"Evaluation of Charcoal Strip Extraction Efficiency Under Varying Subst" by Abby Wester
 

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

Available for download on Friday, April 25, 2025

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