A rapid sequential chromatographic separation of U- and Th-decay series radionuclides in water samples.

A new sequential protocol for the separation and preconcentration of U, Th, Ra, Po and Pb for the same sample aliquot has been designed. The optimized stacking of chromatographic resins [TRU, Sr and a new hybrid Ra resin (composed of Analig Ra-01 and cation exchange AG50Wx8)] enables a rapid loading of the sample (less than 75 min for 300 mL of samples) while ensuring a high retention of the analytes of interest. The use of a hybrid Ra resin allows the complete and selective extraction of Ra on a solid support, a feature lacking in other sequential separation procedures.