Liquid chromatographic systems for the separation of polycyclic aromatic hydrocarbon and nitrogen heterocycle compounds present in coal liquids

Abstract

Normal-phase and reversed-phase high-performance liquid chromatography were compared for the separation of compounds known to be present in solvent refined coal liquids. Several commercially available stationary phases were investigated with standards and compared for their ability to separate polycyclic aromatic hydrocarbons from nitrogen heterocycle compounds. The normal-phase columns investigated were μPorasil, Nucleosil NO 2, basic alumina, μBondapak NH 2, and μBondapak CN. μBondapak C 18 and μBondapak CN packings were investigated under reversed-phase conditions. Utilizing normal-phase chromatography only the μPorasil system was able to resolve polycyclic aromatic hydrocarbons from the nitrogen heterocycles investigated. Both reversed-phase systems studied were able to resolve these functional classes, but the solubility of solvent refined coal liquids in aqueous systems limits the usefulness of this approach.