Analysis of the composition of e-cigarette liquids using LTPI-mass spectrometry (2015)

Undergraduates: Justin Lackey, Rachel A. Harris Steven L. Reeber

Faculty Advisor: Gary Glish
Department: Biology

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Electronic cigarettes (e-cigarettes) are an increasingly popular mode of nicotine delivery, available in many flavors from tobacco and menthol to numerous varieties of food and candy flavors. E-cigarettes are often thought to be safer than conventional tobacco products. However, the composition of e-cigarette liquids is not commonly disclosed by manufacturers and is essentially unregulated. These liquids typically consist of a humectant such as propylene glycol for consistency, a variety of flavorings, and nicotine. To volatilize nicotine and flavoring compounds the liquid is heated in an e-cigarette and the resulting vapor is inhaled. The first step in understanding the chemistry of e-cigarette vapor is determining the composition of the liquids. A selection of e-cigarette liquids was purchased from a local e-cigarette liquid manufacturer and distributor (The Vapor Girl, Chapel Hill NC). E-cigarette liquids were first analyzed by gas chromatography-mass spectrometry, using a library search to identify the compounds detected. Low temperature plasma ionization (LTPI) was used to measure volatile compounds in the e-liquids. Electrospray ionization mass spectrometry experiments were carried out to detect less volatile species. Several different e-liquid samples including Vanilla Tobacco and Hot Cinnamon Candy were analyzed using tandem mass spectrometry to determine constituent compounds.