Title: potentiometry
Long Title: IUPAC Gold Book - potentiometry
DOI: 10.1351/goldbook.09127
Status: current

Definition
Electrochemical measurement principle where the potential difference between an indicator electrode and a reference electrode is measured.

Note
For measurements using ion-selective electrodes, the measurement is made under equilibrium conditions what means that the macroscopic electric current is zero and the concentrations of all species are uniform throughout the solution. The indicator electrode is in direct contact with the analyte solution, whereas the reference electrode is usually separated from the analyte solution by a salt bridge. The potential difference between the indicator and reference electrodes is normally directly proportional to the logarithm of the activity (concentration) of the analyte in the solution (Nernst equation).

Related Terms
- Nernst equation: https://goldbook.iupac.org/terms/view/09068
- salt bridge: https://goldbook.iupac.org/terms/view/09080

Source
- PAC, 2020, 92, 641. 'Terminology of Electrochemical Methods of Analysis (IUPAC Recommendations 2019)' on page 668 (https://doi.org/10.1515/pac-2018-0109)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/09127/html
- json: https://goldbook.iupac.org/terms/view/09127/json
- xml: https://goldbook.iupac.org/terms/view/09127/xml

Citation: Citation: 'potentiometry' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.09127
License: The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms.
Collection: If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .
Disclaimer: The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.
Accessed: 2026-06-27T22:44:47+00:00