HIGH PERFORMANCE CHROMATOGRAPHIC CHARACTERIZATION OF HETEROCYCLIC COMPOUNDS IN SHALE OIL

This dissertation considers the development of new analytical techniques to characterize shale oil, with emphasis on the heteroorganic compounds. A class separation precedure using preparative liquid chromatography on an amino-bonded silica support was developed to allow separation of shale oil into four chemical classes, namely: (1) hydrocarbons (alkanes/alkenes), (2) polynuclear aromatics, (3) acids and neutral polars, and (4) bases. This procedure was applied to the analysis of two different types of shale oil, Tosco II and In-Situ. All four classes of compounds were then characterized by capillary gas chromatography with flame ionization detection and some were also examined with the thermionic nitrogen specific detector. The acids and bases were further characterized by capillary gas chromatography with interfaced mass spectroscopy. Comparison of the two oils showed that although the level of heteroorganic compounds is different, the distribution of compounds within the same class is very similar. An argentation liquid chromatographic procedure was developed for isolation of the thiophenic compounds in shale oil. This is an important class of compounds to study since it encompasses approximately 80% of the organic sulfur content. Existing methods for isolation of thiophenes depend on a chemical reaction step. These methods fail to maintain the integrity of the thiophenes due either to discrimination dependent on the alkyl substituents present or to chemical alteration of some of the compounds. The argentation procedure avoided this discrimination since the retention time on the liquid chromatographic column was almost independent of the number and type of alkyl substituents on the thiophene ring. From direct comparison with the existing chemical methods, the argentation procedure was shown to be superior in recovering the thiophenes without discrimination