Cupric Ion-selective Electrode Research Articles

Chloride interference in cupric ion selective electrode measurements

Chloride interference in cupric ion selective electrode measurements

The use of a cupric ion-selective electrode as end-point detector in precipitation titration of oxalate

It is demonstrated that oxalate can be titrated at pH 6–8 by employing lead(II) as titrant and a cupric ISE as end-point detector in the presence of traces of cupric ions. The response of the ISE to oxalate and E/pH plots have been examined. The method has been tested for the range of 0.8–40 mM oxalate. Recovery was found generally to be better than 98% and relative standard deviation was 0.4% at the 4 mM level. Interferences from carbonate, phosphate and arsenate can in part be overcome by adjusting the pH to 6.0±0.2.

Metal (Fe 3+, Cu 2+) - EDTA Complex Formation Studies in Ethanol-Aqueous Mixtures with Cupric Ion-Selective Electrode

Abstract The influence of the ethanol in ethanol-aqueous mixtures on the formation of Cu(II) -EDTA and Fe(III) -EDTA complexes was investigated. A solid membrane cupric ion-selective electrode as the titration sensor was used for direct determination of copper(II) in the presence of different quantity of iron(III) in non-aqueous media. The direct determination of copper(II) ion is based on the formation of Cu(II) -EDTA complex, which is quantified by measurements with a cupric electrode. The measurements were carried out in 45% v/v ethanol.

Determination of stability constant of copper(II) with thiosemicarbazide by use of a cupric ion-selective electrode

The stability constant of copper(II)—thiosemicarbazide complex has been determined potentiometrically by means of a cupric ion-selective electrode. Value of log K CuL 2 obtained in 0. 1 M KNO 3 at 25 °C corresponded well with the values given in the literature measured spectrophotometrically.

Ligand interference preventive buffer in determination of copper(II) by a cupric ion selective electrode

Ligand interference preventive buffer in determination of copper(II) by a cupric ion selective electrode

Complexometric determination of copper and iron in silicon with a cupric ion-selective electrode

A method is described for the complexometric determination of copper(II) and iron(III) in silicon with the cupric ion-selective electrode as endpoint detector. The sample is dissolved with hydrogen fluoride, hydrogen peroxide, and gold(III) as catalyst. The silicon matrix is then removed distilling off the azeotropic mixture containing hydrofluorosilicic acid. The residue is dissolved with 0.5 M sulfuric acid and the resulting solution divided into two parts. Copper is determined over the first by TETREN at pH 5.0–6.0. The copper-iron sum is determined over the second part, by EDTA at pH 1.0–1.5. The effect of Al(III), Mn(II), and Zn(II) ions is investigated. Applications of the method of the determination of copper and iron in silicon samples from different manufacturers, is illustrated. Copper at level of 10 ppm was analyzed with a relative standard deviation of 6%. Iron at level of 5000 ppm was analyzed with a relative standard deviation of about 2.5%.

CHELATION STUDY OF COPPER (II): FULVIC ACID SYSTEM

The chelation reaction between Cu (II) and fulvic acid has been investigated using a relatively new direct approach — that of titration with a cupric ion-selective electrode. The results of different investigators are in fair agreement with each other if they are interpreted in terms of both pH and mole fraction of reactants. In 0.1 M sodium nitrate solutions with a copper mole fraction equal to 0.5 ± 0.2, the equilibrium quotient at 25 C and pH 3 was found to be 2.2 ± 0.1.

Equilibrium studies of Cu ++-nitrilotriacetic acid with a solid state cupric ion-selective electrode

The system Cu ++-nitrilotriacetic acid (NTA) was studied both by glass electrode and cupric ion-selective electrode (solid state) at 25°C and μ = 0·1 (NaNO 3) to determine the formation of binuclear or higher chelates. Only a 1:1 Cu-NTA (CuHL) was formed in the pH range 2–7 under conditions of either excess [ligand] or [metal ion]. In this pH range, NTA functions as a bidentate ligand with a Log K MHL of 3·39.

Copper/bicarbonate equilibria in solutions of bicarbonate ion at concentrations similar to those found in natural water

The equilibrium constant for the reaction between cupric and bicarbonate ions which results in the formation of the soluble complex species, CuCO 3, was determined by means of a cupric ion selective electrode. The possibility of the formation of complex species other than CuCO 3, was examined. The implications of the presence of the CuCO 3 species to the toxicity of copper to fish in natural waters are discussed.

Determination of formation constants of copper(II) complexes of (hydroxyethylidene)diphosphonic acid with solid state cupric ion-selective electrode

Determination of formation constants of copper(II) complexes of (hydroxyethylidene)diphosphonic acid with solid state cupric ion-selective electrode

Indirect Complexometric Determination of Aluminium using a Solid-Membrane Cupric Ion-Selective Electrode

Abstract Indirect complexometric determination of 0.4–4 mg of A1 in 0.2 M solutions of NaNO3, NH4NO3 and 0.01 M Mg(NO3)2 or 0,01 M Ca(NO3)2 was studied. The solid membrane cupric-ion selective electrode was used for end-point detection in back‐titration of DCTA (added in excess) with a cupric standard solution.

Complex Formation Studies with Cupric Ion-Selective Membrane Electrodes

Abstract A cupric ion-selective electrode of the liquid-liquid membrane type is shown to respond selectively to Cu++ activity over the range of pCu++ = 2–5 in aqueous solutions of pH 3.5–6.5. Cupric ion activity measurements in the presence of complexing ligands have yielded a reliable estimate of formation constants for a number of soluble copper complexes.