Detection of gasoline on suspects' hands: study of different sampling alternatives

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Etat: Public
Version: Author's accepted manuscript
Licence: Non spécifiée
ID Serval
serval:BIB_ABEF580A1518
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Detection of gasoline on suspects' hands: study of different sampling alternatives
Périodique
Forensic Science International
Auteur⸱e⸱s
Büchler Loric, Werner Denis, Delémont Olivier
ISSN
0379-0738
Statut éditorial
Publié
Date de publication
11/11/2020
Peer-reviewed
Oui
Volume
318
Pages
110590
Langue
anglais
Résumé
Arsonists may use ignitable liquids to start, accelerate and amplify fires. The sampling of volatiles present on the hands of suspected arsonists is therefore sometimes carried out in the course of the investigation of (possible) deliberate fires. Several collection protocols have been proposed, relying on the concentration of volatiles by the transfer on PVC gloves and further passive headspace extraction with Activated Charcoal Strips (ACS). Previous research findings assessing the use of Activated Carbon Cloth (ACC) – initially developed for the adsorption of gas in military applications – opens the path to new perspectives regarding the extraction and the concentration of ignitable liquid residues in general, and for the sampling on hands in particular. Five alternative methods (four relying on the use of ACC and one on ACS) were considered for the collection of gasoline traces present on the hands and their subsequent analysis by gas chromatography – mass spectrometry.
Gasoline was deposited onto the palms of volunteers to study the differences between the collection method using ACS and those using ACC. For the latter, either the volunteer hands were placed in nylon bags with an ACC on the palm or suspended, or, powder-free latex gloves were used, with an ACC on the palm or in a separate extraction, with the glove in a nylon bag and the ACC suspended.
The results showed that the background contamination was not distinguishable between ACS and ACC and their sampling ability was comparable. The two methods relying on the deposition of ACC directly on the surface of the palm where gasoline was deposited showed significantly higher collection capacity than other methods, provided that the ACC was in direct contact with the contaminated zone. The results showed that three main factors affected the collection of gasoline on the hands: the distance between the skin and the sorbent (ACC or ACS) in case of direct concentration of volatiles on the sorbent, the exposure time, and the space between the hand and the glove or bag (i.e. the headspace volume).
This research opens new perspectives for the sampling of ignitable liquid residues through the use of ACC. It corroborates the perceived potential of ACC for the extraction and concentration of volatile compounds, particularly for fire debris analysis purposes. While the experiments were focused on the collection of gasoline on hands, the results provide valuable information in a more general way for the sampling of fire debris.
Mots-clé
Ignitable liquid, Extraction, Passive headspace, Activated Carbon Cloth, Activated Charcoal Strip, GC-MS
Création de la notice
26/11/2020 12:31
Dernière modification de la notice
07/07/2021 6:35
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