DETERMINATION OF PLATINUM IN ENVIRONMENTAL AND GEOLOGICAL SAMPLES BY RADIOCHEMICAL NEUTRON-ACTIVATION ANALYSIS

A radiochemical neutron activation analysis technique was developed for the determination of traces of platinum in environmental and geological samples via the indicator radionuclide Au-199, based on the separation of gold on polyurethane foam from 1 M HCl. In the determination of platinum at the ng g-1 level in the presence of antimony at concentrations higher than about 5 mug g-1, owing to a slight co-retention of antimony, further decontamination of the indicator radionuclide fraction was necessary. The effect of neutron flux and irradiation time on the extent of the second-order interfering reaction Au-197(n,gamma)Au-198(n,gamma)Au-199 and the effect of the gold content on the limit of detection of platinum are considered in detail. The feasibility of this technique was tested by the analysis of environmental and geological samples, and the results obtained were compared with those of other methods.