Term: flow injection enthalpimetry https://doi.org/10.1351/goldbook.F02437 Definition: A term used to describe several related methods in which a transient temperature change in a flowing liquid stream, caused by a chemical reaction, is used to quantitatively determine an analyte. The analyte is introduced as a discrete liquid sample (i.e. test portion) into the flowing stream. This definition limits the scope to experiments with primarily an analytical emphasis, performed in a flow injection calorimeter. This maintains a clear distinction from classical flow calorimetric methods where reagents are combined continuously in flowing streams, or where the heat effect is measured via the flowing of a fluid over a reaction vessel. An acceptable synonym is enthalpimetric flow injection analysis. Other non-recommended terms which have been used in the literature include peak enthalpimetry and enzyme thermistor. flow enthalpimetry has been used to describe the flow injection technique, but its use for this purpose is discouraged. Related Terms: 1) test portion (http://doi.org/10.1351/goldbook.T06284). 2) flow injection (http://doi.org/10.1351/goldbook.F02436). 3) peak enthalpimetry (http://doi.org/10.1351/goldbook.P04459). 4) enzyme thermistor (http://doi.org/10.1351/goldbook.E02161). 5) flow enthalpimetry (http://doi.org/10.1351/goldbook.F02435). Source: PAC, 1994, 66, 2487. 'Nomenclature of thermometric and enthalpimetric methods in chemical analysis (IUPAC Recommendations 1994)' on page 2491 (https://doi.org/10.1351/pac199466122487) Citation: 'flow injection enthalpimetry' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.F02437 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. 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.