Determination of trace amounts of coper in environmental water samples by flame atomic absorption spectrometry after preconcentration on Tio/sub 2/ nanotubes

A method using TiO/sub 2/ nanotubes as adsorbent for the preconcentration of trace amounts of Cu/sup 2+/ in environmental water samples prior to its determination by flame atomic absorption spectrometry was developed. The adsorbents were characterized by X-Ray powder diffraction, high-resolution transmission electron microscopy. The experimental parameters such as pH, sample volume, type and amount of eluent and effects of interfering ions on the recovery of the target analyte were evaluated. The recovery of Cu/sup 2+/ at pH 7.0 with 30 mg of TiO/sub 2/ nanotubes was greater than 95% without interference from some common metal ions and the maximum equilibrium adsorption capacity obtained was 81.25 mg/g. The limit of detection of the proposed procedure was found to be 0.17 micro gL-1, and the precision of the preconcentration method, evaluated as the relative standard deviation was 3.7%. This method was applied to the determination of trace copper in natural water samples collected from different places in Yantai. The achieved recoveries, determined by the standard addition technique, were between 96.8-101.5%, showing that the method has a good accuracy. (author)