How much nicotine is destroyed during vaping ?

[Mister]

there are always better ways to skin a cat, and the cat isn't likely to enjoy any of them.

I think you're right about this. Although Schrödinger's cat may well be alive and ought to enjoy it, that isn't really in the nature of cats (Not that I'm much different, wouldn't necessarily appreciate being alive immediately after being skinned. But am definitely enjoying being alive with less smoke and appreciating the ongoing research.)

[exogenesis]

Good to see it is of actual interest, wasn't really sure I was getting carried away here
(ok, I know I'm getting carried away, but this sort of stuff has turned into an extra vaping related hobby).

I'm just happy that DVap realized the simple-to-do titration method for nic. in the first place,
and the initial idea of nic. loss testing.

Vaporer, it's for sure that rig-testing with straight PG versus nic. containing PG shows
quicker vapour collapse with the PG only, like you say anything in it will cause an
electrical conductivity (possibly hence draining away the electostatic charge on the vapour particles qucker)
will be interesting to see how much greater that effect gets with acidified & water added juice.

The original design had a ring of pins pointing upward, so the points presented
some high curvature = better 'launch' for ionised air
(i.e. like a room air-ioniser/de-dusting that the 5kV unit is designed for),
the same 'coating' effect happened with that as well (droplets even)

The simpler design of just multiple long thin (0.1mm) wires works as well, or better,
so maybe thicker rods with greater surface area would indeed be a better design,
without it stopping the intial charge 'jump off' too much.

Don't speak too soon DVap, your lower nic recovery 510 figure may well be
not so far off, don't have a direct comparison here yet.

Wouldn't like to be a cat in the tube - I've already zapped myself a few
times, certainly keeps me alert

(note to self : try to reduce my post sizes)

[kinabaloo]

While the 92% recovery is in-line with expectation before any such experiments were carried out, and so completely believable, it doesn't fit well with general experience.

Most likely now is that exhalation and unaborption are greater than some had believed, though I always thought both were high. Previously I put exhalation as a third (and possibly as high as 50%) Update on efficiency of e-cig nicotine delivery and absorption

As for the 'unabsorbed' nic that does stay in the body initially, presumably much of that is also exhaled over time, and the rest swallowed / pglemmed up and digested.

But I am worried by a few things in the experimental design. Not a criticism of course but we do need to be sure of our figures. It's not as though the recovery was 192%

The main concern is that the 5kv electrostatic precipitator* might be creating extra basic species that are being titrated 'as nicotine'. Thought about ozone and stuff, but it could be an artefact just of simple ionisation, with a (slight) preponderance of cations for some reason. So I feel that it would be best if the method could be backed up by a different method giving pretty much the same result; or better still a specific nicotine measurement in the recovered solution.

Secondly (and i could be being dumb here as just woke up) but :
"Differentiated the pH curve, took the volume difference between the inflection between pH 9.5 & 10, and the inflection between pH 5.5 & 6." - why is the second inflection at pH 5.5-6, not 7? edit: might be normal, as forgot that while a basic solution always has a pH larger than 7, an alkaline solution (i.e. a solution with positive acid neutralizing capacity) does not necessarily have a pH larger than 7**.

Could 45%ish for 510/VG and 92% for 901/PG both be accurate? Yes, possible because both 510 and VG give reasons for lower expectation.

