Determination of minor and trace elements in four Canadian iron-formation standard samples FeR-1, FeR-2, FeR-3, and FeR-4 by INAA, ICP-MS, and ICP-AES

Abstract

Banded iron-formation recorded systematically the distribution of rare-earth elements (REEs) in the environment of ferruginous precipitation. Analyzing banded iron-formation therefore yields detailed information about both the source and the chemical conditions of deposition of REEs and iron. An international iron-formation reference sample would help to minimize the effect of analytical uncertainties (matrix effects, interelement interferences) and could be used as a basis for geochemical investigations of iron-formations. The four Canadian iron-formation samples FeR-1, FeR-2, FeR-3, and FeR-4 are suitable for use as multielement comparators in the analysis of banded iron-formation. A first compilation of analytical data has been presented by Abbey et al. (1983) but the number of published data is small, especially for the REEs. New data for some major, minor, and trace elements obtained by instrumental neutron activation analysis (INAA), inductively coupled plasma mass spectrometry (ICP-MS), and inductively coupled plasma atomic emission spectroscopy (ICP-AES) will be presented. The analytical data obtained by those independent methods agree very well and might improve the available data. For example it can be shown that for Eu, which is used very often as a geochemical probe, in the FeR-1 standard 3.4 þg/g might be the best value. The published value of 0.76 þg/g could not be verified by INAA or ICP-MS. Accuracy of the three methods is demonstrated by comparing the results of INAA, ICP-MS, and ICP-AES with the recommended values of the collaborative studies for the iron-formation sample IF-G and the Ailsa Craig granite AC-E.