Determination of 226 Ra in solid samples of few milligrams after mineralisation and measurement by solid scintillation

A protocol is proposed for the measurement of 226 Ra on 150 mg of solid sample without radiochemistry. To evaluate the performance of this method, standard samples were used and the results were in good agreement with reference values. The detection limit obtained is about 130 Bq kg −1 (dry weight) without mineralised solution concentration by evaporation. A concentration of the solution by 4 and/or an increase of sample mass by 4 in the case of microwave digestion system, allows achieving a detection limit of 30 Bq kg −1 (dry weight) and thus measuring 226 Ra in most soils. This method could also be used for NORM sites on soil and sediment samples.