Would 50-50 ethanol/methanol work as a solvent for extracting caffeine from teat leaves? What kind of tea would be best? I have white, green and
black, all loose leaf. I understand black has the highest caffeine concentration.
The end product does not have to be 100% pure, (wouldn't expect it with this simple of an extraction), even about 50-70% should be fine. I would like
to cook it into stuff, IE cookies and such, to eat instead of early morning coffee when I'm feeling lazy.Lambda-Eyde - 10-5-2012 at 18:19
Are you doing this out of an interest for chemistry, or for the sole purpouse of obtaining caffeine? If it's the latter, then I'd recommend you buy
it. USP grade caffeine (pure powder, not pills) can be had from eBay.liquidlightning - 10-5-2012 at 18:35
Both really. I love chemistry, but I do want some caffeine, so I'd prefer extracting myself. I am aware though that you can buy caffeine powder.sargent1015 - 10-5-2012 at 19:37
If you plan on consuming it, I definitely wouldn't use methanol... Be carefulliquidlightning - 10-5-2012 at 19:59
Even after complete evaporation? I thought methanol left no residue once evaporated.sargent1015 - 10-5-2012 at 19:59
If you trust your meoh as 'pure'liquidlightning - 10-5-2012 at 20:01
Well, I am currently performing this, the solution is currently a murky green color. Presumably due to fine particulate tea inn suspension and
chlorophyll in solution. I have not yet filtered out the tea. I used white tea. In about 30 mins i'll filter it out and and have a looksee.
I used 25g tea and 75ml solvent. Too much solvent, I know, but it is necessary to offset the large volume of the tea.
[Edited on 11-5-2012 by liquidlightning]
[Edited on 11-5-2012 by liquidlightning]liquidlightning - 10-5-2012 at 20:11
What would it be contaminated with? I am using denat alcohol, and the msds for this particular one list nothing but the methanol and ethanol. Lambda-Eyde - 10-5-2012 at 20:31
What would it be contaminated with? I am using denat alcohol, and the msds for this particular one list nothing but the methanol and ethanol.
Well, bitrex would certainly be in there. If you are going to use denatured alcohol, you'll have to distill it first in order to get rid of the
denaturating agent. I wouldn't worry about methanol contamination in the final product, it is of low toxicity unless you're exposed to large
concentrations of vapor or drink it. If dried properly, the amount would be minute and probably comparable to that of orange juice or similar products
we consume daily that naturally contain methanol.
Anyways, I'm not sure if ethanol/methanol is a good solvent for extracting caffeine. You should search the forum, this procedure has been done over
and over. Most procedures use DCM or chloroform, that I would worry about getting in my food.liquidlightning - 10-5-2012 at 20:36
Okay, so I have filtered off the suspended particles, it now is a clear, green yellow color. What I am assuming it contains, is tannins, chlorophyll,
caffeine and some trace impurities.liquidlightning - 10-5-2012 at 21:02
The msds states that there is 45-55% ethanol, and 45-55% methanol. If there were a bittering agent added, I think they'd put it in the msds.
Bot0nist - 10-5-2012 at 21:05
Can you obtain any paint stripper with methylene chloride (DCM, dicloromethane) in it. It is an easy to fraction off and works very well to get crude
caffeine from tea or coffee. diethyl ether will work as well. You can dehydrate ethanol or fractionally distill it from heptanes in a can of starting
fluid.
See Peach's write up in Prepublication on caffeine extraction from coffee using DCM.
Good luck. liquidlightning - 10-5-2012 at 21:07
Yep, I've seen the posts here about this already. I have available to me, xylene, mineral spirits, and a few others. Can't remember as the last time i
was at the hardware store was a while back. Can i just distill the one i currently have?Lambda-Eyde - 10-5-2012 at 21:10
The msds states that there is 45-55% ethanol, and 45-55% methanol. If there were a bittering agent added, I think they'd put it in the msds.
Not nescessarily. The bittering agent is present in minute quantities. As the Wikipedia page I just linked you to shows, bitrex is incredibly bitter
at concentrations as low as 10 ppm. If you want to be sure, taste your solvent. If it tastes worse than moonshine, then it has a denaturing agent in
it.
Can you obtain any paint stripper with methylene chloride (DCM, dicloromethane) in it. It is an easy to fraction off and works very well to get crude
caffeine from tea or coffee. diethyl ether will work as well.
I wouldn't use DCM for anything I'd ingest regularly.liquidlightning - 10-5-2012 at 21:21
Doesn't taste bad at all, I drank a whole beakerfull!
Jk, just itty bit on tip of the finger, but no, it does not taste bitter.DDTea - 11-5-2012 at 12:58
Why even use alcohol to extract the caffeine from tea? Caffeine is soluble in water at 25*C (2 g/100 mL) and more soluble at 100*C (66 g/100 mL)
(values hastily taken from caffeine wiki page). It's actually less soluble in ethanol.
If you really want to, you can extract a few grams of tea leaves in boiling water (i.e., make tea in ~100 mL water), cool the water, add 10 mL of
dichloromethane (DCM, paint stripper), and shake. The caffeine should mostly partition into the DCM, but adding some NaOH and/or NaCl can decrease its
water solubility further. Discard the water, evaporate the DCM, and you will be left with crude tea alkaloids. Recrystallize them and you are good
to go.
It won't be pure caffeine. There will also be some theobromine and theophylline in there. The only way I can think of to separate those from
caffeine is through chromatography.simba - 11-5-2012 at 13:48
Use ethyl acetate for the extraction if you intend to consume the extracted caffeine, since its not so hazardous as other solvents. You can also use
activated charcoal to extract the caffeine.rollercoaster158 - 11-5-2012 at 15:45
