Preconcentration of Heavy Metals from Aqueous Solution Using Chitosan Flake

Chitosan flake was used as solid-phase material to separate and preconcentrate Cu(II), Cd(II) and Pb(II) in an aqueous solution by the solid-phase extraction technique. The effect of pH, salt, flow rate and volume of eluent was investigated. The metals were retained by chitosan at pH 5-7 and were easily eluted by 5 ml of 0.1 M EDTA (pH 6) with a flow rate of 0.5 ml min-1. The metal concentrations were determined by flame atomic absorption spectrometry. The proposed method was applied to the determination of trace amounts of metals in aqueous solution (20 µg l-1). The % recovery and % RSD were within the range of 83-112 % and 2-15 % respectively. The method detection limit was 20, 3 and 10 µg l-1 for Pb, Cu and Cd respectively