Ethylenediaminetetraacetic acid

Ethylenediaminetetraacetic acid, widely abbreviated as EDTA (for other names, see Table), is an aminopolycarboxylic acid and a colourless, water-soluble solid. Its conjugate base is named ethylenediaminetetraacetate. It is widely used to dissolve limescale. Its usefulness arises because of its role as a hexadentate ("six-toothed") ligand and chelating agent, i.e., its ability to "sequester" metal ions such as Ca²⁺ and Fe³⁺. After being bound by EDTA, metal ions remain in solution but exhibit diminished reactivity. EDTA is produced as several salts, notably disodium EDTA and calcium disodium EDTA.

It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.

Uses

Industry

In industry, EDTA is mainly used to sequester metal ions in aqueous solution. In the textile industry, it prevents metal ion impurities from modifying colors of dyed products. In the pulp and paper industry, EDTA inhibits the ability of metal ions, especially Mn²⁺, from catalyzing the disproportionation of hydrogen peroxide, which is used in "chlorine-free bleaching." In a similar manner, EDTA is added to some food as a preservative or stabilizer to prevent catalytic oxidative decoloration, which is catalyzed by metal ions. In soft drinks containing ascorbic acid and sodium benzoate, EDTA mitigates formation of benzene (a carcinogen).

EDTA (disambiguation)

EDTA is ethylenediaminetetraacetic acid (and ethylenediaminetetraacetate), a chemical compound

EDTA may also refer to: