column preconcentration of uranium by 1 -(2-py ridylaz0)-2-naphthol supported on naphthalene using dif'ferentlal pulse polarography

a solid chelating material, 1-(2-pyridy1azo)-2-naphthol (pan) supported on naphthalene provides a rapid and highly selective means of preconcentration of uranium from aqueous solution. uranium is quantitatively retained on this adsorbent in the ph range 9.8-10.7 with a flow rate of 1 ml min . the metal complex was desorbed with 10 ml of 2 m hydrochloric acid and uranium is determined by differential pulse polarography (dpp). the detection limit is 1.5 µg ml (signal to noise ratio = 2). the linearity is maintained in the concentration range 3.0 - 310 ) µ g ml with a correlation coefficient of 0.9994 (n=7) and relative standard deviation of 1.1 %(n=7). characterization of the electroactive process included an examination of the degree of reversibility. various parameters such as the effect of ph, volume of aqueous phase and interference of a number of metal ions on the determination of uranium have been studied in detail to optimize the conditions for determination of uranium.