方法。用该方法分析汽油中0～5%的苯和0～20%的甲苯,两者校正曲线的线性关系良好,相关系数分别为0.9994和0.9999;标准样品5次重复测定的相对标准偏差均小于1.5%;车用汽油实际样品中苯和甲苯的加标回收率在96.8%～103.8%之间。车用汽油实际样品测定结果和SH/T0713-2002标准方法测定结果一致。该方法是车用汽油中苯和甲苯含量测定的一种简便快捷、准确可靠的分析方法。

A novel two-dimensional gas chromatographic method, used for the determination of benzene and toluene in gasoline, was established by the capillary flow technology （Deans Switch） and universal capillary columns HP-5 （30 m×0.32 mm×0.25 μm） and Rtx-TCEP （30 m×0.25 mm×0.4 μm）. Benzene, internal standard and toluene, which co-eluted with some saturated components from a non-polar column HP-5, were cut to a polar column Rtx-TCEP by Deans Switch and allowed to be fully resolved from saturated components. The linearity test showed that the correlation coefficient r^2 values for benzene and toluene were 0.9994 and 0.9999, respectively. The results showed that the relative standard deviations （RSDs） of standard samples in five continued tests were within 1.5% and the recoveries of added standards tests were from 96.8% to 103.8%. This two-dimensional gas chromatographic method was compared to the standard analytical method for determining the concentrations of benzene and toluene in gasoline （SH/T 0713-2002）. The results were in excellent agreement with the values obtained by SH/T 0713. The method is quick, simple and useful for the determination of benzene and toluene in gasoline.