汽油中元素硫的GC-SCD分析方法

Determination of Elemental Sulfur in Gasoline by GC-SCD

采用硫化学发光检测器气相色谱法(GC-SCD)建立了测定汽油中元素硫的气相色谱分析方法。考察了色谱拄温度、样品基质等因素对汽油中元素硫分析的影响,并对元素硫在高温状态下的形态进行了定性分析。结果表明,在高温环境下,元素硫存在S_2、S_4、S_6,S_7、S_8多种形态,且温度越高,元素硫越容易形成小分子硫同素异形体。采用该方法测定质量浓度在2~70mg/L范围的元素硫时,色谱峰面积与质量浓度呈较好的线性关系,定量标准曲线的线性相关系数R2为0.9992,最低检测限为1.0mg/L,元素硫的加标回收率为93%~105%,同时具有较好的重复性,符合色谱分析的一般要求。

A method for determination of elemental sulfur in gasoline by gas chromatography with sulfur chemiluminescence detector（GC-SCD）was established.The effects of injection and oven temperatures,sample matrix on the elemental sulfur analysis were investigated,as well as the qualitative analysis of sulfur allotropes at high temperature.The results showed that the sulfur allotropes of S_2,S_4,S_6,S_7,S_8 were found at high temperature,and the higher the temperature,the more small sulfur allotropes occurred.An external standard quantitative formula for elemental sulfur was established with the linear range of 2-70mg/L and the correlation coefficient more than0.9958.Values of the recovery by standard addition method were in the range of 93%-105%.The repeatability of the method is good and the lower detection limit was 1.0mg/L,which could meet the requirements of routine analysis.