an analytical Perspective on Determination of Free Base Nicotine in E-Liquids.

Introduction:
This article presents a comparative study of two approaches for determining free base nicotine yield in e-liquids: a dilution approach using the henderson-hasselbalch method and liquid-liquid extraction, and a without-dilution approach using 1h NMR method. The study aimed to evaluate the accuracy and limitations of these methods and provide insights for establishing a standardized method for free base nicotine determination in e-liquids.

Key Points:

* The dilution approach using the henderson-hasselbalch method was found to be accurate with a mean percentage difference of 1.12±0.64 for all e-liquids.
* The liquid-liquid extraction method was limited by solvent interactions with flavors, resulting in flavor-dependent inaccuracies in free base nicotine determination.
* The without-dilution approach using 1h NMR method was proposed to offer an independent and alternative scale, but none of the methods have established a strong correlation between pre- and post-vaporization free base nicotine yield.
* The study highlights the need for additional research to establish a standardized method for free base nicotine determination in e-liquids.

Main Message:
The study emphasizes the importance of developing a standardized method for free base nicotine determination in e-liquids to ensure accurate classification and regulation of e-liquids. The dilution approach using the henderson-hasselbalch method was found to be accurate, but the liquid-liquid extraction method was limited by solvent interactions with flavors. The without-dilution approach using 1h NMR method was proposed to offer an independent and alternative scale, but further research is needed to establish a strong correlation between pre- and post-vaporization free base nicotine yield. Overall, the study highlights the need for additional research to establish a standardized method for free base nicotine determination in e-liquids, which is crucial for ensuring accurate classification and regulation of e-liquids.

Gholap VV, heyder RS, Kosmider L, halquist MS. an analytical Perspective on Determination of Free Base Nicotine in E-Liquids. Journal of analytical methods in chemistry. 2020;2020:6178570. doi:10.1155/2020/6178570