High-order derivative spectrophotometric determination of uranium in a cationic micellar medium

A derivative spectrophotometric method is developed for the determination of UVI with 1,4-dihydroxy-9,10-anthracenedione in the presence of cetylpyridinium chloride. The 1 : 1 complex at pH 5.6 shows maximum absorbance at 600 nm; Beer's law is obeyed in the range 4.76 × 10–1–19.04 µg ml–1. The molar absorption coefficient and Sandell's sensitivity of the complex are 1.19 × 104 l mol–1 cm–1 and 2.00 × 10–2µg cm–2, respectively. The proposed method is applied to the determination of UVI in mixtures containing various amounts of ThIV and BeII without pre-separation using second-order derivative absorption plots. A rapid procedure for the simultaneous determination of UO2II and BeII in binary mixtures is also reported.