Reverse isotope dilution technique, elemental

The low concentration of radionuclides has stimulated near-universal application of an isotope dilution technique ( reverse isotope dilution ) that permits measurement of chemical recovery, termed yield. As commonly applied outside the radioanalytical chemistry laboratory, isotope dilution consists of the addition of a known amount of radionuclide tracer to a sample that contains its stable element, i.e., the natural mixture of stable isotopes of the element. The tracer is added at the beginning of the procedure and then measured in the separated and purified sample. If the added tracer and the stable isotopes of interest are assured at the beginning to be in the same chemical and physical form, then the fraction of recovered tracer represents the fraction of recovered stable isotope. 

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