Cyclotron production, radiochemical separation and quality control of platinum radiotracers for toxicological studies

The increasing concn. of Pt, Pd, and Rh in the environment is mainly due to the release of these elements from the catalytic converters of the motor vehicles. This situation makes it necessary to carry out metallotoxicol. expts. on both cell cultures and lab. animals, in order to assess their impact on living organisms after a long-term and low-level exposure (LLE). Both nuclear reactions natIr(p,xn) and natOs(α,xn) were investigated in the energy range up to 45 MeV for protons and 38 MeV for alpha-particles, to optimize the irradn. parameters for the prodn. of 188,189,191Pt. Several sets of thin- and thick-target excitation functions were detd. exptl. by cyclotron irradn. at both Milano and Ispra cyclotrons. This paper reports the irradn. parameters studied and adopted and two radiochem. procedures for the sepn. of radio-Pt from an Os target, as well as from ruthenium, iridium and gold impurities. These procedures were used to obtain very high specific activity Pt radionuclides in No Carrier Added (NCA) form. Radionuclidic, radiochem. and chem. purity measurements were carried out by the use of several techniques like γ-spectrometry, ion-exchange radio-chromatog., at. absorption spectrometry, and neutron activation anal.