Citation

Roberts K, Almond MJ, Bond JW. J. Forensic Sci. 2013; 58(2): 495-499.

Affiliation

Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, U.K.

Copyright

(Copyright © 2013, American Society for Testing and Materials, Publisher John Wiley and Sons)

DOI

10.1111/1556-4029.12049

PMID

23278849

Abstract

Fire investigation is a challenging area for the forensic investigator. The aim of this work was to use spectral changes to paint samples to estimate the temperatures to which a paint has been heated. Five paint samples (one clay paint, two car paints, one metallic paint, and one matt emulsion) have been fully characterized by a combination of attenuated total reflectance Fourier transform infrared (ATR-IR), Raman, X-ray fluorescence spectroscopy and powder X-ray diffraction. The thermal decomposition of these paints has been investigated by means of ATR-IR and thermal gravimetric analysis. Clear temperature markers are observed in the ATR-IR spectra namely: loss of ν(C = O) band, >300°C; appearance of water bands on cooling, >500°C; alterations to ν(Si-O) bands due to dehydration of silicate clays, >700°C; diminution of ν(CO(3) ) and δ(CO(3) ) modes of CaCO(3) , >950°C. We suggest the possible use of portable ATR-IR for nondestructive, in situ analysis of paints.

Language: en