Sciencemadness Discussion Board

Mysterious black crystals from sodium salicylate?

Alpine2048 - 30-1-2020 at 19:50

So I recently decided to extract the salicylic acid from 17% ww wart remover for no apparent reason but for the collection of the salicylate. I did this by adding baking soda solution until no more bubbles appeared ( i added a bit too much baking soda). The nitrocellulose precipitated or at least gelled and was removed, with the bottom liquid being filtered. I filtered and evaporated the liquid and it started turning a light brown at the end before completely drying. However, when I recrystallized it, I got thin, rather fluffy black residue instead, with a pH around 9-10.

I will post pictures when I get home, but does anyone have any idea what happened?

Alpine2048 - 30-1-2020 at 21:26

Pictures

DD7B0C51-36A6-4D16-8851-28EC2525EB9D.jpeg - 1.6MB

Tsjerk - 31-1-2020 at 06:40

Many phenols polymerize under the influence of oxygen to black tarry crap. They usually do this when deprotonated.

What is ww wart remover and what is in it?

morganbw - 31-1-2020 at 08:28

From internet search:

Active ingredient - Purpose:
Salicylic acid 17% w/w - wart remover.
Inactive ingredients: Alcohol, Camphor, Castor Oil, Collodion, Ether, Ethylcellulose, Hypophosphorous Acid, Menthol, Polysorbate 80.

Tsjerk - 31-1-2020 at 09:59

Quote: Originally posted by morganbw  
From internet search:

Active ingredient - Purpose:
Salicylic acid 17% w/w - wart remover.
Inactive ingredients: Alcohol, Camphor, Castor Oil, Collodion, Ether, Ethylcellulose, Hypophosphorous Acid, Menthol, Polysorbate 80.


So a crap load of stuff that won't be removed with the method used by Alpine 2048.

Edit: I would have been surprised if a white product would have been obtained, let alone a pure one.

A better approach would be getting some aspirin pills and purify those. Then hydrolyze the aspirin.

[Edited on 31-1-2020 by Tsjerk]

Alpine2048 - 31-1-2020 at 16:58

Yeah I guess no salicylic acid then. But at least I have some good nitrocellulose to keep!