Sciencemadness Discussion Board

caffeine hcl salt

ronnymac - 1-1-2010 at 08:21

how would one convert caffeine anhydrous to a caffeine,hcl

psychokinetic - 1-1-2010 at 12:43

Add caffeine.xH2O to HCl.xH2O and hope for the best?
Or add ah caffeine to an HCl solution. Either way, you just need to evaporate the water off.

JohnWW - 1-1-2010 at 12:48

Simply by reaction with aqueous HCl, and crystallizing out the product. If you use No-Doz tablets for the caffeine, you will have to filter off the solids in the form of the tableting aids.

ronnymac - 1-1-2010 at 20:53

I bought several grams of caffeine but it is not very soluble.I wanted to convert to a salt so it would mix in a drink easier. How would i recrystalize the caffeine?

not_important - 1-1-2010 at 22:01

Solubility in water
2.17 g/100 ml (25 °C)
18.0 g/100 ml (80 °C)
67.0 g/100 ml (100 °C)

from Merck
---------------------------------
One gram dissolves in 46 ml water, 5.5 ml water at 80°, 1.5 ml boiling water, 66 ml alcohol, 22 ml alcohol at 60', 50 ml acetone, 5.5 ml chloroform, 530 ml ether, 100 ml benzene, 22 ml boiling benzene. Freely sol in pyrrole; in tetrahydrofuran contg about 4% water; also sol in ethyl acetate; slightly in petr ether.

Soly in water is increased by alkali benzoates, cinnamates, citrates or salicylates.

LD50 orally in mice, hamsters, rats, rabbits(mg/kg): 127, 230, 355, 246 (males); 137, 249, 247, 224 (females)

Mixture with citric acid, citrated caffeine, "caffeine citrate" White, crystalline powder; acid reaction. Sol in about 4 parts warm water. Aq solns of caffeine salts dissociate quickly.
--------------------------------

So make a saturated solution of caffeine in boiling water, add an equivalent amount of citric acid as a saturated hot solution, allow to cool. If crystals form, add a little warm water.

Note that by the LD50 numbers, a half liter of room temperature caffeine saturated (without added citric acid) water is likely to make a 50 kg mammal ill and has some chance of killing it.

sonogashira - 2-1-2010 at 03:06

Quote: Originally posted by ronnymac  
I bought several grams of caffeine but it is not very soluble.I wanted to convert to a salt so it would mix in a drink easier. How would i recrystalize the caffeine?

Just add to an acidic drink like fruit juice/squash, even coca cola is probably acidic enough (like most carbonated drinks). Or just put it in your mouth and wash down with liquid. Personally I wouldn't mess with hydrochloric acid just to make it more soluble.

Satan - 2-1-2010 at 05:08

In health preparations in my country, to increase its solubility caffeine is mixed with sodium benzoate, for example in Cardiamid Coffein.

Speaking from experience, caffeine in this form in doses equivalent to that consumed in coffe or tea, is far too strong, if you are looking for replacement for your daily dose

Sedit - 2-1-2010 at 22:16

I know I sound like a prude here but I want you to rethink what your doing just a little bit ronnymac. Your telling us you have very little chemistry experiance yet you want to ingest something you concocted. If your HCl is muratic acid which it more then likely will be then you can not be 100% sure of the purity from heavy metals you are ingesting.

Its no real big issue but think about it a bit first. And remember you CAN OD on caffeine.

ronnymac - 3-1-2010 at 10:45

I've just seen chemicals that were .hcl were more soluble. if i can mix with orange juice or soda that would be fine, and thank eveyone who responded.

Psyclone - 3-1-2010 at 21:06

why do you need/want to ingest so much caffeine??? Seriously isnt having no-doz tablets, or drinking an energy drink enough???? What is the point of ingesting an even larger amount of caffeine?

psychokinetic - 3-1-2010 at 21:57

From http://en.wikipedia.org/wiki/Caffeine#Caffeine_intoxication
Quote:

In cases of extreme overdose, death can result. The median lethal dose (LD50) given orally, is 192 milligrams per kilogram in rats.[2] The LD50 of caffeine in humans is dependent on weight and individual sensitivity and estimated to be about 150 to 200 milligrams per kilogram of body mass, roughly 80 to 100 cups of coffee for an average adult taken within a limited time frame that is dependent on half-life. Though achieving lethal dose with caffeine would be exceptionally difficult with regular coffee, there have been reported deaths from overdosing on caffeine pills, with serious symptoms of overdose requiring hospitalization occurring from as little as 2 grams of caffeine. An exception to this would be taking a drug such as fluvoxamine which blocks the liver enzyme responsible for the metabolism of caffeine, thus increasing the central effects and blood concentrations of caffeine dramatically at 5-fold. It is not contraindicated, but highly advisable to minimize the intake of caffeinated beverages, as drinking one cup of coffee will have the same effect as drinking five under normal conditions.



