Determination of Cu, Ni and Pb in aqueous medium by FAAS after pre-concentration on 2-aminothiazole modified silica gel

this work describes the synthesis and characterization of 2-aminothiazole modified silica gel (siat), and the results of a study of the adsorption and pre-concentration (in batch and using a flow-injection system coupled to an absorption atomic spectrometer) of cu(ii), ni(ii) and pb(ii) in aqueous medium. the adsorption capacities for each metal ions in mmol g-1 were: cu(ii)= 1.18, ni(ii)= 1.15 and pb(ii)= 1.10. the results obtained in the flow experiments showed a recovery of practically 100% of the metal ions adsorbed in a mini-column packed with 100 mg of siat, using 100 μl of 2.0 mol l-1 hcl solution as eluent. the sorption-desorption of the metal ions made possible the application of a flow-injection system for the pre-concentration and quantification by faas of metal ions at trace level in natural water samples digested and not digest by an oxidizing uv photolysis.