EDTA

The acronym EDTA refers to the compound ethylene diamine tetraacetic acid. This compound, or its disodium salt, is a well known chelating agent, forming coordination compounds with many divalent metal ions, but especially calcium(Ca²⁺) and magnesium(Mg²⁺). As a result, this compound is used extensively in the laboratory, to scavenge metal ions, in metal ion titrations, and as a component of buffer solutions. It is used in water quality work, to determine water hardness and as a water softener. It has use in medicine, as an anticoagulant, and in industry, as a food preservative. There is a therapy, perhaps controversial, that has evolved around metal scavengers of this kind, called chelation therapy[?].