From: Niranjan Patel (niranjan.patel@worldnet.att.net)
Date: 10/26/03-08:19:35 PM Z
Sandy:
Could you not selectively dissolve any un-coated/un-replaced/un-toned silver
remaining in the print with dilute nitric acid. Then use various reactions
to detect silver in the solution (check this link:
http://129.93.84.115/Chemistry/DoChem/DoChem109.html>.)
I suppose the above will not answer your first question of whether the
toning occurs by way of replacement or surface-coating. It seems to me
that this question would be best answered by the more involved photonic
techniques. However, you do not have to do it every time.
Sounds like a fun project....
Niranjan.
----- Original Message -----
From: "Sandy King" <sanking@clemson.edu>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Sunday, October 26, 2003 6:19 PM
Subject: Re: Test for Silver Metal in Print?
> I am potentially interested in both things. However, for starters a
> quick-and-dirty test for the presence of silver metal in a print
> would tell me if further investigation is warranted.
>
> Sandy
>
>
>
>
> >Sandy:
> >
> >Are you looking for a quick-and-dirty test you can do in your darkroom as
a
> >way of process control or trying to gain fundamental understanding of
> >scientific value?
> >
> >If the latter is the case, one way would be doing SEM (scanning electron
> >microscopy) on various samples in conjunction with EDS (energy dispersive
> >x-ray) analysis which can detect presence (and relative amounts) of
> >different elements on the grains. You should be able to deduce answers
for
> >both your questions from the results. Of course, this requires sending
out
> >your prints to a custom analytical lab or a materials lab of an
university
> >if you have access to one.
> >
> >Niranjan.
> >
> >
> >
> >----- Original Message -----
> >From: "Sandy King" <sanking@clemson.edu>
> >To: <alt-photo-process-l@sask.usask.ca>
> >Sent: Sunday, October 26, 2003 5:14 PM
> >Subject: Test for Silver Metal in Print?
> >
> >
> >> I have two questions for anyone on the list who might be able to
> >> share some knowledge.
> >>
> >> The issue is this. For some time I have been making platinum and
> >> palladium toned kallitypes. Some of the literature on toning
> >> indicates that during metal toning the more noble metal plates the
> >> less noble one. Other literature indicates that the more noble metal
> >> actually replaces, either completely or in part, the less noble one.
> >>
> >> What I would like to know is this.
> >>
> >> 1. How would one be able to find out whether when toning a silver
> >> image with gold, palladium or platinum the toning action is resulting
> >> in plating or in replacement of silver metal?
> >>
> >> 2. Assuming that toning with gold, palladium and platinum results in
> >> replacement of silver metal, how would one test for the presence of
> >> silver to verify whether the replacement is partial or complete.
> >>
> >> Sandy King
> >>
> >>
>
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