Simultaneous determination of 210Po and 210Pb in solid samples: A new method for 210Pb determination

A new method has been developed for determination of 210Pb and a simultaneous determination of 210Po and 210Pb was performed in solid samples. 210Po and 210Pb were sequentially leached at 250 °C with HNO3+HF, HClO4 and HCl. Twenty percent of the leaching solution was used for 210Po determination by α-spectrometry after 210Po spontaneous deposition on a silver disc from a weak HCl solution that containing hydroxylamine hydrochloride, sodium citrate and 209Po tracer. The remains of the leaching solution were used for determination of 210Pb, conducted by precipitation as PbCrO4 at about pH < 4, purification with an anion-exchange resin column, source preparation as PbSO4, and measurement with a β-counter. The procedure has been checked with the IAEA-327, a certified reference material, showing good agreement with the recommended values. The lower limits of detection for 3 g soil sample were found to be 0.17 Bq kg−1 for 210Po and 0.92 Bq kg−1 for 210Pb. A variety species of soil and sediment samples have been analysed using the procedure, showing average yields of 95.2 ± 2.6% for 210Po and 91.0 ± 8.3% for 210Pb.