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January 1959

Chelation of Stapes Footplate

Author Affiliations

From the Department of Otolaryngology, Jefferson Medical College.

AMA Arch Otolaryngol. 1959;69(1):1-6. doi:10.1001/archotol.1959.00730030005001

A chelating agent is a chemical compound capable of forming a very stable complex with a multivalent positive ion, such as calcium. In this process of chelation a specific type of coordinate bonding occurs in some of the atoms forming the ring, and the calcium becomes such an integral part of the complex that it loses its ionic properties. It cannot be precipitated by generally used precipitating agents.1

Edathamil (ethylenediaminetetraacetic acid [EDTA]) and its salts have been the most investigated and commonly used chelating agents. Figure 1A shows the acid to be tetrabasic with four replaceable hydrogen atoms, so that it is theoretically possible to form four different sodium salts, all of which are chelating agents. Figure 1B shows the disodium salt of edathamil and 1C shows the calcium-disodium salt, which is the end-product of the chelation of the calcium ion. In this study, the disodium salt of edathamil