This work considers the development of a novel analytical procedure for rapid and simple size fractionation of metal species from human serum samples, with a great potential for studying characteristic abnormalities of metal homeostasis associated with Alzheimer's disease and other neurodegenerative disorders. For this purpose, serum samples are subjected to protein precipitation under non-denaturing conditions, taking special care for maintaining the integrity of metal-biomolecule bindings and for preventing species transformation, and then both the supernatant (low molecular mass fraction) and the precipitate (high molecular mass fraction) are analyzed by ICP-MS in order to determine the biodistribution of serum trace elements. This methodology is validated for 11 trace elements, including aluminum, cadmium, cobalt, chromium, copper, iron, manganese, molybdenum, selenium, vanadium, and zinc, in terms of sensitivity, selectivity, accuracy, and precision.