Forensic Chemistry, June 2020
Michelle N. Torres | Florida International University
Nicole B. Valdes | Florida International University
José R. Almirall | Florida International University
A novel extraction device, capillary microextraction of volatiles (CMV) was coupled to a TRIDION-9 GC–MS with a needle trap (NTD) and evaluated for the analysis of ignitable liquids fire debris. The performance of the TRIDION-9 was compared to a benchtop GC–MS using CMV. A system detection limit of ~10 ng for each of 20 key ignitable liquid residue (ILR) compounds was determined for the T9 GC–MS. Dynamic headspace sampling of simulated ILRs was performed in closed and open-air systems. Closed system evaluations the CMV/NTD technique resulted in extraction performance similar to the CMV alone; however, ILR analysis on the T9 was impacted by limited chromatographic resolution. Compound identification was possible for 14 out of the 20 selected compounds on the T9 when 1 µL of a 1% standard accelerant mixture (SAM) was sampled, compared to 17 compounds on the benchtop GC–MS for the same mass loading. Open-air sampling with a modified vapor source resulted in the retention of most compounds with as low as 5 min. sampling, and equilibrium concentrations were reached after 10 min. No significant differences were observed between CMV and CMV/NTD sampling suggesting that the combined technique does not suffer from affinity bias. While the potential of the CMV/NTD extraction coupled to a T9 GC–MS for fire debris analysis was limited by the chromatographic resolution of the instrument, this study serves as proof of concept for the CMV’s potential for the extraction of ILRs in combination with portable GC–MS systems.
- Development of an Extraction Technique for Ignitable Liquid Residues (ILR) in the Field using Capillary Microextraction of Volatiles (CMV) and Person-Portable GC-MS
- Evaluation of Capillary Microextraction of Volatiles (CMV) Coupled to a Person-Portable Gas Chromatograph Mass Spectrometer (GC–MS) for the Analysis of Gasoline Residues
- Modifications to Capillary Microextraction in Volatiles for the Extraction of Ignitable Liquid Residues
Funding for this article was provided by the Forensic Technology Center of Excellence and the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice.
The opinions, findings, and conclusions or recommendations expressed in this article are those of the author(s) and do not necessarily reflect those of the U.S. Department of Justice.