Home testing of e-liquid strength (DIY)

[kinabaloo]

This thread is for discussing ways that one can test the strength of one's e-liquid in one's own home.

There's only one suitable method at the moment - but it is cheap, simple and quick; and also accurate to about 5-10%.

It is based on initial work by DVap and simplification for end-users by Bombjorg. Both these threads are stickied in this DIY e-liquid forum and well worth a read for the more technically minded.

Post your questions, tips, results ...

ps: This test is great for unflavored e-liquid. It will work for many flavored liquids too (but the accuracy in this case is not guaranteed); it will not work for those liquids that have been acidified with something like citric or ascorbic acid (some vendors do this to reduce the nicotine smell though it also redices the nicotine released during vaping somewhat, afaik).

One supplier of a kit based on this method has a forum here : http://www.e-cigarette-forum.com/forum/e-cigarette-suppliers-forum/240767-diy-nicotine-test-kit.html

Which vendors-flavors test ok and anomolous results which can be cross-checked to identify potential problem flavors are better posted here.

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NOTE : The test procedure works very well on unflavored e-liquid. It may not be accurate with all flavored liquids.
A low-strength reading in flavored liquid can be a result of interference from the flavoring. It does not necessarily mean that the nicotine is actually low.
If you find a liquid like this let us know so we can keep tabs on those flavors for which the test will not work.

CAUTION : As always when working nicotine, take care to prevent spills and splashes; particularly of the nicotine liquid. Ideally gloves, long sleeves and eye-protection should be used.

To discuss the use of the test kit specifically, and its use for testing unflavored nicotine base liquid only, go here.

 

[Spazmelda]

Oh okay, so we are doing it here. LOL!

I've ordered a test kit, but it hasn't come in yet. I have 3 batches of RTS that I'm going to test. I expect them to be pretty close to the stated concentration.

Then I also plan on testing some of my juices to see how/if the flavors affect the results.

 

[markfm]

From the BE thread last night:
I did my tryout with the home test kit. Non-BE nic base, bottles of nominal 60mg PG and 60mg VG, plus 5 eliquid tests, my own diy, all fully steeped.

PG60 tested about 56mg. This was my first try, within 10% of nominal, what I would call positive, plenty close enough given the test limits.

I tested 4 eliquids that had been made with this, using combinations of natures flavors caramel/cappuccino/vanilla/black cherry/hazelnut, seedman commercial concentrate, and tpa tobacco blend alc. I blend high flavor, 18 - 20%. The eliquids ranged from 16 - 24 mg/ml nominal. All 4 liquids tested to within about 1mg/ml of nominal, the particular flavorings I use didn't seen to skew results, and the results were consistent with my nic base being about 60 mg/ml.

The vg60 tested at about 48mg/ml, 20% below nominal. Instead of retesting the base, I checked some nominal 15mg/ml car capp, made with the same nf flavors mentioned earlier. The test indicated about 12mg/ml, 20% below target, consistent with the vg nic base being 20% below nominal.

I'll retest when my scale comes in, to see if the results change when I use density to get more accurate volumes.

Overall, the test kit appears user friendly for anyone who does much diy, a simple procedure. I have two bright fluorescent lights where I mix, color change seemed pretty straight forward to gauge. The only change I made was to use my own 1ml pipettes rather than the 3ml supplied with the kit.

This kit is, as others noted, just going to get within a roughly +/- 10% range.

 

[kinabaloo]

It's good news that many flavored liquids can also be tested with this method

I guess TPA is 'tobacco Absolut', right ?

 

[markfm]

The tpa I used is their tobacco blend alc, I believe it is tobacco absolute combined with ethyl maltol, in alcohol.

 

[kinabaloo]

A video guide :



ps : one increase the amount of BB indicator if that helps to see the color better; doing so has been found to have little effect on the result; but don't overdo it.

 

[AzPlumber]

Thanks for the show Kinabaloo.

