Sodium Ferrous Citrate

Sodium Ferrous Citratesodium salt of ferrous 2-hydroxy -1,2-3-propanetricarboxylateContent Sodium Ferrous Citrate contains 10.011.0% of Fe (=55.85).Description Sodium Ferrous Citrate occurs as a green-white to greenish yellowpowder. It is odorless and has a weak iron taste.Identification (1) To 5 ml of Sodium Ferrous Citrate solution (1 100), add 1ml of diluted hydrochloric acid (1 4) and 0.5 ml of freshly prepared potassiumferricyanide solution (1 10). A blue color develops.(2) To 5 ml of Sodium Ferrous Citrate solution (1 100), add 2 ml of aqueousammonia. A red-brown color develops, but no precipitate is formed.(3) Ignite 3 g of Sodium Ferrous Citrate at 500600 for 3 hours. The resultingresidue responds to all tests for Sodium Salt as described in the Qualitative Tests.(4) To 0.5 g of Sodium Ferrous Citrate, add 5 ml of water and 10 ml of potassiumhydroxide solution (1 25), heat in a water bath for 10 minutes while stirring well,cool, and filter. Take a portion of the filtrate, neutralize with diluted acetic acid (1 2), add an excessive amount of calcium chloride solution (3 40), and boil. A white,crystalline precipitate is formed. Collect the precipitate, and add sodium hydroxidesolution (1 25) to a part of it. The precipitate does not dissolve. Add dilutedhydrochloric acid (1 4) to the other part of the precipitate. It dissolves.Purity (1) Sulfate Not more than 0.48% as SO4.Proceed as directed under Purity (2) for Ferric Citrate.(2) Ferric salt Weigh 2.0 g of Sodium Ferrous Citrate, transfer into a flask witha ground-glass stopper, dissolve in 5 ml of hydrochloric acid and 30 ml of water, add 4 gof potassium iodide, stopper, and allow to stand in a dark place for 15 minutes. Add 2ml of starch TS, and shake well. Even if a color develops, the color disappears onaddition of 1.0 ml of 0.1 mol/l sodium thiosulfate to the solution.(3) Heavy metals Not more than 20µg/g as Pb.Proceed as directed under Purity (4) for Ferric Citrate.(4) Arsenic Not more than 4.0µg/g as As2O3.Test Solution Weigh 1.0 g of Sodium Ferrous Citrate, add 10 ml of water, 1 ml ofsulfuric acid, and 10 ml of sulfurous acid, evaporate to about 2 ml, and add water tomake 10 ml. Use 5 ml of this solution as the test solution.Apparatus Apparatus B.

Standard Color To 4.0 ml of Arsenic Standard Solution, add 10 ml of water, 1 mlof sulfuric acid, and 10 ml of sulfurous acid. Proceed in the same manner as for the testsolution.(5) Tartrate Weigh 1.0 g of Sodium Ferrous Citrate, add 5 ml of water and 10ml of potassium hydroxide solution (1 15), heat in a water bath for 10 minuteswhile stirring well, cool, and filter. Measure 5 ml of the filtrate, add diluted acetic acid(1 4) to make it weakly acidic, then add 2 ml of acetic acid, and allow to stand for 24hours. No white, crystalline precipitate is formed.Assay Weigh accurately about 1 g of Sodium Ferrous Citrate, transfer into aflask with a ground-glass stopper, add 25 ml of diluted sulfuric acid (1 20) and 2 mlof nitric acid, and boil for 10 minutes. After cooling, add 20 ml of water and 4 g ofpotassium iodide, immediately stopper tightly, allow to stand in a dark place for 15minutes, add 100 ml of water, and titrate the liberated iodine with 0.1 mol/l sodiumthiosulfate (indicator: starch TS). Perform a blank test in the same manner.1 ml of 0.1 mol/l sodium thiosulfate = 5.585 mg of Fe