title: Chemical separation and mass spectrometry of Cr, Fe, Ni, Zn, and Cu in terrestrial and extraterrestrial materials using thermal ionization mass spectrometry.
abstract: A sequential chemical separation technique for Cr, Fe, Ni, Zn, and Cu in terrestrial and extraterrestrial silicate rocks was developed for precise and accurate determination of elemental concentration by the isotope dilution method (ID). The technique uses a combination of cation-anion exchange chromatography and Eichrom nickel specific resin. The method was tested using a variety of matrixes including bulk meteorite (Allende), terrestrial peridotite (JP-1), and basalt (JB-1b). Concentrations of each element was determined by thermal ionization mass spectrometry (TIMS) using W filaments and a Si-B-Al type activator for Cr, Fe, Ni, and Zn and a Re filament and silicic acid-H3PO4 activator for Cu. The method can be used to precisely determine the concentrations of these elements in very small silicate samples, including meteorites, geochemical reference samples, and mineral standards for microprobe analysis. Furthermore, the Cr mass spectrometry procedure developed in this study can be extended to determine the isotopic ratios of 53Cr/52Cr and 54Cr/52Cr with precision of approximately 0.05epsilon and approximately 0.10epsilon (1epsilon = 0.01%), respectively, enabling cosmochemical applications such as high precision Mn-Cr chronology and investigation of nucleosynthetic isotopic anomalies in meteorites.
authors.affiliation: The Pheasant Memorial Laboratory for Geochemistry and Cosomochemistry, Institute for Study of the Earth's Interior, Okayama University, 827 Yamada, Misasa, Tottori-ken 682-0193, Japan.
authors.forename: Akane
authors.initials: A
authors.lastname: Yamakawa
authors.forename: Katsuyuki
authors.initials: K
authors.lastname: Yamashita
authors.forename: Akio
authors.initials: A
authors.lastname: Makishima
authors.forename: Eizo
authors.initials: E
authors.lastname: Nakamura
mesh_terms: D002857:Chromium / Q000032:analysis / Q000302:isolation & purification; D003300:Copper / Q000032:analysis / Q000302:isolation & purification; D005118:Extraterrestrial Environment / Q000737:chemistry*; D007501:Iron / Q000032:analysis / Q000302:isolation & purification; D007554:Isotopes; D013058:Mass Spectrometry; D009532:Nickel / Q000032:analysis / Q000302:isolation & purification; D017640:Silicates / Q000737:chemistry; D013696:Temperature; D028561:Transition Elements / Q000032:analysis* / Q000302:isolation & purification*; D015032:Zinc / Q000032:analysis / Q000302:isolation & purification
chemical_list: D007554:Isotopes; D017640:Silicates; D028561:Transition Elements; C060346:basalt; D002857:Chromium; D003300:Copper; D009532:Nickel; D007501:Iron; D015032:Zinc