Abstract:
Fire debris analysis is used to help determine the cause of a fire through physical and instrumental examinations. Advancements in the instrumental techniques of fire debris analysis has led to sensitive and accurate detections of ignitable liquids possibly used to start fires. The criminal nature of using ignitable liquids to cause damage to unauthorised property established fire debris analysis as one branch of forensic science. Techniques used for fire debris analysis at The Institute of Environmental Science and Research (ESR) required an update to improve efficiency and representation of all the types of ignitable liquids. This was done with a new, longer column with a slightly polar stationary phase. The longer length of the new column, compared to the old one used at ESR, allowed lighter oxygenated ignitable liquids to separate from the solvent. Earlier protocols required a different column for oxygenated ignitable liquids separations, causing delays in analysis with column installation time. The petroleum-based ignitable liquids would then elute later on the new column, as they did with the old column. The new method was tested with testmix solutions and reference standards to ensure sensitivity, repeatability, and overall quality of performance. The results proved that the method was sufficient for forensic fire debris purposes. Further work to implement the method for official use at ESR can take place. A survey of various substrates was completed to assess oxygenated ignitable liquid signals from background or combustion sources. Substrates were sampled before and after burning to test for background and combustion signals, respectively. Peaks of oxygenated ignitable liquids did occur at varying levels. Some substrates seemed to show stronger signals for certain compounds. The information collected in the survey will be a helpful guide for analysts to use when reporting on oxygenated ignitable liquid residues. Information regarding oxygenated ignitable liquid signals that occur after a known amount of such fuel is added to a substrate could also be helpful in guiding analysts in their reporting on oxygenated ignitable liquid residues.