Combustion Products & Soot
Nearly every type of combustion results in the production of particulate matter, be it natural processes such as forest fires, catastrophes such as structure or automotive fires, or controlled processes such as power plants, refineries, or engines. Some of this particulate matter is originally gaseous and condenses in the air, while residual materials resulting from combustion are in the form of solid chars, soot, slags, and ash.
Examination of this material can provide a variety of information, and Microtrace scientists have been called in to investigate materials from all of these processes for purposes ranging from basic science through litigation.
Solids and volatiles formed during combustion can vary depending on the fuel and the conditions under which the combustion takes place. Investigations focusing on solid materials and residues typically involve light and electron microscopy, while those involving volatiles utilize micro-infrared spectroscopy and gas chromatography – mass spectrometry. Questions addressed during such investigations have ranged from the identity of a particular fuel (i.e., did this soot result from a forest fire or from a power plant) to the presence of a particular chemical.
Soot is a specific solid component that results from most combustion , and in some instances, is produced under controlled conditions as an industrial raw material (carbon black). Identification of soot and characterization of it using light and electron microscopy, elemental analysis, and vibrational spectroscopy can provide insight into sources as well as the specific properties of a given combustion process.
Coals and cokes have been microscopically characterized to recognize them in dusts. Fuels have also been studied to develop signatures for a particular fuel (as in the question of an oil spill attribution). In arson and fire investigations, we also provide identification of accelerants and other volatile compounds.
Other Combustion Processes