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Sample records for stable isotope samples

  1. Stable isotopes

    International Nuclear Information System (INIS)

    Evans, D.K.

    1986-01-01

    Seventy-five percent of the world's stable isotope supply comes from one producer, Oak Ridge Nuclear Laboratory (ORNL) in the US. Canadian concern is that foreign needs will be met only after domestic needs, thus creating a shortage of stable isotopes in Canada. This article describes the present situation in Canada (availability and cost) of stable isotopes, the isotope enrichment techniques, and related research programs at Chalk River Nuclear Laboratories (CRNL)

  2. Tellurium stable isotope fractionation in chondritic meteorites and some terrestrial samples

    Science.gov (United States)

    Fehr, Manuela A.; Hammond, Samantha J.; Parkinson, Ian J.

    2018-02-01

    New methodologies employing a 125Te-128Te double-spike were developed and applied to obtain high precision mass-dependent tellurium stable isotope data for chondritic meteorites and some terrestrial samples by multiple-collector inductively coupled plasma mass spectrometry. Analyses of standard solutions produce Te stable isotope data with a long-term reproducibility (2SD) of 0.064‰ for δ130/125Te. Carbonaceous and enstatite chondrites display a range in δ130/125Te of 0.9‰ (0.2‰ amu-1) in their Te stable isotope signature, whereas ordinary chondrites present larger Te stable isotope fractionation, in particular for unequilibrated ordinary chondrites, with an overall variation of 6.3‰ for δ130/125Te (1.3‰ amu-1). Tellurium stable isotope variations in ordinary chondrites display no correlation with Te contents or metamorphic grade. The large Te stable isotope fractionation in ordinary chondrites is likely caused by evaporation and condensation processes during metamorphism in the meteorite parent bodies, as has been suggested for other moderately and highly volatile elements displaying similar isotope fractionation. Alternatively, they might represent a nebular signature or could have been produced during chondrule formation. Enstatite chondrites display slightly more negative δ130/125Te compared to carbonaceous chondrites and equilibrated ordinary chondrites. Small differences in the Te stable isotope composition are also present within carbonaceous chondrites and increase in the order CV-CO-CM-CI. These Te isotope variations within carbonaceous chondrites may be due to mixing of components that have distinct Te isotope signatures reflecting Te stable isotope fractionation in the early solar system or on the parent bodies and potentially small so-far unresolvable nucleosynthetic isotope anomalies of up to 0.27‰. The Te stable isotope data of carbonaceous and enstatite chondrites displays a general correlation with the oxidation state and hence might

  3. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Directory of Open Access Journals (Sweden)

    Stephen P Good

    Full Text Available Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18O, > 160‰ for δ(2H and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰ were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  4. Stable isotope analysis of precipitation samples obtained via crowdsourcing reveals the spatiotemporal evolution of Superstorm Sandy.

    Science.gov (United States)

    Good, Stephen P; Mallia, Derek V; Lin, John C; Bowen, Gabriel J

    2014-01-01

    Extra-tropical cyclones, such as 2012 Superstorm Sandy, pose a significant climatic threat to the northeastern United Sates, yet prediction of hydrologic and thermodynamic processes within such systems is complicated by their interaction with mid-latitude water patterns as they move poleward. Fortunately, the evolution of these systems is also recorded in the stable isotope ratios of storm-associated precipitation and water vapor, and isotopic analysis provides constraints on difficult-to-observe cyclone dynamics. During Superstorm Sandy, a unique crowdsourced approach enabled 685 precipitation samples to be obtained for oxygen and hydrogen isotopic analysis, constituting the largest isotopic sampling of a synoptic-scale system to date. Isotopically, these waters span an enormous range of values (> 21‰ for δ(18)O, > 160‰ for δ(2)H) and exhibit strong spatiotemporal structure. Low isotope ratios occurred predominantly in the west and south quadrants of the storm, indicating robust isotopic distillation that tracked the intensity of the storm's warm core. Elevated values of deuterium-excess (> 25‰) were found primarily in the New England region after Sandy made landfall. Isotope mass balance calculations and Lagrangian back-trajectory analysis suggest that these samples reflect the moistening of dry continental air entrained from a mid-latitude trough. These results demonstrate the power of rapid-response isotope monitoring to elucidate the structure and dynamics of water cycling within synoptic-scale systems and improve our understanding of storm evolution, hydroclimatological impacts, and paleo-storm proxies.

