Rodinal chemical components?

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Could anybody tell me what the chemical components (and concentrations) are of Rodinal developer. I use this developer to make colloidal metal particles in a research project at work. Knowing the components could give me greater control in the preparation. Thanks

-- Adrian Walsh (a.a.walsh@liv.ac.uk), September 25, 2000

Answers

Rodinol is a proprietary developer of Agfa-Gaevert origin, and as such I don't think that the formula has ever been officially released. However it's fairly widely understood that the developing agent is Para-aminophenol (probably Hydrochloride salt), activated by sodium hydroxide. It's about the only formulation that can give such a highly concentrated developer coupled with such high activity.
I'll check, but I don't think the official Rodinol formula is published anywhere.

-- Pete Andrews (p.l.andrews@bham.ac.uk), September 25, 2000.

Meanwhile here's a link to some very detailed instructions for making up a Rodinol (sic) substitute.

I don't know why there's a disparity in the spelling. Agfa clearly call it Rodinal, and they should know. Meanwhile most of the rest of the world (myself included) seem to think it should be spelled Rodinol.

-- Pete Andrews (p.l.andrews@bham.ac.uk), September 25, 2000.


It's SPELLED "Rodinal" but it should be pronounced "Throatwobbler Mangrove".

-- Patric (jenspatric@mail.bip.net), September 25, 2000.

Sorry! I've watched too much Monty Python! :-))

-- Patric (jenspatric@mail.bip.net), September 26, 2000.

Don't apologise Patric. You can never watch too much Monty P.

-- Pete Andrews (p.l.andrews@bham.ac.uk), September 26, 2000.


See page 117 of The Film Developing Cookbook by Steve Anchell and Bill Troop. Be careful, this developer uses Sodium Hydroxide, aka caustic soda! The 'original' Rodinal formula is reputed to be the ONLY pre-war secret the Germans managed to maintain. Seeing as how a single British mathematician broke their 'unbreakable' Enigma Code, I'd bet this 'unauthorized' formula is quite accurate!

-- Michael D Fraser (mdfraser@earthlink.net), September 29, 2000.

Rodinal contains the potassium salt of para-aminophenol with potassium sulfite used as a preservative. The potassium salts are used because they are photgraphically more active than the sodium salts. No restrainer, such as potassium bromide, is needed because para-aminophenol produces the least base fog of any of the common developing agents. The developer concentrate is made by dissolving para-aminophenol base (as a slurry in a solution of potassium metabisulfite) with a 50% solution of potassium hydroxide.

-- Jerry Koch (gkoch02@harris.com), August 15, 2001.

I wonder why nobody has looked at the bottle of AGFA Rodinal. It claims p-aminophenol, potassium sulphite, potassium hydroxide and potassium Bromide. If they used p-aminophenol.HBr, there would be som KBr in the mixture as they claim. Using the hydrochloride would produce a little KCl.

-- Patrick A. Gainer (pgainer@rtol.net), January 07, 2002.

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