Improved hardware and software for quick gas chromatography-olfactometry using CHARM and GC-"SNIF" analysis.

A multisniffing system has been developed to allow three panelists to simultaneously participate in a GC-olfactometric analysis. This device, associated with a computerized data treatment, allows shortening CHARM and GC-"SNIF' analyses to less than 1 week and less than 1 day, respectively. The program was developed as an extension of an existing commercial chromatography data system, as usual GC processing functions are suited to the treatment of olfactograms (plots of odor response versus GC elution time). Because of the improved algorithm, the consequences of gaps in coincident responses were minimized, and the systematic use of a panel improved the repeatability of CHARM olfactograms. Comparing both methods, GC-SNIF repeatability appears to be higher than that of CHARM, as the former method uses a larger panel, but in a shorter lapse of time.

Headspace analysis study of evaporation rate of perfume ingredients applied onto skin.

Synopsis Diffusion of perfume ingredients from skin or hair is measured using an original method based on dynamic headspace technology. This has been used for pure odorants, fine fragrances, as well as for perfumed cosmetic applications such as soaps, creams or shampoos, in order to characterize diffusion processes and air/skin or air/hair partitioning. Accordingly, a special collection system, applied on the inner face of the forearm, has been developed, allowing the adsorption of diffusing organic vapours from skin onto Tenax (poly-diphenyl phenylene oxide) with a controlled air flow rate. A simple model composition containing eleven volatile synthetic odorants was prepared in an alcoholic matrix and the solution was applied onto the skin. The diffusion rate of the different components was measured by determining the concentration of each in the gas phase versus time. Conversely, the same experiment was effected by the application of an alcoholic solution of each individual component. In this manner, the relative diffusion from skin of the components alone or mixed was compared using the same experimental technique. The effect of a musky component was also tested. Both compositions (with and without musk) were then applied in a soap base. Thus, following a rigorous protocol, the forearm was washed with the perfumed soap and rinsed with water before collection of the headspace. The results show the different diffusion rates of the individual odorants. In particular, components evaporate slower from the skin when they have been applied from a soap bar compared to when they have been applied from alcoholic solution. We also present results describing the characterization of skin types using a panel comprised of 80 people (40 females and 40 males); amount of sebum, hydration and pH were systematically measured on different parts of the face, the neck as well as the outer and inner faces of the forearm. The panelists were then classified into different sub-groups taking into account these parameters. It should be noted that the foregoing results were obtained on an 'average'skin type.