direct (radiochemical) isotope dilution analysis

https://doi.org/10.1351/goldbook.D01772
isotope dilution analysis used for the determination of a non-radioactive element with the aid of one of its radionuclides.
Source:
PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2521 (https://doi.org/10.1351/pac199466122513)