Measurement of low-level radioactivity in bone ash

Bone is a critical organ for the accumulation of many radionuclides including 90Sr and the actinides. The National Institute of Standards and Technology (0NIST) has prepared bone ash samples with a view to producing a standard reference material. The Institute for Reference Materials and Measurements (IRMM) participated in the analysis for the certification of the radionuclide concentrations in the bone ash. This article describes the assaying of the actinides, 90Sr, 210Pb and 226Ra activity concentrations. A radiochemical procedure based on extraction chromatography has been developed to separate these radionuclides from the bone ash. The activity concentrations of the actinides, 210Pb and 226Ra have been measured using gamma-ray spectrometry and alpha-particle spectrometry and that of 90Sr using low-level liquid scintillation counting.