elektroanalitik

Elektroanalytik, or electroanalytical chemistry, is a branch of analytical chemistry that uses electrochemical methods to quantify chemical species. It relies on controlling and measuring electrical signals produced by redox reactions at electrodes. The main techniques include potentiometry, voltammetry, amperometry, and coulometry, as well as impedance spectroscopy and related chrono- and chronopotentiometric approaches. Potentiometry measures a potential with a reference electrode to determine the activity of an ion, while voltammetry involves sweeping or pulsing the potential and monitoring the resulting current to infer concentration. Amperometry keeps the potential fixed and records current, and coulometry integrates current over time to determine the total charge and amount of substance.

Instrumentation centers on a three-electrode cell consisting of a working electrode, a reference electrode, and a counter electrode, all controlled by a potentiostat or galvanostat. The electrochemical response depends on mass transport of the analyte to the electrode surface, governed by diffusion, convection, and migration. Electrode materials, surface modifications, and mediators influence sensitivity, selectivity, and response time. Quantification uses calibration curves, standard addition methods, or internal standards, with the Nernst equation linking potential to ion activity in potentiometry and diffusion-controlled models relating current peaks to concentration in voltammetry.

Applications span environmental monitoring of metals and pollutants, clinical and biomedical analyses, food and beverage testing, industrial process control, and research in energy storage and corrosion. Advantages include high sensitivity, rapid analysis, and small sample requirements, while limitations involve potential interferences, electrode fouling, and the need for careful calibration and electrode maintenance.