Improved method for radium extraction from environmental samples and its analysis by thermal ionization mass spectrometry

Abstract

We have developed an efficient procedure for the chemical separation of 226Ra from environmental samples and its measurement by thermal ionization mass spectrometry. The original step in this procedure consists in a pre-concentration by co-precipitation of radium onto manganese dioxide. This pre-concentration step permits an efficient separation of radium from major elements including, most importantly, calcium. Thus, the present protocol provides a very useful technique for the precise and accurate analysis of radium-226 in carbonate samples. Furthermore, this procedure is also well-suited for seawater samples, since it does not require a preliminary evaporation stage, thereby eliminating problems due to the precipitation of large quantities of salts and permits the analysis of femtogram levels of 226Ra.