From: Monnoyer Philippe (monnoyer@imec.be)
Date: 10/28/03-08:23:20 AM Z
Sandy,
Your question is interesting.
OK, first, you should probably describe your toning formulation so that we chemists could foresee what is likely to happen. This way we could probably discard one of the 3 possibilities. Anyway the 3 possibilities here are:
1/ There is no silver left
2/ You have platinum/gold/palladium plated silver particles
3/ Both silver and platinum/gold/palladium are present and show free surface
First you can check for hypothesis #3:
Take your reflection density on a given spot in a uniform density spot on your toned print.
Process your print with rehalogenating bleach (ferri +bromide), as Judy suggests.
Fix and rinse and dry.
Measure the density again.
If you have a density loss, hypothesis 3 is the right one
If not, hypothesis 3 is wrong. You then have to check for hypothesis 1 or 2.
Therefore, the most straight forward method is indeed X-Ray fluorescence (very close to EDS but more easy to find closeby I think). You just send high energy X Rays on a sample, and it reemits low energy X-Rays with an energy depending on the reflecting material.
Just go in the chemistry of physics departement with a part of your print to analyse. Ask a 3d year student who's the professor/assistant in charge of basic training on this technique (also called Coolidge tube experiment), or a PhD student (they like to play). You will most likely find it in the Physics departement. Student often try this simple technique during the first or second year. Just ask to submit your print to the test. We did it with everything we had at hand.
You will have the Palladium or Platinum or Gold peak, and maybe the silver peak. If you have the silver peak, hypothesis 2 is true.
If you don't, basecally I would say hypothesis 1 is true with some assumptions.
My question: why do you want to know it ?
Hope this might help,
Philippe
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