Date of this Version
Published in Transactions of the Nebraska Academy of Sciences, Volume 3 (1976).
A 3.4 mM ethylenediaminetetraacetic acid (EDT A) aqueous solution and 25 mM Na2EDTA, Na4EDTA and CaNa2EDTA aqueous solutions were fed laboratory white mice as drinking water for 28 day periods. EDT A in the blood plasma of animals used at the end of the 28 day period was undetectable using a colorimetric assay. Ca, Mg and Zn content of the bone, kidney, liver and muscle tissues were determined using atomic absorption spectrophotometry. Liver Ca and kidney Mg were reduced in animals administered CaNa2EDTA; kindey Ca and Mg were elevated in animals administered Na2EDTA; muscle Ca was elevated in animals EDTA; bone, liver and muscle Ca, along with kidney, liver and muscle Zn and bone and liver Mg were reduced in animals administered Na4EDTA; those animals administered Na4EDTA also evidenced an elevation of kidney Mg.
Ethyienediaminetetraacetic acid (EDTA) is commonly associated with a general group of chemicals called chelating agents, ligands or coordination compounds. These chelating agents can react with a metallic ion to form a stable complex. The stability of the complex formed is of course a function of the particular metallic ion chelated. The relative standard heats of formation are indicative of the stability constants of the various ligand-ion complexes. EDTA was first synthesized in 1948 by F.C. Bersworth and was first used the therapeutically in the treatment of acute Pb poisoning (Rubin, 1961). The fact that the heat of formation for the PbEDTA complex is very great offers an explanation as to why EDTA is so effective in this treatment. EDTA has since been used in the treatment of Ba, Ca, Co, Cr, Fe, Hg, Mn, Ni and T1 poisoning and also cases of ingestion of radioactive elements such as Th and U (Foreman, 1961).
EDTA is also used commercially as an additive in some foods and beverages. Because metallic ions such as Cu++ and Fe++ can catalyze reactions leading to deterioration in flavor, coloration, turbidity and vitamin content. EDTA is used as a sequestrant to trap these ions in a nonionic form. Foods which contain oils such as salad dressings are a common source of both CaNa2LDTA and Na2EDTA.