Abstract: The constituents of C9 fraction of pyrolysis gasoline were analyzed by gas chromatography (GC) with flame ionization detector (FID) and gas chromatography/mass spectrometry (GC/MS). A 100 m×0.25 mm i.d.×0.5 μm PONA column was used to improve the separation efficiency and sample load compared with the standard PONA column of 50 m ×0.20 mm i.d. Identifications of compounds were based on the standards of n-alkanes and a few aromatics, high accuracy retention time simulation and live retention time database, and cross-references with MS data. The search in live retention time database gives a few possible compounds that were co-eluting or adjacent from each other. While the MS search results for each peak always report 10 or even more compounds who has similar fragments. The cross-reference of the above method yields much more reliable identification results than normal GC/MS search. Quantitative analysis of each compound and the carbon number distribution were performed by GC with FID. Thirty-nine compounds with contents more than 0.2% in the C9 fraction were identified. The relative standard deviation of quantitative analysis was below 5%. It provides a reliable method for detailed analysis of C9 fraction.

Key words: C9 fraction of pyrolysis gasoline, cross-reference identification , gas chromatography/mass spectrometry (GC/MS), identification by retention time, capillary gas chromatography