on 05-11-201704:40 AM - edited on 11-09-202104:13 AM by usermigration2
Department of Geology, University of Maryland, College Park, MD 20742, USA International Journal of Mass Spectrometry (2012), V309, pp109–117, doi: 10.1016/j.ijms.2011.08.033 High precision tungsten isotope measurement by thermal ionization mass spectrometry Mathieu Touboul and Richard J. Walker We describe a new technique for measuring the isotopic abundance of 182W with improved precision in natural silicate samples. Repeated measurement of a gravimetrically prepared mixture of a natural W standard and a 182W enriched spike shows that differences in 182W/184W of ∼10 ppm can be well resolved using this method. The external reproducibility of ±4.5 ppm is ∼5 times more precise than conventional W isotope measurements by MC-ICP-MS. The new technique constitutes an ideal tool for investigating the W isotope composition of terrestrial rocks for potential contributions from the core, and late accreted extraterrestrial materials.