  5. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  6. Testing sequential extraction methods for the analysis of multiple stable isotope systems from a bone sample

    Science.gov (United States)

    Sahlstedt, Elina; Arppe, Laura

    2017-04-01

    Stable isotope composition of bones, analysed either from the mineral phase (hydroxyapatite) or from the organic phase (mainly collagen) carry important climatological and ecological information and are therefore widely used in paleontological and archaeological research. For the analysis of the stable isotope compositions, both of the phases, hydroxyapatite and collagen, have their more or less well established separation and analytical techniques. Recent development in IRMS and wet chemical extraction methods have facilitated the analysis of very small bone fractions (500 μg or less starting material) for PO43-O isotope composition. However, the uniqueness and (pre-) historical value of each archaeological and paleontological finding lead to preciously little material available for stable isotope analyses, encouraging further development of microanalytical methods for the use of stable isotope analyses. Here we present the first results in developing extraction methods for combining collagen C- and N-isotope analyses to PO43-O-isotope analyses from a single bone sample fraction. We tested sequential extraction starting with dilute acid demineralization and collection of both collagen and PO43-fractions, followed by further purification step by H2O2 (PO43-fraction). First results show that bone sample separates as small as 2 mg may be analysed for their δ15N, δ13C and δ18OPO4 values. The method may be incorporated in detailed investigation of sequentially developing skeletal material such as teeth, potentially allowing for the investigation of interannual variability in climatological/environmental signals or investigation of the early life history of an individual.

  7. Stable isotope mass spectrometry in petroleum exploration

    International Nuclear Information System (INIS)

    Mathur, Manju

    1997-01-01

    The stable isotope mass spectrometry plays an important role to evaluate the stable isotopic composition of hydrocarbons. The isotopic ratios of certain elements in petroleum samples reflect certain characteristics which are useful for petroleum exploration

  8. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1984-03-01

    This report contains a listing of electromagnetically separated stable isotopes which are available at the Oak Ridge National Laboratory for distribution for nondestructive research use on a loan basis. This inventory includes all samples of stable isotopes in the Research Materials Collection and does not designate whether a sample is out on loan or is in reprocessing. For some of the high abundance naturally occurring isotopes, larger amounts can be made available; for example, Ca-40 and Fe-56

  9. Stable isotope studies

    International Nuclear Information System (INIS)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs

  10. Stable isotope analysis

    International Nuclear Information System (INIS)

    Tibari, Elghali; Taous, Fouad; Marah, Hamid

    2014-01-01

    This report presents results related to stable isotopes analysis carried out at the CNESTEN DASTE in Rabat (Morocco), on behalf of Senegal. These analyzes cover 127 samples. These results demonstrate that Oxygen-18 and Deuterium in water analysis were performed by infrared Laser spectroscopy using a LGR / DLT-100 with Autosampler. Also, the results are expressed in δ values (‰) relative to V-SMOW to ± 0.3 ‰ for oxygen-18 and ± 1 ‰ for deuterium.

  11. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  12. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Letolle, R.; Mariotti, A.; Bariac, T.

    1991-06-01

    This report reviews the historical background and the properties of stable isotopes, the methods used for their measurement (mass spectrometry and others), the present technics for isotope enrichment and separation, and at last the various present and foreseeable application (in nuclear energy, physical and chemical research, materials industry and research; tracing in industrial, medical and agronomical tests; the use of natural isotope variations for environmental studies, agronomy, natural resources appraising: water, minerals, energy). Some new possibilities in the use of stable isotope are offered. A last chapter gives the present state and forecast development of stable isotope uses in France and Europe

  13. Stable isotopes labelled compounds

    International Nuclear Information System (INIS)

    1982-09-01

    The catalogue on stable isotopes labelled compounds offers deuterium, nitrogen-15, and multiply labelled compounds. It includes: (1) conditions of sale and delivery, (2) the application of stable isotopes, (3) technical information, (4) product specifications, and (5) the complete delivery programme

  14. Stable Isotope Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tissue samples (skin, bone, blood, muscle) are analyzed for stable carbon, stable nitrogen, and stable sulfur analysis. Many samples are used in their entirety for...

