Alizarine red S (ARS) is one of the most sensitive reagents used for the spectrophotometric determination of Zr/Hf (IV). Duolite 101 A as anion exchanger or green algae (Mougeatia. species) were used for loading ARS as modified chelating agent. Selective enrichment of both Zr and Hf using the modified substrate under batch and column conditions were studied and discussed at different pH values as well as salinity (ionic strength), sorption kinetics, resin capacity, type of eluent, fluoride effect, breakthrough curves, and durability. Both the modified substrate sorbs Zr and/or Hf over a wide range of pH (2.5-8). The maximum sorption capacity for Zr/Hf were 0.26/0.27 mmol g(-1) on modified algae and 0.55/0.57 mmol g(-1) on Duolite resin at pH 3.5, respectively. The lowest detection limits of preconcentration approximate to 0.2 mu gL(-1) with a preconcentration factor for Zr or Hf were 200 fold. Iron (111), Cu(II), Th(IV), UO2(II), and Ce(IV) are also sorbed with different extents, but Ba(II), Sr(II), Ca(II), Mg(II), Mn(II), Ni(II), AI(III), and Cr(III) are not sorbed at pH 3.5. Tolerance limits of NaF, NaCl, Na2SO4, Na2HPO4, and NaNO3 on the sorption are reported. The use of fluoride ion and EDTA as masking agent and a citric-HCl mixtures as an eluent can overcome the metals interferences, leading to 99-100% recovery and selective enrichment of Zr or Hf. The relative standard deviation (RSD) of the separation and preconcentration of Zr and/or Hf on the two supports are in the range approximate to 1.7-2.4, respectively. Zirconium and Hafnium have been separated and preconcentrated from synthetic samples containing UO2(II), Th(IV), and Ce(IV) ions and certified ores.