The stability and absorption spectra of uranium (III) in hydrochloric acid solution

Uranium(III) solution is obtained eletrolytically by reducing uranyl ion on mercury cathode. The effect of the addition of various aminopolycarboxylic acids (such as EDTA, DTPA, DyDTA and TTHA) and organic water-miscible solvents (such as CH3OH, C2H5OH and CH3COCH) on the stability of uranium(III) in air has been investigated. The absorption spectra of uranium(III) and uranium(IV) in 1 mol/l and 9 mol/l hydrochloric acid solutions are examined. The molar extinction coefficient of uranium(III) is 167 · mol-1 · cm-1 in the HCl concentration range 0.5-4.5 mol/l and uranium (IV) practically does not interfere in the photometric determination of uranium(III) at the wavelength of 521 nm