  15. Nitrate stable isotopes and major ions in snow and ice samples from four Svalbard sites

    Directory of Open Access Journals (Sweden)

    Carmen P. Vega

    2015-04-01

    Full Text Available Increasing reactive nitrogen (Nr deposition in the Arctic may adversely impact N-limited ecosystems. To investigate atmospheric transport of Nr to Svalbard, Norwegian Arctic, snow and firn samples were collected from glaciers and analysed to define spatial and temporal variations (1–10 years in major ion concentrations and the stable isotope composition (δ15N and δ18O of nitrate (NO3- across the archipelago. The δ15N NO3- and δ18ONO3- averaged −4‰ and 67‰ in seasonal snow (2010–11 and −9‰ and 74‰ in firn accumulated over the decade 2001–2011. East–west zonal gradients were observed across the archipelago for some major ions (non-sea salt sulphate and magnesium and also for δ15NNO3- and δ18ONO3- in snow, which suggests a different origin for air masses arriving in different sectors of Svalbard. We propose that snowfall associated with long-distance air mass transport over the Arctic Ocean inherits relatively low δ15NNO3- due to in-transport N isotope fractionation. In contrast, faster air mass transport from the north-west Atlantic or northern Europe results in snowfall with higher δ15NNO3- because in-transport fractionation of N is then time-limited.

  16. Optimizing sample pretreatment for compound-specific stable carbon isotopic analysis of amino sugars in marine sediment

    Science.gov (United States)

    Zhu, R.; Lin, Y.-S.; Lipp, J. S.; Meador, T. B.; Hinrichs, K.-U.

    2014-09-01

    Amino sugars are quantitatively significant constituents of soil and marine sediment, but their sources and turnover in environmental samples remain poorly understood. The stable carbon isotopic composition of amino sugars can provide information on the lifestyles of their source organisms and can be monitored during incubations with labeled substrates to estimate the turnover rates of microbial populations. However, until now, such investigation has been carried out only with soil samples, partly because of the much lower abundance of amino sugars in marine environments. We therefore optimized a procedure for compound-specific isotopic analysis of amino sugars in marine sediment, employing gas chromatography-isotope ratio mass spectrometry. The whole procedure consisted of hydrolysis, neutralization, enrichment, and derivatization of amino sugars. Except for the derivatization step, the protocol introduced negligible isotopic fractionation, and the minimum requirement of amino sugar for isotopic analysis was 20 ng, i.e., equivalent to ~8 ng of amino sugar carbon. Compound-specific stable carbon isotopic analysis of amino sugars obtained from marine sediment extracts indicated that glucosamine and galactosamine were mainly derived from organic detritus, whereas muramic acid showed isotopic imprints from indigenous bacterial activities. The δ13C analysis of amino sugars provides a valuable addition to the biomarker-based characterization of microbial metabolism in the deep marine biosphere, which so far has been lipid oriented and biased towards the detection of archaeal signals.

  17. Stable isotope characterization of pan-derived and directly sampled atmospheric water vapour

    International Nuclear Information System (INIS)

    Maric, R.; St. Amour, N.A.; Gibson, J.J.; Edwards, T.W.D.

    2002-01-01

    Isotopic characterization of atmospheric water vapour, δ A , and its temporal variability are important prerequisites for quantifying water balance of surface reservoirs and partitioning of evaporation and transpiration fluxes using isotope techniques. Here we present results from a detailed comparison of several methods for determining δ A in field situations, (i) by back-calculation from isotopic and micrometeorological monitoring of a steady-state terminal reservoir (standard Class-A evaporation pan) using boundary-layer mass transfer models [1], (ii) through direct (cryogenic) sampling of ambient atmospheric moisture, and (iii) using the precipitation-equilibrium approximation (i.e., δ A =δ P - ε*)

  18. Measurements of stable isotope ratios in milk samples from a farm placed in the mountains of Transylvania

    International Nuclear Information System (INIS)

    Magdas, D. A.; Cristea, G.; Bot, A.; Puscas, R.; Radu, S.; Mirel, V.; Cordea, D. V.; Mihaiu, M.

