almost ready-my Parodinal

250ml distilled water
Acetaminophen. 30x500mg tablets pulverized in my coffee bean grinder
Sodium Sulfite (anhydrous ) 50g
Sodium Hydroxide (anhydrous) 20g

It's turning purple as it is supposed to as the Sodium Hydroxide (lye) turns the Acetaminophen into p-Aminophenol Hydrochloride. 2 more days and it will be done.
The Sodium sulfite worked, the Sodium Metabisulfite did not.

-Greg

Greg Heath said:

It's turning purple as it is supposed to as the Sodium Hydroxide (lye) turns the Acetaminophen into p-Aminophenol Hydrochloride.

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This is a small point, but the sodium hydroxide makes sodium p-aminophenolate. This is the active developing agent in Rodinal. You cannot get the hydrochloride salt. Where would the HCl come from?

Hmmm, mine is always amber instead of pink.

Athiril said:

Hmmm, mine is always amber instead of pink.

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Yup, my current batch (with the methanol to separate the tablet fillers) I make last night, also turn Amber. This is my second batch, my first was done on an Amber bottle so don't know the color but it work alright.

Thanks for the replies. Mine is changing color. It's now like the color of my bottle of Rodinal. It's like dark brown.

So explain the methanol method, do you mix it with the acetaminophen and then separate the fillers ?

Greg Heath said:

Thanks for the replies. Mine is changing color. It's now like the color of my bottle of Rodinal. It's like dark brown.

So explain the methanol method, do you mix it with the acetaminophen and then separate the fillers ?

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I got the method from this thread (there was a url link here which no longer exists)
But this is the way I'm doing it, after crushing the tablets, I mix it with methanol (filling it two time the crushed tablet height) and give it a shake, then leaving it overnight until the fillers is in the bottom of the bottle. After it settles I pour out the methanol into a shallow dish, and let the methanol evaporate under a exhaust fan in a unused room. (this is important because clearly the fumes are very dangerous). After all the methanol is gone I just scrape the crystals.

But in my case it looks like I decant the methanol to quick before all the filler settle, because there's still some filler in my PaRodinal batch.

I'm going to try this soon. I think the idea is to dissolve the Paracetamol tablets in the alcohol. The Paracetamol itself will remain suspended in the alcohol and the fillers will drop to the bottom. THe alcohol with the pure Paracetamol can then be poured off and allowed to evaporate leaving just Paracetamol. There have been some suggestions about leaving it in the alcohol and mixing this in instead of some of the water.

EDIT: I have a friend who works as a dispensing chemist in a pharmacy. I am going to see if she can get me some pure Paracetamol then I won't need this step.


Steve.