Determination of copper(II) by direct and solid phase extraction method using a new analytical reagent

SUMMARY Determination of Copper(II) by Direct and Solid Phase Extraction Methods Using a New Analytical Reagent In this work, two different methods using a new reagent, 3-{2-[2-(2-hydroxyimino-l- methyl-propylydeneamino)-ethyleneamino]-ethylimino}-butan-2-one oxime (H2mdo) were applied to determine copper(II) ions in solution. Experimental conditions for copper determination by both developed methods were optimized and their applicability to several samples were examined. H2indo gives a 1:1 blue and stable complex with copper(II) having an absorption maximum at 570 nm with an molar absorptivity of 1.62><1 03 Lmol^cnT1 in alkaline media at room temperature. These properties were used to develop a spectrophotometric method for copper determination. The method has several characteristics as pH range (7-10), complex stability (24 hours), limit of detection (0.19 mg/L) and linear range (0.63-225 mg/L). In addition to being sensitive, acurrate for copper(II) determination and tolerant towards various foreign ions, the method is very easy for application to copper determination in biological and environmental samples. The second method involves copper determination using modified octadecyl bonded silica membranes by H2mdo. In this method, Cu(II) ions in solution were preconcentrated by these modified membranes and subsequently atomic absorption spectrometry was applied for copper determination. The experimental conditions were optimized in terms of volume of solvent eluent (5 mL 1 M HNO3), effect of pH (5-8), effect of eluent flow rate (40 mL/min), effect of sample flow rate (10 mL/min), amount of H2mdo (2-12 mg), maximum sample volume (1500 mL), limit of detection (0.17 ug/L) and capacity of the modified disk (305±5 ug). The method was found to be sensitive and accurate for copper determination and tolerant towards several foreign ions. Furthermore, the method was easily applied to determine amount of trace copper in several water samples. Keywords: Copper Determination, Dione-Dioxime, Solid Phase Extraction, Octadecyl Silica Disk, Spectrophotometry, Preconcentration, Atomic Absorption Specrometry VII