    2013-01-01

    Product origin is of great importance for consumers especially because its association in consumer's perception with food quality, freedom from disease or pollution. Stable isotope ratio analysis is a powerful technique in food authenticity and traceability control which has been introduced within the European wine industry to ensure authenticity of wine provenance and to detect adulteration. Isotopic ratios measurements have also been successfully to other food commodities like: fruit juices, honey and dairy foods. The δ 18 O and δ 2 H content in milk water reflects the isotope composition of the ground water drunk by animals. Seasonal effects are also very important: in summer, milk water contains higher δ 18 O and δ 2 H values due to the fresh plants that are ate by animals. Relative carbon stable isotope abundances in total milk reflect the isotopic composition of the diet fed to the dairy cows. In this study the hydrogen, oxygen and carbon isotopic composition of 15 milk samples coming from a unit placed in the mountains of Transylvania was investigated. The distribution of the obtained isotopic values was than discussed taking into account that all the animals were feed with the same type of forage and consumed water was taken from the same source

  19. Measurements of stable isotope ratios in milk samples from a farm placed in the mountains of Transylvania

    Energy Technology Data Exchange (ETDEWEB)

    Magdas, D. A., E-mail: gabriela.cristea@itim-cj.ro; Cristea, G., E-mail: gabriela.cristea@itim-cj.ro; Bot, A.; Puscas, R.; Radu, S.; Mirel, V. [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania); Cordea, D. V.; Mihaiu, M. [University of Agricultural Science and Veterinary Medicine, 3-5 Calea Manastur, 400372 Cluj-Napoca (Romania)

    2013-11-13

    Product origin is of great importance for consumers especially because its association in consumer's perception with food quality, freedom from disease or pollution. Stable isotope ratio analysis is a powerful technique in food authenticity and traceability control which has been introduced within the European wine industry to ensure authenticity of wine provenance and to detect adulteration. Isotopic ratios measurements have also been successfully to other food commodities like: fruit juices, honey and dairy foods. The δ{sup 18}O and δ{sup 2}H content in milk water reflects the isotope composition of the ground water drunk by animals. Seasonal effects are also very important: in summer, milk water contains higher δ{sup 18}O and δ{sup 2}H values due to the fresh plants that are ate by animals. Relative carbon stable isotope abundances in total milk reflect the isotopic composition of the diet fed to the dairy cows. In this study the hydrogen, oxygen and carbon isotopic composition of 15 milk samples coming from a unit placed in the mountains of Transylvania was investigated. The distribution of the obtained isotopic values was than discussed taking into account that all the animals were feed with the same type of forage and consumed water was taken from the same source.

  20. Measurements of stable isotope ratios in milk samples from a farm placed in the mountains of Transylvania

    Science.gov (United States)

    Magdas, D. A.; Cristea, G.; Cordea, D. V.; Bot, A.; Puscas, R.; Radu, S.; Mirel, V.; Mihaiu, M.

    2013-11-01

    Product origin is of great importance for consumers especially because its association in consumer's perception with food quality, freedom from disease or pollution. Stable isotope ratio analysis is a powerful technique in food authenticity and traceability control which has been introduced within the European wine industry to ensure authenticity of wine provenance and to detect adulteration. Isotopic ratios measurements have also been successfully to other food commodities like: fruit juices, honey and dairy foods. The δ18O and δ2H content in milk water reflects the isotope composition of the ground water drunk by animals. Seasonal effects are also very important: in summer, milk water contains higher δ18O and δ2H values due to the fresh plants that are ate by animals. Relative carbon stable isotope abundances in total milk reflect the isotopic composition of the diet fed to the dairy cows. In this study the hydrogen, oxygen and carbon isotopic composition of 15 milk samples coming from a unit placed in the mountains of Transylvania was investigated. The distribution of the obtained isotopic values was than discussed taking into account that all the animals were feed with the same type of forage and consumed water was taken from the same source.

  1. Stable isotope ratio measurements on highly enriched water samples by means of laser spectrometry

    NARCIS (Netherlands)

    van Trigt, R; Kerstel, E.R.T.; Visser, GH; Meijer, H.A.J.

    2001-01-01

    We demonstrate the feasibility of using laser spectrometry (LS) to analyze isotopically highly enriched water samples (i.e., delta H-2 less than or equal to 15000 parts per thousand, delta O-18 less than or equal to 1200 parts per thousand), as often used in the biomedical doubly labeled water (DLW)

  2. Use of fast atom bombardment mass spectrometry (FAB MS) for the analysis of zinc stable isotopes in biological samples

    International Nuclear Information System (INIS)

    Peirce, P.; Fennessey, P.; Hambidge, M.; Miller, L.; Goss, C.

