ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Utilization of statistical analysis of FT-IR spectra in forensic examination of paper

Radko Tiňo, Katarína Vizárová, Jana Provazníková, Štefan Šutý, and Soňa Kirschnerová

Slovak University of Technology, Bratislava, Slovakia

E-mail: stefan.suty@stuba.sk

Abstract: Studying of paper carriers of information has become increasingly important in forensic practice. This is caused by growing number of bogus or in other manner fraudulently alternated documents. An identification of individual paper sheets and studying their differences are the parts of forensic analysis of multiple sheets documents. This paper focuses on the possibilities of processing of mathematical and statistical data obtained by measurements of FT-IR spectral characteristics of individual paper sheets in a studied document. The spectral data were used to create data matrix which contains values of absorbance and interval of wavenumber. The method of differentiation is based on the comparison of maximum absorbance values within the range of wavenumbers from 1562 to 1215 cm⁻¹. This spectrum range is specific in occurrence of absorption bands that belong to calcium carbonate CaCO₃—an element of paper added into it in relatively high amounts in the form of filler which content or percentage occurrence may be different considering to the paper producer or production technology. Based on the above-said, the paper sheets originating from different producers or from various production technology units can be differentiated one from another using a robust statistical analysis.

Keywords: Forensic examination ; Paper ; Filler content ; FT-IR analysis ; Statistical analysis 

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-018-0482-y

Chemical Papers 72 (9) 2265–2272 (2018)