Isolation of neutral N-PAHs (PAH homologues containing one or more ring nitrogens) is achieved in three steps using acid-base extraction, gel filtration on Sephadex LH-20, and adsorption chromatography on silicic acid. Gas chromatographic/mass spectrometric analysis of the neutral N-PAH fractions indicated the following as major components: C1-C3phenylpyrroles, indole, C1-C6indoles, C1-C3phenylindoles, carbazole, C1-C5carbazoles, benzocarbazoles, and C1-C3benzocarbazoles. The neutral N-PAH fractions were subjected to mutagenicity tests using Salmonella typhimurium/microsomal activation systems devised by Ames. The neutral N-PAH fraction of the coal-derived oil had a specific activity more than twice that of the PAH fraction of the same oil, whereas the shale oil neutral N-PAH fraction showed no activity. These results are discussed in the context of previous work with these oils and with some pure neutral N-PAH compounds. © 1980, All rights reserved.
Ho, C. H., Ma, C. Y., Clark, B. R., Guerin, M. R., Rao, T. K., & Epler, J. L. (1980). Separation of neutral nitrogen compounds from synthetic crude oils for biological testing. Environmental Research, 22(2), 412–422. https://doi.org/10.1016/0013-9351(80)90153-X