Determination of Copper by an Adsorption Differential Pulse Stripping Method with Naphthol Derivative

Cyclopentanone Thiosemicarbazone, a New Complexing Agent for Copper Determination in Biological Samples by Adsorptive Stripping Voltammetry

A selective and sensitive stripping voltammetric method for the determination of trace amounts of copper(II) with cyclopentanone thiosemicarbazone (CPTSC) is presented. The method is based on the adsorptive accumulation of the resulting copper-CPTSC complex on a hanging mercury drop electrode, followed by the stripping voltammetric measurements at the reduction current of the adsorbed complex at -0.37 V vs. Ag/AgCl. The optimal conditions for the stripping analysis of copper include pH 9.3, deposition time of 120 s, and a deposition potential of -0.1 V (vs. Ag/AgCl). The peak current is linearly proportional to the copper concentration over a range 3.14 x 10(-9) M to 1.57 x 10(-6) M with a limit of detection of 1.57 x 10(-9) M. The technique has been applied to the determination of copper in biological samples, like urine and whole blood.

Adsorptive Stripping Voltammetric Determination of Copper(II) Ion Using Phenyl Pyridyl Ketoneoxime (PPKO)

A sensitive and selective procedure is presented for the voltammetric determination of copper(II) ion. The procedure involves an adsorptive accumulation of Cu2+-PPKO on a hanging mercury drop electrode, followed by a stripping voltammetric measurement of reduction current of adsorbed complex at about -0.30 V (vs. SCE). The optimum conditions for the analysis of copper(II) ion include pH (5.8-7.0), 60 microgM PPKO and an accumulation potential of -0.5 V (vs. SCE). The peak current is proportional to the concentration of copper over the range 0.3-76 ng mL(-1) with a detection limit of 0.01ng mL(-1) with an accumulation time of 60 s. The speciation of different forms of complex between copper(II) ion and PPKO, using the Best (Martell program), followed pH measurement were examined. The method was applied to the determination of copper(II) ion content in real samples successfully.

Differential pulse adsorption stripping voltammetric determination of copper(II) with 2-mercaptobenzimidazol at a hanging mercury-drop electrode

Copper(II) was selectively accumulated on a hanging mercury-drop electrode by using 2-mercaptobenzimidazole. Ensuing measurements were carried out by differential pulse adsorption stripping voltammetry. Factors affecting the accumulation, reduction, and stripping steps were investigated and a procedure was developed. The optimum conditions for the analysis of copper were pH 5.0, 5.33 x 10(-5) M 2-mercaptobenzimidazole and an accumulation potential of -0.10 V (vs. Av/AgCl). A linear range was obtained in the concentration range 0.2-100 ng/ml with a 90 s accumulation time and a scan rate of 16 mV/s. For ten successive determinations of 1.0, 20.0 and 70.0 ng/ml copper(II), relative standard deviations of 4.2, 3.5 and 2.8%, respectively, were obtained. The developed method was applied to the determination of copper in commercial salts and aluminium alloys.