[Allen]

I'm am an alternative process photographer.  Meaning I use 19th century formulas to create my prints.  I also like to tie my prints to where they were captured. For example, I captured the image below on the bank of the Arno river.  I then collected a gallon or so of water from the Arno and used it when I mixed the sensitizer and during the development process.  

This is a VanDyke print.  The formula I used was a 9% solution of ferric ammonium citrate, 1.5% tartaric acid, and 4% silver nitrate.
I wish to take this a step further and want to source my own metals. My darkroom is fairly well equipped and I know how to make my own silver nitrate but I need help in synthesizing ferric ammonium citrate (green form).  

There are two sources of iron I wish to use in some future projects.  One will be easier to use than the other.  

The first I wish to use is a sample of Campo del Cielo meteorite (92.9% Fe, 6.7% Ni, 0.4% Co) the other is ironsand (Fe3O4).

Wikipedia is kind enough to provide the ratios of materials found in ferric ammonium citrate--the green form is approximately 7.5% NH3, 14.5-16% Fe, and 75% hydrated citric acid.  It can be prepared by adding Fe(OH)2 to an aqueous solution of citric acid and ammonia.

So, I guess my first question is how does one turn Fe into Iron(II) and the second is how does one turn Fe3O4 into iron(II)?

I am well aware that I will be dealing with toxic fumes and have access to a fume hood.

Many thanks,

--Allen

[Borek]

Welcome to Chemical Forums

In general dissolving in the hydrochloric acid followed by a reduction of Fe(III) present to Fe(II) should do the trick. Whether HCl will work depends on several factors - it may turn out other substances present in your iron samples will inhibit the dissolution, so you may be forced to use some oxidizing acid.

[AWK]

http://holoforum.org/oldforum/viewtopic.php?f=2&t=6561

[Allen]

Welcome to Chemical Forums

In general dissolving in the hydrochloric acid followed by a reduction of Fe(III) present to Fe(II) should do the trick. Whether HCl will work depends on several factors - it may turn out other substances present in your iron samples will inhibit the dissolution, so you may be forced to use some oxidizing acid.

Thank you  sir for both the advice and the welcome.
I have concentrated H2SO4 on the shelf.  I'll give it a shot.

[Allen]

http://holoforum.org/oldforum/viewtopic.php?f=2&t=6561

I bookmarked this for further study.  Thanks.

[Allen]

Welcome to Chemical Forums

In general dissolving in the hydrochloric acid followed by a reduction of Fe(III) present to Fe(II) should do the trick. Whether HCl will work depends on several factors - it may turn out other substances present in your iron samples will inhibit the dissolution, so you may be forced to use some oxidizing acid.

I've been reading up quite a bit.  I also contacted the local university but haven't heard back. 
What redox agent should I be studying.

Again, many thanks,

--Allen

[ajkoer]

Ferric Ammonium Citrate can be prepared by adding Fe(OH)2 to an aqueous solution of citric acid and ammonia (see Wiki http://en.wikipedia.org/wiki/Ammonium_ferric_citrate ).

Note, one can obtain Fe(OH)2 as a precipitate from the reaction of iron(II) sulfate and hydroxide ions (more precisely, from a soluble compound containing hydroxide ion). The reaction is given by:

FeSO4 + 2 OH− → Fe(OH)2 + SO4 2−