NCJ Number
215161
Journal
Journal of Forensic Sciences Volume: 51 Issue: 4 Dated: July 2006 Pages: 919-924
Date Published
July 2006
Length
6 pages
Annotation
This study used Fourier transform infrared spectrometry (FT-IR) and energy-dispersive X-ray fluorescence spectrometry (XRF) to differentiate between black-powder toners used in laser printers and copiers.
Abstract
The research found that if two samples of black-powder toners were similar in polymer composition (FT-IR spectra), additional quantitative elemental compositions from XRF analyses might provide more discrimination. It was possible to differentiate 82.5 percent pairs of examined samples by using only FT-IR, 90.8 percent pairs of examined samples by using only XRF, and 95.8 percent pairs of examined samples by using both methods. Obtained spectra and additional information could be used to build a database. Results confirm the multiplicity and compatibility of toners. The classifications performed can discriminate between samples and classify the type of machine equipped with a given type of toner. As a rule, samples of toners used in individual machines of the same model can be different. If samples known to be from different machines are found to be indistinguishable, this may be due to the compatibility of devices or cartridges. It is also possible that successive cartridges used in the same machine may differ if they are compatible with the machine but are produced by different companies. The study used 162 samples from 82 types of cartridges produced by 21 manufacturers. All samples were available on the Polish markets. The spectra obtained were classified into 14 groups and 28 groups, using FT-IR and XRF, respectively. These classifications were the basis for the development of an analytical scheme for differentiating black-powder toners. This scheme can be used with any two methods that supply different information about an examined sample. 4 tables, 6 figures, and 23 references