Collection of Czechoslovak Chemical Communications · 1993 · 14 citations · 0 references
Natural SciencesChemical EngineeringChemistryAnalytical ChemistryElectroanalytical MethodsElectrochemistryElectroanalytical ChemistryElectrochemical CellsElectrochemical DetectionElectrode KineticsCarbon Paste ElectrodesCoated-wire ElectrodesDifferential Pulse VoltammetryGold ElectrodesPotentiometric DetectionPotentiometric TitrationVoltammetric DetectionVoltammetry
Differential pulse voltammetry was used to determine gold in gold-plated electrotechnical components. Samples were dissolved to form tetrachlorourate, which was determined on a carbon paste electrode containing tricresyl phosphate as pasting liquid. A characteristic cathodic peak for tetrachlorourate, whose selective accumulation is based on extraction, is obtained during cathodic scan from +0.8 to -0.5 V vs Ag/AgCl electrode. The accompanying Fe(III) and Cu(II) ions from the matrix are masked by adding EDTA. Gold can be determined in the presence of their thousand-fold excess in the concentration range 1 . 10 -5 - 1 . 10 -7 mol l -1 . The results were confirmed by potentiometric titration with a solution of 1-(ethoxycarbonyl)pentadecyltrimethylammonium bromide (Septonex) by using a coated-wire indicator electrode with a softened plastic membrane.