二维气相色谱法测定车用汽油中的甲缩醛、碳酸二甲酯、乙酸仲丁酯、乙酸异丁酯和N-甲基苯胺

Determination of Methylal,Dimethyl Carbonate,Sec-Butyl Acetate,Isobutyl Acetate and N-Methyl Aniline in Gasoline by Two-Dimensional Gas Chromatography Method

针对常规车用汽油中非常规添加物的难分离问题,采用二维气相色谱分析技术,将在非极性毛细管色谱柱中与汽油组分难分离的物质——甲缩醛、碳酸二甲酯、乙酸仲丁酯、乙酸异丁酯和N-甲基苯胺切换至极性毛细管色谱柱进行分离,并采用双氢离子火焰检测器（FID）检测,内标法定量。结果表明,采用二维气相色谱分析技术,甲缩醛、碳酸二甲酯、乙酸仲丁酯、乙酸异丁酯和N-甲基苯胺5个组分均能得到较好的分离,回收率在97.9%~102.2%,6次重复测定的相对标准偏差小于2.0%,定量数据准确可靠;在实验范围内,各组分线性响应良好,检测限为质量分数0.01%。该方法简单可靠,重复性和再现性均能满足常规分析要求。

The separation of the five unconventional components, metbylal, dimethyl carbonate, sec-butyl acetate, isobutyl acetate and N-methyl aniline in motor gasoline, which were hard to be separated from gasoline components only by non-polar capillary column, was carried out by twodimensional gas chromatography. In the two-dimensional gas chromatography the five compounds were cut to the second capillary column to be separated and determined by FID detector and internal standard method. The results showed that the five compounds were well separated from gasoline components with the recovery rate range of 97.9%--102. 2%, the relative standard deviation of less than 2.0% and the detection limit of 0.01% （mass fraction）, meaning that the quantitative data were accurate and reliable. The repeatability and reproducibility of the method can meet the requirements for routine analysis.