Nanometer TiO₂ supported on silica gel (supported nanometer TiO₂) was prepared by Sol-Gel method. The product was characterized using XRD and SEM. The adsorption behavior of supported nanometer TiO₂ towards Cd^2＋, Cr^3＋, Cu^2＋and Mn^2＋ was investigated by ICP-AES. It was found that the adsorption percentages of the metal ions studied were more than 90% in pH 8.0～9.0, and 0.5 mol/L HNO₃ was sufficient for complete elution. The adsorption capacity of supported nanometer TiO₂ for Cd^2＋, Cr^3＋, Cu^2＋and Mn^2＋ was found to be 8.3, 13.1, 12.6 and 5.1 mg/g, respectively. A method using supported nanometer TiO₂ as adsorbent coupled with ICP-AES has been developed for the separation/preconcentration and determination of Cd^2＋, Cr^3＋, Cu^2＋and Mn^2＋in environmental sample.

Key words: sol-gel method, supported nanometer TiO₂, adsorption, heavy metal ion, ICP-AES