The Human Nose as a GC Detector

Finally, much has been said about the human nose and its fantastic abdity at detecting even trace amounts of various chemicals...when properly trained that is See reference 43 for an overview of the scope of olfaction (and taste ). Not surprisingly, the human nose has also been put to work as a gas chromatograph 

Marin and co-workers [44] presented an interesting paper in 1992 on the appHcation of GC-olfactometry to the assessment of the effects of plastic polymers on the aroma character of orange juices. They used data generated from GC-FID, GC-MS and GC-Olfactometry to demonstrate the influence of hmonene contents onto the overall aroma of orange juice. The problems at hand with GC-olfactometry are mainly centred around the fact that the human nose does not have a hnear response. Hence cahbration is somewhat more tedious as the specific sensitivities to aU components are non-related to each other. 

A good nose can be trained in a matter of six months and usually will demonstrate a certain bias toward certain odoims. Nevertheless, once the nose well trained , the data it generates from GC-olfactometry can be extremely useful, especially when plotted as another dimension to a regular GC-FlD, or GC-MS traces. 

Needless to say that this detector is somewhat more sensitive to operating conditions prevailing at the time where the GC analysis is performed. Some noses have even been reported as outright useless when inoculated with common cold symptoms...whereas others have been documented to be attracted toward specialty products such as wines, fine hquevirs, and... 

Giddings, Dynamics of Chromatography, Part I, Principles and Theory, Marcel Dekker, New York, 1965. 

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