Tyler B. Coplen, Ph.D.
Dr. Tyler Coplen is the Director of the Reston Stable Isotope Laboratory of the USGS Water Resources Mission Area.
Tyler B. Coplen is an ST scientist in geochemistry. His research focuses on isotope hydrology, development of innovative analytical techniques for isotopic analysis of light elements, provides forensic-quality analytical services to USGS programs, and creates isotopic reference materials for calibration of mass spectrometers and laser absorption spectrometers in isotope laboratories worldwide. In 1974, he joined the U.S. Geological Survey, and in 1978, he set up the Reston Stable Isotope Laboratory, please visit the Reston Stable Isotope Laboratory website. He set up and led the Subcommittee on Natural Isotopic Fractionation (1985–2002) of the International Union of Pure and Applied Chemistry (IUPAC) that resulted in a dozen elements being assigned standard atomic-weight values that are intervals, instead of single values, to indicate that atomic-weight values of many elements are not constants of nature.
Professional Experience
Assistant Research Geochemist, University of California, Riverside 1970–1974
Education and Certifications
Ph.D. 1970, University of Chicago, Department of Geophysical Sciences, Advisor: Prof. Robert N. Clayton
M.S. 1968, University of Chicago, Department of Geophysical Sciences
B.S. 1966, Pacific Lutheran University, Major: Physics
Affiliations and Memberships*
Honorary Member, Commission on Isotopic Abundances and Atomic Weights of the International Union of Pure and Applied Chemistry
Science and Products
Isotope-abundance variations and atomic weights of selected elements: 2016 (IUPAC Technical Report)
New 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
Atomic weights of the elements 2013 (IUPAC Technical Report)
Isotopic compositions of the elements 2013 (IUPAC Technical Report)
Comment on “Reconciliation of the Devils Hole climate record with orbital forcing”
Review of footnotes and annotations to the 1949–2013 tables of standard atomic weights and tables of isotopic compositions of the elements (IUPAC Technical Report)
Three whole-wood isotopic reference materials, USGS54, USGS55, and USGS56, for δ2H, δ13C, δ15N, and δ18O measurements
A revision in hydrogen isotopic composition of USGS42 and USGS43 human-hair stable isotopic reference materials for forensic science
A new organic reference material, L-glutamic acid, USGS41a, for δ13C and δ15N measurements − a replacement for USGS41
Categorisation of northern California rainfall for periods with and without a radar brightband using stable isotopes and a novel automated precipitation collector
LIMS for Lasers 2015 for achieving long-term accuracy and precision of δ2H, δ17O, and δ18O of waters using laser absorption spectrometry
A new isotopic reference material for stable hydrogen and oxygen isotope-ratio measurements of water—USGS50 Lake Kyoga Water
Science and Products
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Isotope-abundance variations and atomic weights of selected elements: 2016 (IUPAC Technical Report)
There are 63 chemical elements that have two or more isotopes that are used to determine their standard atomic weights. The isotopic abundances and atomic weights of these elements can vary in normal materials due to physical and chemical fractionation processes (not due to radioactive decay). These variations are well known for 12 elements (hydrogen, lithium, boron, carbon, nitrogen, oxygen, magnAuthorsTyler B. Coplen, Yesha ShresthaNew 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
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 RAuthorsArndt Schimmelmann, Haiping Qi, Tyler B. Coplen, Willi A. Brand, Jon Fong, Wolfram Meier-Augenstein, Helen F. Kemp, Blaza Toman, Annika Ackermann, Sergey Assonov, Anita Aerts-Bijma, Ramona Brejcha, Yoshito Chikaraishi, Tamim Darwish, Martin Elsner, Matthias Gehre, Heike Geilmann, Manfred Gröning, Jean-François Hélie, Sara Herrero-Martín, Harro A.J. Meijer, Peter E. Sauer, Alex L. Sessions, Roland A. WernerAtomic weights of the elements 2013 (IUPAC Technical Report)
The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights of 19 elements. The standard atomic weights of four elements have been revised based on recent determinations of isotopic abundances in natural terrestrial materials:cadmium to 112.414(4) from 112.411(8),molybdenum to 95.95(1) from 95.96(2),selenium to 78.971(8) from 7AuthorsJuris Meija, Tyler B. Coplen, Michael Berglund, Willi A. Brand, Paul De Bièvre, Manfred Gröning, Norman E. Holden, Johanna Irrgeher, Robert D. Loss, Thomas Walczyk, Thomas ProhaskaIsotopic compositions of the elements 2013 (IUPAC Technical Report)
