Mass-spectrometric REE analysis in sulphide minerals

Abstract

The standard samples of diorite, granite and anorthosite (National Centre for Petrographic and Geochemical Research (CRPG CNRS, Nancy, France) were analyzed to measure rare-earth element (REE) concentrations by the ICP MS method (quadrupole ELAN 9000 DRC-e) without preliminary dilution and concentration procedures. The certified values of REE concentrations measured on ELEMENT-2 mass-spectrometer by ICP MS method in Nancy are also well reproduced on ELAN 9000. The mass-spectrometer analytical environment and modes of operation were adjusted to detect REE in sulphide minerals by the example of the pyrite from the PGE Penikat layered intrusion (Finland) and chalcopyrite from the Talnakh deposit (Kazakhstan). The total REE content in the pyrite is ca. 3.5 ppm, that is enough to establish Sm-Nd age of pyrite. By the example of State Standard Sample 2463 (apatite, Russia) it is shown how to apply the mineral/chondrite spectra to evaluate the accuracy of the REE analytical results.