The Swiss team of the Prof. R. Zenobi from the Department of Chemistry and Applied Biosciences, Swiss Federal Institute of Technology in Zurich, established protocols to investigate the vapor produced by e-cigarettes in real-time with a high resolution mass spectrometeric technique called secondary electrospray ionization (SESI-HRMS).

A novel approach for investigating compositions of e-liquids and e-cigarette aerosols

Renato Zenobi (ETH Zurich) receives Fresenius Award for his achievements in analytical chemistry (Sept 1, 2015 - Credits S. Pauly)
Renato Zenobi (ETH Zurich) receives Fresenius Award for his achievements in analytical chemistry (Sept 1, 2015 – Credits S. Pauly)

The recent application of another mass spectrophotometric technique, PTR-MS, to the real-time analysis of e-cigarette aerosols showed encouraging results. Conducted by Dr. D. García-Gómez a novel approach by SESI-HRMS is also promising and would allow better constrain the large spectrum of volatile constituents of atomized e-liquids and also include nicotine levels that escaped from PTR-MS analysis, due to technical limitations.

The analysis is sensitive to nicotine and also revealed that tobacco alkaloids, some contaminants extracted at the same time as nicotine, have been found, in addition to some potentially harmful volatile organic compounds (VOCs) like benzene and toluene. The presence of light aldehydes (formol and acetaldehyde, for example) however escape from the detection spectrum of the device due to their. The detection potential of the technique should be much higher than what is actually tested in the Swiss laboratory.

SESI-HRMSBy gradually changing the settings of the “SESI smoking device” in order to simulate changes in the power of an e-cigarette (5 to 35 W), the authors confirmed an increase up to two orders of magnitude of some compounds in the gaseous phase compared to the e-liquid. An increase that interests mainly carbonyls, according to the literature, and that can be extended to pyrazine derivatives and other VOCs, thanks to their novel approach.

This technology may be devoted to research but could also be used to check the compliance of e-liquids with standards over a range as large as 7,800 different flavors.

[1] García‐Gómez, D., Gaisl, T., Barrios‐Collado, C., Vidal‐de‐Miguel, G., Kohler, M., & Zenobi, R. (2016). Real‐Time Chemical Analysis of E‐Cigarette Aerosols By Means Of Secondary Electrospray Ionization Mass Spectrometry.Chemistry-A European Journal.