Techniques for the quantitative proof of perfume fixation do not exist in the literature, partly because perfumery is considered more art than science and is rarely discussed in quantitative terms and partly because such a technique would likely be quite difficult and tedious. We undertook the challenge of developing a meaningful, reproducible procedure capable of quantifying fragrance fixation in order to demonstrate this characteristic in a 20 mole propoxylate of methyl glucosidea (fig. A), which had previously demonstrated a strong fixative character in consumer panel testing.
It is fair to say the the usual toilet water or toiletry fragrance contains more than one hundred separate chemical entities. In order to evaluate a fixative effect on a heterogeneous mixture such as the typical fragrance composition, it was decided to select several individual fragrance chemicals derived via synthesis or isolation from natural products, covering a broad range of chemical structures and boiling points.
Perfume blotters are spotted with 1 mg of an aroma compound with and without 1 mg of the fixative. The methanolic solution of the aroma compound, with and without the fixative is applied to the top of these perfume blotters by means of a 10 uI syringe or micropipettor. These blotters are then placed in a “fish tank” where they are allowed to evaporate at ambient room temperature, pressure and humidity, for periods of 1 hr, 3 hrs, 6 hrs and 24 hrs. At the end of each specified time period, the top portion of each blotter is cut off and placed into a suitable vial or flask containing methanol. The aroma compound is extracted from the blotter with methanol. The resulting solution is then appropriately analyzed by GLC or UV.