How much nicotine is destroyed during vaping ?

[exogenesis]

How much nicotine is destroyed during vaping ?

To get going on this topic properly, I'm posting this with just one result so far.

This is all based on DVap's initial work,
hopefully extending it to discover some useful things.

Dvap found that about 55% of the nicotine that was in the juice is just not in the vapour (for a 510).
He used a 'high tech' cryogenic method to liquify the vapour, post #362 here-->
Any interest in determining nicotine--by DVAP

The amount of nicotine was determined by DVap's tritration with acid method, post here-->
Any interest in determining nicotine--by DVAP
+ some qualification here-->
Any interest in determining nicotine--by DVAP



My take on this was that I could collect the vapour without needing difficult/specialist materials (liquid oxygen),
so eventually I built an 'Auto-Vaper Mk2' that would get all the vapour without losses.

My first result, with a DES901 running at non-standard 4.2 volts, showed a nicotine recovery of 92%,
with 70mg/ml 'pharma quality' nicotine in PG (collecting vapour from 5 ml juice, vaped over 24 hours)

This is significantly different to DVap's 45% recovery with a 510 (3.7 V) - this may indicate hotter
running atty's 'kill off' more of the nicotine.

The idea is to test this with various parameters to see what affects the recovery most, possibly to the point where little or no nicotine comes across in the vapour.

1 Carrier, i.e. PG / VG / PEG
2 Nicotine strength
3 Running voltage (actually running current is the parameter) 3.7, 5, 6 v
4 Atomizer model (with different coil resistance, air hole configuration etc)
5 Vaping 'flooded' versus dry
6 Chemical additives, esp. citric & acetic acid as found in some juices
7 Other suggestions welcome....

[exogenesis]

The equipment as it stands at the moment:

(all pictures can be clicked for a bigger, more detailed image)

AutoVaper Mk2 :


The atty under test :


Vapour being collected :



Here's it running if you're desperately interested (4 MByte WindowsMedia file)
http://www.Exogenesis.co.uk/AutoVaperMk2_running.wmv


The thing that makes this work usefully is the 5kV stainless steel wires running down the tube length,
causing vapour droplets to electrostatically repell each other, hit the tube wall, and form a liquid layer that runs down.

Also being able to control the flow rate of juice to the atty bridge (the syringe pump), allows better control.

The 3 'bubblers' after the tube are to trap any small amount of 'escapee' nicotine.

The air pump is a feature in itself, being a semi-antique 'induced magnetic current' design, with proper pistons,
giving very positive air pull.

Won't go into some of the other fine-details, unless anyone's particularly interested.


Question could be : does the missing nicotine end up as 'gunge' on the coil,
or is it oxidised so badly it turns into something else in the vapour, or something else ?

[exogenesis]

Summary of test results for 'nicotine' loss/recovery for vaping:


On left juice (pharma quality nicotine in pharma quality carrier),
on right collected vapour (this example from first row of results in below table)

nicotine   Carrier     Atomizer        volts   amps    ml             mg            %
(mg/ml)                (ohms)                           (collected    'nicotine'    recovery
                                                         vapour or    found
                                                         juice)         

70         PG         901 (3.?)        4.2     ?       4.75 (vapour)   308          93 **


70         Glycerol   901 (3.7)        3.5     0.9     6.74 (vapour)   357          91 **


18         PG         901 (3.4)        3.7     1.0     20.2 (vapour)   345          95


18         PG         -                -       -       20.2 (Juice)    365         101


36         PG         901 (3.4)         5.8     1.6     9.6  (vapour)  351         102


36         PG         510 (2.2)         3.9     1.7     6.5  (vapour)  238         101
                      (wet & cool)


36         PG         510 (2.2)         3.9     1.7     8.2  (vapour)  269          91
                      (dry & hot)

						
6          PG         510 (2.2)         3.9     1.7     47.6 (vapour)  282          98
                      (wettish/normal)

** less reliable than later results due to later improved vapour-collector design change.


So not really much 'nicotine' as %age is lost to combustion or deposition on coil,
no significant trends seen.


Except it looks like a good idea to keep atty coil 'wet & gurgling'
to keep it from starting to glow during a draw, even then > 90% came across.



Other observations:


Definately a small amount of acetic / lactic (or possibly formic) acid produced by vaping PG,
not enough to worry about by some margin.


The collected condensed vapour was sometimes clear & sometimes slightly cloudy,
not sure what the cause was.


The 'nicotine found column' relates to the of 'the main nitrogen' in nicotine (or possibly
nicotine-like compounds).


