²¹⁰Pb in sediments by alpha spectrometry via ²¹⁰Po

The concentration of ²¹⁰Pb is determined by alpha spectrometry through its granddaughter ²¹⁰Po, assuming radioactive equilibrium between the two radionuclides. An acid digestion of the sediment is carried out by using HNO₃ and HF, followed by another digestion using H₃BO₃ in order to eliminate salts formed during the first digestion.

After digestion, the resulting solution is transferred to a Teflon beaker and is evaporated to incipient dryness. Small amounts of concentrated HCl are added to dissolve the sample residuals and to ensure the elimination of HNO₃. Afterwards, samples are diluted to 50-100 ml 1M HCl and approximately 50-100 mg of ascorbic acid is added to reduce the iron Fe(III) to Fe(II) while heating at 80 ℃.

Finally, polonium isotopes are auto-plated onto silver disks at 80 ℃ while stirring for 8 hours. After polonium deposition, Po isotopes emissions are measured by alpha spectrometry using Passivated Implanted Planar Silicon, PIPS detectors