New insights in forensic chemistry: NIR/Chemometrics analysis of toners for questioned documents examination

Stefano Materazzi; Roberta Risoluti; Sara Pinci; Francesco Saverio Romolo

doi:10.1016/j.talanta.2017.06.044

New insights in forensic chemistry: NIR/Chemometrics analysis of toners for questioned documents examination

Talanta. 2017 Nov 1:174:673-678. doi: 10.1016/j.talanta.2017.06.044. Epub 2017 Jun 23.

Authors

Stefano Materazzi¹, Roberta Risoluti², Sara Pinci¹, Francesco Saverio Romolo³

Affiliations

¹ Department of Chemistry - "Sapienza" University of Rome, Italy.
² Department of Chemistry - "Sapienza" University of Rome, Italy. Electronic address: roberta.risoluti@uniroma1.it.
³ Section of Legal Medicine, "Sapienza" University of Rome, Italy.

PMID: 28738640
DOI: 10.1016/j.talanta.2017.06.044

Abstract

Near-Infrared spectroscopy (NIRs) coupled to chemometrics was investigated for the first time as a new tool for the analysis of black toners to evaluate its application in forensic cases. Ten black toners from four manufacturers were included in this study and the acquired spectra were compared in order to differentiate toners. Multivariate statistical analysis based on Principal Component Analysis (PCA) was considered to develop a model of comparison of toners in questioned documents. Results demonstrated the capabilities of the approach NIR/Chemometrics to correctly identify toners when printed on different papers and to be not affected by the printing process. This study has shown that NIRs can be considered as a useful, fast, non-destructive tool providing the characterisation of toners in forensic caseworks.

Keywords: Chemometrics; Forensic chemistry; NIR spectroscopy; Toners.