Can't really tell without sophisticated lab gear whether it
really is all actually nicotine, or substantially altered in any way (e.g. nic. oxide etc).

[DVap]

Exo,

Now that you've "come clean" on the 5 kV electrostatic vapor condenser, I'll say again, freaking brilliant.

Has the breakthrough to impinger 1 ever proven to be an issue, or is it negligible?

[DVap]

I did notice in the video that the cycling is such that the vapor rises into the electrostatic tube, but the tube itself is large enough that the vapor does not reach the top by the time the pump shuts off.

It appears then that a) the tube size during suction being larger than the vapor volume, and b) electrostatically induced vapor collapse during idle time combine to allow very high vapor trapping efficiency.

Did I say "brilliant" already?

[exogenesis]

Text wodge alert!


Maybe one of those inspiraton particles that wizz around the universe must
have hit a neuron in my brain :P (sorry Terry Pratchett)

The 5kV seems to work pretty well, but has intermittent periods of super-quick
vapour cleaance, and not so quick periods, hence the excess volume of the tube,
so that ~40ml vapour pull gets about 2 chances of being deposited.
Think this might be due to build up of a layer of PG, coating the wire,
which drains off & re-exposes the wire again.

Tube vol is 225ml above the inlet, but the 40 ml of vapour rises disproportionately high
due to mixing & also surface-drag causing the central area of tube x-section to flow a bit faster.

As for 'leakage' on the first test, it was worse than I would like, but quantifiable
(due to the 3 sequential bubblers - gives a mathematical progression of losses).

The intial test's tube design was 10mm ID, 1.25 metres long (~100ml), had to reduce juice flow
to the 0.2ml/hr to stop too much carry-over to the bubblers, think I can go quicker with the bigger tube.

Had to re-work my figures for the first test, looks like I rushed it &
got it wrong with the 74% recovery figure, its actually 92.5% (!).
Edited previous posts above.


Vaped amount was 4.94g vaped (weighed difference before/after) = 4.75ml @ 1.04 g/ml for PG.

Collected vapour-liquor (carefully washed tube), added 6.0 ml 0.1M NaOH,
titrated down with 0.10M HCl with pH meter.

Differentiated the pH curve, took the volume difference between the inflection between pH 9.5 & 10,
and the inflection between pH 5.5 & 6.

Volume difference (titre) was 17.85 ml, giving 289.2 mg nicotine = 86.9% of the 332.8 mg in 4.75 ml juice vaped.

Bubblers (containing 70ml DI water) titres were 0.78, 0.26 and 0.11 ml giving a total 'leakage' of 18.6mg nic.

Total recovery 307.8mg nic = 92.5% of input (juice had 333.8mg in 4.75 ml).

Leakage represented 6.4% of the recovered nic (that's what I meant by more than I would like),
in the ratio 1 : 0.33 : 0.14 in sequential bubblers, so around 65% less nic in each sequential bubbler,
carried on to infinity bubblers that would represent a extra 0.8 mg nic, so 3 bubblers are enough.

I hoping this new wider, twice the volume tube, will allow far less leakage to the bubblers.


btw here's a video of the vapour 'collapsing' (sideways on)if you're interested,
strange goings on in the tube, vapour seems to dance & jerk about as it goes clear,
fascinating to watch (for a while at least):
http://www.Exogenesis.co.uk/AutoVaperMk2_Collapsing.wmv

[Vaporer]

Nice setup exo !
Reminds me of the smog scrubbers in a smokestack.
The "dances" you refer to could be due to a capacitance effect of the PG/VG present.
The areas of the wire with the thinnest layer on both surfaces closest points would discharge 1st.

"Pure Propylene Glycol and pure water will have a very high initial resistivity (or very low electrical conductivity)" DOW Chemical

Very interesting.

[TWISTED VICTOR]

I'm at a loss for words. When I see DVap and Vaporer "Ooow" and "Aaah", well, all I can say is........nothing . This is deep.

[HippyGirl]

Too deep for me as well, but fascinating nonetheless!

[DVap]

Exo,

Perhaps if you put the the 5 kV across a couple several mm diameter metal rods, the coating effect might be mitigated somewhat due to the greatly increased metal surface area... more metal for the PG to have to coat per pull.

At this point, I see no sense in my revisiting the cryo-trap. While coil temp on the 510 might account for some of the loss, insufficiency in the design might also be responsible. The highly manual nature of the setup, as well as the limited vaping volume could all contribute to the 46% being a ballpark figure at best.

This, folks, is the beauty of scientific experimentation... there are always better ways to skin a cat, and the cat isn't likely to enjoy any of them.