Polonium concentration distribution in bed load sediment samples along the Romanian sector of the Danube river and the Black Sea coast

Abstract

The concentrations of²¹⁰Po have been determined in 12 sediment samples collected from the bed of the Romanian Danube river and the Black Sea coast during June–September 1994. After the sample preparation and the addition of the²⁰⁸Po tracer, polonium was coprecipitated with manganese dioxide, the precipitate was dissolved in hydrochloric acid and the polonium isotopes deposited on silver planchettes were counted by α-spectrometry. The resolution of the subsequent α-spectra was typically 40 to 60 keV full-width-half-maximum with 450 mm² silicon surface-barrier detectors at 30% counting efficiency. The procedure is quite fast, giving chemical yields between 60 and 80%. The²¹⁰Po concentrations range between 5 and 73 Bq kg⁻¹ dry, showing for the first time the polonium contamination distribution along the Romanian sector of the Danube river and the Black Sea coast.