[pure-silver] Re: Sulfite stabilization
- From: Ryuji Suzuki <rs@xxxxxxxxxxxxxxx>
- To: pure-silver@xxxxxxxxxxxxx
- Date: Fri, 06 May 2005 12:43:54 -0400 (EDT)
From: "John Black" <jblack@xxxxxxxxx>
Subject: [pure-silver] Re: Sulfite stabilization
Date: Fri, 6 May 2005 11:33:00 -0400
> Indeed. There seems to be variables not anticipated by published data. I
> have seen stock Xtol suffer sudden death in unopened glass bottles with
> little or no headspace.
I'm not too surprised about erratic XTOL behavior.
> I still cannot get the activity out of Dimezone-S that I get from
> phenidone. The dimezone-S is much more stable in water solution
> than P though.
Phenidone is more active per mole basis especially in low pH
developers. But when I adjust for the fog level, etc., I don't see
much difference in speed, and overall I prefer Dimezone S.
> I usually don't list failures but this one was so spectacular that
> you might find it humorous. I reasoned that vitamin E
> (a-tocopherol) should substitute for ascorbic acid because they both
> are reducing (anti-oxidant) organic chemicals so I got some and
> tried it. It turns out to be insoluble in water and comes normally
> as a oil solution. I tried many different ways to disperse it in
> water to no effect at all. End of experiment.
This is not humorous... Did you look at the molecular structure of
tocopherols? If you did, all that would be instantaneously obvious.
(In general I don't touch chemicals unless I study the basic
properties, toxicity, possible adverse reactions, toxicity of
potential decomposition/polymerization products, etc. Access to good
industrial chemistry database is very useful here.)
Also, dispersing a reducing agent doesn't help development. You would
have to modify some of the side/terminal methyl groups to something
more hydrophilic.
> Anyone need some vitamine E for health reasons? I got plenty.
Why don't you make skin care products to use after the lab work? (I
actually tried many samples and found out two very good ones. No, I
don't put them in the developer solution.)
--
Ryuji Suzuki
"Keep a good head and always carry a light camera."
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