Gerald Koch said:
One cannot make conclusions from negative results. Failure to produce a darkened spot could mean that the developer is fine and has not adsorbed any water or it could mean that it is completely degraded. In the case where the developer produced a spot is it still active enough to develop film without extending the development time?
I've heard this too. At one time HC-110 Replenisher contained catechol as it was listed on the label. Concerning the developer itself in pre-MSDS times we have no way of knowing as Kodak has no comment on this.
You didn't read the whole thing. Myoriginal simple experiment covered the possibility that the HC-110 was no good from the start by making sure that it was activated by water after having been inactive for a period of time.
I have since concocted many stock solutions of different types that are stored in organic solvents, particularly propylene or ethylene glycols, glycerine, and triethanolamine. I tested one of these by leaving a sample of the stock solution in a thin layer about 100 mm in diameter exposed to air for 30 days. It was till active at the end of that period. Others who read these posts will attest to their long storage lives.
Again, I say, I am not recommending storing any developer, stock or other, exposed to moving or changing air. In fact, considering how easy it is to make the stock solutions of a wide variety of organic stock solutions, I am not even recommending that anyone buy HC-110.