voltametría

Voltametría is a class of electrochemical techniques where the potential applied to a working electrode is systematically varied, and the resulting current is measured as a function of that potential. This allows for the study of redox reactions occurring at the electrode surface. The relationship between the applied potential and the measured current provides valuable information about the analyte's identity, concentration, and electrochemical behavior.

The basic setup for voltammetry involves a three-electrode system: a working electrode, a counter electrode, and a reference electrode. The working electrode is where the electrochemical reaction of interest takes place. The counter electrode completes the electrical circuit, and the reference electrode maintains a stable and known potential. By sweeping the potential, different electrochemical processes can be observed. For instance, oxidation or reduction of a species will result in a current flow at a specific potential.

Different types of voltammetry exist, each with specific applications. Cyclic voltammetry involves sweeping the potential back and forth, providing insights into reversible and irreversible reactions. Stripping voltammetry, such as anodic or cathodic stripping voltammetry, is highly sensitive and used for trace analysis by pre-concentrating the analyte onto the electrode before the potential sweep. Polarography, a historical form of voltammetry, uses a dropping mercury electrode.

Voltammetric techniques are widely used in analytical chemistry for quantitative determination of various substances, including metal ions, organic molecules, and even biological species. They are also employed in research to understand reaction mechanisms, determine thermodynamic data, and study corrosion processes. The simplicity of instrumentation and high sensitivity make voltammetry a versatile and powerful analytical tool.