D-76 or Dektol: does clear mean good?

[bernard_L]

In other words, is there any way that these MQ developers could go bad without changing color? I'm talking about stock solution. And excluding the case of, e.g., mixing with fixer or similar stupid mistakes. I got some useful information there; mainly that Kodak is conservative (surprise!)
(there was a url link here which no longer exists)
But my question is different. Even if these developers are cheap I hate throwing away good stuff, not to mention the impact of hydroquinone on aquatic life.

What is behind my question is that I've had D-76 and Dektol kept in wine pouches (that I believe to incorporate an oxygen barrier), and in darkness, for over a year, and still a clear liquid. Of course I'd make tests before using them, but I'm curious to hear chemists and/or experienced users.

And, while I have (hopefully) the attention of knowledgeable members, is there any trace/secret ingredient in the abovementioned D-76 and Dektol that would set them apart, as concerns the title question, from the home-mixed versions D-72 and D-76d (the buffered version with 8g borax + 8g boric acid)?

Thank you in advance

 

[Ian Grant]

With D76 there's not really a colour chane when it collapses, itbremains clear. Dektol/D72 differs because it contains carbonate so turns brown as it oxidises and goes off.

There's no special ingredients in commercial D76 or Dektol/D72, although they may contain sequestering agents and traces of surfactants.

Ian

 

[Gerald C Koch]

The short answer is NO. The commercial versions differ slightly so that all the ingredients can be packaged in a single bag without decomposition occurring. However once mixed they are identical in their action to the published formulas.

 

[bernard_L]

Ian Grant, Gerald C Koch, thank you for your replies.

 

[darkroommike]

Kodak recommends 6 months for both D-76 and Dektol in full properly stoppered glass bottles. From my reading and own experience that is a very conservative estimate. I have some Dektol made up at least 4 years ago in clear glass that had not turned brown, something has precipitated out into small strings of crystals. I keep it around more from curiosity than any plans to use it. The thing is, it's a print developer so no foal if it doesn't work, at most I'm out a sheet or two of paper. Film developer? I'm a lot more careful with film developer for obvious reasons.

 

[bvy]

My experience with D-76 is that it's prone to developing some sort of suspended "floaters" or precipitate. Suggestions ranged from ignore it to filter it out to dump it. I've since moved on to other developers.

 

[Gerald C Koch]

When a company like Kodak gives a shelf life for its products this is an estimate based on average to worst case conditions.