EDTA,Ethylenediaminetetraacetic acid,CAS 60-00-4

Edetic acid occurs as a white crystalline powder. Ethylenediaminetetraacetic acid is a solid. white crystals or powder EDTA is a white, odorless, crystalline material or white powder

Ethylenediaminetetraacetic acid Use and Manufacturing
Methods of Manufacturing
1. In a 1 L three-necked flask equipped with a stirrer and a thermometer, add 125 g of chloroacetic acid, 150 g of ice and 130 mL of 30% sodium hydroxide solution, and add 20 g of ethylenediamine under stirring. After incubation at 15 ° C for 1 h, 30% sodium hydroxide solution was added to each batch of 10 mL. After each addition, the phenolphthalein indicator was not alkalized and added to the next batch. The final reaction mixture should be basic. After being kept at room temperature for 12 h, the mixture was heated to 90 ° C and decolorized with activated carbon. Filtration, filter residue washed with water, lotion and filtrate combined volume of about 700mL. Concentrated hydrochloric acid to pH = 3, began to precipitate crystal, filter out the crystal, washed with water to chloride-free. Drying, the product ethylenediaminetetraacetic acid 80g, yield 90%.
2. In ethylenediaminetetraacetic acid and water, stirring 30% sodium hydroxide solution, heated to the whole reaction, add hydrochloric acid to pH 4.5, by concentration, filtration, cooling crystallization, washing, drying in ethylenediamine four Acetic acid.
3. 100kg of ice and 135kg of 30% sodium hydroxide solution were added to the 800l stainless steel reaction kettle. Then 18kg of ethylenediamine of 83-84 ℃ was added under stirring. After incubating at 15 ℃ for 1h, 30% sodium hydroxide solution was added in batches. After each addition, the phenolphthalein indicator showed no alkalinity, and then the next batch was added. Finally, the reactant was alkaline. After keeping at room temperature for 12h, the mixture was heated to 90 ℃, activated charcoal was added, filtered and the residue was washed with water. Finally, the total volume of the solution was about 600L. Concentrated hydrochloric acid to ph value of 3, precipitation crystallization. Filtering, washing until no chloride root. Drying, EDTA64kg, yield 95%. And then washed with water is finished.
4. Ethylenediamine reaction with formaldehyde, sodium cyanide 60% ethylenediamine aqueous solution, 30% sodium cyanide solution and sodium hydroxide mixed, maintained at 20 ° C mixed 0.5h. Aqueous formaldehyde was then added dropwise. After the reaction, the water was distilled off under reduced pressure. The procedure described above was then repeated, with the last addition of excess formaldehyde to allow the sodium cyanide to completely react. Adjust the pH value to 1.2 with dilute acid. Precipitation of white precipitate, filtration, washing, drying at 110 ℃. Products.
Uses
Ethylenediaminetetraacetate (EDTA) is a sequestrant and chelating agent that functions in water but not in fats and oils. It is used to control the reaction of trace metals with some organic and inorganic components to prevent deterioration of color, texture, and development of precipitates, as well as to prevent oxidation which results in rancidity. The reactive sites of the metal ions are blocked, which prevents their normal reactions. The most common interfering metal ions in food products are iron and copper. It can be used in combination with the antioxidants bht and propyl gallate. It is used in margarine, mayonnaise, and spreads to prevent the vegetable oil from going rancid. It is used in canned corn prior to retorting to prevent discoloration caused by trace quantities of copper, iron, and chromium. It also inhibits copper-catalyzed oxidation of ascorbic acid. It occurs as disodium calcium and disodium dihydrogen . Its use is approved in specified foods, with an average usage level being in the range of 100–300 ppm.