DETERMINATION OF TRACE AMOUNT OF URANIUM IN ORES BY SPECTROPHOTOMETRY WITH ARSENAZO-p-CH_3CO

Uranium is extracted from the ore, converted into uranyl chloride and purifiedfrom most of the cationic impurities by means of anionexchange resin in 4 N HCl.U (VI) is reduced to U (IV) by Fe (??)-DTPA-ascorbic acid and complexed witharsenazo-p-CH_3CO as the color-forming reagent. The complex shows an absorptionpeak at 700 nm with a molar absorption coefficient of 8.8×10~4, and Beer's lawis obeyed at 0-2 gU/ml. The interference of 37 ions is studied.