Electrochemical Determination and Recovery of Copper Ion in Water Samples by Supported Liquid Membrane using 2-Amino-N-(2-Pyridylmethyl)-Benzamide as Carrier

In the present study, copper ion has been separated from Phosphate Buffer Solution by 2-Amino-N-(2-Pyridyl Methyl)-Benzamide as an organic ligand through a flat type Supported Liquid Membrane (SLM). To this end, the organic ligand was dissolved in various solvents, and then the Polytetrafluoroethylene (PTFE) membrane was immersed in the resulting solutions for 24 h. Before extraction step, solvents with best performances including Ethanol and benzyl acetate were selected as solvent and as plasticizer, respectively. The optimized complexing reagent concentration on the membrane was 0.05 M. The adjusted pH was 4.5 and concentration of Cu solution was 1×10-3 M for feed solution, respectively. Copper ion was then determined using Fast Fourier Transformation Continuous Stripping Cyclic Voltammetry (FFTCCV) technique by a Carbon Paste Electrode (CPE). PTFE with 0.1 μm pore size have more permeability than 0.2 μm. Based on the obtained results, effective parameters imposing sensitivity of copper ion measurement were finally investigated at pH 3.2, at scan rate of 10 mV.s-1, stripping time of 0.1s and potential of -600 mV. Limit of detection of 0.19 μM for copper ion in optimized condition was attained. Under the optimized conditions the recovery of Copper ions from real samples were studied and recovery percentage were 45.71%, 34.28% and 22.58% for tap water, river water and sea water respectively.