An Analytical Method of Pb-210 in Soil

Abstract

As an analytical method of Pb-210 in environmental sample, the radioactivity of Bi-210 built up from Pb-210 after the electrode position of Pb on platinum plate from nitric acid solution was measured by using an aluminum absorber (8 mg/cm²), and the radioactivity of Pb-210 in the sample was determined by calculation from the counting rate of Bi-210 activity, the counting efficiency of Bi-210 activity, and the chemical recovery of Pb carrier.
The separation of Pb-210 together with stable Pb carrier from the sample was based on the extraction of its iodide complex ion with methyl isobutyl ketone after the treatment of sample with HF and HClO₄ and on the reextraction of Pb in mehtyl iso-butyl ketone with 2N HNO₃.
By the above mentioned procedure, the recovery of Pb from nitric acid solution by electrode position was quantitative and the chemical recovery of Pb from soil was 82%. However, as the chemical form of Pb carrier deposited on the platinum plate was weighable PbO₂, the radioactivity of Pb-210 in the soil sample could be determined by correcting the found counting rate with the ratio of the weight of Pb carrier added to that of Pb carrier found.