I've been researching a bit on concentrating Hydrogen Peroxide, and I read about freezing it to get the water out. Is this a reliable method? Can you just go by volume of the original H2O2 to know when you're at 12% (a quarter volume of 3%)? Or does some H2O2 freeze along with the ice? I don't really understand this method, can someone shed a little light?

I've been researching a bit on concentrating Hydrogen Peroxide, and I read about freezing it to get the water out. Is this a reliable method? Can you just go by volume of the original H2O2 to know when you're at 12% (a quarter volume of 3%)? Or does some H2O2 freeze along with the ice? I don't really understand this method, can someone shed a little light?

The peroxide has a lower freezing point than the water, so when the water freezes, the peroxide stays liquid. You'll lose a tiny bit with the water, but really enough to notice.

Also, you can boil it, very carefully keeping the temp below the boiling temp of peroxide, but enough for the water to evap away. Higher losses due to equilibrium and all with this method. Your choice past that, boiling is faster, but that's about it.

Freezing 3% H2O2 is for fools. A gentle steam gets a good enough concentration for peroxides.

Don't boil per-se, just have the heat up enough so that it is lightly steaming away...

Or just buy some already concentrated H2O2...

The only problem is, if you have any sort of residue on your boiling container the entire thing could oxidize. Make sure your container is clean as fuck of any material.

My preferred method is to keep it at a low boil on the stove, and take it off when the fumes turn white. Very simple, and ensures the highest concentration you can get without distilling.

I can get 6% HOOH at the local Pharmacy, the following is my method for concentrating and it's for the chronically lazy.

I start off by placing the solution in the freezer, I usually forget about it, and then when the whole solution is frozen I then take the solution out of the freezer and crush the ice up. Then I place the ice in a plastic sieve that is positioned over a graduation beaker, and this sieve filters the ~30% HOOH(aq) down into the beaker as it melts, when I have 5% (by volume) of the original solution in the beaker I stop filtering and throw the ice away.

I don't have any experince with either of those methods, but there's been plenty of people who have used them, and didn't come back complaining they didn't work.

I don't trust the freezing method all too much.

The one time I tried it, I was up until 5am waiting for enough of it to freeze...

When I had finished concentrating the H2O2, I set up a synthesis using the melted ice that was extracted as though it was the original strength (12%), and it still yielded a lot more AP than I would have preferred.

I don't trust the freezing method all too much.

The one time I tried it, I was up until 5am waiting for enough of it to freeze...

When I had finished concentrating the H2O2, I set up a synthesis using the melted ice that was extracted as though it was the original strength (12%), and it still yielded a lot more AP than I would have preferred.
Fuck even having any AP.

Fuck boiling, I just buy it by the gallons 30%

The only problem is, if you have any sort of residue on your boiling container the entire thing could oxidize. Make sure your container is clean as fuck of any material.

yeah, my pasta sauce usually has trace amounts of oxidizers too :D

But really, even hair dye peroxide has A LOT higher concentrations than 3%. Just go to a hairdresser/factory outlet and just grab some hydrogen peroxide, or go to a chemist. Its a sanitizer, they should stock it.

don't waste your time trying to concentrate 3%

Just do it the old fashion way... distillation. There is a big difference in the temperature of vaporization between the two.

edit - ooh... and as other have said... preferably a closed glass system. HOOH is a very unstable molecule that will catalyze any trace organics within the system you distill it in. Which eventually leads to a lower yield.

The difference in boiling points is negligible at that low a concentration. Also given that heat and light along with just about anything makes HOOH even more unstable distilling would give crappy yields. What I used to do to concentrate mine was dump a liter of H2O2 in a clean glass jar and stick that in a pot of boiling water, keeping the temperature low enough to not bring H2O2 to boiling but hot enough to get it steaming. When the volume gets down to 100mL you've in theory got a 30% solution. Simple and effective enough to make AP, MEKP and HMTD with which is really all peroxide is 'useful' for.

But really, even hair dye peroxide has A LOT higher concentrations than 3%. Just go to a hairdresser/factory outlet and just grab some hydrogen peroxide, or go to a chemist.

I get all of my H2O2 through my mother (hairdresser) and the best she can get is 12%. If you get your peroxide from the hairdressers supply place, make sure it is a liquid, not a cream.

