ISSN: 0022-1198
CODEN: JFSCA
Published Online: 25 May 2005
Page Count: 7

The Effect of Exposure to the Elements on the Forensic Characterization by Infrared Spectroscopy of Poly(ethylene terephthalate) Fibers
Marigo, A
Dipartimento di Scienze Chimiche dell'Universitaà,

Marega, C
Dipartimento di Scienze Chimiche dell'Universitaà,

Guzzini, G
Sezione di Chimica, Esplosivi ed Infiammabili, Reparto Carabinieri Investigazioni Scientifiche,

Causin, V
Dipartimento di Scienze Chimiche dell'Universitaà,

(Received 17 December 2004; accepted 13 March 2005)

Abstract

Validation of a recently proposed differentiation method for single poly (ethylene terephthalate) (PET) fibers, based on integration of IR absorption bands, is presented. IR microscopy in the transmission mode, differential scanning calorimetry and optical microscopy were employed. The reliability of the technique has been extended to the cases in which the fibers being compared have experienced long exposure to the elements, as may happen if these items are recovered from open-air crime scenes. The effect of immersion in water and irradiation by the sun for a three-month period have been considered. The fibers remained morphologically and structurally unaltered. The significance of comparisons between fibers kept in different environments is thus enhanced, because the detrimental effect of the elements can be ruled out. This further validation of the proposed technique contributes to render the data presented by the forensic scientist less vulnerable to context effect and bias.

Keywords:
forensic science, fiber analysis, contact traces, polyethylene terephthalate, Fourier transform infrared spectroscopy

Paper ID: JFS2004519
DOI: 10.1520/JFS2004519
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