reversed (radiochemical) isotope dilution analysis

https://doi.org/10.1351/goldbook.R05375
isotope dilution analysis used for the determination of the isotopic carrier in a solution of a radionuclide with the aid of one of its stable isotopes.
Source:
PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2521 (https://doi.org/10.1351/pac199466122513)