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

Application of ultrafast gas chromatography to recognize odor nuisance

Potentialities of ultrafast gas chromatography applied to periodical monitoring of odor nuisance originating from a municipal landfill have been examined. The results of investigation on classification of the atmospheric air samples collected in a vicinity of the landfill during winter and summer season have been presented. The investigation was performed using ultrafast gas chromatography of Fast/Flash GC type - HERACLES II by Alpha MOS. Data analysis employed principal component analysis (PCA) and linear discriminant function (LDA) supported with the cross-validation method. About 77% of the atmospheric air samples collected during winter season and ca. 87% of the samples collected during summer season were classified correctly. Based on a classification of the atmospheric air samples around the landfill, it can be observed that the biggest number of correctly classified samples originated from the directions characterized by odor nuisance. It was the NW direction during winter season and NE direction during summer season

Instrumentalne techniki oceny jakości żywności

Two instrumental techniques applied for food quality assessment such as gas chromatography-olfactometry (GC-O) and electronic nose (e-nose) are characterized. The principle of each technique and typical analytical approaches in odour determination are briefly described. Furthermore, the examples of applications, performed also in the author’s laboratory, are given.Scharakteryzowano dwie techniki instrumentalne stosowane w ocenie jakości produktów spożywczych, tj. chromatografię gazową w połączeniu z detekcją olfaktometryczną oraz nos elektroniczny. Opisano zasady działania obu technik oraz typowe procedury analityczne stosowane w ocenie zapachu. Ponadto podano przykłady praktycznego zastosowania obu technik, włącznie z tymi, które wykorzystano w pracowni autorów

Instrument for preparation of reference gas mixtures with the use of the process of barbotage and permeation

Gazowe mieszaniny wzorcowe są zaliczane do materiałów odniesienia. Wykorzystuje się je przede wszystkim do monitoringu jakości powietrza atmosferycznego oraz identyfikacji występujących w nim zanieczyszczeń. Mogą być one również używane do kalibracji przyrządów pomiarowych. Obecnie dąży się do opracowania nowych technik przygotowywania gazowych mieszanin wzorcowych [1, 2]. W pracy przedstawiono opis konstrukcji oraz zasadę funkcjonowania prototypowego urządzenia przeznaczonego do wytwarzania gazowych mieszanin wzorcowych, którego działanie oparte jest na wykorzystaniu procesów barbotażu oraz permeacji.Reference gas mixtures are classified to reference materials and are mainly used for quality monitoring and identification of impurities in atmospheric air. They can be also used for calibration of measuring devices. Nowadays, there is a need to develop a new techniques for the preparation of reference gas mixtures [1, 2]. In this paper the design and the operating principles of instrument based on the use of barbotage and permeation processes were presented