radioactive tracer technique

in analysis
https://doi.org/10.1351/goldbook.R05090
A technique for investigating recovery and loss of a microcomponent, in which a radioactively-labelled element or compound chemically identical with the microcomponent is added to the sample before preconcentration and its behaviour is followed by sensitive, rapid and selective radioactivity measurements.
Source:
PAC, 1979, 51, 1195. 'Separation and Preconcentration of Trace Substances. I-Preconcentration for Inorganic Trace Analysis' on page 1200 (https://doi.org/10.1351/pac197951051195)