Comparison of gasolines using gas chromatography/mass spectrometry and target ion response

Gas chromatography/mass spectrometry was used to compare gasoline samples obtained from different sources based on the difference in response of the ion detector to the target ions of certain components found in gasoline. Many suspected arson cases involve comparing an accelerant extracted from fire debris to an ignitable liquid found in a suspect's possession to determine if it could have been used in the fire. These types of comparisons are currently based on pattern recognition and component identification and do not take into account the variation that exists in some commonly used accelerants such as gasoline. Fifty and seventy-five percent-evaporated gasoline samples were both found to contain similar ratios of certain components when compared to the same source gasoline unevaporated. This research proposes ratios to be used to determine if an unevaporated gasoline sample could have originated from the same source as an evaporated gasoline extract from fire debris. The results of the comparisons in this study demonstrate that for cases involving gasoline as the accelerant, that has been evaporated up to 50% and extracted from pine, it is possible to eliminate comparison samples as originating from the same source. The results of the 75% comparisons suggest it may be possible to apply the same type of comparison to cases involving 75% evaporated gasoline.