D-76 Turned green?

[Kirks518]

A while back I mixed up a gallon of D-76, and split it among 3 storage containers. It's been holding up quite well overall, and it's been a few months. All of it is stock, non-diluted. I've been switching back and forth between the two containers that are the fullest, and hadn't touched the 3rd container until the other day.

I wanted to use from that batch because I wanted to use 1+3, and container with the smaller volume was untouched stock. Anyway, I poured it into the measuring beaker, and it was a light lime green! It didn't smell funny, wasn't cloudy, it was just a bright green in color. I tossed it and used the stuff I had been using which came out fine.

The container had only been used for stock D-76 previously, but was still washed before use. Any ideas?

 

[Athiril]

What film did you process? Some colour the developer.

 

[Kirks518]

The developer hadn't been used for anything at that point.

 

[Photo Engineer]

Oxidized HQ forms Quinone, a deep green chemical which is not a developer. I'm curious about why this happened though in the presence of all of that Sulfiite in D76. That would prevent it.

PE

 

[Kirks518]

Would of photo of it help in any way? i still have the rest of the bottle.

 

[Photo Engineer]

Oh, I can visualize it, but if it still develops film, it is good. I wouldn't worry in that case.

PE

 

[pentaxuser]

I may be wrong but this is the first time I can recall seeing a thread on unused, seemingly uncontaminated D76 turning green which in itself is unusual over 11 years and thousands of "What's wrong" thread/posts on developers.

Quite a mystery

pentaxuser

 

[Gerald C Koch]

The reduction product of hydrouinone called quinone forms an addition product with hydroquinone called quinhydrone. In solution quinhydrone is used to make green ink. But as PE points out how can quinone form in the presence of sodium sulfite.

 

[Kirks518]

I haven't used any of it, and I still have it. If anything, I was expecting it to have turned brown. You could imagine my shock when I saw it was green.

Contamination is a possibility, but by what?

 

[Alan Johnson]

Is it possible there was enough exposure to air to oxidize all the sulfite?
Usually the hydroquinone has the job of regenerating metol oxidized by silver bromide but it seems just possible that with air oxidation the sulfite may be all oxidized before hydroquinone,IDK.

 

[Photo Engineer]

There is a quinone-imine formed by Metol, but OTOMH IDK what color it is. Most ones I know of are pink and turn colorless in acid.

PE

 

[Gerald C Koch]

Is it possible there was enough exposure to air to oxidize all the sulfite?
Usually the hydroquinone has the job of regenerating metol oxidized by silver bromide but it seems just possible that with air oxidation the sulfite may be all oxidized before hydroquinone,IDK.

It would be easy to check. Take a 5 ml of the developer and add a drop of tincture of iodine. If the iodine is decolorized then there is still sulfite present. But the evidence has been destroyed.

 

[Alan Johnson]

I did try oxidizing hydroquinone solution but it just went orange.
Quinone imine seems more likely, I did not try it:
http://encyclopedia2.thefreedictionary.com/Quinone+Imine+Dyes