darkflame89 - 19-3-2005 at 20:41
Does anyone know how to prepare ferric ammonium citrate( A compund known to be light sensitive)?
The reaction given on the NET :
2 (NH4)2HFe(C6H5O7)2 ---> 4 NH4+ + 2 Fe2+ + CO2 + C5H4O52- + 3 C6H6O72-
What are the products? I recognise the ammonium ions, ferrous ions, carbon dioxide, but what are the other organic compounds?
Mr. Wizard - 20-3-2005 at 10:21
I had a science kit many years ago that had a tube of Ferric Ammonium Citrate in it, and you could make blue prints with it.
http://www.grokfood.com/regulations/184.1296.htm
[Page 502-503]
TITLE 21--FOOD AND DRUGS
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN
SERVICES (CONTINUED)
PART 184--DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE--Table of Contents
Subpart B--Listing of Specific Substances Affirmed as GRAS
Sec. 184.1296 Ferric ammonium citrate.
(a) Ferric ammonium citrate (iron (III) ammonium citrate) is
prepared by the reaction of ferric hydroxide with citric acid, followed
by treatment with ammonium hydroxide, evaporating, and drying. The
resulting product occurs in two forms depending on the stoichiometry of
the initial reactants.
(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.
(2) Ferric ammonium citrate (iron (III) ammonium citrate, CAS Reg.
No. 1333-00-2) is a complex salt of undetermined structure composed of
14.5 to 16 percent iron, approximately 7.5 percent ammonia, and 75
percent citric acid and occurs as thin transparent green scales, as
granules, as a powder, or as transparent green crystals.
(b) The ingredients meet the specifications of the Food Chemicals
Codex, 3d Ed. (1981), pp. 116-117 (Ferric ammonium citrate, brown) and
p. 117 (Ferric ammonium citrate, green), which is incorporated by
reference. Copies are available from the National Academy Press, 2101
Constitution Ave. NW., Washington, DC 20418, or available for inspection
at the Office of the Federal Register, 800 North Capitol Street, NW.,
suite 700, Washington, DC 20408.
[[Page 503]]
(c) In accordance with Sec. 184.1(b)(1), the ingredients are used in
food as nutrient supplements as defined in Sec. 170.3(o)(20) of this
chapter, with no limitation other than current good manufacturing
practice. The ingredients may also be used in infant formula in
accordance with section 412(g) of the Federal Food, Drug, and Cosmetic
Act (the act) (21 U.S.C. 350a(g)) or with regulations promulgated under
section 412(a)(2) of the act (21 U.S.C. 350a(a)(2)).
(d) Prior sanctions for these ingredients different from the uses
established in this section do not exist or have been waived.
[53 FR 16864, May 12, 1988]
[Edited on 20-3-2005 by Mr. Wizard]
Mephisto - 20-3-2005 at 11:56
darkflame89: The two other products are a 3-oxopentanedioate ion and the citrate ion. A detailed description how to prepare ammonium
ferric citrate can be found in US 2644828 (TIFF-plugin necessary).