Determination Of The Ca/P Molar Ratio
in Calcium Hydroxyapatite
by XRFHydroxyapatite (HA), Ca10(PO4)6(OH)2 is an important biomaterial, as it is able to bond chemically to bone. In clinical applications of dental reconstruction and hip replacement, hydroxyapatite has found wide and accepted use as a source material for plasma sprayed, bonelike coatings deposited onto metallic substrates.
With the advent of mass production of hydroxyapatite-coated devices, reliable measures have to be implemented to assure their chemical integrity. One important and strongly regulated quality indicator of HA is its Ca/P molar ratio. A successful and precise method for the determination of the molar Ca/P ratio in hydroxyapatite is X-ray spectroscopy (XRF). This method, especially in combination with the determination of the crystalline/amorphous ratio of HA by X-ray diffraction method (XRD), provides a suitable procedure for the reliable quality control of hydroxyapatite.
Analysis Services Provided by CAMET Research, Inc.
CAMET Research, Inc. is an independent materials characterization laboratory, which has been providing X-ray analysis services since 1984. We have dedicated a computer controlled, wavelength dispersive X-ray fluorescence spectrometer to hydroxyapatite studies. The evacuated spectrometer, which is completely enclosed in a temperature stabilized unit, is operated with a chromium X-ray source, an RAP analyzing crystal and a flow proportional counter, providing best performance and precision for lighter elements like calcium and phosphorous. The unit is calibrated and monitored with NIST Standard Reference Material #2910, which has a certified calcium to phosphorus molar ratio of 1.664 ±0.005.
CAMET Research, Inc. - 6409 Camino Vista #F, Goleta, California 93117 - Tel. (805) 685-1665 - Fax (805) 685-9082 - E-mail: camet@camet-lab.com