    1986-01-01

    The use of stable isotopes offer a means of measuring human metabolism of trace metals in populations in which radioisotopes are contraindicated. The objective of this research has been to develop stable isotope methodology for the measurement of zinc in biological samples and to apply this methodology in pilot studies of intestinal zinc absorption. Analyses were made with a VG 7070E HF sector mass spectrometer at a resolution of 3000. Samples of 10 μl containing approximately 1 μg Zn were applied directly to a gold target, dried and inserted into the FAB source for ionization. Precision at the 1% level of enrichment was 2% (RSD). Pilot studies of the clinical application have been undertaken on two subjects to each of whom a single oral dose of enriched 70 Zn was administered after an overnight fast. A comparison of aqueous standards and prepared fecal samples showed undetectable levels of contamination at the 64 Zn to 70 Zn masses. Precision of fecal samples is comparable to that of aqueous standards. Calculated absorption after an overnight fast was between 60-65% of the administered dose. The FAB MS provides a simple, sensitive and precise technique for the measurement of zinc stable isotopes in biological samples

  3. A novel high-temperature combustion based system for stable isotope analysis of dissolved organic carbon in aqueous samples. : I development and validation

    NARCIS (Netherlands)

    Federherr, E.; Cerli, C.; Kirkels, F. M. S. A.; Kalbitz, K.; Kupka, H. J.; Dunsbach, R.; Lange, L.; Schmidt, T. C.

    2014-01-01

    RATIONALE: Traditionally, dissolved organic carbon (DOC) stable isotope analysis (SIA) is performed using either offline sample preparation followed by elemental analyzer/isotope ratiomass spectrometry (EA/IRMS) or a wet chemical oxidation (WCO)-based device coupled to an isotope ratio mass

  4. Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moran, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nims, Megan K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Saunders, Danielle L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-04-13

    Fine-grained sediments associated with the Cold Creek Unit at Hanford have caused the formation of a perched water aquifer in the deep vadose zone at the B Complex area, which includes waste sites in the 200-DV-1 Operable Unit and the single-shell tank farms in Waste Management Area B-BX-BY. High levels of contaminants, such as uranium, technetium-99, and nitrate, make this aquifer a continuing source of contamination for the groundwater located a few meters below the perched zone. Analysis of deuterium (2H) and 18-oxygen (18O) of nine perched water samples from three different wells was performed. Samples represent time points from hydraulic tests performed on the perched aquifer using the three wells. The isotope analyses showed that the perched water had δ2H and δ18O ratios consistent with the regional meteoric water line, indicating that local precipitation events at the Hanford site likely account for recharge of the perched water aquifer. Data from the isotope analysis can be used along with pumping and recovery data to help understand the perched water dynamics related to aquifer size and hydraulic control of the aquifer in the future.

  5. The efficacy of scale sampling for monitoring trace element concentrations and stable isotopes in commercially harvested walleye (Sander vitreus).

    Science.gov (United States)

    Ofukany, Amy F A; Hobson, Keith A; Wassenaar, Leonard I; Bond, Alexander L

    2015-01-01

    Commercial and sport fishes are subject to rigorous monitoring for concentrations of elements that could pose threats to human health, with numerous advisories issued by authorities annually for those fisheries with high mercury (Hg) concentrations. In Lake Winnipeg, Manitoba, Canada, the commercial walleye fishery is valued at more than $20 million/year, but has historically been subject to Hg advisories. We used an information theoretic approach to evaluate the utility of non-destructive fish-scale sampling to predict As, Mn and Hg concentrations, as well as stable isotope values in walleye muscle by analysing paired samples. Hg concentrations in scales were significantly related to those in muscle (r(2) = 0.75), but the relationships were weaker for As and Mn. The δ(15)N values in scales predicted δ(15)N in muscle reasonably well (r(2) = 0.72), whereas scale δ(13)C and δ(34)S had less predictive power for estimating their respective muscle stable isotope values. For all three isotope values, sex was a marginal predictor, with parameter confidence intervals bounding zero. Analytical constraints currently limit the utility of non-destructively analysing scales for Hg, but hindcasting trophic changes using archived walleye scales may be useful in understanding shifts in nutrients and production, particularly in impacted lake systems.

