Sciencemadness Discussion Board

Crystalline iodine from iodine alcohol solution

Hellhound - 21-6-2005 at 06:00

Some people have claimed for an easy recipe to obtain iodine crystals from iodine alcohol solution (usually 5%) which is used for medical purposes and for many of us is the most convenient source of I.
Take 2 liter PET bottle (for soda,etc.) and cut off it's bottom. Seal it with original cork , putting a scrap of thick polyethylene tape under the cork.
Pour cold water into the bottle and then pour a few (~5)flasks (25-20 ml) of iodine solution. Leave it for a day in the vented place,or,better outdoors because of disgusting smell which appears(it's like a smell on an oceanic coast,but 20 times stronger).
As time passed,accuratly decant water (water contains some soluted iodine so pour it away,as it has strong odor)and suck it's remains with eyedropper or syringe. Unseal the cork and on the polyethylene there will be crystals of iodine. Dry and store it in your favorite way(as that was discussed hundred of times:))
Yield is 1 gram of crystalline iodine from 5 flasks of iodine solution(considering losses).

12AX7 - 21-6-2005 at 09:23

That's what, 20% yield? Not very good. Should at least add some acid to displace the iodide in solution, which will also drop out the dissolved iodine.


Darkblade48 - 21-6-2005 at 12:18

Originally posted by Hellhound
...and suck it's remains with eyedropper or syringe.

I could have sworn the first time I read it, I saw "and suck it's remains with a straw..."

Needless to say, that wasn't the case, and I'm obviously sleep deprived.

Also, wouldn't using something like KI be a better source of iodine, rather than those overpriced 5% solutions that you get at the pharmacies?

akcapr - 22-6-2005 at 12:11

go to my website. I have done this and it describes it there with pictures. the biggest problem is drying the iodine in the end. the way i dried it worked really poorly, so ud have to sublime it and run it over dessicant to make it dry.

here is my site (its under chem how-to):


aldol - 22-6-2005 at 15:19

it would be better to ph down to 3 with hcl then add sodium hypochlorite this will percipatate out the i2

akcapr - 22-6-2005 at 19:11

bubbling chlorine through the tinture is much more effevctive and the product is purer.

my nootloss - 22-6-2005 at 20:05

I just don’t think you should have put that on an aluminum plate (akcapr).

[Edited on 23-6-2005 by my nootloss]

akcapr - 24-6-2005 at 23:07

i never said it was Al. it was actually steel

[Edited on 25-6-2005 by akcapr]

12AX7 - 25-6-2005 at 00:17

I'd call that even worse, Fe + I2 = FeI2 whereas Al2O3 (Al metal surface) + I2 = not much. Unless that surface is scratched of course.


akcapr - 25-6-2005 at 06:06

wen its watered down liek it was it just wouldnt do anything with the pan