Electrochemical synthesis and characterization of a new selective chelating agent for Ni(II) and its environmental analytical application

摘要

This investigation involved electrochemical synthesis of a new Ni(II) selective chelating agent by electropolymerization of 4-nitrophenol in acetate medium. The prepared polymer was characterized by FT-IR, ~1H-NMR, CHNO elemental analysis, GPC, and UV-Vis spectrometry and a suitable chemical structure was suggested. This new ligand was successfully applied in cloud point extraction (CPE) of Ni(II) before flame atomic absorption spectrometry (FAAS) measurements. The pH and the concentration of the phosphate buffer, chelating agent, surfactant and salt were optimized. In the presence of foreign ions, no significant interferences were observed. Under optimum conditions, the limits of detection (LOD) and quantification (LOQ) were 0.76 and 2.53 ng mL~(-1), respectively. The mean, preconcentration factor, standard error and RSQ for five replicates of 10 ng mL~(-1) Ni(II) were calculated to be 9.78 ng mL~(-1), 29.3, 2.2% and 3.36%, respectively. The method presented good sensitivity and selectivity and was applied for the determination of trace amounts of Ni(II) in various water and wastewater samples. The results obtained by the proposed method were in good agreement with the results of inductively coupled plasma-optical emission spectrometry (ICP-OES).