Friedrich, J.E. and Acree, T.E.
Formulation of a Standard Odorant Mixture to Test Human Sniffers for Specific Anosmia.,
Gas chromatography - olfactometry (GC/O), commonly used to identify odor active chemicals in extracts and headspaces, can present a subject with pure odorants in precise doses. Because of the precision of the gaussian dose delivered by GCO and the ability GC/O to examine scores of chemicals in a single test it is an ideal tool to study differences in subjects. Normal olfactory acuity measured as thresholds is usually defined as responses less than two standard deviations from a population mean or the mean of the most sensative group in a bimodial distribution. Further deviation is then defined as specific anosmia. The objective of this research is to formulate a standard odorant mixture that can be used to test individuals for specific anosmia.
In order to encompus as many of the olfactory modalities as possible an odorant selection of the standard chemicals was based on descriptive aroma categories. An aroma genus of 26 was chosen to include the 23 food anroma catageories defined bt ASTM DS66 plus three additional categories for non-food aromas. Also included were compounds with known specific anosmia, compounds that gave baseline separation (RI OV101), compounds that were stable, available, and low in toxicity. The standard odorant mixture was formulated and analyzed by a reference individual. The concept of the reference individual is to create a benchmark for further GC/O studies. By creating benchmark values for all aroma categories we will be able to quantitatively measure the acuity of individuals and quantitatively compare results from different laboratories. Using this standard odorant mixture we can screen individuals for specific anosmia, obtain coefficients of response to specific aroma classes and eliminate sniffers with general anosmia. Performing GC/O experiments with one individual who has been prescreened with the odorant mixture will minimize the gross error caused by specific anosmia.