The Commission on Isotopic Abundances and Atomic Weights (ciaaw.org) of the International Union of Pure and Applied Chemistry (iupac.org) has revised the Table of Isotopic Compositions of the Elements (TICE). The update involved a critical evaluation of the recent published literature. The new TICE 2013 includes evaluated data from the “best measurement” of the isotopic abundances in a single sampAuthorsJuris Meija, Tyler B. Coplen, Michael Berglund, Willi A. Brand, Paul De Bièvre, Manfred Gröning, Norman E. Holden, Johanna Irrgeher, Robert D. Loss, Thomas Walczyk, Thomas ProhaskaComment on “Reconciliation of the Devils Hole climate record with orbital forcing”
Moseley et al.’s (Reports, 8 January 2016, p. 165) preferred-Termination-II age is subjective, as evidenced by variation in their Termination-II ages of 2500 years per meter. Termination-II-age bias decreases to zero at ~1.5 meters below the present-day water table, if one assumes linear variation with core-sample height. Maintaining the required gradient of thorium isotope 230Th over 3.6 meters fAuthorsTyler B. CoplenReview of footnotes and annotations to the 1949–2013 tables of standard atomic weights and tables of isotopic compositions of the elements (IUPAC Technical Report)
The Commission on Isotopic Abundances and Atomic Weights uses annotations given in footnotes that are an integral part of the Tables of Standard Atomic Weights to alert users to the possibilities of quite extraordinary occurrences, as well as sources with abnormal atomic-weight values outside an otherwise acceptable range. The basic need for footnotes to the Standard Atomic Weights Table and equivAuthorsTyler B. Coplen, Norman E. HoldenThree whole-wood isotopic reference materials, USGS54, USGS55, and USGS56, for δ2H, δ13C, δ15N, and δ18O measurements
Comparative measurements of stable hydrogen and oxygen isotopes in wood are hampered by the lack of proper reference materials (RMs). The U.S. Geological Survey (USGS) has prepared three powdered, whole-wood RMs, USGS54 (Pinus contorta, Canadian lodgepole pine), USGS55 (Cordia cf. dodecandra, Mexican ziricote), and USGS56 (Berchemia cf. zeyheri, South African red ivorywood). The stable isotopes ofAuthorsHaiping Qi, Tyler B. Coplen, James A. JordanA revision in hydrogen isotopic composition of USGS42 and USGS43 human-hair stable isotopic reference materials for forensic science
The hydrogen isotopic composition (δ2HVSMOW-SLAP) of USGS42 and USGS43 human hair stable isotopic reference materials, normalized to the VSMOW (Vienna-Standard Mean Ocean Water)–SLAP (Standard Light Antarctic Precipitation) scale, was originally determined with a high temperature conversion technique using an elemental analyzer (TC/EA) with a glassy carbon tube and glassy carbon filling and analysAuthorsTyler B. Coplen, Haiping QiA new organic reference material, L-glutamic acid, USGS41a, for δ13C and δ15N measurements − a replacement for USGS41
RationaleThe widely used l-glutamic acid isotopic reference material USGS41, enriched in both 13C and 15N, is nearly exhausted. A new material, USGS41a, has been prepared as a replacement for USGS41.MethodsUSGS41a was prepared by dissolving analytical grade l-glutamic acid enriched in 13C and 15N together with l-glutamic acid of normal isotopic composition. The δ13C and δ15N values of USGS41a wereAuthorsHaiping Qi, Tyler B. Coplen, Stanley J. Mroczkowski, Willi A. Brand, Lauren Brandes, Heike Geilmann, Arndt SchimmelmannCategorisation of northern California rainfall for periods with and without a radar brightband using stable isotopes and a novel automated precipitation collector
During landfall of extratropical cyclones between 2005 and 2011, nearly 1400 precipitation samples were collected at intervals of 30-min time resolution with novel automated collectors at four NOAA sites in northern California [Alta (ATA), Bodega Bay (BBY), Cazadero (CZD) and Shasta Dam (STD)] during 43 events. Substantial decreases were commonly followed hours later by substantial increases in hyAuthorsTyler B. Coplen, Paul J. Neiman, Allen B. White, F. Martin RalphLIMS for Lasers 2015 for achieving long-term accuracy and precision of δ2H, δ17O, and δ18O of waters using laser absorption spectrometry
RationaleAlthough laser absorption spectrometry (LAS) instrumentation is easy to use, its incorporation into laboratory operations is not easy, owing to extensive offline manipulation of comma-separated-values files for outlier detection, between-sample memory correction, nonlinearity (δ-variation with water amount) correction, drift correction, normalization to VSMOW-SLAP scales, and difficulty iAuthorsTyler B. Coplen, Leonard I WassenaarA new isotopic reference material for stable hydrogen and oxygen isotope-ratio measurements of water—USGS50 Lake Kyoga Water
Rationale As a result of the need for isotopic reference waters having high δ2HVSMOW-SLAP and δ18OVSMOW-SLAP values for daily use, especially for tropical and equatorial-zone freshwaters, a new secondary isotopic reference material for international distribution was prepared from water collected from Lake Kyoga, Uganda. Methods This isotopic reference lakewater was filtered through a membrane withAuthorsTyler B. Coplen, Leonard I Wassenaar, Christine Mukwaya, Haiping Qi, Jennifer M. Lorenz - Software
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