Radium determination in mineral waters

We have determined the Radium concentration in several samples of natural mineral waters. Using a small volume of sample (≈ 100 ml), Ra isotopes are preconcentrated by adsorption onto a MnO2-impregnated cotton-filter, leached from the column with a hydroxylamine-HCl mixture and coprecipitated with BaSO4. 226Ra concentration has been determined using a low-background proportional counter and also from α-spectrometry. The results obtained show that the Radium concentration is around LLD for mineral surface waters, whereas thermal waters have activities exceeding the EPA limit for Ra in water.