Determination of chemical purity and specific activity of 177g,mLuCl3 by INAA and ET-AAS

Radioactive solutions of 177g,mLuIIICl3 are used for labeling organic compounds for metabolic radiotherapy and radioimmunotherapy. The labeling process involves Lu in III oxidation state, so the presence of other stable impurities in the same oxidation state could result in an isomorphous dilution of radioactive 177gLu. Samples of 177gLuCl3 were analyzed to quantify the chemical impurities with a special regard for trivalent elements with instrumental neutron activation analysis (INAA), carried out in the research nuclear reactor TRIGA MARK II (GA, USA) of the Università degli Studi di Pavia, and electrothermal atomic absorption spectroscopy (ET-AAS) (Varian, USA) at LASA.