Free-Base Nicotine Determination in Electronic Cigarette Liquids by ¹H NMR Spectroscopy.

ABSTRACT: E-liquids usually contain significant nicotine, which will exist primarily in two forms, monoprotonated and free-base, the proportions of which are alterable through the effective pH of the medium. The fraction of nicotine in the free-base form is α_fb, with 0 ≤ α_fb ≤ 1. When dosed via aerosol, the two nicotine forms have different mechanisms and kinetics of delivery, as well as differing implications for harshness of the inhaled aerosol, so α_fb is relevant regarding abuse liability. Previous attempts to determine α_fb in electronic cigarette liquids and vapor have been flawed. We employed the exchange-averaged ¹H NMR chemical shifts of nicotine to determine α_fb in samples of e-liquids. This method is rapid and direct and can

SUBMITTER: Duell AK 

PROVIDER: S-EPMC6008736 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature