Novel method based on ion mobility spectrometry sum spectrum for the characterization of ignitable liquids in fire debris

María José Aliaño-González; Marta Ferreiro-González; Gerardo F Barbero; Miguel Palma

doi:10.1016/j.talanta.2019.02.063

Novel method based on ion mobility spectrometry sum spectrum for the characterization of ignitable liquids in fire debris

Talanta. 2019 Jul 1:199:189-194. doi: 10.1016/j.talanta.2019.02.063. Epub 2019 Feb 16.

Authors

María José Aliaño-González¹, Marta Ferreiro-González², Gerardo F Barbero³, Miguel Palma⁴

Affiliations

¹ Department of Analytical Chemistry, Faculty of Sciences, IVAGRO, ceiA3, University of Cadiz, 11510 Puerto Real, Cadiz, Spain. Electronic address: mariajose.alianogonzalez@alum.uca.es.
² Department of Analytical Chemistry, Faculty of Sciences, IVAGRO, ceiA3, University of Cadiz, 11510 Puerto Real, Cadiz, Spain. Electronic address: marta.ferreiro@uca.es.
³ Department of Analytical Chemistry, Faculty of Sciences, IVAGRO, ceiA3, University of Cadiz, 11510 Puerto Real, Cadiz, Spain. Electronic address: gerardo.fernandez@uca.es.
⁴ Department of Analytical Chemistry, Faculty of Sciences, IVAGRO, ceiA3, University of Cadiz, 11510 Puerto Real, Cadiz, Spain. Electronic address: miguel.palma@uca.es.

PMID: 30952245
DOI: 10.1016/j.talanta.2019.02.063

Abstract

The destructive nature of fire together with a variety of interfering products from pyrolysis or background compounds among others, still offer a challenge on the proper identification of ignitable liquid residues (ILRs) in fire investigations. Nowadays, analysts use chromatography-mass spectrometry to try and classify ignitable liquids (IL) into one of the classes in the American Standards Testing Material method (ASTM E1618). In this study, an alternative approach is proposed to such analysis of fire debris. The proposed method would be based on ion mobility spectrometry sum spectrum (IMSSS) from headspace analysis, in combination with pattern recognition tools (Linear Discriminant Analysis, LDA). Four different substrates (pinewood, cork, paper, and cotton sheet) were burnt with and without different ILs (gasoline, diesel, ethanol, and paraffin). According to LDA, 100% of fire debris samples were correctly classified for presence/absence and type of IL. A characteristic fingerprint for each ILR was created for quick discrimination. These results demonstrate the potential of using IMSSS for a fast, objective and easy interpretation of fire debris data. In addition, ion mobility spectrometry (IMS) presents some advantages over traditional techniques such as its real-time monitoring capability and its capacity to work at atmospheric pressure, which allow the development of portable devices that would perform the analysis at the fire scene.

Keywords: Characterization; Chemometrics; Fire debris; Ignitable liquids; Ion mobility spectrometry sum spectrum.