Any interest in determining nicotine--by DVAP

[exogenesis]

Should have remembered a bit better from my 13 years in the lab,
this was second nature to me at the time, so:

retracting the comments I made earlier about potential 'other' amine forms not being titratable,
they are, since of course a lot of of primary, secondary and tertiary amine compounds
give a titration between freebase and ionised form.
Even quaternary amines, which are always ionised,
but still can be put into OH counter-ion form and can be titrated.

If the 'main' tertiary amine nitrogen in nicotine (the one being titrated)
were decomposed to molecules containing primary & secondary amines,
there is still likely to be a titration value, depending on the
types and conformation of other atoms bonding with the nitrogen.
The titration curve shape could be significantly altered,
although some break-down products would have a very similar quantification
but at a different pH titration end-point (e.g. pyridine).

Another question is then, how much of the 'recovered' nicotine in the vapour,
as determined by titration, actually is nicotine.
i.e. as a seperate concern to whatever happened to the 'missing nicotine'
between juice and vapour.

Although have to say the curve for that first vapour recovery, looked very
close to to the shape of straight nicotine.

A simple surprisingly-specific precipitation of nicotine with dodeca-silicotungstic acid
looks like an accurate method of quantifying the actual nictone,
http://www.coresta.org/recommended_methods/crm_39.pdf
could then subtract from the titre to see if 'other non-nicotine-nitrogen titre' exists.

In itself the above gravimetric method might well be a lot more reliable than titration,
would need an accurate balance (+ some consumables & a bit more patience/time though),
still it's a very simple lab procedure compared to some other possibly useful procedures,
e.g. like total-nitrogen determination by Kjeldahl digestion.

[DVap]

Should have remembered a bit better from my 13 years in the lab,
this was second nature to me at the time, so:

retracting the comments I made earlier about potential 'other' amine forms not being titratable,
they are, since of course a lot of of primary, secondary and tertiary amine compounds
give a titration between freebase and ionised form.
Even quaternary amines, which are always ionised,
but still can be put into OH counter-ion form and can be titrated.

If the 'main' tertiary amine nitrogen in nicotine (the one being titrated)
were decomposed to molecules containing primary & secondary amines,
there is still likely to be a titration value, depending on the
types and conformation of other atoms bonding with the nitrogen.
The titration curve shape could be significantly altered,
although some break-down products would have a very similar quantification
but at a different pH titration end-point (e.g. pyridine).

Another question is then, how much of the 'recovered' nicotine in the vapour,
as determined by titration, actually is nicotine.
i.e. as a seperate concern to whatever happened to the 'missing nicotine'
between juice and vapour.

Although have to say the curve for that first vapour recovery, looked very
close to to the shape of straight nicotine.

A simple surprisingly-specific precipitation of nicotine with dodeca-silicotungstic acid
looks like an accurate method of quantifying the actual nictone,
http://www.coresta.org/recommended_methods/crm_39.pdf
could then subtract from the titre to see if 'other non-nicotine-nitrogen titre' exists.

In itself the above gravimetric method might well be a lot more reliable than titration,
would need an accurate balance (+ some consumables & a bit more patience/time though),
still it's a very simple lab procedure compared to some other possibly useful procedures,
e.g. like total-nitrogen determination by Kjeldahl digestion.

Has good promise. Agreed on simplicity. I've not done a TKN digestion in 25 years, and if another 25 years went by without doing one, that would be fine with me. Can't safely do it outside a laboratory anyway.

[exogenesis]

Might give the silicotungstic acid method a try,
analytical 1mg balance 'accurate' only costs £110 delivered from china
(have already got a 'lesser' 10 mg minature balance, which is remarkably good).


Here's a more accurate 'pharma' nicotine 70mg/ml in PG vapour-nicotine recovery test.

Juice before vaping (very slightly pink), and after collecting vapour (straw colour, but very clear):


72% nicotine recovered as per 'titration' method,
titration curve definately shows slight shape alteration.

Auto-vaping was 5ml vaped : 3 sec on, 40 sec off, over around 24 hours continuous = 0.21 ml/hr,
similar to normal vaping ?


Next up 70mg/ml VG, what's the 'normal' amount of water people add to PG juice
to get it to flow in the atty ?

nb : atty blew out just at the end of the test for some reason,
will dissemble and post picture, to see if it's clagged (or not).

[DVap]

That's pretty impressive. Seems my old 46% with cryo-trapping was definitely toward the low end! Don't know if you're planning to keep your method under your hat, but I can't improve on it so it looks like you've got the lead on this one.

[DVap]

Just letting everyone know I'll be sticking to the background (not disappeared, just low key) for a few weeks once the WTA tester impressions are all reported on the thread in the nicotine section.

Gotta clear my head of all this for a bit and take care of some things like getting married, etc. Makes for a busy boy.

[exogenesis]

I think your cryogenic method is more absolute,
perhaps just needs a bit of tinkering (longer tube?) to be absolutely sure.

Your 46% result is probably correct, given that it was with a Joy510
(hotter coil), this 72% results was with a DSE901.

Haven't posted a picture of the appuratus yet cos my camera's recently packed in,
& web cam on PC is in another room.


Congrats on tying the knot , hope it all goes smoothly !

[Mister]

Gotta clear my head of all this for a bit and take care of some things like getting married

Congratulations Mr. & Mrs. DVap! Please forget us for a while and go do what you wanna do! We'll be glad to see you back (our number one practical theorist you) whenever it is time but don't make it too soon. At its best (which is what you for sure should have) this is a one time permanent up-tick, so take your time enjoying the tick before enjoying the rest.

[kinabaloo]

Might give the silicotungstic acid method a try,
analytical 1mg balance 'accurate' only costs £110 delivered from china
(have already got a 'lesser' 10 mg minature balance, which is remarkably good).


Here's a more accurate 'pharma' nicotine 70mg/ml in PG vapour-nicotine recovery test.

Juice before vaping (very slightly pink), and after collecting vapour (straw colour, but very clear):


72% nicotine recovered as per 'titration' method,
titration curve definately shows slight shape alteration.

Auto-vaping was 5ml vaped : 3 sec on, 40 sec off, over around 24 hours continuous = 0.21 ml/hr,
similar to normal vaping ?


Next up 70mg/ml VG, what's the 'normal' amount of water people add to PG juice to get it to flow in the atty ?

nb : atty blew out just at the end of the test for some reason,
will dissemble and post picture, to see if it's clagged (or not).

A good test - appreciated. Real vaping would have a shorter interval between puffs during activity, when some puffs could also be longer nearing drying out, but this is close enough (just a bit on the ideal side).

Will revise my absorbed amount from e-cigs to 30-60%.

Will be interesting to see how the VG compares. And the 510 compared to the 901. Then we will have a good overall picture. (Perhaps compare a 24mg liquid to see if recovered % is broadly the same too).

btw, just a few % water (perhaps 2-5%) would be enough to add to the VG; I guess just start with 1% and add more till is ok.

ps: a thread asking about 80mg liquid has just been buried. If the thread burning reaches here, welcome all to Vaping Buzzz. 80/79mg is not 'poison' in the UK and is cost-effective for cutting to one's desired strength.

pps: the atty pic will be interesting too. Was it new at the start of the test?

[DVap]

Would possibly expect a 6 volt vaping test to indicate whether wattage is a variable that's in play.

[kinabaloo]

Would possibly expect a 6 volt vaping test to indicate whether wattage is a variable that's in play.

Power-in relates to temperature. Basically, the rate of liquid is not increased, so temps are higher (unnecessarily). Decomp of alkaloids and VG very likely increased.

Always good to know for sure though.