potentiometria

Potentiometria is an electrochemical measurement technique used to determine the concentration of a specific ion in a solution. It relies on measuring the potential difference between two electrodes immersed in the solution without allowing any significant current to flow. The most common setup involves a working electrode, often a specific ion-selective electrode (ISE) sensitive to the target ion, and a reference electrode that maintains a stable potential. The potential difference is related to the concentration of the analyte ion by the Nernst equation.

The Nernst equation describes the relationship between the electrode potential and the concentration or activity of the ion. By calibrating the electrode system with solutions of known concentrations, a calibration curve can be generated. This curve plots the measured potential against the logarithm of the ion concentration. Subsequently, the concentration of the unknown sample can be determined by measuring its potential and interpolating on the calibration curve. Potentiometry is a versatile technique applicable to various ions, including hydrogen (pH measurement), fluoride, chloride, and many others. It is widely used in analytical chemistry, environmental monitoring, and industrial process control due to its simplicity, speed, and non-destructive nature.