A question for the chemists,
From my plumbing background I know any neutral PH water will drop in PH and become acidic (carbonic) over time when left opened and exposed to air. Will this significantly effect the results of the test? If so how long before the water should be discarded and new bought?

 

[kinabaloo]

Thanks for the show Kinabaloo.

A question for the chemists,
From my plumbing background I know any neutral PH water will drop in PH and become acidic (carbonic) over time when left opened and exposed to air. Will this significantly effect the results of the test? If so how long before the water should be discarded and new bought?

Really not sure of the specific answers.

But the chemistry is :

Carbon dioxide dissolves slightly in water to form a weak acid called carbonic acid, H2CO3 :

CO2 + H2O <--> H2CO3

Only around 0.1% of the dissolved CO2 is in the acid form.

The carbonic acid can further react slightly to form a hydronium cation, H3O+ and a bicarbonate ion, HCO3- :

H2CO3 + H2O <--> HCO3- + H3O+

I have seen a pH figure of 5.5 mentioned for when the water is saturated with CO2.

See : http://ion.chem.usu.edu/~sbialkow/Classes/3650/Carbonate/Carbonic Acid.html

Maybe boiling the amount one will use for a little while first (and then letting it cool) would remove excess dissolved CO2. But maybe there's no real problem if the container is kept air-tight and used within say 6 months.

Anyone ?

 

[mjradik]

Thanks for the show Kinabaloo.

A question for the chemists,
From my plumbing background I know any neutral PH water will drop in PH and become acidic (carbonic) over time when left opened and exposed to air. Will this significantly effect the results of the test? If so how long before the water should be discarded and new bought?

I've used the same gallon of distilled water (but it has been kept closed at all times) for the past 4 months. No diviation in test results.

 

[mjradik]

From the BE thread last night:
PG60 tested about 56mg. This was my first try, within 10% of nominal, what I would call positive, plenty close enough given the test limits.

I tested 4 eliquids that had been made with this, using combinations of natures flavors caramel/cappuccino/vanilla/black cherry/hazelnut, seedman commercial concentrate, and tpa tobacco blend alc. I blend high flavor, 18 - 20%. The eliquids ranged from 16 - 24 mg/ml nominal. All 4 liquids tested to within about 1mg/ml of nominal, the particular flavorings I use didn't seen to skew results, and the results were consistent with my nic base being about 60 mg/ml.

The vg60 tested at about 48mg/ml, 20% below nominal. Instead of retesting the base, I checked some nominal 15mg/ml car capp, made with the same nf flavors mentioned earlier. The test indicated about 12mg/ml, 20% below target, consistent with the vg nic base being 20% below nominal.

This kit is, as others noted, just going to get within a roughly +/- 10% range.

One thing that has been tried, and, so far, as been tested to be more accurate is use more nic juice. Do the test the same, but use 2ml of nic, and mulitply the final number by 9.735. Or use 3ml of nic in the beginning, and multiple the final number by 6.49. This reduces the margin of error to +/- 1mg or +/-0.65 mg.

 

[Kurt]

Thanks for posting the video! One thing, however: it looks like her final volume is 3.4 mL, not 3.8 mL, based on the bottom of the meniscus, not the top. Might have seen it wrong.

And with distilled water, I don't think there will be significant carbonation, and as long as you use distilled, this should not be an issue.

 

[Kurt]

Deleted...double post.

 

[kinabaloo]

Thanks for posting the video! One thing, however: it looks like her final volume is 3.4 mL, not 3.8 mL, based on the bottom of the meniscus, not the top. Might have seen it wrong.

And with distilled water, I don't think there will be significant carbonation, and as long as you use distilled, this should not be an issue.

You could have been a detective !

I guess it was a series of clips to show the process rather than a real test

A good tip i noticed is to put tops back on bottles before one knocks them over

 

[kinabaloo]

One thing that has been tried, and, so far, as been tested to be more accurate is use more nic juice. Do the test the same, but use 2ml of nic, and mulitply the final number by 9.735. Or use 3ml of nic in the beginning, and multiple the final number by 6.49. This reduces the margin of error to +/- 1mg or +/-0.65 mg.

