Nicotine has been getting a lot of attention in the vaping industry. The debate over the use of it has been growing, and some companies are starting to market e-liquid with synthetic nicotine or what they call “tobacco-free” vape juice. Nicotine’s origin has been very controversial because there has been some legal deniability since according to regulation bodies worldwide associate nicotine extract to tobacco. So is synthetic nicotine the solution to this problem?
In today’s world where GMO-free, organic and natural labels have been in every product, from food, beverages, medicine to cosmetics, synthetic products’ return can be a step forward.
Tobacco and Nicotine
Nicotine is an alkaloid produced naturally by some Solanaceae, a family which consists of tobacco, tomatoes, eggplants, chili peppers, petunia or potatoes. Among the plants mentioned, tobacco has the highest nicotine content with 8-14%, that’s why it is dried and used as cigarettes.
Nicotine has been associated with tobacco for more than 100 years. Nicotine causes the psychological stimulus making it highly addictive. There is only one way to treat tobacco leaves, by drying. You know tobacco leaves are ready to be harvested if it turns yellow-green, by that time, the sugar content is at its maximum. Big tobacco companies like Philippe Morris have worked on the tobacco’s taste using additives making cigarettes more addictive.
In agriculture, nicotine has been used as an insecticide during the early 50’s and 60’s. But due to the advancement of the chemical engineering industry, its use has been declining after the arrival of a cheaper and more effective synthetic insecticide.
Vape juice can’t use treated leaves of tobacco, so instead, they use liquid nicotine extract, a product from tobacco leaves. Nicotine contains chiral carbon that usually has a non-superposable structure, enantiomers. Nicotine and tobacco have the same chemical formula, but have different atom position.
Fresh Nicotianatabacum or tobacco leaves consist of 93% S-nicotine1, 2.4% S-nornicotine3, 3.9% S-anatabine 2, and 0.5% S-anabasine4. Liquid nicotine is extracted from crushed tobacco leaves using distillation techniques and organic solvents. Nicotine is soluble in solvents like chloroform, ether, petroleum ether, alcohol, water and kerosene. Using microwave heat and solvent mixture is used to maximize the nicotine extract yield as well as reduce the extraction making it reach 99.9% pharmaceutical grade nicotine extract.
Another technique used to extract nicotine from the plant is to use salt processing. The nicotine liquid is turned into sulfate salt, and it requires a bleaching agent to get all the impurities out of the extracted nicotine. The salt is then converted into a reagent bleached quality extract with clearer and higher purity.
(Visit https://en.wikipedia.org/wiki/Nicotiana_tabacum to know more about tobacco plant.)
There’s a reason why manufacturers don’t use potatoes or eggplant and instead, use tobacco leaves to obtain nicotine is that tobacco has a higher nicotine content, specifically S-nicotine, an active enantiomer. A tobacco-free nicotine extract is an S-nicotine from plants other than Nicotianatabacum or tobacco.
Nicotine is difficult to synthesize. It is costly, and the cheapest way is by resolution of RS-nicotine or the racemic mixture. You can also re-crystallize the nicotine and allow to select the right enantiomer to produce s-nicotine. Racemic mixtures also have a disadvantage, because of the presence of 50% r-nicotine which is non-psychoactive and S-nicotine which is psychoactive, it divides the potential activity of the e-liquid into two compared to nicotine from tobacco extract. Unlike organic e juice brands that natural nicotine from tobacco extract and not synthetic, racemic mixture, non-organic brands has lesser nicotine strength.
Nicotine extract that is freshly synthesized is colorless after it is purified. It turns into brownish if exposed to oxygen, light and heat and if put into sealed bottles it sometimes turns into dark brown. The discoloration of nicotine is a natural process, and a clear liquid doesn’t mean it is purer or higher quality.
According to Next Generation Laboratories, nicotine has two selling points:
It should have no impurities, not like the tobacco extract where it came from.
It should be tasteless and odorless. It improves the vape juice’s flavor and providing the same effect tobacco gives.
It is still not clear who has the jurisdiction over synthetic nicotine. According to Micheal Siegel, it escapes FDA’s authority, but according to the Food and Drug Administration, it is under PMTA, depending on the case.