Nanometer-size titanium dioxide separation/preconcentration and FAAS determination of trace Zn and Cd in water sample

A new method using nanoparticle TiO2 as solid-phase extractant coupled with FAAS was proposed for preconcentration and determination of trace Zn and Cd. The effects of pH, contact time, elution solution and interfering ions on the adsorption behavior of nanometer TiO2 towards Zn and Cd were investigated. Under optimum conditions, nanometer TiO2 possesses a significant capacity for the sorption of the metal ions studied. The limits of detection (3delta) of this method were 1.8 ng mL(-1) of Zn and 3.0 ng mL -1 of Cd with an enrichment factor of 12.5, and relative standard deviations were 3.8% and 4.3% for Zn and Cd, respectively (c = 0.5 mug mL(-1) , n = 9). The proposed method was validated by the analysis of water certified reference material.