initial rate method

https://doi.org/10.1351/goldbook.I03040
A mode of measurement in a kinetic method of analysis, in which the initial reaction rate is determined (usually by the slope method) and utilized for the measurement of concentration.
Source:
PAC, 1993, 65, 2291. 'Nomenclature of kinetic methods of analysis (IUPAC Recommendations 1993)' on page 2296 (https://doi.org/10.1351/pac199365102291)