Application of micro-raman and ft-ir spectroscopy in forensic analysis of automotive topcoats in the Republic of Macedonia

Raman and infrared spectroscopy are two complementary spectroscopic techniques that can produce fast, efficient and accurate detection of the pigments and/or binders used in automotive topcoats. Micro-Raman spectroscopy, due to its non-destructiveness, has been extensively used for identification of pigments and dyes in forensic investigation of hit-and-run accidents. This technique provides very useful and significant information from very small samples of evidence without any previous preparation of the sample. The recorded Raman spectra of the unknown/ suspected samples can be compared with a spectrum of the referent sample, which can coincide with the one already existing in the Raman database of pigments. In order to form our own spectral database of automotive paints for forensic investigations in hit-and-run offences in Republic of Macedonia, an investigation of automotive topcoats of different origins was carried out. In our previous study, pigments in some automotive topcoats, produced by Mobihel, have been identified using micro- Raman and FT-IR spectroscopy. In the present study, we report micro-Raman and FT-IR spectra of ten base coat automotive topcoats, as well as some of their mixtures, produced by Glasürit. In order to demonstrate the availability and/or the advantages of the micro-Raman spectroscopic technique in forensic investigation in road accidents, four successfully solved cases from the police investigation in hit-and-run accidents are presented in this work.