A rapid column-adsorption method has been developed for concentrating traces of copper, cadmium, and lead in water prior to their determinations by graphite-furnace atomic-absorption spectrometry. The adsorbent used was prepared by loading a strongly basic anion-exchanger QAE-Sephadex A-25 (50 mg) with thiacalixarenetetrasulfonate (20 μmol). Two-hundredfold preconcentration of the analyte elements was achieved by passing 100 mL of sample solution (pH 8.0) through a column packed with the adsorbent (6 mm i.d.×7 mm high) at a flow rate of 10 mL min-1 and by the subsequent elution with 500 μL of aqueous nitric acid solution (1 mol L-1). The practical applicability of the proposed method was evaluated by analyzing certified reference seawater samples.
- Atomic-absorption spectrometry
- Chelating adsorbent
- Heavy metals