As pointed out by the recent National Academy of Sciences report on forensic sciences, the study of fire patterns and debris in arson fires is in need of additional study and standardization. Part of the current difficulty is in determining the appropriate suite of analytes for which to focus fire debris analyses. This has been done with time consuming accelerant weathering or evaporation studies. In this paper we discuss a recently introduced method that has the potential of providing predicted evaporation patterns for accelerants. The method is complex fluid analysis protocol called the advanced distillation curve approach, which features: (1) a composition explicit data channel for each distillate fraction (for both qualitative and quantitative analysis), (2) temperature measurements that are true thermodynamic state points that can be modeled with an equation of state, (3) temperature, volume and pressure measurements of low uncertainty suitable for equation of state development, (4) consistency with a century of historical data, (5) an assessment of the energy content of each distillate fraction, (6) trace chemical analysis of each distillate fraction, and (7) a corrosivity assessment of each distillate fraction. As applied to accelerants, the method allows the rapid prediction of the evaporation or weathering pattern as a function of temperature. It can also provide an enthalpic analysis of the accelerant, as well as trace analysis of constituents that can serve as taggents. We discuss the application of the method to kerosenes and gasolines, and outline how expansion of the scope of fluids to other accelerants can benefit the criminalist in the analysis of fire debris for arson.
Citation: Journal of Forensic Sciences
Pub Type: Journals
accelerants, advanced distillation curve, evaporation patterns, trace analysis