Photo‐ and Thermal‐Degradation Studies of Select Eccrine Fingerprint Constituents

Abstract

Photo- and thermal-degradation studies on eccrine fingerprint components are presented herein. Dilute distinct solutions of urea, lactic acid, and seven amino acids were deposited on steel coupons and Teflon disks, exposed to artificial sunlight or heat, extracted, and analyzed. This aim of this study was to determine whether the investigated eccrine components, previously determined to be Raman active for a parallel study, experienced photo- or thermally induced degradation, and if so, to determine the rate and identify any detectable products. Neither the amino acids nor urea exhibited photo-degradation; however, when heated for a period of three minutes, the onset of thermal-degradation was initiated at 100 degrees C for the amino acids and 100 degrees C for urea. Lactic acid, the major polymerization initiator of superglue fuming, showed photochemical and thermal-degradation. These results could be used for future development of new latent fingerprint visualization methods, especially when lactic acid is degraded.

Fingerprint composition and aging: A literature review

“…Findings indicate high temperature results in increased degradation of amino acids compared to aging at room temperature [61,110]. The study explored pure compounds present in eccrine sweat and determined amino acids undergo thermal degradation as opposed to photo-degradation [110], as the seven amino acids monitored were all degraded after 3 min at 100°C.…”

“…The study explored pure compounds present in eccrine sweat and determined amino acids undergo thermal degradation as opposed to photo-degradation [110], as the seven amino acids monitored were all degraded after 3 min at 100°C. These findings have not been replicated using fingerprints.…”

Portable hyperspectral imager with continuous wave green laser for identification and detection of untreated latent fingerprints on walls

“…When the wavelength of the excitation light is fixed so as to allow light absorption, the fluorescence wavelengths are in general longer than the excitation wavelength because of relaxation processes peculiar to the medium. Changes in fluorescence spectra due to the constituents of fingerprints/palm prints are thus attributed to their degeneration due to photochemical and thermal effects [4,[6][7][8][9][10][11].…”

Microscopic examination of fingermark residues: Opportunities for fundamental studies

“…Extensive studies of the residue itself have been conducted and reviews are available [15,16]. The chemical decomposition processes within the residue are currently under study by several research groups around the world, mainly for age estimation purposes [17][18][19]. Even if the chemical composition of fingermarks represents critical information to determine which components to target specifically, it is not sufficient in itself.…”