Abstract
Sodium hexametaphosphate has recently become established as an effective agent in reducing calcium ion concentration. Most of the research work on the compound has been done in the field of industrial chemistry where it has demonstrated its use as an outstanding water softener.
In this report we are concerned with the mechanism by which this compound reduces calcium ion concentration. The consensus seems to favor the formula (NaPO3)6 or Na6P6C16. This compound can react with calcium ion to form Na2Ca2P6O18 thus leaving the calcium in the form of a complex since the compound ionizes into 2 sodium ions and the negatively charged Ca2P6O18 ion. The dissociation of this complex ion to yield calcium ion is so slight that the addition of sodium hexametaphosphate depresses the calcium ion to such an extent that it will dissolve the most insoluble calcium salts such as the carbonate, the oxalate, and the phosphate. At present it is impossible to express mathematically the equilibrium constant for the dissociation of the complex ion but indications are that its effective value approaches 10-15.
Comparatively little work has been done on the biochemical and physiological properties of the compound. This paper represents the first report of results of work in progress in our laboratories on the application of properties of sodium hexametaphosphate to the fields of biology and medicine.
The effect of this compound on the clotting of blood was tested by the following method. A stock solution of 20% sodium hexametaphosphate was made up. Varying quantities were added to calibrated tubes so that the final concentrations after blood was added ranged from 0.1 g per 100 cc to 2.0 g per 100 cc. Blood was allowed to flow directly from the sheep being used into the tubes. Each tube was rocked carefully to insure complete mixing.
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