What is natural compound nicotine salt?

There are many kinds of nicotine salts, such as nicotine citrate, nicotine benzoate and nicotine sulfate. Natural tobacco contains a variety of organic endogenous acids, which combine with nicotine to form different nicotine salts. The natural compound nicotine salt is formed by combining these endogenous acid radicals with free nicotine. Nicotine in e-cigarette liquid is generally a single citrate or benzoate. As far as I know, bink China, the only e-cigarette brand at present, has this technology, and it seems that it has applied for a patent.