The formula for GVM1, a custom and unique phenidone-glycin film developer

[grainyvision]

I think the more important thing than phenidone being soluble in glycol is that glycin, after being neutralized is incredibly soluble in glycol. Regardless, unsure why use a different solvent if glycol gives no issues? It's also less volatile than isopropyl (less evaporation)

Either way, I kept the GVM1.2 concentrate in my fridge overnight, at a stable 34F or about 1C. No crystalization at all. I'd say this batch won't have solubility issues. I'm also really curious about how much longer this will last if kept in the fridge. I've obvserved glycin powder is very well preserved by freezing, so maybe that would extend to mixed formulas as well (but kept cold, not frozen). such a small amount is used that it wouldn't greatly affect temperature of working solution to dilute from cold concentrate either.

 

[bnxvs]

Hi. You can get a solution of phenidone of any concentration (up to 70%) in DMSO (dimethyl sulfoxide).

 

[grainyvision]

Hi. You can get a solution of phenidone of any concentration (up to 70%) in DMSO (dimethyl sulfoxide).

DMSO is an excellent solvent. Unfortunately it also is extremely smelly and contaminates any solution in your workflow. I used as little as 5ml/L of DMSO in a test developer and I had to throw out the fixer because it smelled so strongly of sulfur from the DMSO contamination. The smell is not toxic or anything, just greatly annoying. Another issue with DMSO is that it functions are a carrier solvent which performs excellently at allowing chemicals to traverse the skin-blood boundary. If you get a drop of DMSO on you, you'll taste sulfury garlic after just a few seconds. Thus, if you're using DMSO as a solvent, proper PPE is an absolute must. Dimezone isn't too harmful, but you really don't want it floating around in your blood.

 

[lantau]

The danger of DMSO is just as you say. Lab discipline is of importance when using it. However, DMSO isn't supposed to smell. Must be a rather strong impurity in your supply.

 

[grainyvision]

The danger of DMSO is just as you say. Lab discipline is of importance when using it. However, DMSO isn't supposed to smell. Must be a rather strong impurity in your supply.

The DMSO I use is for veterinarian purposes, not the human grade stuff. It doesn't have much smell initially but once I add hydroquinone it gets smelly really fast. I've never tried DMSO with dimezone or phenidone though.

 

[Pixophrenic]

You would not want DMSO in any developer because it is an oxidant. Reactions that it will undergo in a mixed developer are somewhat difficult to predict, but one of the results will be dimethylsulfide. And citing Wikipedia, "Dimethyl sulfide...<snip> is one of the strongest odours known in organic chemistry. Humans can detect this compound in concentrations as low as 0.02 to 0.1 parts per million."

 

[Pixophrenic]

I think this DMSO thing effectively hijacked the thread, and I am sorry. To put it back on track, I think using a phenidone derivative in propylene glycol is a productive idea for "spiking", adding a little bit into an existing developer.. Now you can take AGFA 72 (sulfite-glycin-potassium carbonate) and "spike" it with phenidone in glycol (pioneered by Gainer). Or you can reproduce Levenson developer from British patent GB871571A. The latter is basically Rodinal augmented with phenidone and hydroquinone. It can be diluted 100 times to get times similar to D-76. Of course, an enterprising individual can vary the P and the Q for the desired effect.

 

[ruilourosa]

Can you transcribe the patent? I just found a paper but of no significance for the scope here treated.

 

[Raghu Kuvempunagar]

Can you transcribe the patent?

+1

 

[bnxvs]

There is no need to store a solution of the phenidone in the DMSO in large quantities. It is enough to dissolve a small amount (needed to create a concentrate) and add the already obtained solution to propylene glycol (etc.). This will at least save you the hassle of constant stirring and reheating.

 

[grainyvision]

DMSO does not appear to be an oxidant, in fact it appears to actually preserve developing agents and to reduce free radicals. In a low sulfite lith developer formulated with a "part A" of 10% hydroquinone in ~75/25% DMSO/propylene glycol, I observed that I can use about 10-20% less sulfite than with 10% hydroquinone in propylene glycol. I still have the bottle of 10% hydroquinone in DMSO though I rarely use it due to the smell, it's a very pale yellow which matches the color when freshly mixed.