Chemosensory detectability of 1-butanol and 2-heptanone singly and in binary mixtures

Using l-butanol and 2-heptanone as stimuli, we measured detectability (i.e. , psychometric) functions for the odor, nasal pungency, and eye irritation of these two substances alone and in binary mixtures. Nasal pungency respon ses were tested in subjects lacking olfaction (i.e., anosmics) for whom odo rs do not interfere. Eye irritation responses were tested in normosmics and anosmics, and found to be similar in both groups so their results were poo led. When all stimuli-single and mixtures-were transformed into concentrati on units of one (or the other) chemical, a single function could fit all da ta from the same sensory end point with a correlation coefficient of 0.91 o r higher. The outcome lends support, as a first approximation, to the notio n of chemosensory agonism, in the sense of dose additivity, between the mem bers of binary mixtures presented at perithreshold levels. (C) 1999 Elsevie r Science Inc.