Preconcentration of Uranium(VI) on Modified and Unmodified Amberlite XAD 4 Sorbent

Abstract
The sorption of uranyl ions on columns with the macrophorus hydrophobic sorbent Amberlite XAD 4 modified with 1-(2-pyridylazo)-2-naphthol and sodium diethyldithiocarbamate was examined. Following elution of the uranyl ion with HNO3 (2 - 4 mol l-1) or of the diethyldithiocarbamate UO22+-chelate with a methanolic solution of HCl (0.1 mol l-1), uranium was determined spectrophotometrically with 4-(2-pyridylazo)resorcinol or with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol. The preconcentration of uranium on Amberlite XAD 4 type sorbents is convenient for its spectrophotometric determination in waters.