Sciencemadness Discussion Board

Nature of typical oxidizeable substances in OTC glacial acetic acid?

Petit Homme - 10-10-2025 at 16:23


I've got a fair amount of GAA, and I'd like to purify it.

This normally entails first oxidizing whatever is not GAA in there (typically with the very elementary KMnO4) and then distilling it.

Being born in this current location and time I cannot order KMnO4 without being flagged as a potential criminal of one kind or another, which I'd like to avoid since I want – as much as reasonably possible – to live in peace and harmony with all of creation.

Which leaves me wondering: What might be the typical oxidize-able substances that may be found in OTC glacial acetic acid? As in: what would be the implications of skipping the KMnO4 step altogether?

[Edited on 11-10-2025 by Petit Homme]

bnull - 10-10-2025 at 18:16

Acetaldehyde and maybe acetone.
Quote:
Being born in this current location and time I cannot order KMnO4 without being flagged as a potential criminal of one kind or another, which I'd like to avoid since I want – as much as reasonably possible – to live in peace and harmony with all of creation.

As far as I remember, you can buy KMnO4 in drugstores, pharmacies or whatever they are called where you are. It is used to treat some skin conditions. It will not be cheap but won't send funny people to your house.

I suggest you check up Armarego (Purification of Laboratory Chemicals). It has always references for the purification methods used.

Never skip steps in a published procedure unless you know what you're doing or another procedure says so.

macckone - 10-10-2025 at 18:24

Where you are would determine the type of impurities as well as how it was made. For oxidizers, you can use any strong oxidizer. Potassium dichromate is an ideal substitute in this reaction. Dichromates are less often flagged. Note that there is a fire risk adding any oxidizer to an organic acid, so take appropriate precautions. Add a small amount of sulphuric acid to the acetic acid before adding dichromate and stop when it no longer turns green then add a small amount of dry ethanol. Ethanol boils off acetic acid easily and dry ethanol takes water with it.

If it was from fermented acetic acid, there can be a huge range.
If it is from chemically oxidizing ethanol it depends on the method of ethanol production as well as oxidation.
If it was from sodium acetate that was pure then the range is much lower.

We don't have enough information to provide a list of impurities.

macckone - 10-10-2025 at 18:38

Ps. I am assuming you are in the USA since the dea 'watches' potassium permanganate. You can buy it in small quantities without any trouble. There are a large number of places that sell small quantities. Home science tools sells 30 grams which is probably enough for several liters of glacial acetic acid. However if you buy more than 2lbs expect to get on a list. Etsy and Amazon sell larger quantities and again the 1kg limit applies. Unless you have barrels of acetic acid, you don't need much. Maybe 1%. Prepper sites also sell it.

chempyre235 - 11-10-2025 at 07:09

It's also available as "Pot Perm" for water filtration systems. I'm not sure of the purity.

Potassium permanganate is actually a list II precursor, according to DEA, which is the same rank as sulfuric acid, toluene, and acetone. However, it's sold at this site, which I've never purchased from, so take with a grain of salt.
https://us.chemicalstore.com/potassium-permanganate-free-fas...

DEA Lists I and II:
https://www.deadiversion.usdoj.gov/schedules/orangebook/f_ch...

As for dichromate, it's much more readily available in the US, and that cheaply. Here are a couple of sites that sell dichromate as an oxidizer for pyrotechnics formulations:
https://www.fireworkscookbook.com/product/potassium-dichroma...
https://www.skylighter.com/products/potassium-dichromate-ora...

Photography suppliers also sell it, but it's much more expensive. It's also availble here:
https://artcraftchemicals.com/products/potassium-dichromate-...

Petit Homme - 13-10-2025 at 03:14


Thanks for all your contributions!

If there's nothing else than small amounts of acetaldehyde and acetone (should total <0.5%), the I'm fine just distilling it as is for my use, until I can get some KMnO4 under reasonable terms. I would be more worried if there were other stuff than that (though I'm not terribly happy with acetaldehyde, it's fine is tiny amounts).

I reacted some of this GAA with fairly clean MgO with a gradual dilution in water and noticed a small amount of gunk coming to the surface from this reaction. I figured this must be magnesium reacting with some organics in there other than acetic acid (since magnesium acetate is very soluble in water).

I have 20L GAA to purify and if I'm going to get KMnO4 for this I might just get twice as much as I need not to run into the same problem in the near future. The purification calls for first refluxing with 5% KMnO4 if I recall well, before distilling, so a tiny amount of KMnO4 won't do, and if I had to pay much more for KMnO4 than it's reasonable price, I might just as well buy a reasonable quantity of ACS grade GAA instead and save some time.

I know that this can be done with potassium dichromate, but I'm much happier handling KMnO4, because it decomposes into stuff I consider to be (in minute amounts) non-problematic in terms of personal exposure and in terms of environmental impact (typically, that I'd be fine throwing in my garden).

[Edited on 13-10-2025 by Petit Homme]

Texium - 13-10-2025 at 05:50

I have a lot of permanganate available for sale, along with tons of other stuff at reasonable prices. See my thread:

https://www.sciencemadness.org/whisper/viewthread.php?tid=16...

Petit Homme - 13-10-2025 at 06:18

Quote: Originally posted by Texium  
I have a lot of permanganate available for sale, along with tons of other stuff at reasonable prices. See my thread:

https://www.sciencemadness.org/whisper/viewthread.php?tid=16...



Thank you Texium! Lots of nice stuff in there indeed. I would be happy to buy KMnO4 from you but I think this might be impractical/uninteresting to ship since I live on the other side of the big pond away from you (on the old continent).

I wish you great luck with finding a nice new home with great use / leverage for all these nice things you have to offer.





[Edited on 13-10-2025 by Petit Homme]