'Bone Broth is So Last Year - I Vape my Vitamins now' - The vaporisation of bioactive molecules in e-cigarette devices.

Abstract

The use of electronic cigarettes as alternative nicotine delivery devices has seen a dramatic increase in recent years. Regulations (TGO110) have been introduced in an attempt to set out minimum safety and quality requirements for nicotine vaping products. These regulations provide restrictions not only pertaining to the nicotine content but also prohibiting the use of certain flavourings and the addition of any bioactive molecules other than nicotine to these products. However, these regulations do not apply to any e-liquids that do not contain nicotine including nicotine-free vitamin vaping products. The content of 32 samples from five different brands of nicotine-free disposable vaporisers claiming to contain vitamins and other bioactive molecules were examined as part of this study. There was no evidence in the literature of vitamins ever being quantified within this e-liquid matrix. As part of this project a new LC-MS method for the quantification of bioactive molecules in vaporiser e-liquids was developed and validated. Of the 9 targeted bioactive molecules (water soluble vitamins, caffeine and melatonin), very few were able to be quantified or even detected within these e-liquid samples, while some samples contained bioactives in quantifiable concentrations which were not listed in the ingredients. A concurrent degradation study was carried out to monitor the behaviour of targeted bioactive molecules in different mixtures of carrier fluids, which found that many, but especially vitamin B12, were unstable over time and were prone to degradation. To collect additional content information, GC-MS analysis was also carried out on the purchased samples. Tentative content analysis was carried out by library matching to an in house library created from purchased standards of common flavouring molecules and previously synthesised acetals and to a commercially available database (NIST17). GC-MS analysis confirmed the presence of propylene glycol and vegetable glycerin as carrier fluids in all samples. In addition, artificial flavouring molecules, synthetic cooling agents (WS-23) and adduct formation were also observed in a wide range of samples. The findings of this study indicate that the claims made by these companies are demonstrably false and that further investigation is needed into the contents of these vaporisers and their potential toxicity, especially given their lack of regulation.