Cendre - 11-5-2024 at 11:32
I recently got my hands on urea peroxide as a source for H2O2 as it’s not available where I am. Does anyone know how to precipitate out the urea
from the solution once dissolved in water to get a solution of only water and hydrogen peroxide?
Thanks
bnull - 12-5-2024 at 11:31
I remember reading about a method for separation of urea and hydrogen peroxide using high-performance liquid chromatography (HPLC). They never
mentioned yields, though.
Depending on the reactions you intend to perform with H2O2, you can use urea peroxide with no problem. It has even some
advantages over "pure" peroxide.
Precipitates - 12-5-2024 at 19:57
As bnull mentioned, it may be best to use as is.
But...if you do want to have a go at isolating hydrogen peroxide...
If you have chloroform (can be made relatively easily from acetone and bleach), you could try dissolving the hydrogen peroxide-urea in this solvent,
H2O2 should dissolve (1), whilst the urea will be practically insoluble (2).
But note that in the presence of light (UV) H2O2 will be decomposed by chloroform - but it can probably be stored in amber
bottles for a short length of time (3).
This chloroform-H2O2 solution can then be mixed with a small quantity of water, the two solutions allowed to separate, and the
water-H2O2 layer decanted into a suitable storage container. This solution will still contain some chloroform and trace urea.
Depending on the concentration of H2O2 at this point or/and the equipment you have available, you may then be able to freeze
concentrate your H2O2 (4), which may allow further purification.
This method is theoretical, and is in no means a good way to prepare "clean" H2O2.
(1) Solubility and miscibility of hydrogen peroxide
(2) Solubility of urea in chloroform
(3) A kinetic study of hydroxyl radical-catalyzed decomposition of chloroform
(4) Sciencemadness thread: Hydrogen Peroxide - Illustrated Practical Guide
Sir_Gawain - 13-5-2024 at 10:08
You could also extract the hydrogen peroxide from solution with diethyl ether, but this is practically a death wish.