Solid-phase Extraction Using Modified Carbon Nanotube and Cupferron Ligand for Preconcentration and Determination of Trace Amounts of Copper in Real Samples

A solid phase extraction procedure for simultaneous separation and preconcentration of trace amounts of Cu+2 ion from various real samples prior to its determination by flame atomic absorption spectrometry has been developed. The proposed method is based on the utilization of multiwalled carbon nanotube in combination with Cupferron ligand as a solid phase extractant. The influences of the analytical parameters, including pH, amounts of ligand and adsorbent, sample volume, volume and concentration of eluent, flow rates of solution and , interference effects from the foreign metal ions were investigated for the optimum recoveries of the analyte ion. The optimum pH for the separation of Cu+2 ion on the new sorbent was 7.0. The relative standard deviation (RSDs) and the recoveries of standard addition for this method were lower than 5 % and 95-100 %, respectively. A sample volume of 200 mL resulted in a preconcentration factor of 100. The proposed procedure was successfully applied to the determination of copper in various real samples with satisfactory results.