Quality Control of Eliquids
E-Liquid analysis is fundamental in assuring E-Liquid quality and safety. Different analytical techniques are used by manufactures during the development and the production of these substances. However, refractive Index and density determination are two of the most important parameters used to determine propylene glycol (PG) and vegetable glycerin (VG) concentration. By assessing the PG and VG content manufacturers can not only control the quality, but also tailor the flavor, intensity, vaporization characteristics and more, ensuring that the best product is produced for the customer.
In this application note you will learn:
- More about the background of quality control for E-liquids
- The best material and methods to determine PG/VG
- The techniques and temperature of measurements specified by USP, EU, FCC, European Pharmacopoiea
- Additional information about the results obtained as shown in the figure below
- And more!
Density dependence as a function of different PG/VG ratios.
Black dots are the experimental data points, the red solid line represents the quadratic fit. The red-dotted line indicates the density-PG/VG ratio relationship for the 55/45 % w/w sample.
What does e-liquid mean?
E-liquid refers to a liquid solution used in e-cigarettes, which heats the e-liquid, producing a vapor that the user inhales. Other names for an e-liquid are e-juice or e-fluid. E-liquids generally contain different levels of nicotine, flavors, in a basis of propylene glycol (PG) and vegetable glycerin (VG) in different concentrations. E-liquids manufactures must verify the concentration of each substance as well as the final product. Two common simple and accurate techniques are used for concentration verification, density measurement and refractive index.