Detection of Dried Saliva on Human Skin using an Ultra Violet Spectrometer: A Technical Report

Abstract

Introduction: Human beings produce saliva, which is a vital secreted fluid. A significant quantity of saliva is left on the skin while biting, sucking, or licking. This saliva if effectively detected could be utilized as forensic evidence. DNA extraction and typing is complex and expensive technique; hence, ultraviolet (UV) spectroscopy could be used as an effective tool in detecting saliva. Aim: The aim was to detect the presence of dried saliva on the human skin using a UV spectrometer. Materials and Methodology: In this study, 50 volunteers deposited their saliva on their own arm. The saliva was air‑dried, then, the absorption spectra were recorded utilizing the UV spectrometer. Results: Saliva was detected with 64% of samples showing a peak at 282 nm. The technique proved to be very specific and sensitive, and it did not deteriorate the sample. Conclusion: UV‑spectroscopy is a specific and technique sensitive method that could detect the presence of saliva without deteriorating the quality of the given sample.