A simple method for the preparation of immobilized β-diketone chelates on silica gel, controlled pore glass as well as chemically modfied β -diketone filter papers is described. This support material shows complexing affinity only for Cu(II), UO2(II) and Fe(III) and no significant affinity is observed for Ni(II), Co(II), Zn(II), Mg(II), Ca(II), La(III), Th(IV), etc. Effect of pH, time and complexing agents on the extraction of UO2(II) is investigated. Exchange capacities, desorption studies as well separation of UO2(II) from Cu(II), La(III), and Th(IV) were conducted. The distribution coefficients determined in presence of 0.5 M NaCl for UO2(II) is of the order of > 104 as compared with > 102 for Cu(II) and Fe(III), indicating its potential application as a preconcentration aid for UO2(II) ion from sea water and natural waters. © 1979 Springer-Verlag.