Now this contains something I'm really tired of seeing: "water-based aerosol" ... this guy doesn't want to play the word game with the name and yet does it with the contents. E-fluid is NOT water based, the majority contain no significant amount of water at all. Sounds good but it's a lie.
Well that guy is one of the most experienced technical experts on ecigs around, so we could at least give him the benefit of the doubt. I agree with him because I've analysed about three dozen ecig vapour tests in detail, and a common feature of the more accurate vapour [1] analyses (not the liquid of course - as you say, there isn't much water in it) is that they all give a water content in the vapour as over 50%, and there is plenty of evidence that the vapour (again, not the liquid) is mostly water vapour. Ecig vapour is a water-based mist, containing mostly water (over 50%), and with the next largest components typically PG at 6%, VG at 5%, nicotine at 1%, and flavourings the remainder.
The reason for the high water content compared to the liquid is (a) the two things are not directly comparable (see below); (b) the purpose of the PG and VG content of any stage fogger or ecig is to bind to and make visible the atmospheric water; and (c) inhaled and exhaled vapour will contain very large quantities of water vapour indeed, because there's lots of water vapour present in the respiratory tract - the purpose and the function of PG (and even glycerine) is to bind to water vapour and create larger aerosolised droplets so that they can be felt in the throat and seen in the air (to make water vapour act like smoke). You have probably seen the mist that people exhale made visible on a cold morning; that mist of water vapour is always there of course, and the purpose of the PG etc (among other things) is to do the same as a cold morning does: agglomerate the mist droplets.
No doubt you are aware that the proportions of ingredients in the vapour are different from the liquid? As a good example of this, only about 50% of the nicotine in the refill liquid is transferred to the vapour. The transfer efficiency is reported to vary between 10% and 80% - see Goniewicz 1, Goniewicz 2 on the References page of the site you mention.
It is also crucial to note that there is no such thing, in reality, as an 'accurate' ecig vapour analysis because there are no reference products and no protocols. I have seen dozens of different variations on each, and until protocols are agreed then no analysis has any value whatsoever: no results are repeatable by anyone else. The foundation of research is that it must be repeatable by anyone else, using the same methods, otherwise the result is useless and may be an anomaly or even a deliberate attempt to misrepresent the data. Here, 'methods' means a reference set of products and agreed protocols to measure the vapour, as below.
The single thing I would like people to takeaway about ecig vapour analyses is that they are all useless at this point in time. Until reference products and protocols are agreed by a standards committee, all test results can be regarded as of no more than interest value. Results vary wildly and none are repeatable, which immediately invalidates them all. As an example, I have seen results of vapour tests showing zero water content and some with over 60%. Some with <1% nicotine content (quite possible) and even some with 5% (an impossible figure for retail e-liquid).
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Ecig testing protocol
1. A reference hardware product combination is required first. This is a device agreed as the benchmark for testing purposes. It will comprise an agreed combination of battery holder and head. Example:
a. Joyetech (basic) eGo device 650mAh size plus Kanger (standard) cartomiser.
b. Joyetech (basic) eGo device 900mAh size plus Smok (standard) CE4 clearomiser.
The reference product can be any good-quality product regarded as a benchmark that is commonly available to purchase online, which is then agreed by a suitable committee as the relevant benchmark.
Note that variable output devices cannot be used as any form of benchmark and therefore in any protocol, since:
i) the user-controlled outputs cannot be standardised for lab use
ii) user-controlled outputs vary between devices (e.g. waveform) and users, so a standard cannot be maintained
iii) the outputs can be wrongly set to create a result that no human user could inhale
A benchmark product combination shall be one that is regarded as a common, good quality, mid-range product, that is widely used and in no way exceptional.
2. A reference liquid is needed. This refill liquid must be commonly available and of good quality, and represent a benchmark product; it must not be exceptional in any way. For example:
a. (International) Hangsen tobacco flavour 24mg 10ml bottle.
b. (USA) Johnson Creek tobacco flavour 24mg.
c. (UK) Halo tobacco flavour 24mg.
3. Agreed testing protocols are then needed, such as:
Setup
The carto or clearo is filled with 1ml of liquid.
The device is held firmly in a stand.
The device is held at a permanent angle of 45 degrees downward angle, with the battery low and the mouthpiece high.
The device is connected to an
ad hoc flask and pump arrangement (details given) or a reference cigarette smoking machine (details given).
The device is switched on for 3 seconds and the puff is taken concurrently.
The puff volume is 70ml.
The puff interval is 40 seconds.
A maximum of 60 puffs are taken before refilling.
Any solvent wash used for collection of vapour must conform to agreed protocols and must be documented as part of the test result.
Process
At the commencement of each test run, and never omitted between multiple runs, the plain air throughput of the test rig is recorded and measured, to ensure that background atmospherics are deducted from the test measurements.
The ecig is connected.
5 puffs are taken and discarded.
A human user tests the output after 5 puffs and ensures the device is working correctly, by judging the taste to be satisfactory (a device can be faulty or set up incorrectly, making the product unpleasant and out of parameter, and this will be undetectable by a machine even though impossible to inhale by a human user).
The test run is performed, with the set number of puffs.
A human user tests the output at the end of the test run and ensures the device is still working correctly, by judging the taste to be satisfactory (a device can be faulty or set up incorrectly, making the product unpleasant and out of parameter, and this will be undetectable by a machine even though impossible to inhale by a human user).
Test runs with an output that fails the human user test are discarded and the equipment changed.
Consumer products are not medical products and are of a quality and a price point that means medical laboratory performance is not obtainable; all equipment must pass a user test at the beginning and end of each test run.
Reuse of equipment
An agreed cleaning protocol will be carried out between test runs.
At the commencement of each test run, after cleaning the equipment by use of agreed cleaning protocols, and never omitted between multiple runs, the plain air throughput of the test rig is recorded and measured, to ensure that remaining compounds from previous runs, and background atmospherics, are measured and deducted from each run.
Every step, every method, every quantity, every cleaning method and material used, every solvent, every human test or omission of human test, every machine used, every pipe used in pipework and its type and its manufacturer, every baseline measurement and calibration sequence, every container used for storing solvents or vapour or reclaimed vapour wash - MUST BE RECORDED AND DOCUMENTED AND THE DETAILS PROVIDED IN THE FULL TEST RESULTS. Any missing data invalidates the result.
The test must be
repeatable and testable by other researchers USING IDENTICAL REFERENCE PRODUCTS AND PROTOCOLS.
end
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[1] I use the term 'vapour' (or 'vapor') in its common meaning not the scientific one. It is a synonym for mist. It has no implied technical meaning. There is a great deal of debate about which term is most scientifically-accurate for the product of an EV (electric/electonic vapouriser), and aerosol is about the closest. But if we are going to talk about e-cigarettes: a purely marketing term that has absolutely no scientific relationship whatsoever with the product, which is an electric or electronic nebuliser that creates an aerosol, then we are clearly using words in their common meaning rather then their technically-accurate one; and therefore the term vapor is used in its common meaning, that is to say as a synonym for mist.