EDTA is the commonly used abbreviation for (Ethylene­dinitrilo)­ tetra­acetic Acid (also called Ethylene­diamine­tetra­acetic Acid or Edetic Acid).

Application

The Disodium salt of EDTA is the most commonly used form of this versatile organic complexing agent, which is used for the determination of many metal ions either by direct titration or by back-titration. Adjustment of reaction conditions, either by controlling the pH or by use of masking agents, and selection of the appropriate indicator permits a wide variety of metal ions to be determined using EDTA.

Technical Specification

EDTA is most commonly used to determine hardness (i.e., Calcium and Magnesium ions) in water, where the pH must be approximately 10 and is usually controlled by adding a buffer such as Water Hardness Buffer. Water Hardness Indicator (Eriochrome Black T), Eriochrome Blue Black R, Calmagite, and Murexide are used for hardness or Calcium determinations using EDTA.