Effects on Carbonyl Formation from Addition of Vanillin to Electronic Cigarette Vape Liquids

NICHOLAS ROBERTSON, Haylee Hunsaker, Elizabeth Chiu, Tran Nguyen, University of California, Davis

     Abstract Number: 232
     Working Group: Aerosol Chemistry

Abstract
Electronic cigarettes (e-cigarettes) have become one of the most popular forms of nicotine consumption in recent years. Various flavoring chemicals are added to the vaping solution (e-liquids) to make the vaping experience more enjoyable, especially to adolescents. To limit adolescent usage, the FDA has placed a ban on flavoring chemicals in refillable e-cigarettes. Despite this, flavors are still present in disposable e-cigarettes. The mechanisms in which these flavorant chemicals affect the chemistry of the vaping process is still not fully understood. This work focuses on studying the effects of vanillin when used in three nicotine-containing e-liquids: an acid free solution (Free base nicotine) and Benzoic and Lactic acid containing nicotine salt e-liquids. Collected aerosols were analyzed via Liquid Chromatography coupled High Resolution Mass Spectrometry (LC-HRMS). Our results show that the addition of low concentrations of vanillin to these e-liquids decreases the production of most carbonyl emissions quantified in this study. Multiple carbonyl compounds are formed via reactive oxygen species chemistry and of these species (methylglyoxal, lactaldehyde, etc.) showed a decrease upon addition of vanillin. This data indicate that vanillin may have antioxidant properties that could be protective to vape users. In contrast, some carbonyls formed through thermal degradation (acrolein and propionaldehyde) increased upon addition of vanillin. Higher concentrations of vanillin showed an increase in carbonyls similar to the concentrations of the flavor free e-liquid or greater. Thus, vanillin cannot be definitively considered a beneficial additive to e-cigarettes, especially due to concerns over the toxicity of the vanillin itself, but this work shows that vanillin alters the chemical processes that produce toxic emissions in e-cigarettes.