Application of Correlation Gas Chromatography and Two-dimensional Volatility Basis Set to Determine the Physicochemical Properties of E-cigarette Aerosol Constituents
LINHUI TIAN, Alexa Canchola, Kunpeng Chen, Ying-Hsuan Lin,
University of California, Riverside Abstract Number: 139
Working Group: Indoor Aerosols
AbstractE-cigarette aerosols contain a complex mixture of many harmful and potentially harmful chemicals. Once released into the environment, they continue to evolve and become a new source of indoor air pollutants that could pose a significant threat to both users and non-users, especially vulnerable populations. However, the current understanding of the physicochemical properties of e-cigarette aerosol constituents, such as vapor pressure or volatility, that govern gas-particle partitioning in the atmospheric environment is limited, making it difficult to estimate the health risks associated with exposure. In this study, we applied the correlation gas chromatography and two-dimensional volatility basis set (2D-VBS) to determine the sub-cooled liquid vapor pressures and volatility at T/K = 298 for commonly reported toxic and irritating e-cigarette aerosol constituents. The vapor pressures (ln(p
298/p
0, p
0 = 101325 Pa)) of target compounds at 298K were estimated from the linear relationship between the vapor pressure of reference standards and their retention times. Our results showed that ln(p
298/p
0) by correlation gas chromatography had good overall agreement with estimates using the Modified Grain Method (Epi Suite), with the correlation coefficient (R) around 0.84. Using the 2D-VBS method to estimate volatility, fresh e-cigarette aerosols mainly fell into the bins of SVOCs and IVOCs, and their volatility correlated well with both the calculated vapor pressure from correlation gas chromatography (R = 0.80) and the estimated vapor pressure from Epi Suite (R = 0.81). Overall, this study provides a comprehensive analysis of the physicochemical properties of e-cigarette aerosols, which can assist in the interpretation of the dynamic chemical composition and associated health risks of e-cigarette aerosols in the indoor environment.