https://www.selleckchem.com/pr....oducts/GSK1904529A.h
An important design aspect of electronic cigarettes ("e-cigarettes" is the nature of the acid/base chemistry in the e-liquid phase. E-liquids having formulations similar to those of early products are mixes of propylene glycol/glycerol (PG/GL) plus free-base (fb) nicotine and (usually), flavor chemicals that are either non- or rather-weak acid/base actors in PG/GL. The fraction of nicotine in the fb form is denoted (αfb)e-liquid; the possible range is 0 less then (αfb)e-liquid less then 1. For e-liquids of an early design, (αfb)e-l