Ethylenediaminetetraacetic acid complex with calcium

The determination of calcium in meat products, especially in mechanically recovered (or separated) meat (MRM/MSM), is an important estimation of the amount of bone material included in the meat. The AOAC method describes an acid digestion of the sample and reaction of an aliquot of the filtered digest with excess ethylenediaminetetraacetic acid (EDTA) under alkaline conditions to form a chelated complex with calcium ion. The excess EDTA is then titrated with calcium carbonate using hydroxynaph-thol blue as indicator. 

Thennodynamic inhibitors are complexing and chelating agents, suitable for specific scales. For example, for scale inhibition of barium sulfate, common chemicals are ethylenediaminetetraacetic acid (EDTA) andnitrilotriacetic acid. The solubility of calcium carbonate can be influenced by varying the pH or the partial pressure of carbon dioxide (CO2). The solubility increases with decreasing pH and increasing partial pressure of CO2, and it decreases with temperature. 

With carboxylic acids Ca forms so-called calcium soaps, which abolish the cleaning effect of the soaps. With synthetic ligands like ethylenediaminetetraacetic acid (EDTA) or nitrilotriacetic acid (NTA), Ca forms very stable complexes these are used to sequester Ca in order to enhance the effect of soap. The same applies also to other detergents. 

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