Raman Spectra of Phosphate and Monofluorophosphate Ions in Several Dentally-Relevant Materials

Raman spectra of octacalcium phosphate, sodium monofluorophosphate and aqueous monofluorophosphate solutions were obtained, some at temperatures as low as 40°K. The internal modes of phosphate and monofluorophosphate (PO3F2––) moieties in these materials were compared with each other and with previously reported spectra of carbonated apatites and dental enamel. Octacalcium phosphate could be identified from apatite by differences in the phosphate bands of their Raman spectra. Monofluorophosphate ions, either located in a crystal structure or in aqueous solution, could be easily distinguished from phosphate ions using Raman spectroscopy.