Identification of odor of volatile organic compounds using classical sensory analysis and electronic nose technique

To methods of analysis of odor of volatile organic compounds have been compared: classical sensory analysis and electronic nose technique. Eight volunteers participated in two-week classical sensory tests. The instrumental odor analysis involved a prototype of 6-sensor electronic nose designed by the authors. This device provided higher reproducibility and reliability of the results as compared to the ones obtained via the sensory analysis. Three compounds of specific odor and differing in chemical structure were utilized in the studies: 1-propanol, benzaldehyde and 2,3-butanedione. Aqueous solutions of the compounds and their mixtures were prepared at three concentration levels: 50 ppb, 1 ppm, 50 ppm v/v. The electronic nose technique, unlike the classical sensory analysis, made it possible to differentiate between particular solutions below the level of odor perceptibility and also allowed differentiation between the solutions of similar odor intensity reported by the volunteers.