Any interest in determining nicotine--by DVAP

[olderthandirt]

Hey Dvap, here's 2 for ya.

1) Very interested!

2) Who is a decent supplier for the labware? Recommendations would be appreciated.

[DVap]

[outdated procedure edited out - see post #26 in this thread for updated procedure to determine nicotine in e-liquid]

[DVap]

Hi OTD...

Just try eBay or search on Froogle. The only critical piece of labware is the burette. While, I recommend a burette clamp and ringstand, anybody sufficiently creative can come up with something to hold the burette still over the flask during the titration.

I also highly recommend the 250 mL erlenmeyer flask since it's wide bottom and narrow mouth is designed to allow swirling without splashing. You could do it with a jelly-jar, but you'd have to be much more careful.

Good luck!

[bearscreek]

Okay, so (if correct, and it probably is) that would be a way to verify that you got what you paid for, but I'm not sure that could be related to an unknown juice, as in DIY extraction from homegrown tobacco, snus, etc. Right?

[DVap]

Originally Posted by bearscreek

Okay, so (if correct, and it probably is) that would be a way to verify that you got what you paid for, but I'm not sure that could be related to an unknown juice, as in DIY extraction from homegrown tobacco, snus, etc. Right?

It could be related to an unknown juice. You would start with say 10 mL of the juice and find the volume of acid to reach end point. You would then know moles of acid used to reach end point. moles of acid used to reach endpoint = moles of nicotine present in the 10 mL of liquid.

so if it took 5.7 mL of 0.1N acid to reach endpoint with 10 mL of an unknown liquid, 5.7 mL of 0.1N acid = 0.00057 moles of acid. Therefore, there are 0.00057 moles of nicotine in 10 mL of liquid. 0.00057 * 162.26 = 0.0925 grams (92.5 mg) nicotine in the 10 mL of liquid, or 9.25 mg/mL.

Warning.. and something I didn't consider enough... with colored e-liquids, especially the typically yellow to yellow-brown liquids bromothymol blue may appear green when it would be otherwise blue (blue and yellow makes green, remember that?), in this case, you might have to slow down and the green to yellow transition isn't so easy as with a clear liquid. Titrations are ALWAYS easier to judge endpoints in an otherwise colorlesss solution.

[DVap]

I've just had a very surprising result with a very well known e-liquid.

I've run it twice now, with an identical result.

I'm heading into the lab for a late night session at the 5 decimal place balance to confirm what I'm seeing. More to come.

[DVap]

[edit: ignore this post. This turned out to be a bad idea]

Warning.. don't start buying all that equipment. I've come up with a procedure that works on a smaller scale with an endpoint that can be read easily, even with colored e-liquids. It is an order of magnitude simpler and cheaper than version 1.

Isn't science fun?

[BlondieLocs]

Originally Posted by DVap

Kevin, I can't help with the absorption/vape. That sort of testing is far outside my expertise.

The only thing I can point to is a bunch of research that indicates that smokers do a remarkable job at self-maintaining their desired nicotine levels.

I'd love to see that research, DVap!

[DVap]

[edited out for stupidity]


When I ran the USA Mix 18 mg at work it came out 17.8 mg/mL.

I also ran the well known e-liquid I mentioned earlier, I ran it three time. Got results of 27.3 mg/mL, 27.8 mg/mL, and 28.4 mg/mL. This liquid is sold as a 36 mg/mL liquid. That an average approx. 3/4 of the label concentration. No, I will not reveal the identity of the liquid. I don't have enough of it left to do the work required to convince myself my method is foolproof, not until I order more. (I've got to have SOMETHING to vape with after all!) I also don't feel like I should stand behind the methodology (and likely piss a certain supplier off) until I can get my hands on some more e-liquid to check results at various levels. Right now, I've got high precision, and I'm guessing I have accuracy based on the USA Mix result being so close to the label concentration, but short of titrating known standards, assuming accuracy is not a sound scientific assumption.

(But the un-scientific part of me thinks it's solid)

[DVap]

Originally Posted by BlondieLocs

I'd love to see that research, DVap!

Just Google "smokers" and "self-titrating"