Characterization of phenolic compounds in coal tar by gas chromatography/negative-ion atmospheric pressure chemical ionization mass spectrometry: Negative ion GC-APCI/MS for phenolic compounds analysis

Sutian Ma , Chao Ma , Kejun Qian  , Yasong Zhou and Quan Shi*

State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China

Waters Corporation, Building 13, 1000 Jinhai Roa

*Correspondence to: Q. Shi, State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249,China.E-mail: sq@cup.edu.cn

DOI:10.1002/rcm.76

Abstract:

RATIONALE: Phenolic compounds are commonly found in fossel fuels and bio-oils, and have a detrimental effect on thechemical stability of the fuels. A selective analytical method is needed to characterize the phenolic compounds in complexhydrocarbon mixtures.

METHODS: Gas chromatography/atmospheric pressure chemical ionization mass spectrometry (GC/APCI-MS)was used to characterize the phenolic compounds in a low-temperature coal tar and its narrow distillatefractions.RESULTS: Negative-ion APCI selectively ionized phenolic compounds in the coal tar. The [M-H]^- and [M-H+O]^- ionswere derived from monohydric phenols, while [M-H]^-, [M-2H]^-, and [M-2H+O]^- were from benzenediols. Monohydricphenolic compounds with 1–4 aromatic rings and some dihydric phenolic compounds were identified. The results fromGC/APCI-MS were validated by those from negative electrospray ionization Fourier transform ion cyclotron resonancemass spectrometry (ESI FT-ICRMS).

CONCLUSIONS: Negative-ion GC/APCI-MS was proposed and successfully used to characterize phenolic compounds incoal tar samples. This technique can potentially be used for the characterization of phenolic compounds in other complexhydrocarbon systems.