A Combined Use of Analytical and Chemometric Strategies for Fire Debris Investigation

Marco Vincenti, Chemistry, University of Turin, Torino, Italy (marco.vincenti@unito.it)
Marco Pazzi, Chemistry, University Of Turin, Torino, Italy
Fabrizio Malaspina, Unità Di Intervento Nucleare Biologico Chimico Radiologico, Corpo Nazionale Vigili Del Fuoco - Comando Di Torino, Torino, Italy
Laura Pacifici, Chemistry, University Of Turin, Torino, Italy
Filomena I. Finizio, Chemistry, University Of Turin, Torino, Italy
Simone Bourcet, Chemistry, University Of Turin, Torino, Italy
Eugenio Alladio, Chemistry, University Of Turin, Torino, Italy

The possibility to recognize whether collected evidences might be associated to an arson still represents a crucial issue in the field of fire debris investigations. Indeed, GC-MS analysis and/or ATR-IR spectroscopy on recovered fire debris may be quite easily compared to the corresponding data obtained from ignitable liquids or firelighters, e.g. found in possession of a suspected arsonist. In the present study, the use of gasoline, diesel fuel and firelighters as fire accelerants have been tested. Several gasolines and diesel fuels sampled from different oil stations located within the area of the city of Turin were analysed by SPME-GC-MS. Fresh and weathered samples were compared to reference materials (ASTM1618). Gasoline and diesel fuel samples were examined both as pure liquids and as mixtures of fresh and weathered mixtures at different percentages. Moreover, several firelighters were studied by ATR-IR spectroscopy. The data were subsequently interpreted by different targeted and untargeted approaches of multivariate data analysis, with the aim of developing explorative, classification and likelihood ratio models. The last approach provided the probability that fire accelerants have been actually employed (or not) to set the fire. At the current stage, Principal Component Analysis allowed to locate the fresh gasoline and diesel fuel samples within a scores plot according to their origin, i.e. the different oil stations. Similarly, different types of firelighters were differently located in their relative scores plot according to similarity features. Moreover, the development of N-Way strategies and Self-Organizing Maps proved successful in identifying the usage of fire accelerants. Even if in a preliminary stage, this study emphasize the adoption of multivariate strategies in order to assist the traditional interpretative process of fire debris investigations.

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Short Biography of Presenting Author

Marco Vincenti is Professor of Analytical Chemistry at the University of Torino and Director of the Department of Chemistry since 2015.  In 2001, he founded a Master Degree in "Clinical, Forensic Chemistry and Doping Control" at the University of Turin, where he currently teaches “Instrumental Analysis” and “Chemometrics”.

Since 2008, he is Director of the Regional Antidoping and Toxicology Laboratory “A. Bertinaria" of Turin, built for the 2006 Winter Olympics.  Since 2009, the Laboratory obtained ISO 17025 accreditation for a wide range of analytical determinations regarding drugs of abuse and alcohol abuse in a variety of biological matrices (blood, urine, hair, oral fluid). The Laboratory executes about 300,000 analytical determinations/year on 65,000 biological samples/year, including 18,000 hair samples per year.

In 1986, he was Visiting Scientist in the "Aston Laboratory" of Prof. Graham R. Cooks at the Purdue University (Indiana - USA).  He investigated innovative tandem mass spectrometric techniques, associated with collisional activation on solid surfaces and gases. During his academic activity, he also collaborated with the U.S. Environmental Protection Agency for the determination of new and unpredictable water disinfection byproducts in potable water. 

His current research interests are directed toward various applications of analytical chemistry, including toxicology, forensic investigation, doping control, clinical analysis, chemometrics, and the development of innovative methods for determining new psychoactive substances (NPS) and drugs with anabolic activity, illegally used in sport as well as in animal breeding. He collaborates with the Justice, the Police forces, and the Regione Piemonte government for the chemical analysis of biological samples and drug mixtures seized during law enforcement and crime prosecution activities.

He is a member of the Italian Chemical Society, the American Society for Mass Spectrometry, The International Association of Forensic Toxicologists (TIAFT), and the Society of Hair Testing (SoHT), where he serves as Board Member since 2016.