ABSTRACT

Paint samples received at a forensic laboratory usually consist of small chips or smears. Analytical methods, therefore, must be capable of producing significant information from microsamples. Infrared (IR) spectroscopy is one of the most useful and powerful tools for this purpose. Its microsampling capabilities are well established and it provides molecular structure information on both organic and inorganic constituents of multicomponent mixtures such as paint layers. IR spectroscopy can be applied both to identifying probable sources of paint through use of databases and to comparing samples from different sources to determine if they could have had a common origin. When comparing single layers of paint, IR data are often combined with data from other techniques such as pyrolysis gas chromatography (PGC), solvent tests and elemental analysis.