pH values and harshness of eliquid

[Kate]

There has been some talk about what causes the harshness of some eliquids. One view is that it is nicotine and another is that it's to do with additives. It's not been clear cut about either theory because some high nic eliquids have a smooth taste but there aren't many low nic harsh eliquids apparently.

TBob has posted another little gem of information that might enlighten us a bit more on this. He said:

"... GENERALLY, the higher the nicotine, the greater the hit. Nicotine hits the top of the airway passages and causes the muscles there to contract sharply. It's like gasping, or being punched in the chest. If the hit is strong enough, a user involuntarily coughs to expand the muscles.

But .. and this is interesting .. the PH of the liquid has an effect also. Alkaline cigar smoke, if inhaled, has a much harsher hit than acidic cigarette smoke, even when the cigar smoke has less nicotine. That means a liquid maker, to increase hit without relying on nicotine, might manipulate the PH of the liquid so that it mimics a nic hit. ..."
Wich e-liquid has the most powerfull throat hit?

So it looks like the harshness is to do with both nicotine and the pH of the vapour.

What I'd like is for manufacturers to grade pH and sell eliquid with a range of acidity levels for different tastes in the same way they sell different nic strengths.

I still wonder what ingredients cause more or less alkalinity. Dr Loi said he had taken these measurements:

"..my litmus test shows it to be alkaline in nature with reading from pH 7.8 to 8.5...highest found in E-liquids from E-cig and lowest from Ruyan cart samples..."
Questions about Nicotine..

So what is the difference in composition of the Ecig juice that is causing more alkalinity compared with Ruyan juice?

[Kate]

I've found some information on pH and nicotine and don't really know where to post it. This is the only thread on the subject but this isn't so much a design or product request as an information exchange.

From this document - Effect of pH on Nicotine Absorption and Side Effects Produced by Aerosolized Nicotine

It says

"Increasing pH was associated with a higher mean rise in plasma nicotine concentration."

"In a previous study, we gave 5 mg of aerosolized nicotine with a pH of 11 to smokers and produced nicotine levels which were similar to those reached with cigarettes and superior to those produced by 2 mg nicotine gum"

"... the rapid onset of action and the potential for high blood levels, are factors that might increase the potential for physical or behavioral dependence on the aerosol nicotine itself"

[Kate]

Kate, that document is a jewel in favor of e-smoking! Consider that it was done in 1993, before e-cigs were invented, and shows how effective nicotine delivery as an aerosol can be in satisfying smokers' cravings. Its bottom line is, as you noted, that the greater the pH of the smoke, the higher the blood nicotine levels achieved.

I went through it line by line and pulled some stuff we e-smokers need to know:

We (researchers) conclude that a more alkaline aerosol enhances absorption from the respiratory tract. The vapor we inhale in on the alkaline side.

Delivery of nicotine as an aerosol may have potential in nicotine replacement therapy for smoking cessation. You bet, and e-smokers are proof.

Since cigar smoke is alkaline whereas cigarette smoke is acidic, the pH of cigar smoke may contribute to its greater irritant effect on the airway. Same with our vapor; you want hit, go alkaline with the pH.

Course, the test involved some heavy nicotine. The base liquid, for instance, was 130mg per ml. Our "high" liquid is 16mg per ml. Our vapor yields 0.053mg per puff. The strong test liquid made 0.457mg per puff. I want some of that!

As the researchers note, The dose used was four to five times that of a standard cigarette.

Russell and Feyerabend proposed that it may be the puff-by-puff nicotine bolus effect of cigarette smoking that leads to such fierce dependence, not just to nicotine itself but to that particular form of nicotine, so that other forms of nicotine do not satisfy. Nicotine aerosol would provide a pattern of nicotine substitution that would be more like the use of cigarettes. In theory, it might be more successful in preventing withdrawal symptoms, allowing more patients to achieve initial abstinence from smoking. However these same features, such as the rapid onset of action and the potential for high blood levels, are factors that might increase the potential for physical or behavioral dependence on the aerosol nicotine itself. Yep, I'm now addicted to e-cig vapor.

