The DIYnicotine strength test kit for testing nicotine base liquids (no flavorings)

[Cool_Breeze]

Vendor: Void Mist
Nicotine Base Label: 60mg/ml 80/20 PG/VG (120ml)
Date of Purchase: 9-18-2011
Test Date: 11-25-2011

Accuracy Limits: 60mg +/- 10% = 54mg/ml -66mg/ml

Nic Base: 1ml
Bromothymol Blue: 4 Drops
Final Liquid Level: 6.0ml

Calculations
6.0ml - 3.0ml = 3.0ml
3.0ml * 19.47 = 58.41mg/ml

Result: 54mg/ml < 58.41mg/ml < 66mg/ml

Calculated nicotine content per test
58.41mg/60mg = 0.9735
0.9735 * 100 = 97.35% of labeled nicotine content

This nicotine base tests within the limits of accuracy!

 

[kinabaloo]

Vendor: Void Mist
Nicotine Base: 60mg 80/20 PG/VG (120ml)
Date of Purchase: 9-18-2011
Test Date: 11-25-2011

Accuracy Limits: 60mg +/- 10% = 54mg-66mg

Nic Base: 1ml
Bromothymol Blue: 4 Drops
Final Liquid Level: 6.0ml

Calculations
6.0ml - 3.0ml = 3.0ml
3.0ml * 19.47 = 58.41mg/ml

Result: 54mg < 58.41mg < 66mg

Calculated deviation
58.41mg/60mg = 0.9735
0.9735 * 100 = 97.35% of specified nicotine content

This nicotine base tests within the limits of accuracy!

Nicely presented

Kurt will tick you off though for stating 97.35% - have you not been paying attention ?!

While it is sensible to describe the kit as being +/- 10%, done carefully one can get within +/- 5%.

Interestingly, all the results I have seen have been just under, none just over. There a few possibilities (if we assume for a moment that the sample size is sufficiently significant) but perhaps most likely is stopping before the green tinge has completely given way to pure yellow.

Was this test carried out near to or after sunset ?? You didn't say !

Nor the ambient teperature, air pressure and relative humidity.
lol. Nice work.

+++

The difference between 97% and 100% is just under 0.1ml - i.e. one graduation on the cylinder.

 

[Cool_Breeze]

The calculation is a value based on imperfect observation and/or perception. There are (at least) two points in the process where judgement may come into play. First is the observed level of liquid(s) and second is the determination of 'pure yellow.'

I've been paying attention. However, memory may be imperfect as well.

 

[kinabaloo]

Ha! The old 'I don't recall' line ...

 

[Cool_Breeze]

I think the calculated percentage can have significance. If Vendor A's nicotine base consistently tested as, oh say, within a 2% of the indicated value and Vendor B's calculations typically came to 5%, that is some information. As well, a vendor's nicotine base 'percentage' consistently varying from batch to batch, though within testing limits might be an indication of some sort.

 

[kinabaloo]

I think the calculated percentage can have significance. If Vendor A's nicotine base consistently tested as, oh say, within a 2% of the indicated value and Vendor B's calculations typically came to 5%, that is some information. As well, a vendor's nicotine base 'percentage' consistently varying from batch to batch, though within testing limits might be an indication of some sort.

I was only referring to the use of 4 sig. fig.s.

Kina's law on the conservation of inaccuracy - one cannot get less out than put in.

 

[Cool_Breeze]

I was only referring to the use of 4 sig. fig.s.

Kina's law on the conservation of inaccuracy - one cannot get less out than put in.

Certainly you're not confusing (in)accuracy and (im)precision...

 

[kinabaloo]

Certainly you're not confusing (in)accuracy and (im)precision...

You win !

That was the law of conversational imprecision

 

[Iffy]

"Measure with a micrometer, mark with a crayon and cut with an ax..."

Nice test result description, Cool_Breeze!

 

[AzPlumber]

Is there something that can be used in place of the Bromothymol Blue?

I spent some time today looking for the test kit items locally. Found everything except Bromothymol Blue, the one item I assumed would be easy to get. I did find an aquarium PH indicator that has the exact same color range, Yellow at 6.0 and Blue at 7.6. Not sure what this stuff is and the supplier web site was not much help, it is Brown/Orange in color. I have ordered some BTB but have the weekend off and want to play Chemist.

 

[kinabaloo]

Is there something that can be used in place of the Bromothymol Blue?

I spent some time today looking for the test kit items locally. Found everything except Bromothymol Blue, the one item I assumed would be easy to get. I did find an aquarium PH indicator that has the exact same color range, Yellow at 6.0 and Blue at 7.6. Not sure what this stuff is and the supplier web site was not much help, it is Brown/Orange in color. I have ordered some BTB but have the weekend off and want to play Chemist.

Sounds like it is indeed BromoThymol Blue (Yellow to blue at pH7.6).

Have a look : Bromothymol blue - Wikipedia, the free encyclopedia

BB has a pKa of 7.1, so is itself (very) slightly acidic, that's why we can't add too much. There's about 20 drops to 1ml, so 4 drops is ~0.2ml.*

When you add just 4 drops in say 3ml it will look yellow. Have fun

+++

* I think that's why I have noticed that the results, though within 5%, are slightly on the low side - it's down to the BB ! Duh !!! Issue detected and solved

+++

Hold on --- that is part of the answer; the other part is not quite going to pure yellow (no blue left)#.

