Optimum chemical recovery and detection of radium in water samples

226Ra and 224Ra were determined in the water samples using chemical separation from the water by BaSO4 co-precipitation, followed by α-spectrometry. 133Ba isotope, a gamma emitting radionuclide, is used as spike for the determination of chemical recovery of radium. The chemical recovery is enhanced by increasing the amount of added barium carrier, however, increasing the amount of barium carrier leads to an increase of the Ba(Ra)SO4 co-precipitate and consequently to poor alpha spectrum characteristics. Therefore, it is important to use the optimum amount of barium carrier that would increase the chemical recovery of radium and decrease the sample source self-shielding effect in alpha spectrometry in order to avoid underestimation of radium isotopes, and to increase the detection sensitivity. In this work, the optimum amount of barium carrier was found. (author)