Raman Spectroscopy of Automotive and Architectural Paints: In situ Pigment Identification and Evidentiary Significance.

摘要

Pigments are encountered in many kinds of trace evidence, including automotive and architectural paints, inks, fibers, and plastics. Traditionally, pigments have been studied by polarized light microscopy, microchemistry, infrared spectroscopy, py-GC/MS, SEM/EDS and X-ray diffraction. However, imitations inherent to each of these techniques have constrained the practical use of pigment identification in the analysis of trace evidence. Raman spectroscopy, which is becoming more widely available to forensic science laboratories, is the first analytical technique to provide the spatial resolution, sensitivity and specificity necessary to quickly and specifically identify a wide variety of pigments in situ. The research presented here is a follow-up to internal research and a prior NIJ grant that resulted in a report entitled Fundamentals of forensic pigment identification by Raman microspectroscopy (Palenik et al., 2011). That initial research focused on developing the fundamental techniques that were required to identify pigments in microscopic specimens of forensic interest.