Simultaneous determination of 226Ra, 228Ra and 210Pb in drinking water using 3M Empore™ RAD disk by LSC-PLS

- Rapid determination of 226Ra, 228Ra and 210Pb has been described.
- Selective elution of 210Pb from the RAD disk has been achieved.
- PLS models were used to determine 226Ra, 228Ra and 210Pb.
- The procedure was validated with quality control materials.
- Five natural water sources were analysed using the validated procedure.

A procedure for the rapid and simultaneous determination of 226Ra, 228Ra and 210Pb in drinking water by means of extraction with a 3M Empore™ Radium RAD disk and liquid scintillation spectrometry is described. The selective elution of 210Pb from the RAD disk and a multivariate calibration using partial least squares regression (PLS) are tested as methods to avoid overlap in the spectra between 228Ra and 210Pb. The validated procedure was tested with mixtures of radionuclides and interlaboratory materials; finally, it was applied to natural waters.