Analytical Techniques for Organic Matter Characterization in Ore Deposits
The objective of this review is to introduce some organic analytical methods that may be used to study organic matter in ore deposits. It is not a comprehensive guide to all techniques. The underlying theme is to guide the interested reader toward an analytical strategy that is appropriate for the information sought. Some of the background issues that an analyst has to consider are initially introduced, with a brief summary of the thermal maturation of organic matter. Following an introduction to sample preparation, the remainder of the chapter summarizes general and spectroscopic methods that provide a general indication of organic composition, followed by physical techniques that ultimately yield information at a molecular scale. Each analytical technique will be introduced, followed by its applications. Where applicable, a case study will be described. The hydrothermal alteration of organic matter from immature precursors to mature products is used as an analog of a process responsible for the maturation of organic matter found in ore deposits. The intention is to indicate how information obtained from these analytical methods can be used to solve problems stemming from the occurrence of organic matter in ore deposits.
In order to understand the applicability and limitations of organic analytical techniques, it is first necessary to understand the forms in which organic matter can be present in and around ore deposits (see Giże, 2000; and Leventhal and Giordano, 2000). The simple reason is that all organic analytical methods are constrained by the organic matter form, such as phase (solid, liquid, or gas) and, often, by the molecular structure and molecular weight. To date, a single analytical method that provides a complete analysis of organic matter exists only in science fiction films. Consequently, part of the analyst' s consideration is in rendering the organic material into a form that can be analyzed by the techniques and instruments available without losing the information sought.