用气相色谱-质谱和气相色谱-红外联用技术分析热裂解汽油C9馏分中的组成

采用气相色谱-质谱和气相色谱-红外联用技术对热裂解汽油C9馏分中的组分进行分离和定性分析。实验使用了50m聚甲基硅氧烷毛细管色谱柱，EI电离源，电离能70eV和10eV，红外光谱仪的检测器为MCT。通过分析确定了热裂解汽油C9馏分中52个化合物的结构。降低质谱的电离能有利于确定组分的分子量。质谱可以提供被测组分的裂解碎片离子和分子量的信息，红外在确定官能团和同分异构体时要优于质谱。两种联用技术的使用较好地解决了单一方法测定复杂混合物中组分结构所存在的缺陷。

Analysis of Components in C9 Fraction By Gas Chromatography-Mass Spectrometry and Gas Chromatography-Infrared Spectroscopy

The components in C 9 fraction of the pyrolysis gasoline were separated and identified by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-infrared spectroscopy (GC-IR). All analyses were performed on a 50 m capillary column coated with methylsilicone. An electron-impact ionization source (EI) was used in the experiments. The ionizing voltages of 70eV and 10eV were chose. A mercury cadmium telluride (MCT) was used as the detector of GC-IR. 52 components in C 9 fraction were identified The abundance of molecular ion peaks are increased remarkably with lowering down the ionization voltage, which benefits to measure molecular mass. Mass spectra can provide information of molecular mass and fragment ions of components and infrared spectroscopy has advantages over mass spectrometry on identifying isomers and functional groups. The simultaneous use of the two techniques can solve the problems caused by single technique of the both when analyzing the components in a complex mixture.