Alternating Current Polarographic Determination of Uranium in Complex Minerals Characterized by Electron Probe Analysis

specificity for undertaking the direct determination of a particular element in complex systems such as those encountered in geochemical analysis. In this work, it is shown that phase-selective high frequency ac polarography enables the determination of uranium in extremely complex minerals such as euxenite, samarskite, thorite, thorianite, and monazite and in glasses without the usually required separation procedures. The minerals are completely characterized by electron probe data, to show the wide range of other elements tolerable. The attempted determination of uranium by atomic absorption spectrometry, X-ray fluorescence, and fission track analysis is also reported. The difficulties encountered in these methods because of the large matrix corrections required, or other reasons, demonstrate the usefulness of the proposed polarographic method. The specificity, not usually attributed to polarography, results from the ability of the high frequency ac method to discriminate against nonreversible electrode processes and species reduced at more positive potentials than uranium. However, high quality polarographic instrumentation is needed as the use of the conventional two-electrode cell arrangement can give rise to undesirable instrumental artefacts, possibly explaining previously reported interferences.