Sherlock X™ Fire Debris Analysis - Automated Ignitable Liquid Identification using Agilent GC-MS

Significance of the Topic

Fire debris analysis is a vital component of forensic investigations, enabling reliable detection of ignitable liquids in post-fire residues. Automated identification of hydrocarbon profiles accelerates casework and reduces subjective errors associated with manual peak interpretation.

Objectives and Overview

This application note presents the Sherlock X Fire Debris Software, which integrates with Agilent GC-MS systems to automatically recognize over 130 hydrocarbons in fire debris samples. The software aims to streamline compound naming, categorization, and compliance with ASTM E1618 standards.

Methodology

Sherlock X processes GC-MS chromatograms by extracting absolute responses, calculating relative percentages for each detected compound, and matching retention times against an established library. It then groups compounds into functional classes and evaluates sample composition against expected profiles for various ignitable liquids.

Used Instrumentation

• Agilent 6890 or 7890 Gas Chromatograph
• Agilent 5973, 5975, or 5977 Mass Spectrometer
• MS ChemStation or MassHunter data acquisition software

Main Results and Discussion

The software successfully identified major and minor hydrocarbons, reporting key analytes such as m,p-xylene (8.06%), ethylbenzene (1.70%), toluene (2.16%), and a range of branched and straight alkanes. Classification output indicated aromatics dominated the profile (67.40%), followed by branched alkanes (14.63%), condensed rings (9.47%), straight alkanes (6.43%), cycloalkanes (1.76%), and heterocyclic rings (0.32%). Standard Comparison Reports highlighted required versus observed compounds per ASTM E1618 guidelines.

Benefits and Practical Applications

Automated workflows deliver consistent, reproducible results and reduce analyst workload by approximately 30 minutes per sample. Sherlock X supports analysis of diesel, biodiesel, kerosene, charcoal lighter fluid, mineral spirits, camp fuels, and other ignitable liquids, improving throughput in forensic and QA/QC laboratories.

Future Trends and Applications

Advances may include expansion of compound libraries, integration with cloud-based AI for predictive profiling, real-time on-site analysis via portable GC-MS, and enhanced data analytics for complex mixture deconvolution.

Conclusion

Sherlock X Fire Debris Software offers a robust, automated solution for hydrocarbon identification in fire investigation. By leveraging Agilent GC-MS data and standardized protocols, it enhances accuracy, efficiency, and compliance in forensic laboratories.

Reference

1. MIDI, Inc. Sherlock X Fire Debris Analysis Application Note, November 2015