Chapter 21 Fossil fuels

Abstract

Publisher Summary This chapter discusses applications of various chromatographic techniques, such as gas chromatography (GC), high-performance liquid chromatography (HPLC), supercritical-fluid chromatography (SFC), and size-exclusion chromatography (SEC) to the analysis and characterization of various types of fossil fuels. The methods used in the characterization of fossil fuels will vary greatly according to the nature of the fossil fuel being analyzed and the type of compounds present in the sample. For many years gas chromatography, originally with packed columns and now with high-resolution fused-silica capillary columns with bonded phases, has been the method of choice for the analysis of the extremely complex mixtures of organic compounds present in fossil fuels. As a result of the complexity of the mixtures, a number of pre-analysis steps are generally required to fractionate the extracts from these samples. Combined GC/mass spectrometry (MS) has been utilized for many years for the characterization of all types of fossil fuels, and it is the first choice of chromatographic techniques for most organic geochemistry laboratories. The use of these chromatographic analyses provides important information, concerning the type of source material in the original sample when it was deposited millions of years ago. Furthermore, it has become possible to predict the type of depositional environment, maturity, extent of migration and biodegradation from the distributions of these compounds. Chromatography also plays a very important role in identifying the types of combustion products derived from the coals. This is particularly useful for predicting the presence of possible environmental pollutants.