BIO

I am currently interested in research on sensory receptors and how it advances our understanding of the brain as I am a Cell and Molecular Neuroscience major. I aspire to continue this passion for pursuing knowledge of the brain in medical school as I study to become a neurosurgeon.

Measuring the relationship between liquid- and vapor-phase concentrations for esters diluted in mineral oil using a photoionization detection-based approach.

Abstract

Esters, such as ethyl tiglate and methyl butyrate, are colorless liquids that have a sweet, fruit-like odor. The volatiles from this chemical class are commonly used as olfactory stimuli to assess odor perception and probe odor coding in the brain. To manipulate vapor-phase concentrations, researchers often rely on liquid dilutions. However, the relationship between liquid dilution and vapor concentration is dependent upon the odor / solvent pair and can significantly deviate from predictions based on ideal gas laws. In other words, a 10-fold liquid dilution does not always result in a 10-fold decrease in vapor concentration. Unfortunately, the relationship between the liquid dilution and vapor-phase concentration of an odorant cannot be predicted based on their chemical features and thus, must be empirically determined. The goal of my study was to assess the relationship between liquid and vapor-phase concentrations of various esters using a photoionization detector (PID) based approach. Using a simplified olfactometer, the volatiles from different liquid dilutions (0.01% in mineral oil to the pure odorant) were delivered to the PID. Inside the PID sensor, these volatile molecules were ionized by exposure to high-intensity ultraviolet light, creating a current that is proportional to the vapor phase concentration of the odorant. The resultant data were fit with a power function, yielding liquid-/vapor-phase equilibrium equations that can be used by olfactory researchers to obtain more accurate depictions of the vapor-phase odorant concentrations used in their experiments.

Keywords: PID, Esters