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 tissu es is needed and the contemporary use of more than one isotope of some element is often necessary. Moreover the use of radioactive tracers i s normally forbidden in healthy persons. PNA is usually obtained induc ing (p, xn) reactions on the target nuclei by means of a proton beam o f adequate energy. The large power released by the charged particle be am in biological targets (dried serum samples) requires an efficient c ooling system and imposes a limitation in the beam intensity. The spec ial irradiation chamber built to irradiate 30 samples at a time is des cribed. An account will be given of metabolic studies on Fe, Mo, and T e in man and/or animal. Some fundamental metabolic parameters are extr acted by means of compartment analysis. Data on blood serum clearance constants and relative intestinal absorption coefficients are discusse d.