Abstract: The Ginkgo Biloba Linn sample was digested by HNO3-H2O2, and using nanoparticle TiO2 as adsorbent, Cd(Ⅱ) could be determined by single-sweep polarography in supporting electrolytes of KI-NaKC4H4O6-VC-HCl-N(C4H9)4I . The TiO2 needed not to be separated when determining. The results showed that the rate of cadmium adsorption was over 90% at pH=7～ 8. When the eluted conditions were: HCl 0.05mol/L, heated by water-bath at 50℃ and 5-minnute-long radiation of ultrasonic wave, the eluted rate was over 95%. The linear range of this method was 0.008～1.2μg/ml and the detection limit 0.002μg/ml, the RSD 4.8% and 2.5% respectively. Afte assaying eight times (n=8)at 0.1μg/ml and 0.8μg/ml level for Cd(Ⅱ), the recovery was in the range of 95%～105%.

Key words: nano-TiO2, preconcentration, single-seep polarography, Ginkgo Biloba Linn, cadmium