全二维气相色谱-飞行时间质谱对催化裂化汽油的定性与定量分析

采用全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)对催化裂化汽油全馏分进行了定性与定量分析,建立了相应的分析方法.结果表明,汽油族组成中的烷烃、烯烃、环烷烃、芳烃在全二维点阵谱图中呈分区域、带状的分布特点.GC×GC-TOF MS根据催化裂化汽油组分内分子的沸点及极性差异对其进行两个维度分离,极大地避免了普通色谱法分析过程中沸点相似化合物共流的弊端,实现催化裂化汽油组分的精确分离和准确定性分析.通过引入响应因子,修正了不同性质的烃类在电离源上电离效率的差异,使得TOF对催化裂化汽油族组成的定量结果与普通气相色谱法的定量结果的相关性较好,且应用GC×GC-TOF MS方法获得了催化裂化汽油更为精确的族组成信息.GC×GC-TOF MS为催化裂化汽油精确表征提供了一种有效方法.

A Method of Qualitative and Quantitative Analysis on Fluid Catalytic Cracking Full Range Gasoline by Comprehensive Two-Dimensional Gas Chromatography Coupled with Time-of-Flight Mass Spectrometry

A method of qualitative and quantitative analysis on fluid catalytic cracking (FCC) full range gasoline by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOF MS) was established. The results showed that paraffins, olefins, naphthenes and aromatics in FCC gasoline had regional and zonal distribution in two-dimensional contour plots. The distinctions of boiling points and polarity between different compounds were used to achieve the accurate separation and determination in GC×GC-TOF MS analysis, and consequently the co-current flow which was often present in the conventional GC analysis was greatly suppressed. The difference of ionizing efficiency between different compounds was modified by response factors, and moreover, a good quantitative dependency was found between the analysis results of GC and GC×GC-TOF MS on FCC gasoline. Due to the high separation resolution, GC×GC-TOF MS gave more accurate results about the group compositions of FCC gasoline. GC×GC-TOF MS provided an effective way with high precision for the characterization of FCC gasoline.