It is worth noting also that 92% (perhaps even higher) is an ideal unlikely in real-life where the atty is more likely to experience frequent (nearly every puff even) slight drying as opposed to the very calm action of the experimental apparatus. DVap's experimental design may have had a faster puff action, as well as being based on partial VG and the hotter running 510.

~~~

* Normally used for situations such as cleaning furnace and power stations exhaust gases of particulates. http://www.neundorfer.com/knowledge_...ipitators.aspx

** Acid neutralizing capacity: http://en.wikipedia.org/wiki/Acid_neutralizing_capacity
The inflection at pH 5.5-6 suggests a lot of disssolved organic acids (dissolved CO2 - carbonic acid ?) which is curious in its own right (such as the orange line in the chart below).



Even so, extra cations from ESP could be skewing the result.

[Silence]

Makes me wish I knew as much about anything as these guys know about chemistry good work and keep the experiments rolling. I love reading this stuff!

[Scottes]

I love reading this stuff!

Yep, same here. I just wish it came with an Easy Button.

[exogenesis]

It's not necessary to get involved in all the details unless you want to

The 3rd post in the thread is supposed to be a summary of results,
hopefully I will be updating it as I get more results.


Kin, good thinking (as usual), think I can say some stuff about the points you've raised:

Personally I think there's possibly a lot more nic. exhaled for 'wet' vapour then for 'dry' ciggie smoke
(as a %age of what's there), adsorption to mucous-membranes & lung surface
probably has a completely different degree/rate.
Maybe a much bigger factor that we realise, to test that I'd have to manually vape &
collect 5ml of 70mg/ml juice - hmmm, pass for the moment

I did worry about the 5kV altering the chemisty, but any change to the nitrogen would probably
still titrate similarly (or almost the same), for example if the nicotine
molecule was literally being split (probably unlikely) into the two main components
then the titration would be identical at the pH 5/6 inflection point, (as I posted elsewhere) :
Pyridine : Pyrrolidine : Nicotine :

Modelling the titration of the pure components (using CurTiPot):


Pyrrolidine (blue line) : contains the 'stronger' more-basic nitrogen
- at 10 ml you see the titration point at pH 6.5.
Pyridine (red line) : contains the 'weaker' nitrogen
- titration point still 10 ml, but at pH 3.5.

Mix them together (pink line, first part is under the blue line)
- the shape shows both nitrogens as being clearly 'titratable' (at 10 & 20 ml, pHs 8.5 & 3.5).

Nicotine (green line) has both nitrogens, but the weaker one is even weaker now
- you can't make out the weaker one's titration point anymore,
- but the stronger one still titrates at 10 ml, but now at pH 5.5 (rather than 6.5).

There's a simple nicotine (almost) specific gravimetric-method using tungstosilicilic acid precipitation,
was thinking of trying that, but probably would need a more accurate balance than I've got atm.
Would be a good confirmation.

The inflection pH is determined by the nitrogen species i.e. the molecular bonds to and around it,
the vapour has a different inflection pH to un-vaped juice, and the gradient at the inflection
is definitely shallower, so something has changed chemically,
but not vastly, still get a 'correct' looking titration curve.



The piston pump is pretty 'positive', I think it's fairly close to a someone pulling on a e-cig,
volume per time is similar to that which DVap found manually , ie 10ml 'vapour volume' per sec of pull
(containing about 0.001g juice as vapour).

[kinabaloo]

I'm happy to go with 92% nic survival in this case (901, PG, 70mg nic, robot inhaler). And that's good news; though leaves the absorbed amount unchanged of course. At least this diminishes the amounts of potentially noxious by-products there might be.

It will be fascinating to see how the alternative power, liquid type etc line up.

[Vaporer]

No doubt the more additives included will reduce the capacitance value and the discharge will be more pronounced and more of a solid "hit/discharge".

This setup is very similar to the electric companies "self healing " capacitors. Unlike the wax paper & aluminum foil type used in electric equipment. If they arc, the aluminum melts and the waxpaper burns leaving a carbon path resulting in a short circuit electrically and a failed component.

On the electrical companies liquid one yrs ago PCB was the favored liquid as it could arc leaving no carbon trace path and dissipated the discharge as heat. Unless it was great enough to super heat the liquid and exploded the capacitor. As in a lightning strike.
These were commonly used on thier 7K and 13K feed lines to residental homes.

As long as the current is kept low you should have no carbon tracing causing a failure. Current is where the heat is produced.

If the constiuents would conduct more easily you may have to increase the discharge frequency or increase the dia of the tube to increase the capacitance to get the recovery 'back under control". If not, the discharge won't be clearing the tube.

Food for thought...................................

[exogenesis]

Not seen any discharges as such, but maybe the 'jerking' of the vapour
is just that, just no light or heat?

5kV unit is 30 to 50 mA consumption (12V), peak output 7kV DC
(it says on this bit of paper here),
so in theory it could pass 0.1-ish milliamps at 5kV (?).

Not a huge amount, bit shocking when it flows through me me though.

I see what you're saying about increasing the capacitance by increasing
the distance between electrodes, we'll see what happens with variations
of juice tested I guess.

[kinabaloo]

My original point was not about discharges, just ionisation - creating ions that are then attracted to one or other side of the tube where the condensing in increased.

In theory, the net charge in the liquid after is neutral. But what if a tiny amount of the anions form say H2 and sail away leaving the liquid more basic? (something like that)

I did a set of experiments on the the surface properties of various metals when placed in a a high voltage electric field. And later experimented with chrging natural gas so that the flame would be attracted to the saucepan increasing heating efficiciency as the charged ions headed to make contact. All many years ago though.

Ion imalance in the air is quite normal. I believe the lower atmosphere is more positive and lighting serves to discharge the imbalance bringing more negative ions to ground level. Air surrounding electrical equipment tends to be positive ion creating; perhaps because the earth is normally connected to the negative rail?

Air ionisers can eject more negative ions by making the negative electrode a good ionising surface, such as a sharp point, on the outside of the box.

People generally feel better in a surfeit of negative ions; out of the city, by sea or up mountain is best. Sounds like a question on QI: where is negative energy positive?