Chelation of EDTA with metal ions

Details:

 disodium EDTA

As a familiar blood anticoagulant, EDTA is also a chelating agent and an important complexing agent. Although its function is far more than that, today we focus on some problems about its chelation with metal ions.

What are the characteristics of EDTA as a metal ion chelator

1. The complex formed by EDTA and metal ions is quite stable.

2. The molar ratio of EDTA to most metal ions is 1:1, which is 1:2 complex with tetravalent zirconium and pentavalent molybdenum.

3. Most of the complexes formed by EDTA and metal ions are soluble in water.

4. The color of the complex mainly depends on the color of metal ions.

5. Most metal ions in the periodic table can form multiple five ring chelates with EDTA.

Which of tetrasodium EDTA and disodium EDTA is good as chelating agent for metal ions

In fact, it also depends on what state of metal ions to chelate. Tetrasodium EDTA is suitable for chelating metal ions in acidic aqueous solutions; Disodium EDTA is suitable for chelating metal ions in alkaline aqueous solution and solid precipitation.

When EDTA forms chelates with metal ions, the chelation ratio is generally

EDTA is complexed with metal ions in a ratio of 1:1

Why are most nucleases inhibited by metal chelator EDTA

Because most nucleases need Mg2 + to play their role. When the metal chelating agent EDTA is added, Mg2 + will be chelated, thus inhibiting the activity of nuclease.

What is the mechanism of metal chelate EDTA

EDTA and other synergists chelate with metal ions to prevent the catalytic effect of metal ions on the automatic oxidation of substances. Antioxidants such as EMQ, BHA and BHT provide hydrogen atoms or directly combine with free radicals or peroxides to produce stable compounds to prevent the extension of the automatic oxidation chain of substances.

Chelates are usually more stable than general complexes, and the five or six membered ring structure often enhances the stability. Because of this, the stability constants of chelates are very high. Many chelation reactions are carried out quantitatively and can be used for titration. Chelates can also mask metal ions.

EDTA produced by Desheng company is mainly in the form of sodium salt and potassium salt, which is mainly used as blood collection additive as anticoagulant. However, this does not hinder its use as a chelating agent. If we want it to play a greater value, we can only constantly understand more uses, master more information we don't know, and constantly learn and explore.