Preparation of a Chelating Resin and its Application as a Preconcentration System for Determination of Cadmium in River Water by Flow Injection Analysis

ABSTRACT: A chelating resin of polystyrene divinylbenzene resin functionalized by 1-(2-pyridylazo) 2-naphtol (PSDVB-PAN) has been synthesized and its sorption properties have been investigated for pre-concentration and determination of cadmium at µg/L level by flame atomic absorption spectrometry. The procedure is based on the sorption of Cd(II) ions on a minicolumn of synthesized chelating resin. The retained cadmium ions can be quickly eluted from sorbent material, with the eluent stream consisting of nitric acid solution, directly to the nebulizer burner system of the flame atomic absorption spectrometer. The sorption capacity of PSDVB-PAN was found to be 7.5 mg/g at optimum pH and the chelating resin showed rapid kinetic sorption. The sorption equilibrium of Cd(II) on synthesized chelating resin was achieved just in 15 minutes. Parameters such as the pH effect on the cadmium sorption, sample volume, the sorption capacity of resin, the cadmium desorption from the resin and the analytical characteristics of the procedure were studied for the quantitative recoveries of the analyte ions. The developed system allowed a throughput rate of 15 samples h-1 with a detection limit of 1.5 µg/L. Relative standard deviation for 5 replicated injections of 50 µg/ L was 1.8%. This procedure was applied for cadmium determination in river water samples collected fro