Zdrojový dokument:Scientific papers of the University of Pardubice. Series A, Faculty of Chemical Technology. 19/2013
ISSN:1211-5541
Abstrakt:
Material analysis of writing means is very important part of forensic examination
of the questioned documents. Mostly is it used to confirm/refute the authenticity
of the document or dating the time of document formation. Nowadays, commonly
used writing means can be divided to ballpoint, ink and gel pens, according to the
nature of their writing fluid cartridge. The various group of writing means differ
in ink composition and principle of supplying writing materials on a substrate.
During examination of the document usually routine analysis such as optical
microscopic methods are applied first. Their preliminary results can facilitate the
choice of other methods which are needed to submit a sample. Widely used are
spectroscopic (mostly non-destructive) and chromatographic (destructive)
methods. The aim of our study was to utilize a combination of suitable spectroscopic methods in IR region and XRF spectroscopy in order to develop the most
appropriate methods of measurement and subsequent data processing in identification
of the writing resource. The database of 19 model samples of different
kinds of blue pens applied on paper substrate was created. More attention was
fixed on micro-FTIR and FTIR analysis. We focused on searching for the optimum
technique enabling the analysis of thin lines on a paper substrate and subsequent
separation of the spectrum of writing means. It was established what is the
minimum required number of measurements from a single sample. In the spectra,
the correlation/difference between groups of writing means (ball, gel and roller
ball pens) and between individual means within a particular group were studied.
The results were supplemented by elemental analysis and by XRF method.