Rapid Untargeted Puff‐by‐Puff Analysis of (Electronic) Cigarette Emissions by Concentric Dielectric Barrier Discharge Ionisation Mass Spectrometry

Abstract Despite the soaring popularity of e‐cigarettes among teenagers and young adults, our understanding of the full extent of their health hazards have remained limited. This is due to the vast complexities of e‐cigarette aerosols and the difficulty in their full characterisation. Conventional mass spectrometry methods of e‐cigarette analysis, though pioneering in driving political and medical discourse, have been limited in their capabilities to uncover all compounds in its emissions due to prominent limitations in experimental setup. To overcome this major hurdle, we have developed a setup for puff‐by‐puff analysis of electronic and conventional cigarette emissions by concentric dielectric barrier discharge ionisation mass spectrometry. In this pilot study, the simple setup of in‐line dilution and high‐resolution mass spectrometry analysis allowed us to directly uncover 225 compounds in e‐cigarette puffs across a wide spectrum of chemical classes in two sequential 5‐minute runs. These include acids, carbonyls, aromatic cyclics, heterocyclics, unsaturated and saturated hydrocarbons, alcohols, esters, alkaloids, sulfur‐containing compounds, oxides, and nitriles. As a result, our setup provided a significant improvement in rapid compound identification, and demonstrated a much broader chemical landscape in e‐cigarette emissions than previously reported.