NICKEL DETERMINATION IN BIOLOGICAL-MATERIALS AT ULTRATRACE LEVEL BY FAST-NEUTRON RADIOCHEMICAL ACTIVATION-ANALYSIS

Using radiochemical separation of cobalt following the fast neutron reaction Ni-58(n, p.)Co-58 and long high fluence irradiation, we attempted to improve the determination limit for Ni to the nanogram and sub-nanogram level. A Compton suppression spectrometer was shown to be the best choice compared to co-axial or well-type HPGe detectors. Results for low level biological reference materials such as serum and milk powder are discussed. Use of both dried and pre-ashed samples showed that losses of Ni and Co on ashing are non-significant. The influence of the silica ampoule blank was also investigated.