Determination of Na, K, Rb and Cs Distribution in Human Brain Using Neutron Activation Analysis

This study aims to investigate the distribution of Na, K, Rb and Cs in human brains (5 individuals, 12 brain parts, mean age: 75 years). Distribution of the trace metals between lipid fraction and brain tissue was investigated in solvent extraction experiments. Determinations were carried out by instrumental neutron activation analysis. The present results show a rather non-homogeneous distribution for Na and a relatively uniform distribution for K, Rb and Cs. The mean concentrations found are 7440 µg Na g−1 dry weight, 12800 µg K g−1, 14 µg Rb g−1 and 50 ng Cs g−1. A highly significant positive correlation was found between Rb and Cs. Solvent extraction experiments showed that 19% of Rb and 26% of Cs of the total content is located in lipid fraction.