  6. Laser-based measurements of 18O/16O stable isotope ratios (δ18O in wine samples

    Directory of Open Access Journals (Sweden)

    Gupta M

    2013-09-01

    Full Text Available Manish Gupta,1 J Brian Leen,1 Elena Simone Franklin Berman,1 Aldo Ciambotti2 1Los Gatos Research, Mountain View, CA, USA; 2Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centro di Ricerca per l'Enologia, Asti, Italy Abstract: Wine counterfeiting is an international, multi-billion dollar issue, with some estimates suggesting that up to 5% of wines sold at auctions or secondary markets are fraudulent. Isotope ratio mass spectrometer (IRMS measurements of the 18O/16O stable isotope ratio (δ18O of water-in-wine have been used for wine authentication; however, these analyses are time-consuming and costly. In this preliminary study, off-axis integrated cavity output spectroscopy (OA-ICOS is used to quantify δ18O in wines. This laser-based method has been extensively used to study water isotopes for hydrological and medical applications. Recently, the development of a spectral contaminant identifier (SCI has extended the application of these OA-ICOS analyzers to contaminated water samples (eg, plant, soil, and leaf waters. Here, we utilize OA-ICOS with the SCI to characterize wine samples (9%–15% ethanol, and show that the laser-based instrument provides a δ18O measurement precision of ±0.07‰ (1σ and agrees with IRMS to within ±0.63‰ (1σ. Moreover, by training the SCI on isotopically-characterized wines, the agreement with IRMS improves to within ±0.30‰ (1σ. The utility of the instrument is demonstrated by measuring watered and mixed wines. The method presented here can be readily extended to address other food authentication applications. Keywords: wine isotopes, wine fraud, counterfeit wines, OA-ICOS

  7. Stable isotope separation

    International Nuclear Information System (INIS)

    Botter, F.; Molinari, Ph.; Dirian, G.

    1964-01-01

    Pure deuterium has been separated from gaseous mixtures of hydrogen and deuterium by band displacement chromatography, using columns of palladium on a support. The best results were obtained with columns of Pd on sintered α alumina. With a column of this type, of total capacity about 2 liters, a preparative apparatus of low dead volume has been built which produces 1 liter of pure D 2 from a 50 p. 100 D 2 , 50 p. 100 100 H 2 mixture in about 12 minutes. As a first approximation chromatography is likened theoretically to counter current fractionation, neglecting superficial resistance to the exchange. and also longitudinal diffusions. The number of theoretical plates required necessary for a certain enrichment of the gas phase is determined graphically or by calculation, enabling comparisons to be made between the efficiencies of columns containing different amounts of palladium. Thermal Diffusion: For the separation of hydrogen isotopes a thermal diffusion installation, made of stainless steel and entirely tele-commanded has been constructed. The separation cascade is made up of two identical pairs of hot wire columns. Each pair can work separately or they may be connected by a thermosyphon. The temperature of the hot wire is kept at around 1000 deg C by direct current. With this installation, hydrogen samples with a deuterium content lower than o,5 ppm were obtained from a gas originally containing 32 ppm. It was thus possible to prepare tritium of 99,3 p. 100 concentration from gas with an initial content of 6 p. 100. For quantitative separation of xenon enriched five time in 124 Xe by thermal diffusion, two identical cascades were constructed, each consisting of 5 columns, working in parallel and the two being connected by thermosyphon or by a capillary tube linked to a thermal gas oscillation. The central tungsten wire is heated to 1200 deg C. The columns are grouped like cluster of a heat exchanger, in shell of 30 cm diameter through which cooling water

  8. SELDI-TOF-MS determination of hepcidin in clinical samples using stable isotope labelled hepcidin as an internal standard

    Directory of Open Access Journals (Sweden)

    Johnson Philip J

    2008-10-01

    Full Text Available Abstract Background Hepcidin is a 25-residue peptide hormone crucial to iron homeostasis. It is essential to measure the concentration of hepcidin in cells, tissues and body fluids to understand its mechanisms and roles in physiology and pathophysiology. With a mass of 2791 Da hepcidin is readily detectable by mass spectrometry and LC-ESI, MALDI and SELDI have been used to estimate systemic hepcidin concentrations by analysing serum or urine. However, peak heights in mass spectra may not always reflect concentrations in samples due to competition during binding steps and variations in ionisation efficiency. Thus the purpose of this study was to develop a robust assay for measuring hepcidin using a stable isotope labelled hepcidin spiking approach in conjunction with SELDI-TOF-MS. Results We synthesised and re-folded hepcidin labelled with 13C/15N phenylalanine at position 9 to generate an internal standard for mass spectrometry experiments. This labelled hepcidin is 10 Daltons heavier than the endogenous peptides and does not overlap with the isotopic envelope of the endogenous hepcidin or other common peaks in human serum or urine mass spectra and can be distinguished in low resolution mass spectrometers. We report the validation of adding labelled hepcidin into serum followed by SELDI analysis to generate an improved assay for hepcidin. Conclusion We demonstrate that without utilising a spiking approach the hepcidin peak height in SELDI spectra gives a good indication of hepcidin concentration. However, a stable isotope labelled hepcidin spiking approach provides a more robust assay, measures the absolute concentration of hepcidin and should facilitate inter-laboratory hepcidin comparisons.

