Na4EDTA

Na4EDTA, or tetra-sodium ethylenediaminetetraacetate, is the tetra-sodium salt of ethylenediaminetetraacetic acid (EDTA). In solution it acts as a chelating agent, binding metal ions through the four carboxylate groups and the two amine nitrogens of the EDTA ligand to form stable, often hexadentate, complexes. The binding affinity is high for many metal ions, especially Ca2+, Mg2+, Fe3+, Cu2+, and Zn2+. The chelation effectiveness is pH-dependent and increases as the ligand becomes more deprotonated; at neutral to basic pH it exists predominantly as the fully deprotonated anion with sodium counterions.

Na4EDTA is produced by neutralizing the acid H4EDTA with sodium hydroxide or via salt exchange, and it is available as the tetra-sodium salt. It is highly soluble in water, making it suitable for aqueous solutions and buffers. Other common EDTA salts include disodium EDTA and dipotassium EDTA, but Na4EDTA is specifically used where a fully deprotonated ligand is required.

Applications and safety: In analytical chemistry Na4EDTA is used in complexometric titrations to quantify metal ions and in various laboratory protocols to control metal activity. In industry and consumer products it serves as a sequestrant to prevent metal-catalyzed oxidation and to stabilize formulations such as cleaners, cosmetics, and some pharmaceuticals. In biological settings, EDTA chelators can help preserve samples or regulate metal ion levels, though inappropriate use can disrupt essential metal balances. Handling requires standard chemical hygiene; EDTA salts can cause irritation in some exposures, and excessive ingestion should be avoided.