Authors: S C Batra J M de Man
Publish Date: 1965/03/01
Volume: 5, Issue: 3-4, Pages: 183-186
Abstract
The calcium ion complexing ability of orthophosphates polyphosphates and citrate was determined by measuring free calcium ions in mixtures of these salts and calcium chloride Primary and secondary orthophosphates showed no calcium complexing ability sodium citrate sodium hexametaphosphate sodium tripolyphosphate and sodium tetra phosphate were effective calcium complexing agents and the pK values in the presence of sodium chloride and of tetraethylammonium bromide were determined All pK values were higher in the absence of sodium ions indicating a competitive effect of the sodium ion The lack of calcium complexing ability of orthophosphate could also be demonstrated by a cryoscopic technique
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