Detection thresholds for phenyl ethyl alcohol using serial dilutions in different solvents

Area of Science:

• Olfactory Science
• Analytical Chemistry
• Sensory Science

Background:

• Odor detection thresholds are influenced by various factors, including the diluent solvent.
• Previous studies noted variations in phenyl ethyl alcohol (PEA) detection thresholds based on solvent choice.

Purpose of the Study:

• To investigate the effect of different solvents on odor detection thresholds for PEA.
• To determine PEA thresholds using gas chromatography (GC) to analyze solvent influence.

Main Methods:

• Serial dilutions of PEA in four solvents: liquid paraffin (LP), mineral oil (MO), propylene glycol (PG), and dipropylene glycol (DPG).
• Odor detection thresholds determined using a single ascending method with 31 adult subjects.
• GC analysis to measure liquid and headspace gas concentrations of PEA for LP and PG dilutions.

Main Results:

• Significantly lower PEA detection thresholds were found in LP (step 6.5) and MO (step 5.5) compared to PG (step 4.0) and DPG (step 4.0).
• Despite differences in liquid PEA concentrations, the headspace gas concentrations of PEA were identical for LP and PG dilutions.
• This highlights discrepancies between liquid and gas phase measurements.

Conclusions:

• Solvent choice critically affects odor detection threshold measurements.
• Determining the gas concentration of odorant stimuli is essential for accurate odor threshold assessment.
• Standardizing gas phase measurements is vital for comparing odor detection thresholds across different solvents.