SOLID-STATE P-31 NMR-STUDIES OF SYNTHETIC INORGANIC CALCIUM PHOSPHATES

Solid-state phosphorus-31 NMR has been used to examine a number of synthetic calcium phosphate samples. A particular multicomponent sample proved to be of interest as its spectrum showed changes with time. One of the components was identified to be monetite. The ability to distinguish between protonated and non-protonated phosphate units proved to be particularly valuable in the interpretation of spectra for this type of sample. Linewidths are seen to be chracteristic of the degree of crystallinity within a sample of amorphous calcium phosphate (ACP). The maturation of ACP together with the effects of introduced carbonate on the crystallinity of ACP have been monitored using NMR.