Molecular characterization of heteroatomic compounds in a high-temperature coal tar using three mass spectrometers

Abstract

A high-temperature coal tar (HTCT) was extracted by petroleum ether (PE) and the extract (denoted by PE-HTCT) was characterized using three mass spectrometers to obtain and compare molecular compositional information. Gas chromatography/mass spectrometry detected molecules with low molecular weight and polarity such as hydrocarbons. A time-of-flight MS coupled with an atmospheric solids analysis probe ion source realized rapid and in-situ analysis of compounds with mid-polarity in PE-HTCT without sample pretreatment. An electrospray ionization (ESI) Orbitrap MS was used to characterize heteroatom-containing compounds in PE-HTCT. Most heteroatomic species identified by ESI-Orbitrap MS contained oxygen, nitrogen, or both atoms, and the total percentage of both Oo and Nn species was approximate 13%. Ketene and furan derivatives were identified in Oo class, as well as aliphatic amine compounds, azoles, aniline and pyridine derivatives for Nn class. The combination of three mass spectrometers gave a detailed characterization of coal tar and provided a full view of the corresponding constituents.