Determination of trace metals in hydrothermal calcites by ICP-methods

Lanthanum, cerium, and europium in calcites from carbonate-sulfide banded ores were determined by standard addition using inductively coupled plasma mass spectrometry (ICP-MS). The concentration ranges in solution were for La 700-36 ng/g, Ce 2000-149 ng/g, and for Eu 140-2.4 ng/g. Only Ce was determined by both ICP methods, and the results agree within 3 to 4%. In a second step, a scan over the mass range of the rare earth elements (REE) was performed. The solutions were analyzed directly without applying preconcentration or separation procedures. ICP atomic emission spectrometry (AES) was used to determine Ca, Mn, and Fe. The matrix Ca is present in a concentration range from 1600 to 1300 g/g and the major impurities Mn and Fe are 152-32 and 100-28 g/g, respectively. The detection limits of ICP-MS for REE are found to be better by two orders of magnitude than for ICP-AES. A commercially available SCIEX Elan ICP-MS with additional software was used to make mathematical corrections for isobaric interferences and molecular ions.Presented in part at the 1989 European Winter Conference on Plasma Spectrochemistry, Reutte, Austria