DETERMINATION OF THORIUM IN NATIVE GOLD BY RADIOCHEMICAL NEUTRON-ACTIVATION ANALYSIS

Thorium concentrations in 11 native gold samples from different source s, e.g. placer gold, vein and lode gold were determined. Thorium was d etermined by radiochemical separation and measurement of protactinium from irradiated native gold samples. The chemical yield of the separat ion procedures is 90%. Other elements were measured by gamma-ray spect roscopy. The radiochemical separation procedures described in this wor k make accurate determination of Th concentrations in native gold at p icogram concentrations possible.