A5041235674- Isotope Analysis in Ecology
- Groundwater and Isotope Geochemistry
- Radioactive contamination and transfer
- Nuclear Physics and Applications
- Chemical Thermodynamics and Molecular Structure
- Radioactive element chemistry and processing
- Geology and Paleoclimatology Research
- History and advancements in chemistry
- Radioactivity and Radon Measurements
- Astronomical and nuclear sciences
- Mass Spectrometry Techniques and Applications
- Groundwater flow and contamination studies
- Groundwater and Watershed Analysis
- Hydrocarbon exploration and reservoir analysis
- Genetic and phenotypic traits in livestock
- Astro and Planetary Science
- Renal function and acid-base balance
- Transboundary Water Resource Management
- Scientific Measurement and Uncertainty Evaluation
- Methane Hydrates and Related Phenomena
- Particle accelerators and beam dynamics
- Metabolomics and Mass Spectrometry Studies
- Radioactive Decay and Measurement Techniques
- Medical Imaging and Pathology Studies
- Engine and Fuel Emissions
International Atomic Energy Agency
2010-2023
United States Geological Survey
2006
Max Planck Institute for Biogeochemistry
2006
Heidelberg University
1992
University of Veterinary Medicine Hannover, Foundation
1967
Consistency of delta13C measurements can be improved 39-47% by anchoring the scale with two isotopic reference materials differing substantially in 13C/12C. It is recommended that values both organic and inorganic measured expressed relative to VPDB (Vienna Peedee belemnite) on a normalized assigning consensus -46.6 per thousand L-SVEC lithium carbonate +1.95 NBS 19 calcium carbonate. Uncertainties other material this are factors up or more, some have been notably shifted: 22 oil -30.03 thousand.
Abstract The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights 19 elements. four elements have been revised based on recent isotopic abundances natural terrestrial materials: cadmium to 112.414(4) from 112.411(8), molybdenum 95.95(1) 95.96(2), selenium 78.971(8) 78.96(3), thorium 232.0377(4) 232.038 06(2). Commission Isotopic Abundances Atomic Weights (ciaaw.org) also fifteen 2012 Mass Evaluation: aluminium...
Abstract The Commission on Isotopic Abundances and Atomic Weights (ciaaw.org) of the International Union Pure Applied Chemistry (iupac.org) has revised Table Compositions Elements (TICE). update involved a critical evaluation recent published literature. new TICE 2013 includes evaluated data from “best measurement” isotopic abundances in single sample, along with set representative uncertainties that accommodate known variations normal terrestrial materials.
The biennial review of atomic-weight determinations and other cognate data has resulted in changes for the standard atomic weights five elements. weight bromine changed from 79.904(1) to interval [79.901, 79.907], germanium 72.63(1) 72.630(8), indium 114.818(3) 114.818(1), magnesium 24.3050(6) [24.304, 24.307], mercury 200.59(2) 200.592(3). For magnesium, assignment intervals new reflects common occurrence variations those elements normal terrestrial materials.
Abstract Following the reviews of atomic-weight determinations and other cognate data in 2015, 2017, 2019 2021, IUPAC (International Union Pure Applied Chemistry) Commission on Isotopic Abundances Atomic Weights (CIAAW) reports changes standard atomic weights. The symbol A r °(E) was selected for weight an element to distinguish it from E a specific substance P, designated (E, P). CIAAW has changed values weights five elements based recent terrestrial isotopic abundances: Ar (argon): 39.948...
In 1999 the Istituto di Geoscienze e Georisorse (IGG), with support of International Atomic Energy Agency (IAEA), undertook collection, preparation and distribution eight geological materials intended for a blind interlaboratory comparison measurements boron isotopic composition concentration. The came from Italian sources consist three natural waters (Mediterranean seawater two groundwaters) five rocks minerals (tourmaline, basalt, obsidian, limestone clay). solid were crushed, milled...
Abstract Internationally distributed organic and inorganic oxygen isotopic reference materials have been calibrated by six laboratories carrying out more than 5300 measurements using a variety of high‐temperature conversion techniques (HTC) in an evaluation sponsored the International Union Pure Applied Chemistry (IUPAC). To aid calibration these materials, which span 125‰, artificially enriched water ( δ 18 O +78.91‰) two barium sulfates (one depleted one O) were prepared relative to VSMOW2...
