Application of some physical techniques for forensic discrimination of printer toner

Abstract

THE DOCUMENTS examiner had trouble with forensic discrimination between types of toner using a single analysis method. In our study seven samples of toner removed from laser printers of various and same brands of different models will be analysed using more than one method as Fourier transform infrared (FT-IR), Raman spectroscopy, X-ray fluorescence (XRF) and X-ray diffraction (XRD) to distinguish between different toner samples and applying apply all analysis data for forensic evidence. Results of FT-IR analysis show that all toner samples of HP brand had the same polymeric resin. Raman spectroscopy used to differentiate between toner samples had the same polymeric resin in FT-IR analysis by comparing their Raman spectrum.Toner samples of HP 2300 and HP 4700 printers were indistinguishable by using results of FT-IR and Raman spectroscopy,therefore, more elemental analysis will be required. XRF used to differentiate between indistinguishable toner samples of HP 2300 and HP 4700 printers by FT-IR and Raman spectroscopy. Also for all toner samples, results of XRFshown showed that iron, silicon, cupper, calcium, and ruthenium were the major percent elements present in toner. The results of XRD show thatt here are common compounds (phases) between the analyzed tonersamples and the composition for major elementspresent were oxides.