[alt-photo] Re: Clerc and am fe citrate

[Peter Friedrichsen]

Alberto,

I found this description some time ago. It doesn't tell you that the 
green and brown forms depend not only on the composition, but also 
how the starting chemicals are combined.

(1) Ferric ammonium citrate (iron (III) ammonium citrate, CAS Reg. 
No. 1332-98-5) is a complex salt of undetermined structure composed 
of 16.5 to 18.5 percent iron, approximately 9 percent ammonia, and 65 
percent citric acid and occurs as reddish brown or garnet red scales 
or granules or as a brownish-yellowish powder.
From:
http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfCFR/CFRSearch.cfm?fr=184.1296

Peter Friedrichsen


At 03:03 AM 04/03/2012, you wrote:
>I am looking for the chemical definition brown ammonium ferric 
>citrate given by Clerc. I remember a footnote in:
>Clerc, L.P. (1950) "La Technique Photographique"
>5th Ed, tome II, Publications photographiques et cinematographiques 
>Paul Montel, Paris V, 1950, pp.816-817
>I have had the oppportunity of taking some notes about the empirical 
>formula of the green form, but unfortunately I did not save the 
>information about the brown one.
>Now I nave not the opportunity to look at Clerc anymore. May you help me?
>Alberto
>www.grupponamias.com
>www.alternativephotography.com/wp/photographers/rodolfo-namias-group
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