  9. Determination of Resistant Starch Assimilating Bacteria in Fecal Samples of Mice by In vitro RNA-Based Stable Isotope Probing

    Directory of Open Access Journals (Sweden)

    Elena Herrmann

    2017-07-01

    Full Text Available The impact of the intestinal microbiota on human health is becoming increasingly appreciated in recent years. In consequence, and fueled by major technological advances, the composition of the intestinal microbiota in health and disease has been intensively studied by high throughput sequencing approaches. Observations linking dysbiosis of the intestinal microbiota with a number of serious medical conditions including chronic inflammatory disorders and allergic diseases suggest that restoration of the composition and activity of the intestinal microbiota may be a treatment option at least for some of these diseases. One possibility to shape the intestinal microbiota is the administration of prebiotic carbohydrates such as resistant starch (RS. In the present study, we aim at establishing RNA-based stable isotope probing (RNA-SIP to identify bacterial populations that are involved in the assimilation of RS using anaerobic in vitro fermentation of murine fecal material with stable [U13C] isotope-labeled potato starch. Total RNA from these incubations was extracted, processed by gradient ultracentrifugation and fractionated by density. 16S rRNA gene sequences were amplified from reverse transcribed RNA of high and low density fractions suspected to contain labeled and unlabeled RNA, respectively. Phylogenetic analysis of the obtained sequences revealed a distinct subset of the intestinal microbiota involved in starch metabolism. The results suggest Bacteroidetes, in particular genera affiliated with Prevotellaceae, as well as members of the Ruminococcacea family to be primary assimilators of resistant starch due to a significantly higher relative abundance in higher density fractions in RNA samples isolated after 2 h of incubation. Using high performance liquid chromatography coupled to isotope ratio mass spectrometry (HPLC-IRMS analysis, some stable isotope label was recovered from acetate, propionate and butyrate. Here, we demonstrate the

  10. Pharmaceuticals labelled with stable isotopes

    International Nuclear Information System (INIS)

    Krumbiegel, P.

    1986-11-01

    The relatively new field of pharmaceuticals labelled with stable isotopes is reviewed. Scientific, juridical, and ethical questions are discussed concerning the application of these pharmaceuticals in human medicine. 13 C, 15 N, and 2 H are the stable isotopes mainly utilized in metabolic function tests. Methodical contributions are given to the application of 2 H, 13 C, and 15 N pharmaceuticals showing new aspects and different states of development in the field under discussion. (author)

  11. Quality assurance and quality control in light stable isotope laboratories: A case study of Rio Grande, Texas, water samples

    Science.gov (United States)

    Coplen, T.B.; Qi, H.

    2009-01-01

    New isotope laboratories can achieve the goal of reporting the same isotopic composition within analytical uncertainty for the same material analysed decades apart by (1) writing their own acceptance testing procedures and putting them into their mass spectrometric or laser-based isotope-ratio equipment procurement contract, (2) requiring a manufacturer to demonstrate acceptable performance using all sample ports provided with the instrumentation, (3) for each medium to be analysed, prepare two local reference materials substantially different in isotopic composition to encompass the range in isotopic composition expected in the laboratory and calibrated them with isotopic reference materials available from the International Atomic Energy Agency (IAEA) or the US National Institute of Standards and Technology (NIST), (4) using the optimum storage containers (for water samples, sealing in glass ampoules that are sterilised after sealing is satisfactory), (5) interspersing among sample unknowns local laboratory isotopic reference materials daily (internationally distributed isotopic reference materials can be ordered at three-year intervals, and can be used for elemental analyser analyses and other analyses that consume less than 1 mg of material) - this process applies to H, C, N, O, and S isotope ratios, (6) calculating isotopic compositions of unknowns by normalising isotopic data to that of local reference materials, which have been calibrated to internationally distributed isotopic reference materials, (7) reporting results on scales normalised to internationally distributed isotopic reference materials (where they are available) and providing to sample submitters the isotopic compositions of internationally distributed isotopic reference materials of the same substance had they been analysed with unknowns, (8) providing an audit trail in the laboratory for analytical results - this trail commonly will be in electronic format and might include a laboratory

