Mass spectrometric determination of the absolute atomic weight of a reference sample of natural iron
Absolute values have been obtained by means of thermal ionisation mass spectrometry for the Fe isotope abundance ratios of a sample of metallic iron of natural isotopic composition. This was achieved by calibrating the mass spectrometric measurement procedure using five different synthetic isotope mixtures, prepared from carefully characterised enriched isotope carrier compounds, 54Fe(2)O(3) and 56Fe(2)O(3). Three different mass spectrometric measurement procedures were developed, all using a silica-gel/boric acid ionisation enhancer. Measurements were carried out on two different instruments; a mass spectrometer with Faraday detector and an instrument equipped with a calibrated ion counting device. Compared to current IUPAC data, which have not been changed since 1961 and which date back to uncalibrated measurements during the 1940s, the uncertainty of the isotope abundances obtained in this work has been improved by a factor of four to sixteen, and that of the atomic weight by a factor of seven, even with a very conservative 2s uncertainty estimate.
Bibliographic Reference: Paper presented: XXVIII Colloquium Spectroscopium Internationale, York (GB), June 29 - July 4, 1993
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Record Number: 199311589 / Last updated on: 1994-11-28
Original language: en
Available languages: en