Analysis of Accelerants in Fire Debris - Data Interpretation.
1Department of Chemistry, The University of Alabama, Tuscaloosa, AL, USA.
Forensic Science Review
|August 14, 2015
Summary
Forensic analysis of fire debris uses gas chromatography (GC) to identify accelerants. Advances like GC/MS improve pattern recognition, but challenges in sample preparation and identifying partially evaporated distillates persist.
Area of Science:
- Forensic Science
- Analytical Chemistry
- Chemical Analysis
Background:
- Analysis of fire debris for accelerants is crucial in arson investigations.
- Gas chromatography (GC) is a primary technique for analyzing volatile residues.
- Interpreting GC chromatograms relies on comparing results to established accelerant libraries.
Purpose of the Study:
- To review the state-of-the-art in accelerant analysis in fire debris.
- To discuss methods for improving chromatogram resolution and reducing interference.
- To present findings from proficiency tests regarding instrumentation and persistent analytical challenges.
Main Methods:
- Isolation of residual volatiles from fire debris.
- Analysis using gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS).
- Comparison of chromatograms to ASTM-classified accelerant libraries and pattern recognition algorithms.
Main Results:
- Gas chromatography-mass spectrometry (GC/MS) offers enhanced pattern recognition through common ion display.
- Improved chromatographic columns and sample preparation techniques can enhance resolution and reduce interference.
- Proficiency tests (1987-1995) show increased GC/MS use but persistent issues like false positives and difficulties with partially evaporated samples.
Conclusions:
- GC/MS represents a significant advancement in identifying fire accelerants.
- Further refinement in sample preparation and pattern recognition algorithms is needed to address remaining analytical challenges.
- Accurate identification of accelerants remains critical for forensic investigations, despite ongoing technical hurdles.
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