RNAA for arsenic, cadmium, copper, and molybdenum in CNS tissues from subjects with age-related neurodegenerative diseases

Reactor thermal neutron irradiation of biological matrices induces high levels of intense gamma-ray or bremsstrahlung radiation from⁸²Br,⁴²K,²⁴Na, and³²P, that interfere with the determination of As, Cd, Cu, and Mo by INAA. Central nervous system (CNS) issue samples from subjects with Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and controls were analyzed using a simple RNAA procedure involving a rapid two-step solvent extraction procedure to determine these four elements. Significant increases (p≤0.05) in concentrations of Cd and Mo were observed for brain of AD subjects compared to controls, but significant imbalances were not observed for ALS subjects. Concentration data for these elements in selected international reference standards are also presented.