NCJ Number
210773
Journal
Journal of Forensic Sciences Volume: 50 Issue: 4 Dated: July 2005 Pages: 832-841
Date Published
July 2005
Length
10 pages
Annotation
This study examined the ability of infrared chemical (hyperspectral) imaging to provide a forensic analysis of paint chips in particular and multicomponent (e.g., layered) samples in general.
Abstract
Infrared chemical imaging suggests itself as a method for discrimination within evidence types such as paint chips because it simultaneously delivers chemical and spatial information about the sample; however, at the time of this report, no publication of this process for analyzing paint chips was found. This report describes improved sample preparation procedures for the infrared analysis of paint chips. It is recommended that when mounting resins are chemically incompatible with the sample, it is better to mount and section the sample in a soft wax, from which the sections can be removed and pressed into a KBr disk for transmission analysis. Infrared chemical imaging was found to have a number of significant advantages over conventional "single-point" infrared spectroscopy in analyzing multilayered paint chips. These advantages are based in the simultaneous collection of thousands of infrared spectra across the sample in a matter of minutes. Most importantly, the data can be used to visualize the spatial distribution of the various chemical components of a sample, which is an important advantage in comparison studies. Although the current study examined only one evidence type, it is apparent that infrared chemical imaging should be examined as a tool for the forensic analysis of other multicomponent samples. 6 figures and 34 references