POLAROGRAPHIC DETERMINATION OF URANIUM IN BIOLOGICAL MATERIAL

An analytical method is described for the polarographic determination of microgram quantities of uranium in human urine and in rat kidneys. The biological material is destroyed by nitric acid. During the mineralization uranium is transformed into uranium (VI) regardless of the form in which it was initially present in the biological material. Uranium (VI) is then extracted by means of tetrahydropyran in an automatic micro liquid-liquid extractor. The addition of ferric nitrate allows a complete extraction of uranyl nitrate in the presence of foreign ions, originally present in biological material such as phosphates, sulphates and chlorides. The polarographic determination is made in the supporting electrolyte containing 1 M orthophosphoric acid and 5 × 10-4% Triton X-100 as a maximum suppressor. For this purpose d.c. and a.c. as well as pulse polarographic techniques have been applied. The determination limits are 5 μg, 2 μg and 0.5 μg U/100 ml urine, respectively. © 1969.