standard subtraction method

in electroanalytical chemistry
https://doi.org/10.1351/goldbook.S05926
A variation of the standard addition method. In this procedure changes in the potential resulting from the addition of a known amount of a species which reacts stoichiometrically with the ion of interest (e.g. a complexing agent) are employed to determine the original activity or concentration of the ion.
Source:
Orange Book, 2nd ed., p. 171 [Terms]