5. Separations in the Sample Preparation for Sulfur Compound Analysis

Analytical chemists have been interested in the sulfur compounds found in petroleum for over 100 years. They have developed an impressive array of methods for separating the sulfur compounds from the matrix and for separating the several functional groups from each other. These separations greatly aid in molecular characterization of these materials, which is of fundamental importance in areas such as desulfurization, catalyst development, geochemical studies, etc. Here, such methods are reviewed from the methodological perspective. Chemical transformations have a prominent place in this area and can reversibly or irreversibly change the compounds. Chromatographic separations are shown to have contributed greatly to our knowledge of the composition of petroleum. Areas where current methods fail are also pointed out.