title: Equilibrium constant for calcium ion and ascorbate ion.
abstract: The combination of calcium and ascorbic acid in water at 25 degrees C has been examined by measuring the change of free calcium ion concentration as ascorbate was added in small increment to a solution of calcium. The data show clearly that complex formation between calcium ion and ascorbate ion occurred. At ionic strength mu = 0.1-0.2, the equilibrium constant of Ca++ and the singly-charged ascorbate ion has been measured to be 2.1 M-1. The precision of the result is better than 5% and the accuracy is estimated to be better than 20%. The application of the equilibrium constants is discussed.
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis*; D002118:Calcium / Q000032:analysis*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008433:Mathematics; D009994:Osmolar Concentration
chemical_list: D001205:Ascorbic Acid; D002118:Calcium