Investigation of Water Effect on Ignitable Liquid Residue Analysis by Coupling Solid-Phase Microextraction with Direct Analysis in Real Time Mass Spectrometry

Abstract

Arson investigation and explosive analysis is a subfield of forensic science that focuses on examining the physical evidence that is collected from a scene in which a fire occurred. Accelerants and ignitable liquids (ILs) are often used in arson fires to maximize the damage that the fire creates. Common ILs include lighter fluid and gasoline, with gasoline being one of the most volatile compounds. Direct analysis in real time-mass spectrometry (DART-MS) is known for its ability to analyze volatile weather-exposed compounds and to demonstrate sensitive detection of explosives. In recent research, the DART-MS was coupled with an extraction method called Solid Phase Microextraction (SPME) to aid in the analysis of IL residue on substrates (i.e., wood floor, paper). This study hypothesizes that water could interfere with gasoline residue analysis by DART-MS which is dependent on the gasoline to water ratios and the type of substrates. The objective is to conduct a comprehensive evaluation of the water effect in gasoline residue detection by DART-MS method to provide results that will aid in a better understanding of water and substrates factors in the IL detection method.