Sciencemadness Discussion Board

Separating ammonium nitrate from urea

horsie - 23-9-2010 at 13:17

The cold packs I found say "contains ammonium nitrate" but down below it says "Ingredients: Mixture of nitrogenous salts". I asked the company selling them for an MSDS, they didn't send me one but they told me that they are "made of water and nitrogenous salts - which are urea and ammonium nitrate in the ratio complying with EU directives. "

I'm a bit confused here, urea isn't even a salt. The person who replied is clearly a salesperson and not a chemist so I'm not sure if I can trust that info but assuming it is a mixture of AN and urea, they are both compounds I'd like to have in my lab. Is there an easy method of separating a salt from an organic compound like this?

Contrabasso - 23-9-2010 at 13:53

well urea is available on ebay in the UK so that's not a great find. Firstly look at the cost of a pack and how much ammonium nitrate you night get for that money.

Probably then it would be best to do a proper sampling and a quantitative analysis to determine the proportion of the salts.

I'm simply guessing that solubility in selected solvents may be the way to go. AND also guessing that the EU approved mixture may not be the easiest to separate.

bbartlog - 23-9-2010 at 20:27

Your best bet might be to hydrolyze the urea (via hot/boiling water), turning it into CO2 and ammonia. Not sure how long you'd have to boil it to destroy substantially all of it, though.

(edit) - ah, you want to *keep* the urea as well. Never mind then.

[Edited on 24-9-2010 by bbartlog]

horsie - 24-9-2010 at 13:18

Quote: Originally posted by bbartlog  
Your best bet might be to hydrolyze the urea (via hot/boiling water), turning it into CO2 and ammonia. Not sure how long you'd have to boil it to destroy substantially all of it, though.

(edit) - ah, you want to *keep* the urea as well. Never mind then.

[Edited on 24-9-2010 by bbartlog]


I'd be happy with just the AN. I like this hydrolysis approach I'm gonna it out, thanks a lot.

[Edited on 24-9-2010 by horsie]