DETERMINATION OF 18 SIDEROPHILE ELEMENTS INCLUDING ALL PLATINUM-GROUPELEMENTS IN CHONDRITIC METALS AND IRON-METEORITES BY INSTRUMENTAL NEUTRON-ACTIVATION

An instrumental neutron activation method is developed to analyze chon dritic metals and iron meteorites. By changing irradiation and decay t imes, and selecting suitable gamma-ray and X-ray photopeaks, not only all platinum group elements (Ru, Rh, Pd, Os, Ir, Pt) but also other si derophilic elements (Fe, Co, Ni, Cu, Ga, Ge, As, Mo, Sb, W, Re, Au) ca n be nondestructively determined in the meteoritic metal samples, To o btain analytical data as accurate as possible, interfering reactions a nd neutron nux gradients during irradiation are considered, Siderophil e elemental abundances measured for the Odessa iron meteorite are high ly consistent with the literature values, Rh abundances for bulk H, L, LL, EH, and EL chondrites, which had been scarcely reported in the li terature, are derived from Rh/Ni abundance ratios in the metal separat es of the corresponding chondritic groups.