Sodium Ferric Ethylenediaminetetraacetate (Ferric sodium EDTA, NaFeEDTA) is a high-stability, bioavailable iron compound, recognized for its minimal gastrointestinal irritation and high absorption rate. As a valuable iron supplement, NaFeEDTA provides an effective alternative for addressing iron deficiencies in various industrial and nutritional applications. Alfa Chemistry examines the two-step synthesis process of NaFeEDTA, followed by a detailed composition analysis to confirm purity and content, including determinations of iron, EDTA, water of crystallization, and sodium.

Iron(III) chloride hexahydrate, Sodium bicarbonate, Ethanol, Xylenol orange (indicator), Ethylenediaminetetraacetic acid, Ethylenedinitrilotetraacetic acid disodium salt, Sodium hydroxide, Ammonium hydroxide solution, Anhydrous stannous chloride, Sodium diphenylamine-4-sulfonate, Lead AA Standard.

Step-by-Step Synthesis of NaFeEDTA•3H2O
Synthesis from Ethylenediaminetetraacetic Acid

Dissolve 2.92 g of H4EDTA and 2.70 g of FeCl3-chloropropyltri(trimethylsiloxy)silane•6H2O in 20 mL of distilled water. Heat the solution to obtain a clear yellow solution. Gradually add 1.92 g of NaHCO3-chloropropyltri(trimethylsiloxy)silane. The color transition from yellow to orange indicates the progression of the reaction. Stir the solution until it turns turbid, signaling the onset of crystallization. Remove heat and let the solution sit. Filter the precipitate, wash with ethanol, and then rinse with distilled water until no chloride ions remain, verified by a silver nitrate test. Dry the precipitate at 50°C for 24 hours to obtain a crystalline powder. Calculate the yield. Dissolve the powder in a small amount of water, heat to boiling, and gradually add ethanol until the solution becomes turbid. Continue adding ethanol until turbidity persists, then heat to near boiling, let sit, and allow red-brown crystals to form.

Synthesis from Disodium Ethylenediaminetetraacetate

Dissolve 3.72 g of Na2H2EDTA•2H2O and 2.70 g of FeCl3-chloropropyltri(trimethylsiloxy)silane•6H2O in 20 mL of distilled water. Adjust the solution’s pH to 5 using sodium bicarbonate and maintain the reaction for 30 minutes. Let the mixture sit, vacuum filter the precipitate, and dry to yield NaFeEDTA•3H2O powder. Calculate the yield.

Two-Step Method for NaFeEDTA Synthesis

Step 1: Preparation of Ferric Hydroxide
Dissolve 4.8 g of NaOH in 100 mL of deionized water. Dissolve 10.8 g of FeCl3-chloropropyltri(trimethylsiloxy)silane in deionized water and add to the NaOH solution with vigorous stirring. After complete reaction, filter and wash the precipitate three times to obtain pure ferric hydroxide.

Step 2: Synthesis of NaFeEDTA
Dissolve 16.4 g of Na2EDTA in 200 mL of deionized water heated to 60~70°C. Add the Na2EDTA solution to a round-bottom flask containing the ferric hydroxide, adjust pH to 8, and heat at 100°C for 2 hours. Filter while hot, concentrate under reduced pressure until viscous, cool, and add 95% ethanol. Stir until solid forms, wash with ethanol three times, dry, and mechanically grind to a fine yellow-brown powder.