EXTRACTION AND SPECTROPHOTOMETRIC DETERMINATION OF URANIUM(VI) WITH N-PHENYLCINNAMOHYDROXAMIC ACID

Uranium(VI) reacts with N-phenylcinnamohydroxamic acid to form an oran ge-yellow complex in the pH range 5.5-8.5. The orange-yellow complex, having the composition of 1 : 2 (metal : ligand), is quantitatively ex tractable into ethyl acetate. The spectrum of the complex exhibits a m aximum absorption at 400 nm with a molar absorptivity of 6500 M-1.cm(- 1). The coloured system obeys Beer's law in the concentration range 2- 40 mu g.ml(-1) of uranium(VI). The photometric sensitivity of the colo ur reaction is 0.037 mu g.cm(-2) of uranium(VI). Most of the common io ns do not interfere and the method has been found to be simple, precis e, and free from the rigid control of experimental conditions. The met hod has been applied to the determination of uranium in synthetic matr ices and potable water.