E‑Cigarettes Generate Gas Phase Ions

Area of Science:

• Analytical Chemistry
• Environmental Health

Background:

• Electronic cigarettes (e-cigs) produce aerosols through atomization of e-liquids.
• The composition and potential health effects of e-cig aerosols are a growing concern.
• Traditional cigarettes (t-cigs) also produce aerosols, but their ionization properties differ.

Purpose of the Study:

• To investigate the presence and levels of gas phase ions emitted directly from electronic cigarettes (e-cigs).
• To compare ion emission levels from e-cigs to traditional cigarettes (t-cigs) and ambient air.
• To explore the potential for direct mass spectrometry analysis of e-cig aerosols.

Main Methods:

• Disposable e-cigs were sampled at atmospheric pressure directly into a mass spectrometer.
• Mass spectrometry (MS) was used to analyze the ion content of e-cig aerosols.
• Atmospheric pressure thermospray ionization (APTSI) was identified as a potential dominant ionization pathway.

Main Results:

• E-cigs directly emitted gas phase ions at levels orders of magnitude higher than t-cigs or ambient air.
• E-cig aerosols were found to be ion-rich upon exiting the mouthpieces.
• A self-ionization process in e-cigs allows for direct MS analysis without precollection.

Conclusions:

• E-cig aerosols are significantly more ionized than previously understood.
• The direct emission of ions has implications for user exposure and requires further toxicological investigation.
• E-cig self-ionization offers a novel and direct method for aerosol characterization by MS.