ビスマスのジチゾン抽出による鉛-210の定量法

概要

論文の詳細を見る
The cause of abnormality in the dithizone extraction of trace of bismuth from an acidic solution was clarified. A minimum extractability appeared at pH 4 in the presence of citric acid and at pH 6 in the presence of halogen ions. The tendency was increased in the chloroform solution than in the carbontetrachloride solution. Although the pH 2.53.5 had been hitherto considered as the optimum condition for the extraction of bismuth, the authors recommended the extraction from the solution adjusted to pH 1.5 by nitric acid and ammonia in the presence of acetate ion, whereby trace bismuth could be separated completely even from 1 g of lead. Phosphate and sulfate also disturbed the extraction. An optimum condition was determined for the extraction with 10 ml of dithizone (1 × 10-3M)carbontetrachloride from 50 ml of aqueous solution of pH 1.5. 210Pb in a uranium are from Ningyo-Toge mine was preliminarily separated by the precipitation as lead sulfate using a large amount of lead carrier, the daughter 210Bi was extracted by the proposed method, and the β-activity was measured for the determination of 210Pb. The amount of 210Pb was only 75% of that expected from the radiation equilibrium.
社団法人日本分析化学会の論文