[Determination of Ca/P atomic ratio in calcium-hydroxyapatite by neutron activation analysis]

The Ca/P atomic ratios of synthesized calcium-hydroxyapatite (Ca10(PO4)6(OH2) were determined by neutron activation analysis. In order to obtain calibration curves, the standard samples, such as calcium monohydrogenphosphate, calcium dihydrogenphosphate, etc., were prepared. gamma and beta ray spectra, and beta ray intensities of calcium-hydroxyapatite and standard samples irradiated with reactor neutrons were measured by using a Ge(Li) detector, a low background beta ray spectrometer and GM detector. Based on these results, deviation coefficient of the calibration curve, accuracy of the Ca/P atomic ratio, minimum determination limit, etc. were compared in detail. From the present analysis, the Ca/P atomic ratio of calcium-hydroxyapatite was able to obtain with the standard deviation of about 2% for 1 mg sample.