Defense Date
2024
Document Type
Directed Research Project
First Advisor
Eric Hazelrigg
Second Advisor
Christopher Ehrhardt
Third Advisor
Chad Schennum
Abstract
The ability of a forensic examiner to identify the presence of ignitable liquids (ILs) in fire debris collected from the area of origin of a fire is an essential component for determining intent in fire investigations. However, this relies on an effective extraction method that provides a complete picture of what is present in the debris. In this study, eight substrate materials underwent three different treatments: a low-volume of substrate that was unburned, a low-volume of substrate that was burned, and a high-volume of substrate that was unburned. Each sample was spiked with a 1:1 mixture of gasoline and diesel fuel before being extracted using the charcoal strip method and analyzed through gas chromatography-mass spectrometry (GC-MS). External calibration curves were created for four chosen compounds of interest - toluene, 1,2,4-trimethylbenzene, n-tridecane, and n-hexadecane - that each showed R2 values exceeding 0.99. Extraction efficiencies for each substrate were calculated across the three treatments and averaged from multiple replicates. ANOVA and t-test statistics were performed to compare the extraction efficiencies and determine whether there was a significant difference in the efficacy of the charcoal strip method to extract the IL mixture depending on the type of substrate or treatment. Overall, there was strong evidence (p < 0.001) that the method had a significantly different extraction efficiency for high-volume carpet samples compared to other substrates, as well as in comparison to unburned carpet samples. This can be a foundation for future research investigating the effect of substrate type and sample volume on the extraction efficiency of the charcoal strip method.
Rights
© The Author(s)
Is Part Of
VCU Master of Science in Forensic Science Directed Research Projects
Date of Submission
4-25-2024