BB is such a (very) weak acid that you can add twice as much to see the color better and it will make less than 0.1ml difference to the volume of acid reading (<5% change to the calculated nic mg). Probably much less than that; the color change detection falling short is likely the main factor. So you'd probably be more accurate by using more BB; that's my conclusion, as the impact of the BB is (much) less than the problem caused by weak color.

+++

It will mostly be die to this that the results for the average person will be ~2% lower than the actual nic mg. So if it is expected to be 50mg and the result is 49 - that's the 2% factor (what the eye can discern wrt color).

Add the 2% more Kina Fudge to get the Kina-Fudge corrected mg of the nic. If you get 48mg, it's more likely 50mg; if you get 98mg it's more likely 100mg.

+++

Hence I recommend to the test kit maker to ammend the instructions to use 1.5 - 2 x as much BB per ml of liquid under test. And / or suggest less added distilled water, more nic liquid; 2ml nic liquid + 2ml water seems a good compromise; it's only ~1-2 days use of liquid that is used up, not too much.

 

[mjradik]

Add the 2% more Kina Fudge to get the Kina-Fudge corrected mg of the nic. If you get 48mg, it's more likely 50mg; if you get 98mg it's more likely 100mg.

LOL, thats what I've been saying from the begining. All MY tests have always been within 2mg, hense the 2mg margin of error if done properly. Add the human error element, and thats 2mg more off, so marging of error is 2-4mg reguardless of strength of NIC.

And yes, it usually 2mg off on the low side, which the BB prolly does have something to do with that. I think DVAP said BB turns yellow at 5.8-6.0PH, and his origial 'mole caculations' need the PH to be at 5.6 or 5.8 or something like that, which would make send why the test always tests 2mg low every time. I think if you add 2 drops of acid AFTER it turns yellow, then it would take out the 2mg low side fidge factor.

But agian, its a quick DIY test, and being off by 2mg is close enough. There are instructions on using more nic, and the 2-4mg low fudge factor turns into a 1mg or less fudge factor.

 

[mjradik]

Is there something that can be used in place of the Bromothymol Blue?

I spent some time today looking for the test kit items locally. Found everything except Bromothymol Blue, the one item I assumed would be easy to get. I did find an aquarium PH indicator that has the exact same color range, Yellow at 6.0 and Blue at 7.6. Not sure what this stuff is and the supplier web site was not much help, it is Brown/Orange in color. I have ordered some BTB but have the weekend off and want to play Chemist.

Did you ever try it with this chemical? I'm sure it would work. Let us know, and what chemical it is so it gives peple more options to test with.

 

[kinabaloo]

Good to hear from you mjradik.

Don't know what happened to AzPlumber ...

 

[AzPlumber]

I'm right here, just trying to get caught up after a short week.

I have not found much info on this stuff other than it is a solution for testing aquarium fresh water ph. The MSDS View attachment API Fresh Water Test Solution.pdf is not much help. The product is sold by a company called API and has the exact same color range as BTB.

I did try three drops of this stuff on 1ml of mfs 100mg and came up with 110mg. In the bottle this stuff is a orange/brown color, but turned blue when added to the nic juice.


Will do further testing on this same nic base with BTB and the API Fresh Water PH Test Solution and report back.

 

[markfm]

Tried the kit on 2ml of gp pg36 nic base, tested at 34mg, within the expected error range.

(nice discussion on the bb possibly leading to a slightly low result - good info)

I used the little scale again, expect to always do so. I check 10ml of the liquid to be tested, to get the density.

 

[AzPlumber]

I had an opportunity tonight to do a little side by side testing with API Fresh Water Test Solution and Bromothymol Blue and came up with the exact same results. MFS 100mg unflavored VG tested at 101mg with both solutions using a syringe for measurements and three drops of the Ph indicators. Although the results are the same, I did notice a couple of slight differences in the two indicators. The API indicator is orange/brown in the bottle but turns a dark blue when added to the nic solution and the color is a bit darker than the Bromothymol Blue when using the same amounts. The other difference I noticed was the Bromothymol Blue's change to yellow was much quicker and the API Test Solution was more gradual. I still have no idea what this API test solution is but it apears to work just as well as the btb.

 

[kinabaloo]

I had an opportunity tonight to do a little side by side testing with API Fresh Water Test Solution and Bromothymol Blue and came up with the exact same results. MFS 100mg unflavored VG tested at 101mg with both solutions using a syringe for measurements and three drops of the Ph indicators. Although the results are the same, I did notice a couple of slight differences in the two indicators. The API indicator is orange/brown in the bottle but turns a dark blue when added to the nic solution and the color is a bit darker than the Bromothymol Blue when using the same amounts. The other difference I noticed was the Bromothymol Blue's change to yellow was much quicker and the API Test Solution was more gradual. I still have no idea what this API test solution is but it apears to work just as well as the btb.

The API must be BB; perhaps more concentrated, hence the differences. It has to be the same to have the color change at the same pH.

Good to hear you clearly found the kit / method to be accurate and useful to have