Proton, photon and neutron activation analysis for the determination of stable isotopes of gadolinium in human blood plasma

The biokinetics of radioactive substances can be studied using stable tracers. For the highly radiotoxic actinides, for which no stable isotopes are available as tracers, the use of stable isotopes of lanthanides as chemically related surrogates has been suggested. In this work, the possibility of using activation analysis with protons, photons, or thermal neutrons for the determination of single stable isotopes of gadolinium in biological samples has been tested. All the techniques show very good linearity response, and may be considered as complementary. Whereas activation analysis with protons is recommendable for the simultaneous determination of two different isotopes, neutron and photon (gamma) activation analysis should be chosen whenever a better sensitivity or simplicity of the analysis is required.