Sciencemadness Discussion Board
Not logged in [Login ]
Go To Bottom

Printable Version  
Author: Subject: Crystallize caffeine?
math
Hazard to Others
***




Posts: 101
Registered: 21-7-2006
Member Is Offline

Mood: No Mood

smile.gif posted on 25-8-2015 at 17:09
Crystallize caffeine?


Hi,

got some supplement-grade caffeine powder, anhydrous.

Would like to know if dissolving it in dH2O is sufficient to make large crystals or if I need to salt it with HCl to get something crystallizable, possibly not too hygroscopic.


Thank you :)
View user's profile View All Posts By User
TGT
Harmless
*




Posts: 46
Registered: 9-11-2014
Member Is Offline

Mood: No Mood

[*] posted on 25-8-2015 at 20:07


I have extracted caffeine from wake up pills and the pure crystals tend to clump together and almost look like pieces of wet paper or tissue paper. They were extremely fine. I think it would be difficult to make them large, although I could be wrong. I am sure someone here will be able to help you better. Good luck and if you succeed some pictures would be nice.

TGT
View user's profile View All Posts By User
j_sum1
Administrator
********




Posts: 5453
Registered: 4-10-2014
Location: Oz
Member Is Offline

Mood: Taking opportunities to breathe.

[*] posted on 25-8-2015 at 21:15


Here is a beautifully presented extraction of caffeine from coffee. It shows a sublimation method to purify resulting in frosty-looking crystals. This is followed by recrystallisation using ethyl acetate. In the absence of better information i would start by mimicking a procedure that works.
View user's profile View All Posts By User
innervision
Harmless
*




Posts: 49
Registered: 6-2-2006
Member Is Offline

Mood: eh.

[*] posted on 26-8-2015 at 18:07


In case you're interested in sublimation. This is from the Merck Index 14:

Properties: Hexagonal prisms by sublimation, mp 238°. Odorless with bitter taste. Sublimes 178°. Fast sublimation is obtained at 160-165° under 1 mm press. at 5 mm distance. d418 1.23. pH of 1% soln 6.9. Absorption spectrum: Hartley, J. Chem. Soc. 87, 1802 (1905). 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) (Palm).
Melting point: mp 238°
Density: d418 1.23
Toxicity data: LD50 orally in mice, hamsters, rats, rabbits (mg/kg): 127, 230, 355, 246 (males); 137, 249, 247, 224 (females) (Palm)

Derivative Type: Monohydrate
Properties: Felted needles, contg 8.5% H2O. Efflorescent in air; complete dehydration takes place at 80°.
View user's profile View All Posts By User
innervision
Harmless
*




Posts: 49
Registered: 6-2-2006
Member Is Offline

Mood: eh.

[*] posted on 26-8-2015 at 18:10


In case you're interested in sublimation. This is from the Merck Index 14:

Properties: Hexagonal prisms by sublimation, mp 238°. Odorless with bitter taste. Sublimes 178°. Fast sublimation is obtained at 160-165° under 1 mm press. at 5 mm distance. d418 1.23. pH of 1% soln 6.9. Absorption spectrum: Hartley, J. Chem. Soc. 87, 1802 (1905). 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) (Palm).
Melting point: mp 238°
Density: d418 1.23
Toxicity data: LD50 orally in mice, hamsters, rats, rabbits (mg/kg): 127, 230, 355, 246 (males); 137, 249, 247, 224 (females) (Palm)

Derivative Type: Monohydrate
Properties: Felted needles, contg 8.5% H2O. Efflorescent in air; complete dehydration takes place at 80°.
View user's profile View All Posts By User
chemrox
International Hazard
*****




Posts: 2928
Registered: 18-1-2007
Location: UTM
Member Is Offline

Mood: psychedelic

[*] posted on 27-8-2015 at 14:26


You copied and pasted this I presume? Where's the e-copy of Merck? Library?
I would make the citrate.




"Ignorance is the Mother of Devotion." — Robert Burton.
View user's profile View All Posts By User
innervision
Harmless
*




Posts: 49
Registered: 6-2-2006
Member Is Offline

Mood: eh.

[*] posted on 28-8-2015 at 01:32


I don't remember where I got it. It's been installed on my computer for a long time. A google search should yield something.

I left the Merck part out about citrate. I suppose if you're going that route, here's that:

Derivative Type: Mixture with citric acid
CAS Registry Number: 69-22-7
Additional Names: Caffeine citrate; citrated caffeine
Trademarks: Cafcit (Roxane)
Literature References: Clinical trial in treatment of apnea in premature neonates: P. B. Larsen et al., Acta Paediatr. 84, 360 (1995).
Properties: White, crystalline powder; acid reaction. Sol in about 4 parts warm water.
View user's profile View All Posts By User
innervision
Harmless
*




Posts: 49
Registered: 6-2-2006
Member Is Offline

Mood: eh.

[*] posted on 28-8-2015 at 01:35


I don't remember where I got it. It's been installed on my computer for a long time. A google search should yield something.

I left the Merck part out about citrate. I suppose if you're going that route, here's that:

Derivative Type: Mixture with citric acid
CAS Registry Number: 69-22-7
Additional Names: Caffeine citrate; citrated caffeine
Trademarks: Cafcit (Roxane)
Literature References: Clinical trial in treatment of apnea in premature neonates: P. B. Larsen et al., Acta Paediatr. 84, 360 (1995).
Properties: White, crystalline powder; acid reaction. Sol in about 4 parts warm water.
View user's profile View All Posts By User

  Go To Top