EDTA

EDTA, short for ethylenediaminetetraacetic acid, is a synthetic polyamino carboxylic acid that functions as a strong chelating agent. In neutral or basic solution, it coordinates metal ions through its two amine nitrogens and four carboxylate groups, forming stable chelates with many divalent and trivalent metals, such as calcium, magnesium, iron, zinc, copper, and lead. It exists as the free acid and as various salts, most commonly the disodium EDTA and calcium disodium EDTA; these salts are highly water-soluble.

EDTA's chelating properties underlie its principal uses. In chemistry and biochemistry, it is employed to sequester trace metals, prevent metal-catalyzed oxidation, stabilize enzymes and nucleic acids, and in complexometric titrations to determine metal ion concentrations.

Medical use includes calcium disodium EDTA for the treatment of lead poisoning and other heavy-metal overdoses, typically given by injection under medical supervision. EDTA chelation therapy, sometimes marketed for cardiovascular disease, is controversial and not supported by conclusive evidence in mainstream medicine.

Other applications include its use as a food additive (sequestering agent; known as E385), cosmetics and personal care products as a chelating stabilizer, and in agriculture and horticulture to supply micronutrients (for example, Fe-EDTA) to plants in soils where nutrients are poorly available. It is also used in laboratory settings to preserve samples and in various industrial processes.

Safety and environmental notes: EDTA is of relatively low acute toxicity, but excessive chelation can disrupt essential metal balances and may cause kidney damage if improperly administered. It forms stable complexes that can increase excretion of metals; proper dosing and medical supervision are essential in therapeutic uses.