Squarewave voltammetry

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Squarewave potential sweep

Squarewave voltammetry (SWV) is a further improvement of staircase voltammetry which is itself a derivative of linear sweep voltammetry. In linear sweep voltammetry the current at a working electrode is measured while the potential between the working electrode and a reference electrode is swept linearly in time. In squarewave voltammetry, a squarewave is superimposed on the potential staircase sweep. Oxidation or reduction of species is registered as a peak or trough in the current signal at the potential at which the species begins to be oxidized or reduced. In staircase voltammetry the potential sweep is a series of stair steps. The current is measured at the end of each potential change, right before the next, so that the contribution to the current signal from the capacitive charging current is minimized. The differential current is then plotted as a function of potential, and the reduction or oxidation of species is measured as a peak or trough. Due to the lesser contribution of capacitative charging current the detection limits for SWV are on the order of nanomolar concentrations.

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v t e Electroanalytical methods

Techniques	Adsorptive stripping voltammetry Amperometric titration Anodic stripping voltammetry Bulk electrolysis Cathodic stripping voltammetry Chronoamperometry Coulometry Cyclic voltammetry Differential pulse voltammetry Electrogravimetry Hydrodynamic technique Linear sweep voltammetry Normal pulse voltammetry Polarography Potentiometry Rotated electrode voltammetry Squarewave voltammetry Staircase voltammetry Voltammetry

Instrumentation	Amperostat Auxiliary electrode Dropping mercury electrode Electrode Electrolytic cell Galvanic cell Hanging mercury drop electrode Ion selective electrode Mercury coulometer pH meter Potentiostat Reference electrode Rotating disk electrode Rotating ring-disk electrode Salt bridge Saturated calomel electrode Silver chloride electrode Standard hydrogen electrode Ultramicroelectrode Voltameter Working electrode

Theory	Activity coefficient Butler–Volmer equation Cell notation Cottrell equation Debye–Hückel equation Double layer Faraday's laws of electrolysis Half-reaction Ionic strength Nernst equation

Analytical Chemistry

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Squarewave voltammetry

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References