Table of Contents
What is meant by stripping voltammetry?
Stripping voltammetry (SV) is based on analyte preconcentration onto or into the working electrode, followed by a potential scan during which the analyte is stripped back to the solution; the current response is proportional to its concentration.
What is meant by stripping analysis?
Stripping analysis is an analytical technique that involves (i) preconcentration of a metal phase onto a solid electrode surface or into Hg (liquid) at negative potentials and (ii) selective oxidation of each metal phase species during an anodic potential sweep.
Why is stripping voltammetry so sensitive?
Stripping methods are generally more sensitive than other voltammetric techniques because of a preconcentration step which accumulates the desired analyte on the surface of the electrode. In this technique the analyte, typically a metal ion, is preconcentrated on the electrode surface by reductive electrodeposition.
What is anodic stripping voltammetry used for?
Anodic Stripping Voltammetry is widely used for testing drinking water quality, surface water and sewage or waste water – water that leaves the treatment plant before being discharged into surface water.
What is the difference between linear sweep and cyclic voltammetry?
Like linear sweep voltammetry, cyclic voltammetry applies a linear potential over time and at a certain potential the potentiostat will reverse the potential applied and sweep back to the beginning point. Cyclic voltammetry provides information about the oxidation and reduction reactions.
What is Amperometry used for?
Amperometry involves the measurements of currents at constant voltage applied at the dropping mercury electrode. The value of electrode potential is chosen in such a way that only the metal ion is reduced. This method is generally used for the determination of metal ion present in aqueous solution.
What is a mercury film electrode?
There is one additional type of mercury electrode: the mercury film electrode. A solid electrode—typically carbon, platinum, or gold—is placed in a solution of Hg2+ and held at a potential where the reduction of Hg2+ to Hg is favorable, forming a thin mercury film on the solid electrode’s surface.
What is a Voltammogram?
A voltammogram is a graph that can be drawn after an electrochemical experiment. This graph has a typical, recognizable form in which the electron flow (current: i) is measured in Volt against the potential (E).
What is potentiometric stripping analysis?
The analytical possibilities of potentiometric stripping analysis are outlined. The technique comprises reduction of metal ions at a stationary mercury drop or thin-film electrode. The amalgamated metals are then re-oxidized with mercury(II) ions, and the time—potential behaviour of the mercury electrode is recorded.
What is sweep rate in cyclic voltammetry?
The common practice is to use 50 to 500 mV/s as sweep rate in CV. For the first try start with 100 mV/s. Your objective is to have the redox peaks well profiled.
What does cyclic voltammetry tell us?
Cyclic Voltammetry (CV) is an electrochemical technique which measures the current that develops in an electrochemical cell under conditions where voltage is in excess of that predicted by the Nernst equation. CV is performed by cycling the potential of a working electrode, and measuring the resulting current.
What is the difference between voltammetry and amperometry?
Voltammetry involves the current in any cell being calculated in terms of applied potential. In amperometry, the current in the cell is evaluated or determined at a fixed voltage.