Problems of Forensic Sciences 2003 Vol. 53 (LIII) 60-73
RAMAN SPECTROSCOPY AS A NEW TECHNIQUE FOR DETERMINING THE ASEQUENCE OF INTERSECTING LINES
Ewa FABIAŃSKA, Marcin KUNICKI
Institute of Forensic Research, Cracow
Streszczenie
Ascertaining the sequence of intersecting lines has been a matter of interest to document examiners for many years. The most effective methods for doing this include optical microscopy and scanning electron microscopy. However, these methods do not always give unambiguous results, and so new techniques are constantly being sought which will enable intersecting line sequences to be determined in difficult cases as objectively as possible. Arelatively new technique that is being increasingly applied in forensic science is Raman spectroscopy. This is a non-destructive method that determines the composition of a given sample accurately. Scientists have recently begun to use it in investigations to differentiate inks. In this work, we have attempted to assess how useful it is in ascertaining the order in which intersecting graphic lines have been drawn . both homogenous (i.e. drawn by the same type of instrument) and heterogeneous ones (i.e. drawn by different types of instrument). The samples studied were intersecting graphic lines made by popular writing instruments (e.g. ball point pens and fibre tip pens) in different combinations, and intersections in which one line was made by an ink jet printer and the other by various writing materials (ballpoint inks and fluid inks). Raman spectra were obtained using Foram 685-2 apparatus by Foster & Freeman. The investigations were carried out on samples prepared on the same type of paper. Five readings were taken for each sample, and the spectra obtained were averaged and compared with spectra of pure inks.
Słowa kluczowe
Inks; Crossing line; Raman spectroscopy.