Chemical Composition and Evaluation of Nicotine, Tobacco alkaloids, ph, and Selected Flavors in E-Cigarette Cartridges and Refill Solutions

Introduction:
This text provides an analysis of the chemical composition of e-cigarette cartridges and refill solutions, including nicotine, tobacco alkaloids, ph, and selected flavors. The study selected e-cigarette products based on consumer approval ratings from online review websites and used strict quality assurance/quality control validated methods to determine the concentrations of the substances.

Key Points:

* The study found that three-quarters of the products contained lower measured nicotine levels than the stated label values (6%-42% by concentration).
* The ph for e-liquids ranged from 5.1-9.1.
* Minor tobacco alkaloids were found in all samples containing nicotine, and their relative concentrations varied widely among manufacturers.
* a number of common flavor compounds were analyzed in all e-liquids.
* Free nicotine levels calculated from the measurement of ph correlated with total nicotine content.
* a higher percentage of nicotine exists in the more absorbable free form as total nicotine concentration increases.
* a number of products contained tobacco alkaloids at concentrations that exceed U.S. pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products.

Main Message:
The study highlights the inconsistency between labeled and measured nicotine concentrations in e-cigarette cartridges and refill solutions. The direct correlation between total nicotine concentration and ph suggests that the alkalinity of nicotine drives the ph of e-cigarette solutions. The presence of tobacco alkaloids at concentrations that exceed U.S. pharmacopeia limits for impurities in nicotine used in pharmaceutical and food products raises concerns about the safety of e-cigarettes. Further research is needed to fully characterize e-cigarettes and assess potential public health concerns resulting from increased use of e-cigarettes and other electronic nicotine delivery devices.

Lisko, Joseph G., hang Tran, Stephen B. Stanfill, Benjamin C. Blount, and Clifford h. Watson. “Chemical Composition and Evaluation of Nicotine, Tobacco alkaloids, ph, and Selected Flavors in E-Cigarette Cartridges and Refill Solutions.” Nicotine & Tobacco Research 17, no. 10 (October 2015): 1270–78. https://doi.org/10.1093/ntr/ntu279.