Sciencemadness Discussion Board

Caffeine

Korialstrasz69 - 2-10-2015 at 14:13

First,how to test if what i have is caffeine?then how can i tell how pure is it(if possible without advanced equipment)like precipitating it out and measuring the mass or something.
thanks ahead.

aga - 2-10-2015 at 14:24

Google 'Caffeine Titration'

Many results, including an electrochemical one.

ave369 - 3-10-2015 at 02:23

Caffeine can sublime. Try subliming the powder you have by heating it in a beaker (or jar), with a flask filled with cold water sitting on top of it. If crystals condense on the bottom of the flask, you've got caffeine, rather than some other alkaloid.

Also, what exactly do you know for sure about the substance? Do you know for sure that it's some alkaloid, maybe caffeine, maybe not?

[Edited on 3-10-2015 by ave369]

j_sum1 - 3-10-2015 at 02:37

This vid shows the sublimation of caffeine quite nicely. https://www.youtube.com/watch?v=fkhO3461T0E

In my (limited) experience, I get a purer (looking) product from tea than from coffee. If I was serious, I would look for a quantitative test of what I had produced.

DalisAndy - 6-10-2015 at 20:56

J_sum1 you have a video or a particular way to make caffeine?

j_sum1 - 6-10-2015 at 23:08

I followed a handful of yt vids: the one I cited before is the best. Julyana (whom we haven't seen here for a while) made another.
It's a simple liquid liquid extraction using DCM and a sep funnel.
I don't have any additional knowledge to offer - only what I gleaned watchibg youtube. It's an easy search.
Tea seems easier than coffee. Limited success with caffeinated soft drinks and I am not sure why. DCM seems to be the most common solvent although ethyl acetate is also used.

Korialstrasz69 - 7-10-2015 at 00:31

Well i'll be trying a new easier way (To me at least) using MgO.gonna post it as soon as i get the oxide.And thanks everyone for replies.

aga - 7-10-2015 at 12:07

DCM has a low boiling point (39C) so you can rip it out with just vacuum if ambient temperature is reasonably comfortable - no heating, no flames, nothing.

It will be wonderful Korialstrasz69 to see some notes, references and/or photos of your experiments.

If you do that, more sensible people will comment and give you great information.

DalisAndy - 7-10-2015 at 21:08

Quote: Originally posted by Korialstrasz69  
Well i'll be trying a new easier way (To me at least) using MgO.gonna post it as soon as i get the oxide.And thanks everyone for replies.

If you have Epsom salt, heat up in a furnace to make MgO. But why use MgO and what for?