Future-proofing chemical profiling of tobacco and nicotine products: standardised non-targeted analysis (NTA) of e-liquid flavour profiles for monitoring and regulation purposes

Background The tobacco industry increasingly targets youth through products such as electronic cigarettes and heated tobacco devices. In Italy, 9.6% of children aged 11–13 use tobacco and nicotine products, with e-cigarettes being the most prevalent, reflecting a global trend. Articles 9 and 10 of the WHO Framework Convention on Tobacco Control mandate testing and disclosure of ingredients, including flavours, highlighting the need for standardised analytical methods. Objectives To develop and validate a standardised non-targeted analysis (NTA) method for the compositional assessment of e-cigarette liquids. Methods A gas chromatography–mass spectrometry based NTA method was developed and validated through an interlaboratory study involving 21 laboratories worldwide. The method enables direct analysis of e-liquids and semi-quantitative evaluation of detected compounds. Results The method was applied to 23 commercial e-liquids from different WHO regions, identifying flavouring agents, allergens, and potential skin, eye, and respiratory irritants. Predominant flavour profiles included candy-sweet, fruity, and cooling compounds, with regional variability observed. The method demonstrated robustness and reproducibility across laboratories, including those with limited instrumentation. Conclusions This standardised NTA approach, now adopted as a WHO Standard Operating Procedure, provides a reliable tool for regulatory monitoring, supporting compliance, detecting undeclared substances, and strengthening flavour-related regulations globally.