Preparation of 1-(2-pyridylazo)-2-naphthol functionalized benzophenone/naphthalene and their uses in solid phase extractive preconcentration/separation of uranium(VI)

Summary

The preparation of solid reagent 1-(2-pyridylazo)-2-naphthol functionalized benzophenone/naphthalene for preconcentration/separation of uranium (VI) is described. These reagents enriches uranium(VI) quantitatively from dilute aqueous solutions in the pH range 10.5-11.0. The solid mixture consisting of the enriched metal ion along with solid phase extractant were dissolved in 2ml of acetone and uranium(VI) content was established spectrophotometrically by using Arsenazo III procedure. Calibration graphs were rectilinear over the uranium(VI) concentration in the range 0.002-0.1μg cm^-3. Five replicate determinations of 40μg of uranium present in 1dm³ of sample solution gave a mean absorbance of 0.185 with a relative standard deviation of 1.4. The detection limit (corresponding to 3 times the standard deviation of the blank) and the enrichment factor were found to be 2μg dm^-3 and 500 respectively. Further the possible separation of uranium(VI) from several bivalent, trivalent and tetravalent elements was also established. In addition to validating the developed method by successfully analysing marine sediment reference material (MESS-3), uranium content was established in soil, river and marine sediment samples by the developed method and compared with standard inductively coupled plasma mass spectrometry (ICP-MS) values.