Patent ID: 8378126

Claim:
A method of making the compound of formula (1): (ascorbate) 2 Sr:(M +a ) x (ascorbate) y wherein ascorbate refers to the ascorbate anion: wherein y is a positive integer, wherein x is a positive integer, wherein a is a positive integer reflecting the valence of M; wherein (y)=((x) multiplied by (+a)) such that a total positive charge ((x) multiplied by (+a)) equals a total negative charge (y) provided that the ascorbate anion has a negative valence of (−1); and wherein M is an alkali metal, an alkali earth metal or Mn, Cu, Zn, Fe or a combination thereof, the method comprising: (a) dissolving at least a stoichiometric amount of ascorbic acid in water at a first solution temperature sufficient to dissolve the ascorbic acid in a solution; (b) adding at least a stoichiometric amount of strontium carbonate (SrCO 3 ) to the solution of ascorbic acid; (c) adding at least a stoichiometric amount of M carbonate (M +a ) x1 (CO 3 ) y1 to the solution having a second solution temperature, where (+a) ×(x1) =(−2) ×(y1), where x1 is an integer and y1 is an integer; (d) adjusting the second solution temperature within a range from about 40° C. to about 80° C. for a time sufficient to form the compound of formula (1); and (e) optionally, drying the slurry at a drying temperature and for a drying time sufficient to yield at least the compound of formula (1) in solid or semi-solid form, wherein the strontium carbonate (SrCO 3 ) is provided in powder or granular form; and wherein the ratio of the moles of Sr to the moles of M is selected from 1.0, 1.1, 1.2, 1.25, 1.3, 1.4, 1.5, 1.6, 1.7, 1.75, 1.8, 1.9, 2, 2.25, 2.5, 2.75, 3, and 4.