Skip to main content
TSRC, Tob. Sci. Res. Conf., 2023, 76, abstr. 48

Flavorant transport prediction from e-liquid matrices

Juul Labs, Inc., Washington, DC, USA

The two most common solvent carriers used in e-cigarettes, glycerol (VG) and polyethylene glycol (PG), are highly polar molecules that can form extensive hydrogen bonding networks. High polarity solvent matrices can create an inhospitable environment for many of the flavoring compounds used in e-cigarettes which are generally less polar relative to VG and PG. As PG and VG often form 90% or more of an e-liquid formulation, such polarity mismatches can result in non-ideal behavior and can potentially play a role in the relative transport of these molecules into and out of the e-liquid matrix. While the chemistry adage that “like dissolves like” can be used to qualitatively describe the solvation of molecules with disparate properties, several parameterized solvation methodologies can be used to quantify and predict solvent/solute interactions. Hansen Solubility Parameters (HSP) is one such approach that uses three parameters, dispersion (δD), polarity (δP), and hydrogen bonding (δH), to describe solvent/solute interactions. In e-liquid formulations, HSP can be used to determine the relative solubility of common e-cigarette flavorants and deviation from ideal behavior in mixtures of VG and PG. In this work HSP calculations are used to predict the relative transport characteristics of a variety of flavor analytes from proxy e-liquids in a sealed system from the e-liquid matrix into the gas phase as well as predicting the transport of flavor analytes from the headspace into e-liquid matrix. GC-Headspace at 40 °C and liquid GC-MS measurements were used to provide experimental verification. Flavorants with HSP distances from VG greater than ~22 MPa1/2 showed lower affinities to transfer from the headspace into VG relative to PG.