Separation and determination of trace amount of Cu (II) in environmental samples using ?-benzoin oxime, dispersive liquid-liquid microextraction and inductively couple plasma atomic emission spectrometryAuthor(s): Jalal Hassan, Soheila Nilouyal, Mohammad Saber Tehrani
In present study, a selective and simple method for preconcentration and determination of copper ion was developed by dispersive liquid-liquid microextraction (DLLME) without using disperser solvent followed by inductively coupled plasma atomic emission spectrometry (ICP-AES). One variable at the time method was applied to select the type and volume of extraction and disperser solvent and other parameter that have effect on the microextraction efficiency such as, ligand to metal mole ratio , pH and interfering cations. In the proposed approach, butyl acetate and α-benzoin oxime were used as extracting solvent and chelating agent, respectively. The optimal conditions were: volume of extraction solvent, 400 μL; the ligand concentration, 0.44 mol L-1 and pH= 8. The linear dynamic range of analysis was 3.0-100.0 μg L-1 with correlation coefficient of r2> 0.9998. The method detection limit was 0.96 μgL-1.The precision (RSD %) of the method was 4.2% for 5 replicates and recoveries of 50.0 μg L-1 Cu (II) was in the range of 92-110%. The proposed method was successfully applied for determination of trace amount of copper in the tap, mineral and lake water samples satisfactory.