DETERMINATION OF PHOSPHORUS BY INSTRUMENTAL NEUTRON-ACTIVATION AND BREMSSTRAHLUNG MEASUREMENT IN BONE SAMPLES

A non destructive method based on the P-31(n,gamma)P-32 reaction for t he assay of phosphorus in bone samples is described. This method invol ves a thermal neutron irradiatioa of 2 minutes in a reactor followed b y the measurement of the bremsstrahlung produced by the beta(-)emissio n of P-32 in a Ge-detector surrounded by an anti-Compton shield. Accur acy and precision were tested by analysing the certified NIST 1486 Bon e Meal reference material and tricalcium phosphate (Ca-3(PO4)(2)) samp les. The value obtained for the reference material was in good agreeme nt with the certified value and with relative standard deviation of 4. 1% the precision was acceptable. The value obtained for Ca-3(PO4)(2) s hows a deviation of -6% from the expected value, reflecting the effect of the sample density in bremsstrahlung measurement.