[alt-photo] Re: Fluka / Sigma-Adrich Ammonium Iron(III) Citrate -contains Fe(II)!!!

[C.Breukel at lumc.nl]

Loris,

I am sure you know that a peroxide stock isn't stable anyway; it
gradually looses strength, so your empirical method is the best in this
case

Best,

Cor

> -----Original Message-----
> From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-
> photo-process-list-bounces at lists.altphotolist.org] On Behalf Of Loris
> Medici
> Sent: zondag 27 juni 2010 21:06
> To: The alternative photographic processes mailing list
> Subject: [alt-photo] Re: Fluka / Sigma-Adrich Ammonium Iron(III)
Citrate -
> contains Fe(II)!!!
> 
> I thought the same way, OTOH, I fear to add in excess since I'm going
to
> use for iron-silver processes too - I think that wouldn't be nice for
> those... I guess ferricyanide is the best test; even a small amnt.
will
> cause prussian blue pigment that has high-tinting strength.
> 
> Regards,
> Loris.
> 
> On 27.Haz.2010, at 20:52, Alberto Novo wrote:
> 
> >> 2. I'm going to test in order to find the min. amnt. of peroxide
that
> cures the problem. (Tell me if you want it to share here later...)
OTOH,
> I'm not sure if there's any adverse effect in adding peroxide to the
stock
> solution, both in terms of stability and picture-making. I would
> definitely like to have your comments and warnings (if any) on this
issue.
> >
> > In the old texts (don't ask me which one, I am only remembering...)
it
> was recommended the use of potassium permanganate in order to oxidize
the
> iron(II). However, I don't see any adverse effect of H2O2 if you add
it
> drop by drop, checking for the blue reaction after each drop.
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