Comprehensive characterization of volatile and semi-volatile compounds in e-liquids for electronic cigarette using gas chromatography accurate mass spectrometry.

Introduction:
This article presents a comprehensive characterization of volatile and semi-volatile compounds in e-liquids for electronic cigarettes using gas chromatography accurate mass spectrometry. The study identified over 250 chemicals in a set of e-liquids from different suppliers, flavors, and additives, including nicotine and cannabidiol.

Key Points:

* The study used a non-target screening methodology and gas chromatography accurate mass spectrometry with a time-of-flight mass analyzer.
* The combination of deconvoluted electronic ionization mass spectra with linear retention index values obtained for two columns with different selectivity permitted the identification of chemicals with different confidence levels.
* among the identified chemicals, respiratory pro-inflammatory compounds, acetals of propylene glycol and glycerin with aldehydes, nicotine-related and non-related alkaloids, and psychoactive cannabinoids were confirmed as concerning compounds in e-liquid samples.
* Concentration ratios between propylene glycol acetals and parent aldehydes varied in the range from 2% (ethyl vanillin) to more than 80% (case of benzaldehyde).
* The ratios between the concentrations of delta-9-tetrahydrocannabinol and cannabidiol in e-liquids stayed in the range from 0.02% to 0.3%.

Main Message:
The study emphasizes the importance of understanding the composition of e-liquids used in electronic cigarettes to evaluate their potential impact on consumers' health. The characterization of e-liquids is the first step towards identifying concerning compounds based on their toxicity, addictive potential, and role as precursors of toxic by-products. The study's findings provide valuable information for regulatory agencies and the public to make informed decisions about the use of electronic cigarettes.

Golpe MC, Ramil M, Rodríguez I. Comprehensive characterization of volatile and semi-volatile compounds in e-liquids for electronic cigarette using gas chromatography accurate mass spectrometry. Journal of chromatography a. 2023;1703:464114. doi:10.1016/j.chroma.2023.464114