THE STABILITY AND ABSORPTION SPECTRA OF URANIUM (Ⅲ) IN HYDROCHLORIC ACID SOLUTION

Uranium(Ⅲ) solution is obtained electrolytically by reducing uranyl ion on mercury cathode. The effect of the addition of various aminopolycarboxylic acids (such as EDTA, DTPA, CyDTA and TTHA) and organic water-miscible solvents (such as CH3OH, C2H5OH and CH3COCH3) on the stability of ura-nium(Ⅲ) in air has been investigated.The absorption spectra of uranium(Ⅲ)and uranium(Ⅳ)in 1 mol/l and 9mol/l hydrochloric acid solutions are examined. The molar extinction coefficient of uranium(Ⅲ) is 167 1-mol-1·cm-1 in the HC1 concentration range 0. 5-4. 5mol/l and uranium (Ⅳ) practically does not interfere in the photometric determination of uranium(Ⅲ) at the wavelength of 521nm.