USE OF CYCLOTRONS FOR TRACE-ELEMENT ANALYSIS IN BIOLOGICAL SAMPLES AND RELATED METABOLISM STUDIES

In this work metabolic studies based on proton nuclear activation (PNA) are described. For such kind of experiments a very high sensitivity in concentration determination of adequate tracers in biological tissues is needed and the contemporary use of more than one isotope of some element is often necessary. Moreover the use of radioactive tracers is normally forbidden in healthy persons. PNA is usually obtained inducing (p, xn) reactions on the target nuclei by means of a proton beam of adequate energy. The large power released by the charged particle beam in biological targets (dried serum samples) requires an efficient cooling system and imposes a limitation in the beam intensity. The special irradiation chamber built to irradiate 30 samples at a time is described. An account will be given of metabolic studies on Fe, Mo, and Te in man and/or animal. Some fundamental metabolic parameters are extracted by means of compartment analysis. Data on blood serum clearance constants and relative intestinal absorption coefficients are discussed.