An international project developed, quality-tested, and determined isotope−δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), IAEA-600 (caffeine). These enable users normalize measurements samples scales. The span a range δ2HVSMOW-SLAP from −210.8 +397.0 mUr or ‰, δ13CVPDB-LSVEC −40.81 +0.49 δ15NAir −5.21 +61.53 mUr. Many the are amenable...
The Istituto di Geoscienze e Georisorse (IGG), on behalf and with the support of International Atomic Energy Agency (IAEA), prepared eight geological materials (three natural waters five rocks minerals), intended for a blind interlaboratory comparison measurements boron isotopic composition concentration. were distributed to twenty seven laboratories ‐ virtually all those performing geochemical isotope analyses in world ‐which agreed participate intercomparison exercise. Only fifteen...
Abstract Stable hydrogen, carbon, nitrogen, oxygen and sulfur (HCNOS) isotope compositions expressed as isotope-delta values are typically reported relative to international standards such Vienna Standard Mean Ocean Water (VSMOW), Peedee belemnite (VPDB) or Cañon Diablo Troilite (VCDT). These chosen by convention the calibration methods used realise them in practice undergo occasional changes. To ensure longevity reusability of published data, a comprehensive description (1) analytical...
Two new 14 C reference materials have been developed for international use, filling a gap in the present C1–C6 series available from IAEA. By mixing modern and synthetic substance, 150 kg of C7 ( ca . 50 pMC activity) C8 15 activity), respectively, were obtained.
The calibration of all δ 2 H and 18 O measurements on the VSMOW/SLAP scale should be performed consistently, based similar principles, independent instrumentation used. basic principles a comprehensive strategy are discussed taking water as example. most common raw data corrections for memory drift effects described. Those result in considerable improvement consistency, especially laboratories analyzing samples quite variable isotopic composition (e.g. doubly labelled water). need reliable...
A new method to seal water in silver tubes for use a TC/EA (thermal conversion/elemental analyzer) reduction unit using semi-automated sealing apparatus can yield reproducibilities (1 standard deviation) of delta(2)H and delta(18)O measurements 1.0 per thousand 0.06 thousand, respectively. These containing reference waters may be preferred the calibration H- O-bearing materials analyzed with unit. The employs computer-controlled stepping motor produce identical length. reproducibility mass...
Due to exhaustion of the two primary calibration materials, Vienna Standard Mean Ocean Water (VSMOW) and Light Antarctic Precipitation (SLAP), replacement VSMOW2 SLAP2, were created with isotopic compositions as close possible original standards in their D/H (18)O/(16)O ratios. Measurements delta(17)O composition constitute therefore an appropriate independent check achieved adjustment. Aliquots from ampoules VSMOW, VSMOW2, SLAP, SLAP2 fluorinated by BrF(5) analyzed using a dual-inlet Delta...
Rationale LSVEC, the second anchor Reference Material (RM) for VPDB δ 13 C scale realisation, was introduced in 2006. In 2015, its value found to be drifting and, 2017, use as an RM officially discontinued by IUPAC. New RMs of low uncertainty are needed. This paper describes preparation and characterisation IAEA‐610, IAEA‐611 IAEA‐612 (calcium carbonate, chemical origin) which shall serve a set aimed at anchoring negative values. Methods The were performed addressing contemporary technical...
Rationale In recent years, the primary reference material (RM) for VPDB scale, NBS19, has become unavailable, and RM used low‐end scale‐anchoring, LSVEC, was found unsuitable due a drift in δ 13 C value. Given these problems, new RMs aimed at realising scale with low uncertainty were produced. Establishing consistency of “old” prompted our revision underlying principles value assignments, realisation its long‐term sustainability. Methods Analysis major developments review contemporary...
Abstract The Guide to the Expression of Uncertainty in Measurement (GUM) provides a framework for evaluating analytical data and characterizing their dispersion consistent manner. This is eminent importance case reference materials recommended values that are used calibration further measurements. proper propagation uncertainties those essential. Guidance provided GUM on how calculate combined standard uncertainty mean value or central based multiple individual measurements including...
Stable isotope‐ratio measurements of the light elements have been used in increasingly important ways to understand processes geochemistry, hydrology, oceanography, atmospheric sciences, environmental studies, and many other fields. Progress these fields requires better precision reproducibility stable measurements. Some laboratories are claiming accuracies 0.02‰; or for δ 13 C 18 0. However, 0 analyses same sample by different can differ more than 0.3‰. Recognizing that isotopic homogeneous...