EDTA is an organic compound with the chemical formula C10H16N2O8 and is a white powder under normal temperature and pressure. It is a chelating agent that can bind with Mg2+, Ca2+, Mn2+, Fe2+ and other divalent metal ions. Mg2+ is often used as an inhibitor of nucleases and proteases because most nucleases and some proteases require Mg2+. It can also be used to remove the inhibition of heavy metal ions on enzymes.

Basic information

Physical and chemical properties

White odorless, tasteless, colorless crystalline powder, melting point 250℃ (decomposition). Insoluble in ethanol and general organic solvents, slightly soluble in cold water, soluble in aqueous solutions of sodium hydroxide, sodium carbonate and ammonia. Can dissolve in more than 5% of inorganic acid, can also dissolve in ammonia and 160 parts of boiling water. Its alkali metal salts are soluble in water. 

Use

EDTA is an important complexing agent. EDTA has a wide range of uses. It can be used as bleaching fixative solution for color sensitive material washing processing, dyeing aid, fiber treatment aid, cosmetic additive, blood anticoagulant, detergent, stabilizer and synthetic rubber polymerization initiator. EDTA is a representative chelating agent. It can form stable water-soluble complexes with alkaline earth metals, rare earth elements and transition metals. In addition to sodium, there are ammonium salts and various salts of iron, magnesium, calcium, copper, manganese, zinc, cobalt and aluminum, all of which have different uses. In addition, EDTA can also be used to enable the rapid excretion of harmful radioactive metals from the body to play a detoxification role. It's also a water treatment agent. EDTA is also an important indicator, but it is used for titrating metals such as nickel and copper. When used, it should be used together with ammonia to play the role of indicator.

Principle of production

It is prepared by acidification after reaction of ethylenediamine with sodium chloroacetic acid. Tetra sodium salt can also be obtained by the reaction of ethylenediamine with formaldehyde and sodium cyanide, and then acidified by sulfuric acid.

Index of quality

Content ≥90% iron (Fe) ≤0.01%

Burning residue ≤0.15% heavy metal (Pb2+) ≤0.001%

The solubility in Na2CO3 is qualified