Great tip !

And I think there was another about adding water which would not be included in the volume calculation ?

Well done on putting the test kit together; I didn't realise it was you till today when i looked through your site more.

That there will now be thousands of testers out there has changed the landscape permanently - any issues can be detected much earlier. This really is a major positive for all; certainly comfort for vapers, even those without kits, and also the industry as a whole. It will play a big part in the 'self-regulation' that has been needed; and prompt a step up from vendors too no doubt.

 

[mjradik]

Thanks for posting the video! One thing, however: it looks like her final volume is 3.4 mL, not 3.8 mL, based on the bottom of the meniscus, not the top. Might have seen it wrong.

I saw that but after closer inspection, she had the cylinder leaning AWAY from the camera, so the front was low, and the back was above 4.0ml. She put the 'top' green ring thing at the 3.8ml mark, so I'm sure thats where it measured before she showed it to the camera.

 

[markfm]

I retested my VG60. This time I bumped to 5ml distilled water (it is from a fresh gallon).

Same result, to within 1mg/ml.

Down side is it looks like I have a bottle of vg48, not 60. Up side is I would personally rather be down one level rather than up one. The other positive is it is nice to see the same results as yesterday, from a repeatability standpoint

 

[Kurt]

Regardless, the way to do it is clearly presented and quite good. Glad this is up.

I think it needs to be mentioned that this test will have the least uncertainty with unflavored freebase nic liquid. pH-adjusted liquid, like Vermont Vapor, which uses citric acid to lower the pH, will not give accurate results. Also some flavors can alter the pH themselves, like citruses, cinnamon, and others. There are 1000s of flavor notes out there and I do not have a list of basicities or acidities of them, and their effect may be very complicated on how the liquid titrates, so I think this test is best for unflavored, before mixing a flavored DIY.

 

[rkayw]

Regardless, the way to do it is clearly presented and quite good. Glad this is up.

I think it needs to be mentioned that this test will have the least uncertainty with unflavored freebase nic liquid. pH-adjusted liquid, like Vermont Vapor, which uses citric acid to lower the pH, will not give accurate results. Also some flavors can alter the pH themselves, like citruses, cinnamon, and others. There are 1000s of flavor notes out there and I do not have a list of basicities or acidities of them, and their effect may be very complicated on how the liquid titrates, so I think this test is best for unflavored, before mixing a flavored DIY.

I like that you posted this here Kurt.
I sincerely hope we don't see home testing kits become a vendor witch hunt flaming pre-mixed juice vendors for lower nic then paid for. Just saying.

 

[mjradik]

I retested my VG60. This time I bumped to 5ml distilled water (it is from a fresh gallon).

You want to bump the amount of the nic, not the water. The only thing the water does is allow the mixture to be easier to work with. You could do it with out water, but near impossible to mix especiall if it VG.

Do the test, start off with 2mg nic (from the 60mg unflavored nic base), add 6 drops blue, then fill with water to 4.0 ml mark on cylinder. Do the test, then subtract 4 from the final volume, then mulitple that number by 9.735. (If the nic is close to 48, total volume in the cyliner will be about 8.7ml. If its close to 60mg, the final volume will be around 10.1ml, just off the scale of the cylinder.)

 

[markfm]

I wil retry the vg60, 2ml.

That is why I don't bother mentioning the vendor I got the nic from that seems a level low, but do feel free to mention flavorings that do not appear to skew results.

I'm getting more nic base in the next week or two. If the vg base measures low again, then I will check with the source, see if they have any insight (eg, maybe they did the acid tweak Kurt had previously mentioned), or see if Kurt can take a look. If it tests to be the right level, then I shrug off the one low bottle, an honest human error that is in the safe direction.

I need to test some of my diy with other flavorings, interested in building a list of ones that don't seem to change results.