Voltammetry (also polarography, invers voltammetry or cyclo voltammetry) is based on the acquisition of current voltage diagrams, that are used to investigate redox systems.
The classical research field comprises polarography with a mercury dripping electrode as working electrode. Here apart from quantitative information also qualitative information can be obtained. Thus, in a mixture of salts of transition metal ions the metals can be identified side by side and can be quantified simultaneously. Typically polarography in DP mode (differential pulse) has a detection limit of ca. 0.01 ppm = 10 µg/kg. For the application of invers voltammetry, which contains an additional concentration enhancement step prior to analysis the detection limit is 0.001 ppm = 1 µg/kg.
A special form of voltammetry is cyclo voltammetry, in which a known redox system that shall be investigated deeper will be repeatedly oxidized and reduced, thus in a cyclic. Depending on different chemical environment in the solution the redox potential or the kinetics of the electron transition can be investigated and allow deeper insight into possible applications of these redox systems.
A voltammetry instrument consists typically on a galvanostate with a three-electrode measuring cell working electrode (e.g. mercury dripping electrode), reference electrode, and counter electrode.
(in cooperation with the University of Applied Sciences Merseburg)
- Required sample amount: minimum 10 ml
- Concentration range of the sample to be investigated according to method: 0.001 to 100 ppm
- Metrohm VA Computrace Systems 757
- Measurement at room temperature
- Only dissolved samples can be investigated
Prof. Dr. Valentin Cepus
Telefon: +49 (0)3461 30889-51
- Identification and quantification of metals
- Identification of application of redox systems