420. The colloidal phosphate of milk: I. Composition and titrimetric estimation

Abstract

1. A new type of oxalate titration permitting determination of the nature of the colloidal phosphate of milk has been developed. 2. About 88% of the colloidal phosphate appears to be tricalcic, the remainder is thought to be dicalcic. 3. Estimates of tricalcium phosphate by the Ling titration are distinctly higher than the foregoing. This would seem to be due mainly to the divergent pH values to which milk and whey are titrated in this method. There is no evidence of any conversion of colloidal dicalcium to tricalcium phosphate during the Ling titration, as had been suggested.