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°C for the amino acids and 100°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.