Nicotine Salt = Freebase Nicotine + Acid
In chemical terms, a salt results when an acid reacts with a base.
Freebase nicotine was invented by tobacco companies in the 1960’s. Freebase means that the nicotine is in the purest form compared to the other nicotine derivatives. This form of nicotine is used in cigarettes and many common nicotine replacement therapies (NRT’s). The form of nicotine ordinarily used in standard e-liquid is freebase nicotine.