GC/HRMS Analysis of E-Liquids Complements In Vivo Modeling Methods and can Help to Predict Toxicity

Area of Science:

• Toxicology
• Environmental Health
• Inhalation Exposure Science

Background:

• Tobacco smoking is a significant health risk due to toxic chemical inhalation.
• E-cigarettes (vaping) also involve inhaling chemicals, with limited data on pre- and post-vaping compositions.
• Understanding e-liquid chemistry and biological effects is crucial for public health.

Purpose of the Study:

• To analyze chemical differences in e-liquids before and after vaping.
• To assess the biological impact of vaped e-liquids using in vivo models.
• To investigate the role of flavors in e-liquid toxicity.

Main Methods:

• Gas chromatography/high-resolution mass spectrometry (GC/HRMS) for chemical signature analysis.
• In vivo studies using zebrafish and C57-BL/6J mice exposed to vaped e-liquids.
• Assays for oxidative stress and inflammatory immune cell responses.

Main Results:

• Chemical signatures varied between unvaped and vaped e-liquids, and between flavored and unflavored samples.
• Known irritants were upregulated in vaped and flavored e-liquids.
• Respiratory irritants were primarily found in vaped e-liquids.
• Menthol-flavored e-liquid induced oxidative stress and inflammation, unlike tobacco-flavored e-liquid.

Conclusions:

• Vaping alters e-liquid chemical composition, introducing potential irritants.
• Flavors significantly influence e-liquid chemical profiles and biological responses.
• Menthol and other flavors may contribute to pro-inflammatory and cytotoxic effects.