In-vitro assay for mutagenic activity and gas chromatographic-mass spectral analysis of coal liquefaction material and the products resulting from its hydrogenation

Abstract Employing assays for microbial mutagenesis activity together with solvent fractionation and gas chromatographic-mass spectral analysis, coal liquefaction material was compared to its catalytically hydrogenated products with regard to biological activity and chemical composition. The mutagenic activity of the moderate and severly hydrogenated products was substantially reduced compared to that of the feedstock. In contrast to the essentially aromatic nature of the principal components in the coal oil feedstock, the hydrogenated products were shown to contain mainly hydroaromatic species with a significant decrease in the fraction of basic and tar components as obtained by our acid-base solvent separation procedure. Subfractions of the basic and tar components obtained from the feedstock were shown to contain primary aromatic amines, the concentrations of which were essentially in direct proportion to the observed microbial mutagenic activity. No primary aromatic amines were detected in the hydrogenated products. Hydrotreating appears to produce a coalderived liquid with far less mutagenic activity than the untreated coal liquefaction material.