title: 1H NMR metabolite fingerprinting as a new tool for body fluid identification in forensic science.
abstract: In this feasibility study, we propose, for the first time, (1)H NMR spectroscopy coupled with mathematical strategies as a valid tool for body fluid (BF) trace identification in forensic science. In order to assess the ability of this approach to identify traces composed either by a single or by two different BFs, samples of blood, urine, saliva, and semen were collected from different donors, and binary mixtures were prepared. (1)H NMR analyses were carried out for all samples. Spectral data of the whole set were firstly submitted to unsupervised principal component analysis (PCA); it showed that samples of the same BF cluster well on the basis of their characterizing molecular components and that mixtures exhibit intermediate characteristics among BF typologies. Furthermore, samples were divided into a training set and a test set. An average NMR spectral profile for each typology of BF was obtained from the training set and validated as representative of each BF class. Finally, a fitting procedure, based on a system of linear equations with the four obtained average spectral profiles, was applied to the test set and the mixture samples; it showed that BFs can be unambiguously identified, even as components of a mixture. The successful use of this mathematical procedure has the advantage, in forensics, of overcoming bias due to the analyst's personal judgment. We therefore propose this combined approach as a valid, fast, and non-destructive tool for addressing the challenges in the identification of composite traces in forensics.
authors.affiliation: Dipartimento di Scienze Chimiche, Università di Cagliari, Cittadella Universitaria di Monserrato, SS 554 Bivio per Sestu, 09042, Monserrato (CA), Italy. scano@unica.it
authors.forename: Paola
authors.initials: P
authors.lastname: Scano
authors.forename: Emanuela
authors.initials: E
authors.lastname: Locci
authors.forename: Antonio
authors.initials: A
authors.lastname: Noto
authors.forename: Gabriele
authors.initials: G
authors.lastname: Navarra
authors.forename: Federica
authors.initials: F
authors.lastname: Murgia
authors.forename: Milena
authors.initials: M
authors.lastname: Lussu
authors.forename: Luigi
authors.initials: L
authors.lastname: Barberini
authors.forename: Luigi
authors.initials: L
authors.lastname: Atzori
authors.forename: Fabio
authors.initials: F
authors.lastname: De Giorgio
authors.forename: Maria Francesca
authors.initials: MF
authors.lastname: Rosa
authors.forename: Ernesto
authors.initials: E
authors.lastname: d'Aloja
mesh_terms: D000328:Adult; D001826:Body Fluids / Q000737:chemistry* / Q000378:metabolism*; D005260:Female; D044707:Forensic Sciences / Q000295:instrumentation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019906:Nuclear Magnetic Resonance, Biomolecular; D025341:Principal Component Analysis; D011522:Protons; D012016:Reference Values
chemical_list: D011522:Protons
keywords: 1H; NMR; body fluids traces; forensic science; metabolite profile