Odour Quantification

in the case of printing house, we cannot use the electronic nose to monitor the odour. But, in the case of compost emission, such monitoring should be possible as long as the relationship between odour and sensor response is kept after eventual sample preparation (eventual pre-concentration, filtering, drying, etc.). 

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Cemy, C. and Grosch, W. 1993. Quantification of character-impact odour compounds of roasted beef. Z. Lebensm.-Unters. -Forsch. A 196 417-422. 

The clinical features of overdose with etiichlorvynol resemble those due to poisoning with other hypnotics, but coma is often prolonged and accompanied by severe respiratory depression. Ethchlorvynol has a pungent odour which is often detected in the stomach contents. A qualitative test for ethchlorvynol in stomach contents is given on p. 6. A gas chromatographic mediod for the quantification of ethchlorvynol in plasma is given on p. 17. 

Enantiomeric purity and enantiomeric excess (ee) are usual terms used in the determination of enantiomers. Enantiomeric purity is defined as the measured ratio (expressed as a percentage) of the detected enantiomers, whereas ee-values describe the relative difference of the separated enantiomers (expressed as a percentage). Usually quantifications are given in ee-values, but one should note, that convincing results can be concluded only for baseline-resolved enantiomers (cRs > 1.50). Exact calculations of partially resolved mirror images, as frequently happened in the current literature, remain unintelligible in view of differences in sensory qualities and odour thresholds of enantiomers Eig. 6.25, [1-9]. 

To detect the odour-active volatiles. Fuller et al. [6] described a system for the sniffing of GC effluents which was improved and applied to food samples by Dravnieks and O Donnell [7]. The new technique, named GC olfactometry (GCO), was the starting point for the development of a systematic approach to the identification of the compounds which cause food aromas. As summarised in Table 6.23 the analytical procedure consists of screening for key odorants by special GCO techniques, quantification and calculation of OAVs as well as aroma-recombination studies. During the last decade these steps have been critically reviewed by Acree [8], Blank [9], Grosch [10, 11 ], Mistry et al. [12] and Schieberle /fi/. 

Kubickova, J., Grosch, W. (1998) Quantification of potent odorants in Camembert cheese and calculation of their odour activity values. Int. Dairy J. 8, 17-23... 

Figure 12. Odour chromatogram, quantification, and virtual sensor response for odours of C4.

Multivariate data obtained from different strains of bacteria are especially suitedforPCA mostexamplesthusconcemantibacterials [1,20-25,181,184,187, 208]. Other applications deal with herbicides [26], opioids [4], structure-odour relationships [186], anti-inflammatory compounds [27, 182] and with the quantification of toxic compounds [207], respectively. Niemi et al. carried out a PCA of 90 molecular connectivity indices and needed eight PCs to explain more... 

It can be concluded that gas sensors can be made very small and with small consumption of the molecules to be detected. They can, therefore, be used to analyze gas evalution from small samples and with small gas flows with both industrial and medical applications. Furthermore, the use of sensor arrays gives the possibility to construct electronic noses for more complicated situations related to identification, classification and quantification of gas mixtures or odours. The final microanalysis system for gases may perhaps consist of microfabricated gas handling, an integrated sensor array and a dedicated chip for signal treatment and pattern recognition. 

A. Buettner and P. Schieberle, Stable isotope dilution assays for the quantification of odour-active thiols in hand-squeezed grapefruit juices (Citrus Paradisi Mac-Fayden), Frontiers of Flavour Science (P. Schieberle and K. H. Engel, eds.), WB-Druck GmbH, Rieden am Forggensee, 2000, p. 132. 

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