E.D.T.A.

EDTA is also known as H4EDTA, diamino ethanetetra acetic acid, edetic acid, edetate, ethylenedinitrilotetraacetic acid, celon A, gluma cleanser, versene acid, nervanaid B acid, nullapon B acid, ethylene diamine tetracetic acid, tetrine acid, trilon BS, vinkeil 100, warkeelate acid, N,N'-1,2-ethanediylbis(N-(carboxymethyl)glycine)edetic acid, YD-30.

In coordination chemistry, H4EDTA is a member of the aminocarboxylate family of ligands that includes imidodiacetic acid ("H₂IDA") and nitrilotriacetic acid ("H₃NTA"). More specialized relatives include N,N'-ethylenediaminediacetic acid ("H2EDDA") and 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid ("H₄CyDTA"). These ligands are all formally derived from the amino acid glycine.

H4EDTA forms highly stable coordination compounds that are soluble in water. In these complexes, the ligand is usually either hexa- or pentadentate, EDTA^4- or HEDTA^3-, respectively. Such complexes are chiral, and [Co(EDTA)]- has been resolved into enantiomers._[4]

Iron is an essential nutrient for plant growth. However, if you put a simple iron compound such as iron nitrate in your solution, it will form a precipitate with other chemicals in the solution such as phosphate. To avoid this, you must use chelated iron. A chelating agent is a molecule that grabs onto an ion such as iron and holds it tightly so that it cannot precipitate. However, plants still have ways of extracting the iron they need from these compounds. EDTA iron is one type of chelated iron that you can use in a nutrient solution.