I was giving you a possible answer. It might have oxidized to Potassium Sulfate which is much less soluable! Thats all.
Reading the Film Developing Cookbook it's apparent that there are misconceptions about the "Rodinal Type" developer listed and Agfa Rodinal of all vintages over the years.
1. First the date is given as 1881 but Andresen didn't discover p-Aminophenol until 1888, Rodinal came on the market in 1891.
2. Rodinal has always been a p-Aminophenol developer using the free base, although in the early years the hydrochloride was used to prepare the free base.
3. Rodinal (except Agfa after 1964) has always used Potassium Sulphite and just enough Hydroxide to form p-Aminophenolate, and no excess. The level of Hydroxide was increased by Agfa in their 1964 re-formulation, not decreased.
The FDC states that "Agfa Rodinal still contains p-Aminophenol and Potassium Hyrdroxide but in much smaller amounts". The Major change in 1964 was an increase in the Hydroxide taking the concentrate pH from 11.8 to 14, at the same time the amount of developing agent was cut by approx 20%. The FDC makes no reference to the continued production of the older formula by Orwo/Calbe so no comparison.
It's easy to see where this misunderstanding comes from. As Agfa themselves stated around the beginning of last century "In addition to neutral sulphite and water "Agfa"-Rodinal contains only an alkaline salt of Paramidophenol, but no excess of caustic alkali".
The older formula (in the FDC and in the first post in this thread) uses 100 g of p-Aminophenol and 300gms of Potassium Metabisulphite, and about 216ml of a 400ml 50% Sodium Hydroxide solution (107.95 g) to form a 50/50 mix of Sodium and Potassium Sulphite (170.1 g + 213.5g). A small additional amount of Sodium Hydroxide is used to convert the p-Aminophenol free base, and slightly more for the Hydrochloride.
Agfa stopped using Metabisulphite as the source of the Sulphite sometime before WWII and began using Potassium Sulphite instead, probably for economic reasons, the direct replacement in the FDC formula would be 427.11g, the amount of Hydroxide needed would fall to around 50g, a bit more if you use p-Aminophenol Hydrochloride rather than the free base.
It's the amount of Hydroxide in the final developer that's important, rather than any used to convert Metabisulphite to Sulphite which completely disappears in the process anyway.
One molecule of Potassium Metabisulphite and two Potassium Hydroxide react to give two Potassium Sulphite and water :D
4. Bromide and anti-foggant. In the FDC Page 59 (Agfa Rodinal - 1964 onwards) Bill Troop states that "Potassium Bromide has also been added, which would not be necessary if p-Aminophenol was the sole developing agent"
However we know that Agfa were already using Potassium Bromide and another anti-foggant (P.1347) many years earlier in Rodinal from F.I.A.T. and British RAF reports, they were probably introduced during the 1930's, so the statement doesn't make sense. The amount of Bromide then works out at less than 1% (0.77%) so would not be shown on Calbe's MSDS if they use a similar level.
There are unsubstantiated reports that that the formulae Andresen himself published can sometimes cause Dichroic fog, whether this is due to the use of the Hydrochloride or incorrect balancing of the alkali by adding excess we can't know.
But an increase in the alkalinity particularly as it's a hydroxide will greatly increase the potential for fog even more so because there's such a low level of sulphite and we know that dilute Agfa Rodinal has a higher pH than even the Calbe R09 concentrate, before that drops itself with dilution.
5. If Agfa Rodinal is added to Bill Troop's table of High Acutance developers on page 59 of the FDC then a 1 in 50 working solution would fit extremely nicely alongside Beutler etc
P-Aminophenol 0.82 g
Potassium Sulphite 6.8g
Potassium Hydroxide 0.12
There's about 6 g per litre free Potassium Hydroxide in Agfa Rodinal concentrate and the p-Aminophenolate is also alkali so the pH is somewhere around 11.55 even when diluted 1+50, (Agfa's own pH figure).
In comparison Calbe R09 needs to be used at 1 in 40 to achieve roughly comparable results and in this case we would have:
p-Aminophenol 1.25 g
Potassium Sulphite 6 g
Relying on the alkalinity of the phenolate itself the pH will be much lower than Agfa Rodinal which is why over 50% more developing agent is needed.
6. We do know the precise amount of p-Aminophenol in Rodinal, it's in the MSDS along with the Hydroxide, 4.1% and 2.7%, also all Rodinal MSDS's etc confirm it's the free base, typical German precision.
