Rapid Method for the Determination of Malthene and Asphaltene Content in Bitumen, Heavy Oils, and Synthetic Fuels by Pyrolysis TLC

Abstract

A rapid pyrolysis thin layer chromatographic (TLC) method for the determination of malthene and asphaltene content in bitumens, heavy oils, and their synthetic fuel products is described. The malthenes are separated from the asphaltenes (defined as the portion that is insoluble in n-paraffinic hydrocarbon and soluble in benzene) by spotting 1 μ of a 25 mg/ml sample solution on a silica gel chromarod, followed by development with an n-paraffinic hydrocarbon:isopropanol mixture (95:5). Benzene insolubles are removed prior to the determination. The separation is quantified by a TLC analyzer equipped with a flame ionization detector. Complete analysis of nine samples requires 30 min excluding time necessary for sample preparation prior to spotting. The method is applied to 16 samples of bitumen, heavy oils, and synthetic fuels. Repeatability of the results is compared with that obtained by a standard procedure.