Quantification of selected aroma compounds in e-cigarette products and toxicity evaluation in HUVEC/Tert2 cells

During recent years, the number of consumers using so-called e-cigarettes, which are electrical devices to aerosolize a liquid consisting of propylene glycol, glycerol, optional nicotine and flavoring chemicals, has been increasing. Aromas vary from common flavors such as mint to more unusual flavors such as buttermilk or pepperoni pizza. Consumers today can buy e-concentrates that consist of propylene glycol and aroma to blend their own desired flavor at home. Little is known about the composition and concentration of various aroma molecules in the different e-liquids and e-concentrates. In addition, the process of EU-wide regulation is still ongoing. The aim of this research study was to identify and quantify possible undesirable aroma compounds in e-liquids and e-concentrates. Flavoring chemicals such as estragole, benzaldehyde and cinnamaldehyde were quantified. The measurements were carried out on a GC-MS system. The results show the presence of highly concentrated flavoring compounds and limonene oxide in lemon-flavored e-concentrates. In the final step, samples and single-aroma standards were tested for their toxicity to HUVEC/Tert2 cells, where some single-flavoring chemicals such as cinnamic aldehyde revealed significant toxic effects.