Free-base Nicotine in Shredded Tobacco

[Tobaccofieldsforever]

So, I was doing a little research online today and came across this little blurb: American Spirit cigarettes contain 36 percent free-base nicotine, compared with 9.6 percent in a Marlboro, 2.7 percent in a Camel, and 6.2 percent in a Winston.
I understand free-base nicotine to be the nicotine that's available for absorption in a tobacco product. How can this figure be correct when the tobacco American Spirit uses is additive free? Any ideas? I thought that free-base nicotine percentage was based on PH. It also seems to be a very broad statement and is claiming that percentage is true across the board for every cigarette the entire brand makes?? I'm not sure. Any ideas would be appreciated.

 

[deluxestogie]

Absorption of nicotine through the mucus membranes of the mouth and naso-pharynx is pH dependent. More alkaline, then more oral/naso-pharyngeal absorption of nicotine. Absorption of nicotine from the alveoli in the lungs is not dependent on the smoke being more alkaline. That is the primary reason that cigarette smokers are actually required to inhale the smoke, in order to get the nicotine, and smokers of cigars and pipe tobacco do not need to inhale the smoke.

As for a specific brand, I have no specific knowledge. But the same pH dependency applies. That is just the biochemistry and physiology of nicotine absorption from combusted tobacco.

Bob

 

[Tobaccofieldsforever]

Thank you Bob. So all brand specificity aside, if cigarette x has 25% nicotine bioavailability and cigarette y has 10% nic BA, where both x and y are additive free shredded tobacco cigarettes, then is the difference in the bioavailability solely due to the inherent nature of the tobacco/s in x and y? Are there certain growing techniques that can raise or lower free-base nicotine/bioavailability naturally in a tobacco? Curing techniques? I was just surprised at the large difference in the percentage knowing that American Spirit is simply tobacco and water. It piqued my interest into the nature of naturally occuring nicotine bioavailability. Thanks!

 

[Tobaccofieldsforever]

@deluxestogie Also, is free-base nicotine percentage of inhaled tobacco dependent on any specific physical or chemical property of the tobacco leaf if it is not PH dependent like you stated?

 

[deluxestogie]

As I often discuss in my posted pipe blends, burley, Maryland, cigar varieties and dark air-cured, when traditionally cured, offer higher nicotine within the leaf, as well as slightly more alkaline smoke, when compared to Orientals and flue-cured varieties. Perique-processed tobacco (anaerobically pressure cured) becomes more significantly alkaline, while its nicotine content depends on the variety processed.

In general, to increase the proportion of free-base nicotine within a blend, the simplest approach for a grower is to include some of the naturally more bio-available varieties in the blend. And, of course, there are "natural" methods to adjust the pH.

A simple test of all this is to make a blend with which you are familiar, then add 10 or 20% dark air-cured. Boom!

Bob

 

[Tobaccofieldsforever]

As I often discuss in my posted pipe blends, burley, Maryland, cigar varieties and dark air-cured, when traditionally cured, offer higher nicotine within the leaf, as well as slightly more alkaline smoke, when compared to Orientals and flue-cured varieties. Perique-processed tobacco (anaerobically pressure cured) becomes more significantly alkaline, while its nicotine content depends on the variety processed.

In general, to increase the proportion of free-base nicotine within a blend, the simplest approach for a grower is to include some of the naturally more bio-available varieties in the blend. And, of course, there are "natural" methods to adjust the pH.

A simple test of all this is to make a blend with which you are familiar, then add 10 or 20% dark air-cured. Boom!

Bob

Thank you, and yes I need to purchase some Dark air cured. I keep hearing so much about it and it seems very usefull in blending. Maybe I was just thinking too far into what I read. I was thinking that maybe American Spirit had some kind of special growing/curing technique that naturally (without any additives) increased the nicotine bioavailability in their tobacco. The truth is they probably just do exactly as you just stated and use larger amounts of higher nictotine content leaf. They are one of the only large cigarette manufacturers I know of that make a perique blend cigarette so that would make sense. Leave it to me to overthink something!!!

 

[ChinaVoodoo]

Many additives are acidic, like citric and malic acid. Added glucose when burned forms formic acid, so tobacco with additives often has smoke which is lower in pH. I think that might be a simple explanation.

Bob, are you sure about the lung absorption being unaffected by pH? Isn't the function of the lungs to expel CO2 in order to raise the pH of the blood? Isn't the... I can't think of the word, the slope(?) of pH such that the blood automatically is geared to expel acid and absorb alkaline via the kidneys and lungs?

 

[Tobaccofieldsforever]

Here is an excerpt from a very interesting article i found : Nicotine is distilled from burning tobacco and carried proximally on tar droplets (also called particulate matter), which are inhaled. Absorption of nicotine across biological membranes depends on pH. Nicotine is a weak base with a pKa of 8.0. Here is the entire article:

Nicotine Chemistry, Metabolism, Kinetics and Biomarkers

.
I'm only partially through it right now but wow...very interesting. I don't know about this figure though: Nicotine (Fig. 1) is a natural ingredient acting as a botanical insecticide in tobacco leaves. It is the principal tobacco alkaloid, occurring to the extent of about 1.5% by weight in commercial cigarette tobacco and comprising about 95% of the total alkaloid content.
I would've expected higher percentages but maybe that's correct for the collective average of the blend used across the board. Great article so far.

 

[Tobaccofieldsforever]

So if i'm understanding correctly, nicotine absorption is always ph dependent. However, the absorption in the lungs is much less dependent on the PH of the smoke that enters the lungs (vs. oral absorption) because of the " huge surface area of the alveoli and small airways, and dissolution of nicotine in the fluid of pH 7.4 in the human lung which facilitates transfer across membranes." (cited from linked article)

 

[deluxestogie]

Bob, are you sure about the lung absorption being unaffected by pH?

For your reading enjoyment:

Gas Transport. (2020, August 13). Retrieved May 6, 2021, from https://med.libretexts.org/@go/page/9549

 

[Ruffseas]

One thing worth noting, regardless of bioavailability due to ph, the more alkaline the smoke the more difficult it is to inhale, an important attribute for cigarette smokers is smooth inhale, so cigarette tobacco is produced by combining varieties of tobacco and processed (casings, additives) to enhance "smoke-ability" (lower ph). Pipe tobacco on the other hand, bite tends to be the primary concern for blenders. I have developed a very scientifical method of blending, when blending for cigs, if it makes me cough I add more Virginia. When blending for pipe, if it bites the tip of the tongue I reduce the Virginia, if it bites the back of the tongue I increase the Virginia. In either case, if after 15 puffs or so I start to see lil shadow bats n mice, it's just right, cut back number of puffs to reduce hallucinations as needed. (just funnin)

Great thread folks! It's always fun to learn the finer details.
Ruff

 

[deluxestogie]

You have truly settled on the secret of blending tobacco. It can be science, if you want to fall into rabbit holes (which I sometimes enjoy). But it really comes down to the same sort of skill as seasoning a soup to your taste.

Bob

 

[eebenz]

"Additive free" sounds like marketing bs. Do they contain any humectant (=glycerin)?

 

[Tobaccofieldsforever]

"Additive free" sounds like marketing bs. Do they contain any humectant (=glycerin)?

I don't know for sure because I didn't blend it myself. Even if there are no preservatives or additives they are outrageously expensive. The last time I bought a pack of them it was around $8 I believe and that was many years ago. This is what the label says: