Composition-Induced Variations in SIMS Instrumental Mass Fractionation during Boron Isotope Ratio Measurements of Silicate Glasses |
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| Authors: | Martin Rosner Michael Wiedenbeck Thomas Ludwig |
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| Institution: | GeoForschungsZentrum Potsdam, Section 4.2 Inorganic and Isotope Geochemistry, Telegrafenberg, 14473 Potsdam, Germany;University of Bremen, Department Petrology of the Ocean Crust, Klagenfurter Strasse GEO Geb., 28334 Bremen, Germany;Federal Institute for Materials Research and Testing, Division 1.5 Bioanalytics, Unter den Eichen 87, 12205 Berlin, Germany;University of Heidelberg, Institute of Mineralogy, Im Neuenheimer Feld 236, 69120 Heidelberg, Germany |
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| Abstract: | An analytical artefact is reported here related to differences in instrumental mass fractionation between NIST SRM glasses and natural geological glasses during SIMS boron isotope determinations. The data presented demonstrated an average 3.4‰ difference between the NIST glasses and natural basaltic to rhyolitic glasses mainly in terms of their sputtering-induced fractionation of boron isotopes. As no matrix effect was found among basaltic to rhyolitic glasses, instrumental mass fractionation of most natural glass samples can be corrected by using appropriate glass reference materials. In order to confirm the existence of the compositionally induced variations in boron SIMS instrumental mass bias, the observed offset in SIMS instrumental mass bias has been independently reproduced in two laboratories and the phenomenon has been found to be stable over a period of more than one year. This study highlights the need for a close match between the chemical composition of the reference material and the samples being investigated. |
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| Keywords: | boron isotopes SIMS matrix effect glass reference materials instrumental mass fractionation |
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