Turkish Journal of Chemistry, Vol.29, No.1, 17-25, 2005
Determination of trace copper by FAAS after solid phase extraction and preconcentration onto Amberlite XAD-2 loaded with nitroso-R salt
A procedure for the separation and preconcentration of trace amounts of copper is proposed. It is based on the adsorption of copper(II) ions solution onto a column of Amberlite XAD-2 resin loaded with disodium 1-nitroso-2-naphthol-3, 6-disulfonate (nitroso-R salt). Copper is quantitatively retained on the column in the pH range 5.5-7.8 at a flow rate of 2 mL min(-1). The copper complex eluted with 5 mL of dimethylformamide (DMF) and copper was measured by flame atomic absorption spectrometry (FAAS) at 324.8 nm. In this case, 0.10 mu g of copper can be concentrated in the column from 800 mL of aqueous sample, where its concentration is as low as 0.125 ng mL(-1). Eight replicate determinations of 1.0 mu g mL(-1) of copper in the final DMF solution gave a relative standard deviation of 1.8%. The sensitivity for 1% absorption was 27.5 ng mL(-1). The interference of a large number of anions and cations was studied and the optimized conditions developed were utilized for the trace determination of copper in various environmental and standard samples.
Keywords:Amberlite XAD-2;flame atomic absorption spectrometry;solid phase extraction of copper;standard alloys and biological samples