Although Agfa Rodinal has nearly 20% less developing agent than Calbe R09 (old Rodinal formula) it's working at a much higher pH
So these facts rule out Bill Troop's speculation in the FDC & on the Internet that a second developing agent has been added. p-Aminophenol shows good additivity & super-additivity with other developing agents so add even a trace at Agfa Rodinal's high pH's and the increase in activity would take Rodinal into a completely new realm hitherto unexplored :D which more than compensates.
The FDC Rodinal type dev will work better with 133.4 g of p-Aminophenol Hydrochloride per litre, and made up to a litre will be more similar to R09 but with a lower sulphite content and no anti foggants. Of course it works as is it's such a simple develop.
I don't find Bill speculating in the book at all. He may have in a post, but I have not looked that up. In the book it is rather straightforward regarding Rodinal and the formula is quite reasonable.
That's speculation :D
I have the same formula as Bill publishes in the FDC in many books, and Dr Momme Andresen published it in an Agfa publication himself, it's often listed as a Paramidophenol single solution developer, which is Agfa's original name for p-Aminophenol.
No-one doubts the formula is close to Rodinal, but no book I have other than the FDC/DCB states it's the original Rodinal, in fact none even use the word Rodinal.
J.Desalme & others state that Rodinal type developers use the free base rather than the hydrochloride. Desalme is likely to have been well informed, he was researching similar developing agents to Andresen including phenylene diamines, aminophenols, and disclosed Pyramidol as a developing agent in 1912. (His first research papers are from the1890's).
A 1912 research paper from Cornell University, quotes from work done by Sheppard and Mees (1907 so pre-Kodak) indicating that p-Aminophenol developers aren't suppressed by high levels of Bromide. So there's no reason what so ever why a high level of Bromide can't be present in modern Rodinal purely to suppress fog caused by the higher level of Hydroxide.
Thanks, I was looking on the wrong page. Found it. I can agree with what you say, to an extent. You see, you are right also about p-Aminophenol developers not being supressed by high levels of Bromide (AFAIK) but OTOH, this is an interaction with all ingredients and hydroxide is quite similar in all versions and so Bromide would have no extra effect as a function of hydroxide in any version of Rodinal.
Therefore, there must be a reason for the high level of Bromide. Something else is going on if Bromide does not act as an effective antifoggant with Hydroxide. I would like to suggest that it might be moderating edge effects which began to become prominent as film emulsions evolved. Think about it.
Ron, I think what Sheppard & Mees found was that Bromide works well as an anti-foggant in p-Aminophenol devlopers, but with some developers/developing agents at a higher level the Bromide suppresses overall development, Metol & MQ developers are prone to this.
Anyway Rodinal has been using a combination of Bromide and an organic anti-foggant for over 64 years, so this seems to dispel the speculative statement. How much they might have raised it by when the reformulated is less important.
People who prefer the older Calbe R09 version claim it's cleaner working, it's probable the extra hydroxide in Rodinal may lead to a higher base fog, but in all honesty Agfa Rodinal is a superb developer and with Tmax 100 or Agfapan 100 delivers cleaner sharper negatives than ID-11/D76 IMO. It was my main developer for personal work 35mm to LF for about 19n years.
Was Kodinol, the Kodak p-Aminophenol concentrated developer, ever sold in the US. There's nothing on the internet at all, but it's listed in my Kodak UK 40's & 50's books.
Kodinol does not appear in any of my books back to 1941. I don't remember ever having heard of a PAP developer either when I started developing pictures in the 40s or when at Kodak. I would have to assume that it was not sold in the US.
If Rodinal works well with no bromide then that should tell us something about fogging and about development in this developer at this pH with this deveoping agent. Something slightly different is going on than in average developers and I think I am beginning to understand it.
My train of thought does suggest that there are some variants that can be designed with some superior trait or other.
Just as a matter of p-aminophenol interest, I have a U. S. War Department Technical Manual of Basic Photography dated July 1, 1941 that lists a Tropical Developer:
Water (at 125 F)..............96 ounces.
Para-aminophenol hydrochloride.....400 grains.
Sodium sulfite (des.)....................6 ounces, 200 grains.
Sodium carbonate (des.)...............6 ounces, 200 grains.
Water to make 1 gallon.
This translates to 7, 50 and 50 grams per liter. It was to be used full strength. Adding the sulfite should result in precipitation of the p-aminophenol base, as it does when making Rodinal, and I suppose a paraminophenolate is formed to make it soluble as the carbonate is added.