Concentration of ignitable liquid residue from simulated fire debris by dynamic vapor microextraction: Sensitivity to instrument settings and debris characteristics

• NCJ Number: 307455
• Journal: Forensic Chemistry Volume: 35 Dated: September 2023
• Author(s): Jennifer L. Berry; Mary E. Gregg; Amanda A. Koepke; Reta Newman; Kavita M. Jeerage
• Date Published: September 2023
• Grant Number(s): DJO-NIJ-19-RO-0007
• Agencies: NIJ-Sponsored
• Publication Type: Research (Applied/Empirical)
• Award: Extraction of Ignitable Liquid Residues by Dynamic Capillary Headspace Sampling and Comparison to the Carbon Strip Method

Annotation

This study quantitatively evaluates dynamic vapor microextraction (DVME) in terms of the effect of 11 factors via a sensitivity analysis with simulated fire debris.

Abstract

The authors quantitatively evaluate dynamic vapor microextraction (DVME) in terms of the effect of 11 factors via a sensitivity analysis with simulated fire debris. Six factors were found to be significant; IL volume, IL weathering, and debris quantity significantly affected the recovered eluates, whereas water content did not. As related to recovering IL residue from simulated fire debris, recommended instrument settings include a higher oven temperature, longer equilibration time, larger volume of extracted headspace (collection volume), and a lower inlet flow rate. Together with the covariance mapping metric, the fractional factorial design successfully addressed questions about the effect of instrument factors, debris factors, and their interactions with an efficient number of experiments. DVME is a potential method for the extraction and concentration of ignitable liquid (IL) residue in fire debris. This low flow rate, purge-and-trap headspace concentration method collects IL vapors onto a chilled adsorbent capillary and recovers them by elution with acetone. The factors studied included six controllable instrument settings and five reflecting debris characteristics. The authors quantified performance by covariance mapping between gas chromatography – mass spectrometry (GC–MS) retention time – ion abundance matrices for the recovered eluates and corresponding reference samples. (Published Abstract Provided)