Human Scent
This study is focused on finding an optimal preparation of the human scent samples for their detailed chemical analysis in connection with the possible forensic identifications of human individuals in the future. At the present time, the scent identification of people is carried out nearly exclusively using specially trained dogs. It is assumed that the human scent contains a certain group of compounds which allows the identification of people, the so-called human scent signature; however, its chemical composition is completely unknown, as of now. The principal problem of human scent studies consists in the very low concentrations of thousands of the scent compounds, whereas their relative concentrations are usually dramatically different. It seems to be obvious that the most appropriate analytical technique for these thousands of different chemical compounds is GC/MS. However, it is also necessary to find the most suitable sorbent material for human scent collection, an extraction solvent, and a pre-concentration technique. The selection of the appropriate gas chromatographic method is also important to achieve the optimal resolution of the targeted compounds. Of course, in the first instance, it is necessary to decide what it means “the most suitable” for human scent chemical analysis.The human skin scent is a complex chemical mixture of several thousands of more or less volatile organic compounds (VOCs) with dramatically different abundances, whereas the relative concentrations of some compounds significantly vary over time It is assumed that the human skin scent contains the so-called primary as well as secondary parts. The primary part includes compounds whose relative concentrations are rather static, while the secondary part contains chemical compounds whose abundances depend on environmental factors, diet, weather, humidity, the visceral state, the emotional state, illnesses, the menstrual cycle, medication etc. Besides these primary and secondary human scent parts, there are tertiary compounds that come from the external environment, e.g., from cosmetics, the scent of the workplace, gasoline, smoking, domestic animals as well as the primary and secondary scents of other people.Only several hundred chemical compounds of the human scent have been successfully described so far The human scent contains, e.g., alkanes, aldehydes, ketones, amines, alcohols, amides, fatty acids, and their esters. The chemical analysis of such a complex mixture provides several thousands of different compounds, where some of them have distinctively varied concentrations and some of them have concentrations under the detection limits of any analytical chemistry instruments.
Last Updated on: Nov 28, 2024