title: Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils.
abstract: An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.8 to +397.0 mUr or ‰, for δ(13)C(VPDB-LSVEC) from -40.81 to +0.49 mUr and for δ(15)N(Air) from -5.21 to +61.53 mUr. Many of the new RMs are amenable to gas and liquid chromatography. The RMs include triads of isotopically contrasting caffeines, C16 n-alkanes, n-C20-fatty acid methyl esters (FAMEs), glycines, and l-valines, together with polyethylene powder and string, one n-C17-FAME, a vacuum oil (NBS 22a) to replace NBS 22 oil, and a (2)H-enriched vacuum oil. A total of 11 laboratories from 7 countries used multiple analytical approaches and instrumentation for 2-point isotopic normalization against international primary measurement standards. The use of reference waters in silver tubes allowed direct normalization of δ(2)H values of organic materials against isotopic reference waters following the principle of identical treatment. Bayesian statistical analysis yielded the mean values reported here. New RMs are numbered from USGS61 through USGS78, in addition to NBS 22a. Because of exchangeable hydrogen, amino acid RMs currently are recommended only for carbon- and nitrogen-isotope measurements. Some amino acids contain (13)C and carbon-bound organic (2)H-enrichments at different molecular sites to provide RMs for potential site-specific isotopic analysis in future studies.
authors.affiliation: Department of Geological Sciences, Indiana University , 1001 East 10th Street, Bloomington, Indiana 47405, United States.
authors.forename: Arndt
authors.initials: A
authors.lastname: Schimmelmann
authors.affiliation: U.S. Geological Survey , 431 National Center, Reston, Virginia 20192, United States.
authors.forename: Haiping
authors.initials: H
authors.lastname: Qi
authors.affiliation: U.S. Geological Survey , 431 National Center, Reston, Virginia 20192, United States.
authors.forename: Tyler B
authors.initials: TB
authors.lastname: Coplen
authors.affiliation: Max-Planck-Institute for Biogeochemistry , Beutenberg Campus, P.O. Box 100164, 07701 Jena, Germany.
authors.forename: Willi A
authors.initials: WA
authors.lastname: Brand
authors.affiliation: Department of Geological Sciences, Indiana University , 1001 East 10th Street, Bloomington, Indiana 47405, United States.
authors.forename: Jon
authors.initials: J
authors.lastname: Fong
authors.affiliation: Stable Isotope Forensics Lab, James Hutton Institute , Invergowrie, Dundee, DD2 5DA, United Kingdom.
authors.forename: Wolfram
authors.initials: W
authors.lastname: Meier-Augenstein
authors.affiliation: Stable Isotope Forensics Lab, James Hutton Institute , Invergowrie, Dundee, DD2 5DA, United Kingdom.
authors.forename: Helen F
authors.initials: HF
authors.lastname: Kemp
authors.affiliation: National Institute of Standards and Technology (NIST) Information Technology Laboratory , 100 Bureau Drive, M/S 8980, Gaithersburg, Maryland 20899-8980, United States.
authors.forename: Blaza
authors.initials: B
authors.lastname: Toman
authors.affiliation: Institut für Agrarwissenschaften, ETH Zürich , LFW C48.1, Universitätsstrasse 2, 8092 Zürich, Switzerland.
authors.forename: Annika
authors.initials: A
authors.lastname: Ackermann
authors.affiliation: Terrestrial Environment Laboratory, Environmental Laboratories, Department of Nuclear Applications, International Atomic Energy Agency (IAEA) , 1400 Vienna, Austria.
authors.forename: Sergey
authors.initials: S
authors.lastname: Assonov
authors.affiliation: Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Anita T
authors.initials: AT
authors.lastname: Aerts-Bijma
authors.affiliation: Helmholtz Zentrum München, Institut für Grundwasserökologie , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
authors.forename: Ramona
authors.initials: R
authors.lastname: Brejcha
authors.affiliation: Department of Biogeochemistry, Japan Agency for Marine-Earth Science and Technology (JAMSTEC) , 2-15 Natsushima-Cho, Yokosuka, 237-0061, Japan.
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Chikaraishi
authors.affiliation: National Deuteration Facility, Australian Nuclear Science and Technology Organisation , Locked Bag 2001, Kirrawee DC, New South Wales 2232, Australia.
authors.forename: Tamim
authors.initials: T
authors.lastname: Darwish
authors.affiliation: Helmholtz Zentrum München, Institut für Grundwasserökologie , Ingolstädter Landstrasse 1, 85764 Neuherberg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Elsner
authors.affiliation: Department for Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ) , Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Gehre
authors.affiliation: Max-Planck-Institute for Biogeochemistry , Beutenberg Campus, P.O. Box 100164, 07701 Jena, Germany.
authors.forename: Heike
authors.initials: H
authors.lastname: Geilmann
authors.affiliation: Terrestrial Environment Laboratory, Environmental Laboratories, Department of Nuclear Applications, International Atomic Energy Agency (IAEA) , 1400 Vienna, Austria.
authors.forename: Manfred
authors.initials: M
authors.lastname: Gröning
authors.affiliation: Centre de Recherche GEOTOP, Département des Sciences de la Terre et de l'Atmosphère, Université du Québec à Montréal , Montréal, Québec, Canada , H3C 3P8.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Hélie
authors.affiliation: Department for Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research (UFZ) , Permoserstrasse 15, 04318 Leipzig, Germany.
authors.forename: Sara
authors.initials: S
authors.lastname: Herrero-Martín
authors.affiliation: Centre for Isotope Research (CIO), Energy and Sustainability Research Institute Groningen (ESRIG), University of Groningen , Nijenborgh 4, 9747 AG Groningen, The Netherlands.
authors.forename: Harro A J
authors.initials: HA
authors.lastname: Meijer
authors.affiliation: Department of Geological Sciences, Indiana University , 1001 East 10th Street, Bloomington, Indiana 47405, United States.
authors.forename: Peter E
authors.initials: PE
authors.lastname: Sauer
authors.affiliation: Division of Geological and Planetary Sciences, California Institute of Technology , Pasadena, California 91125, United States.
authors.forename: Alex L
authors.initials: AL
authors.lastname: Sessions
authors.affiliation: Institut für Agrarwissenschaften, ETH Zürich , LFW C48.1, Universitätsstrasse 2, 8092 Zürich, Switzerland.
authors.forename: Roland A
authors.initials: RA
authors.lastname: Werner