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-->
http://www.e-cigarette-forum.com/fo...-determining-nicotine-dvap-37.html#post609611

The amount of nicotine was determined by DVap's tritration with acid method, post here-->
http://www.e-cigarette-forum.com/fo...t-determining-nicotine-dvap-3.html#post550005
+ some qualification here-->
http://www.e-cigarette-forum.com/fo...t-determining-nicotine-dvap-5.html#post554902



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 (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.

 

[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_base/electrostatic_precipitators.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?