Successful nicotine substitution might ultimately utilize multiple modalities that could be tailored to each patient. Benowitz proposed that more studies be done to evaluate the potential of rapid-delivery systems, such as nicotine aerosol, particularly in combination with slow-delivery systems like gum or transdermal patches. In summary, we have shown that inhalation of an aerosolized nicotine solution produced rapid peak plasma levels that increased significantly as the aerosol pH was increased.

We are using what they concluded could be a successful way to say goodbye to cigarettes. Nice study.

Fans of throat hits and 0 nic?

[nicowolf]

I have been thinking about this, but don't know how to find the right info. When you look up nicotine, the first bit of info you find is that it is an 'alkaloid'. Does this word alkaloid have a relationship to the Ph level? Does alkaloid mean it is on the alkaline end of the Ph scale? Is this why higher nic levels provide better throat hit? I realize these are very basic chemistry questions, but I cut high school chemistry to go smoke with my buds. Is there anyone here who has these answers?

[Kate]

Here is a link to some tobacco research and some quotes:

Nicotine is chemically classified as a base which means that it has a pH at 7 in its pure form.

... relatively small changes in pH between 6 and 8 have a very large effect on the proportion of freebase nicotine in the smoke.

Freebase nicotine is the most chemically and physiologically active form because it is most rapidly absorbed . At a pH of 5 .6, very little freebase nicotine is present and very little would be absorbed through the mouth lining, but at a pH of 8 about 60 percent of the nicotine would be in the freebase form and would be rapidly absorbed through the oral mucosa. This illustrates why it is ineffective in terms of nicotine intake to puff without inhaling on a Virginia cigarette but it is effective to puff on a cigar without inhaling.

... products that are not designed to be inhaled such as cigar smoke, pipe smoke and wet snuffs must have a pH that is alkaline so that the free base nicotine may be absorbed in the mouth.

The sensory attribute most associated with nicotine is described within the company as 'impact'. It may be described by consumers as throat catch, throat hit, throat grip, etc. Our definition of impact is : the sudden sharp but short-lived sensation (typically less than one second in duration) which is noticed immediately the smoke makes contact with the back of the throat . A physiological explanation of the impact sensation is that nicotine causes smooth muscle to contract . The contraction is proportional to the dose of nicotine applied to it. In fact, the relationship between the applied dose and the magnitude of the contraction is logarithmic, but for all practical purposes, the more nicotine the stronger the contraction and hence the impact sensation.

http://www.health.gov.bc.ca/guildfor...2/00012275.pdf

This suggests that zero nicotine eliquid cannot give a throat hit. It also suggests that because our eliquid has high alkalinity/pH the nicotine in it is efficiently absorbed by the mucus membrane in our mouths, inhaling isn't necessary.

[surbitonPete]

Kate is so amazing at collating and organizing information....another good info thread kate!

[Cymri]

Kate is so amazing at collating and organizing information....another good info thread kate!

I so agree! Fellow member Rejoice is going to use a pH meter tomorrow and see what the pH of her eliquid is.

Anyone else here have access to a pH meter and would be willing to test their eliquid as well? It would be very interesting to find out if our eliquids are generally in the proper pH range (8 I believe) to favor the more readily absorbed form of nicotine.

[rejoice]

Cymri, Do you think I should test the different mg's? To see if there is a different. I was thinking of trying the 36mg, 24 mg unflavored, 11mg, 6mg. I don't think I have any 18mg. I will be testing the liquid that I have without anything added. I have some 18mg,but have added VG and flavors. The PH meter ,we have is very accurate. It has to be very accurate. We have a special company check every three months to make sure.

[Doostin]

I had a friend who used to calibrate assorted weights & measures device for organizations around canada, crazy stuff, it was dizzying trying to comprehend her sometimes!

Is there anyway someone could test the nicotine concentration without using $500k equipment?

[Faethe]

I had a friend who used to calibrate assorted weights & measures device for organizations around canada, crazy stuff, it was dizzying trying to comprehend her sometimes!

Is there anyway someone could test the nicotine concentration without using $500k equipment?

Can't you just stick a ph strip in it like you get at the pet supply for fishtanks?