Hi all. I've seen a few posts here and there in the DIY e-liquid section from folks asking if there is a way to determine if the bulk (500 mL - 1000 mL) e-liquids contain the advertised concentration of nicotine. There are many way, most of them far outside the reach of DIY'ers. These is one very accurate way within the reach of DIY'ers. I've been a chemist for 22 years, and if there's interest, I'll be happy to detail how to do it. Post if you're interested.