Article on Impurity contribution to odour code published

Chemical senses are highly sensitive to minute amounts of odorants in the environment. Therefore, when testing the responses of olfactory receptors, substances of highest purity are used, generally 95% or 99%, i.e., with impurities of 5% or 1%. We report a case where an impurity of 0.0006% was sufficient to explain the full response of an olfactory receptor in a test situation. We demonstrate why all experiments investigating the selectivity of odor receptors have to be performed with gas-chromatography-purified odors to eliminated potential impurity artifacts:

M. Paoli, D. Münch, A. Haase, E. Skoulakis, L. Turin and C. G. Galizia, Minute Impurities Contribute Significantly to Olfactory Receptor Ligand Studies: tales from Testing the Vibration Theory.,