The difference in boiling points is negligible at that low a concentration. Also given that heat and light along with just about anything makes HOOH even more unstable distilling would give crappy yields. What I used to do to concentrate mine was dump a liter of H2O2 in a clean glass jar and stick that in a pot of boiling water, keeping the temperature low enough to not bring H2O2 to boiling but hot enough to get it steaming. When the volume gets down to 100mL you've in theory got a 30% solution. Simple and effective enough to make AP, MEKP and HMTD with which is really all peroxide is 'useful' for.

edit - ooh... and as other have said... preferably a closed glass system.

I guess I should have emphasized that, initially. Also, it may take longer, but you don't even have to reach boiling point in such a system which keeps the yield higher. Hell, you could even keep the temperature low enough to be no where near boiling point if you connect a pump to the system.

Boat shops carry 30% peroxides ;) You know the wood of the boat has to bleached some times ;)

Your going to try and whip up AP aren't you?

Be honest.

The best way to concentrate H2O2 IMO is not by freezing but by just boiling it down. Take 250 mL and boil to 25 mL. Etc Etc.. Throw it on a hotplate and open a window so your eyes wont burn from the vapor.

You "should" have around 30% H2O2 from 3% doing this. You obviously won't have it anywhere near 30 though but it is generally high enough for a 27-30% application... For AP, haha, it'll work fine. Be careful =/

Fractional freezing might be preferred for some people, but its boiling it down for me.

The best way to get H2O2 is the 27% Baquacil Oxidizer. Its like 14 bucks for a Gallon, purple container at pool stores in the chemical section



Nice to see everyone again!!

Yo what are you guys talking about. What is the benefit of concentrating H2O2?

Sorry I'm from ARAR and am bored :x

Yo what are you guys talking about. What is the benefit of concentrating H2O2?

Sorry I'm from ARAR and am bored :x

Better yields when using it to synthesise organic peroxides, and a popular one, MEKP, won't even work with low-conc H2O2 as far as I know.

Yeah MEKP you need a decent concentration level. But like I said just go to a pool store and save 15 dollars you'll have a gallon of 27% (For those in USA)

Yeah MEKP you need a decent concentration level. But like I said just go to a pool store and save 15 dollars you'll have a gallon of 27% (For those in USA)

jhgsdOGhil;rejaw;yhjzdrp'jhzprjhsropHJSR WTF since when are you alive?

msn bitch

Ozzy shut up this isnt a messager in here it's a thread about conentrating hydrogen peroxide.

Aside of that, I dont use MSN anymore, because it wont let me... Catch me on AIM or Email if you want.

ITT: instant messenger

I've been researching a bit on concentrating Hydrogen Peroxide, and I read about freezing it to get the water out. Is this a reliable method? Can you just go by volume of the original H2O2 to know when you're at 12% (a quarter volume of 3%)? Or does some H2O2 freeze along with the ice? I don't really understand this method, can someone shed a little light?

i used to do this by heating at a low temperature, it it was effective, but it took too long,
i would recommend going to a hair supply shop, its easy to find 12%ish h2o2 there and its alot cheaper than buying many bottles of 3%
of course, my AP days are over after i realized that its not worth blowing my hands off, just be careful

Why the fuck do you guys need so much concentrated Hydrogen Peroxide in the first place? Wouldnt you rather get Nitrous Oxide and pour it on things?

To poster:

Pool Store FTW. At this time of year you can get some 30% from a pool store for under 10 US dollars. Just call around. Its used in non-chlorine pools and hottubs. Boiling off the H2O also works pretty well, it just takes a while, and you get more bang for your buck with pool store kind.

Be careful with OP's for godsake.

/AV/

i'd really go with AreteVeteran's plan, a lot more convenient possibly even cost efficent


If you go to sallys beauty supply and get the highest number bottle of clear developer should be like 40 or something that is plain h2o2 the highest number is 12% from what i remember, and if you go to some pool stores they carry big gallon jugs of like 29% or 35% but i can't remember what its called or what the purpose is for, it has something to do with pools and like disinfecting them, but if there is a sallys beauty supply around you go get that, it is a lot better then boiling down jewel-osco brand 3% bottles and not knowing what the fuck percent you have, its pretty cheap too, idk yea