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

A new method has been developed for determination of 210 Pb and a simultaneous determination of 210 Po and 210 Pb was performed in solid samples. 210 Po and 210 Pb were sequentially leached at 250 °C with HNO3 +HF, HClO4 and HCl. Twenty percent of the leaching solution was used for 210 Po determination by α-spectrometry after 210 Po spontaneous deposition on a silver disc from a weak HCl solution that containing hydroxylamine hydrochloride, sodium citrate and 209 Po tracer. The remains of the leaching solution were used for determination of 210 Pb, 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 210 Po and 0.92 Bq kg-1 for 210 Pb. A variety species of soil and sediment samples have been analysed using the procedure, showing average yields of 95.2 ± 2.6% for 210 Po and 91.0 ± 8.3% for 210 Pb.