Sounds like a fun night in.

Nicodem - 4-1-2010 at 02:42

Quote: Originally posted by ronnymac  
I've just seen chemicals that were .hcl were more soluble. if i can mix with orange juice or soda that would be fine, and thank eveyone who responded.

Have you even bothered checking the pKa of protonated caffeine? Have you any idea of how acidic (and unstable) the hydrate of caffeine hydrochloride is? And then you say you want to add this into something humans will drink? Are you completely insane or you just want to make us feel uncomfortable? One can easily overdose with caffeine even with its saturated aqueous solution, so why would someone want to increase its solubility when its solubility is already high as it is? Are you trying to poison yourself or someone else, or what else are you up to? Death in convulsions is terrible and dying from caffeine is no better than dying from strychnine. Common sense would tell you to at least read the scientific literature before messing with dangerous stuff.

sonogashira - 7-1-2010 at 02:29

Quote: Originally posted by Satan  
In health preparations in my country, to increase its solubility caffeine is mixed with sodium benzoate, for example in Cardiamid Coffein.

Speaking from experience, caffeine in this form in doses equivalent to that consumed in coffe or tea, is far too strong, if you are looking for replacement for your daily dose


For what health problem would one be given this? It is said to contain caffeine, nikethamide and strychnine?! :o

But have you mixed caffeine with sodium benzoate in your own preparation? And does it change the effect besides the potency? Thanks!


(I don't know why people assume ronnymac will take it all at once?! I didn't get that impression.)

[Edited on 7-1-2010 by sonogashira]

Satan - 7-1-2010 at 02:55

Quote: Originally posted by sonogashira  

But have you mixed caffeine with sodium benzoate in your own preparation? And does it change the effect besides the potency? Thanks!


Its OTC medication, old generation also. Its used for hypotension, problems with breathing, in asthma with ephedrine, for minor poisoning with other medications(translation from website).

I did it with caffeine unhydrous(Merck) with sodium benzoate, and sodium citrate in another run, both increase solubility of caffeine. I didnt used it because I like my green tea :) Also benzoates with vitamin C, may genrate benzene*, so its not so tasty(its smell bad too because of benzoate).

*http://209.85.135.132/search?q=cache:f3A-Hbm9P9sJ:www.fda.gov/Food/FoodSafety/FoodContaminantsAdulteration/ChemicalContaminants/Benzene/ucm055815.htm +ChemicalContaminants/Benzene/ucm055815.htm&hl=pl&client=opera&gl=pl&strip=1

Gui316 - 22-2-2012 at 15:36

Uhmm...What is pKa? How do we check that? After reacting caffeine with hydrochloric acid, what should I do to cristalize the material from the solution?

Neil - 22-2-2012 at 18:02

pKa is the sound the yellow electrical Pokemon made.

See here.

Rich_Insane - 24-2-2012 at 16:28

I wonder if bubbling HCL through a solution of caffeine in CCl4 or CHCl3 would work. This would only be really efficient if Caffeine HCl is insoluble in those two. I know that there is a formula to calculate percent ionization based on pKa.

I shall procure it.

Here it is:

For the % dissociation of an acid: "%=100*(10^-pKa)/(10^-pH + 10^-pKa)"

For the % dissociation of a base: "%=100*(10^pKa)/(10^pH+10^pKa) "

mooseheadgreen - 19-7-2012 at 18:33

Quote: Originally posted by Satan  
increase its solubility caffeine is mixed with sodium benzoate.


I am trying to increase solublity using sodium fumarate instead, I am assuming it would work similar, like citrate..

Does Anyone else have further knowledge about the hydrotropic solubilization of caffeine?

simba - 19-7-2012 at 18:51

Quote: Originally posted by Neil  
pKa is the sound the yellow electrical Pokemon made.


You surely made my day after this one. :)

mooseheadgreen - 19-7-2012 at 19:40

Quote: Originally posted by simba  
Quote: Originally posted by Neil  
pKa is the sound the yellow electrical Pokemon made.


You surely made my day after this one. :)


hehe, you got me laughing on that one too.

And also, on topic, using sodium fumarate was successful, as suspected. Using equal masses of sodium fumarate and anhydrous caffeine, it was much more soluble in 25C water. But I have not recorded any quantitative data.

achem500 - 22-7-2012 at 12:04

Quote: Originally posted by ronnymac  
I bought several grams of caffeine but it is not very soluble.I wanted to convert to a salt so it would mix in a drink easier. How would i recrystalize the caffeine?


Be very, very careful with caffeine consumption. You don't want to hurt yourself.