HIGH-ORDER DERIVATIVE SPECTROPHOTOMETRIC DETERMINATION OF URANIUM IN A CATIONIC MICELLAR MEDIUM

A derivative spectrophotometric method is developed for the determinat ion of U-VI with 1,4-dihydroxy-9,10-anthracenedione in the presence of cetylpyridinium chloride. The 1:1 complex at pH 5.6 shows maximum abs orbance at 600 nm; Beer's law is obeyed in the range 4.76 X 10-(1)-19. 04 mu g ml(-1). The molar absorption coefficient and Sandell's sensiti vity of the complex are 1.19 x 10(4) l mol(-1) cm(-1) and 2.00 x 10(-2 ) mu g cm(-2), respectively. The proposed method is applied to the det ermination of U-VI in mixtures containing various amounts of Th-IV and Be-II without preseparation using second-order derivative absorption plots. A rapid procedure for the simultaneous determination of UO2II a nd Ben in binary mixtures is also reported.