Identification and comparative genotoxicity of polycyclic aromatic hydrocarbons and related nitrogen-containing heteroatomic species in products from coal liquefaction processes

Abstract

A series of process distillation cuts from a solvent refined coal process were separated into polycyclic aromatic hydrocarbons (PAH) and nitrogen-containing polycyclic aromatic hydrocarbons (N-PAC) chemical classes and the fractions tested for biological activity by both microbial mutagenicity and mammalian skin carcinogenicity assays. Qualitative and quantitative chemical characterization of individual PAH and N-PAC in these materials was also performed. The results of biological and chemical analyses are presented in this paper and used to assess the comparative mutagenicity of the PAH and N-PAC from complex mixtures of coal liquefaction materials. Chemical class separation was obtained using adsorption column chromatography. Gas chromatography and mass spectroscopy were used to identify the fractions. The following PAH compounds were identified and quantitiated: phenanthrene, fluoranthene, pyrene, benzoanthracene, chrysene, methylchrysens, benzo(j) or (b)fluoranthene, benzo (k) fluoranthene, 7,12-Dimethyl-benzanthracene, benzopyrene, and benzoperylene. N-PAC compounds identified were: carbazole, benzo(a)carbazole, phenanthridine, 1-azapyrene, 2-azafluoranthene, benz(c)acridine, 2-aminofluorene, 3-aminophenanthrene, 2-aminoanthracene, 2-aminopyrene, 8-aminofluoranthene, 3-aminochrysene, and 7-aminobenzo(a)pyrene. In terms of microbial mutagenicity using the Ames test, the N-PAC, in general, are more active than the PAH; the principal mutagenic N-PAC agents being the amino-PAH. If carcinogenicity is investigated by the mouse skin initiation/promotion approach, the PAH are the most potent carcinogens with activity increasing withmore » increasing distillation temperature. (DMC)« less