I've lurked your posts for a while, you clearly know your stuff...(wish you e-cig/juice stuff was in english

)
Thanks for you kind words, friend.
So tell us, what do YOU think about the extraction of nicotine by the average (or even skilled) DIYer?
Can it be done?
Theoretically it can be done, but only by someone really skilled. A professional chemist could do it, provided he has an access to some lab equipment and some stuff that he could use to determine nicotine content.
Doing it at home without support doesn't make sense. All you'd get is some mixed stuff containing not only nicotine, but also other chemicals like TSNAs (tobacco-specific nitrosamines), which are quite cancerogenic.
I haven't heard of any method of separating them from nicotine without really specialist equipment.
To sum up, as long as we can buy nic solution from reliable vendors, I wouldn't think of DIY nicotine extraction.