The inorganic fraction in e-liquids used in vapor products including e-cigarettes

Nowadays, e-cigarettes are largely used, they are considered less dangerous than the traditional cigarettes. Actually, there are a lot of investigations on the health effects of nanoparticles and smoke emitted by them whereas there are very few studies on the e-liquid composition. For the first time this paper would like to investigate the inorganic composition of the e-liquids at different nicotine content (0, 9 and 18 mg mL−1) by means of the instrumental nuclear activation analysis. More than 20 elements at trace/ultra-trace levels were determined: elements such as Na, W, Br, Fe and Co show similar distribution in all the samples, toxic elements as As, Ni and Sb are at μg kg−1 levels whereas Hg is present only in the sample at 0 mg mL−1 nicotine (0.56 μg kg−1). Further, based on transfer rate data of some metals from tobacco to smoke, an evaluation of inhaled element amount during a single vape is also reported.