Measurement of radium-226 by alpha spectrometry

The radium-226 α-spectrometric analytical method, developed by the Subatech laboratory (Nantes), offers an alternative to the already existing techniques. It is based on the faculty of hydrated manganese oxides to adsorb selectively radium. The technique is dependent on two main steps: (1) the preparation of thin layer of MnO2 and (2) the adsorption of 226Ra on these oxide films. The adsorption parameters as well as the analytical characteristics of the method have been studied. Moreover, the radium-226 contents of some mineral waters have been determined. This technique allows an easy and fast α-spectrometric measurement of radium 226 in solution at low activity levels. (authors)