  12. Stable Isotope Group 1983 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1984-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and related fields, and mass spectrometer instrumentation, during 1983, is described

  13. Stable Isotope Group 1982 progress report

    International Nuclear Information System (INIS)

    Stewart, M.K.

    1983-06-01

    The work of the Stable Isotope Group of the Institute of Nuclear Sciences during 1982, in the fields of isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation, is described

  14. Applications of stable isotopes

    International Nuclear Information System (INIS)

    Gregg, C.T.

    1977-01-01

    Clinical applications include the galactose breath test which consists of oral administration of 13 C-labeled galactose and measurement of the 13 C content of respired CO 2 as a function of time in patients with cirrhotic livers for diagnosis of liver dysfunction. Another application was the breath test to study glucose metabolism in children. Respired 13 CO 2 from ingested glucose- 13 C was measured for normal and diabetic children. Studies on mice in which 60 percent of the body carbon was replaced with 13 C failed to show significant effects of the isotope. Studies on biochemical applications include nuclear magnetic resonance studies of 13 C-labeled amino acids from Chlorella pyrenoidosa; studies on 15 N nmr spectra of arginine-guanidino- 13 C-2,3-- 15 N 2 as a function of pH; and isolation of fatty acids from algae

  15. Persistent organic pollutants and stable isotopes in biopsy samples (2004/2006) from Southern Resident killer whales

    Energy Technology Data Exchange (ETDEWEB)

    Krahn, Margaret M. [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112 (United States)], E-mail: peggy.krahn@noaa.gov; Hanson, M. Bradley [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112 (United States); Baird, Robin W. [Cascadia Research, 218 1/2 W, 4th Avenue, Olympia, WA 98501 (United States); Boyer, Richard H.; Burrows, Douglas G.; Emmons, Candice K. [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112 (United States); Ford, John K.B. [Fisheries and Oceans Canada, Pacific Biological Station, Nanaimo, BC, V9R 5K6 (Canada); Jones, Linda L.; Noren, Dawn P. [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112 (United States); Ross, Peter S. [Fisheries and Oceans Canada, Institute of Ocean Sciences, P.O. Box 6000, Sidney, BC, V8L 4B2 (Canada); Schorr, Gregory S. [Cascadia Research, 218 1/2 W, 4th Avenue, Olympia, WA 98501 (United States); Collier, Tracy K. [NOAA Fisheries, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112 (United States)

    2007-12-15

    'Southern Resident' killer whales include three 'pods' (J, K and L) that reside primarily in Puget Sound/Georgia Basin during the spring, summer and fall. This population was listed as 'endangered' in the US and Canada following a 20% decline between 1996 and 2001. The current study, using blubber/epidermis biopsy samples, contributes contemporary information about potential factors (i.e., levels of pollutants or changes in diet) that could adversely affect Southern Residents. Carbon and nitrogen stable isotopes indicated J- and L-pod consumed prey from similar trophic levels in 2004/2006 and also showed no evidence for a large shift in the trophic level of prey consumed by L-pod between 1996 and 2004/2006. {sigma}PCBs decreased for Southern Residents biopsied in 2004/2006 compared to 1993-1995. Surprisingly, however, a three-year-old male whale (J39) had the highest concentrations of {sigma}PBDEs, {sigma}HCHs and HCB. POP ratio differences between J- and L-pod suggested that they occupy different ranges in winter.

  16. Metabolic studies in man using stable isotopes

    International Nuclear Information System (INIS)

    Faust, H.; Jung, K.; Krumbiegel, P.

    1993-01-01

    In this project, stable isotope compounds and stable isotope pharmaceuticals were used (with emphasis on the application of 15 N) to study several aspects of nitrogen metabolism in man. Of the many methods available, the 15 N stable isotope tracer technique holds a special position because the methodology for application and nitrogen isotope analysis is proven and reliable. Valid routine methods using 15 N analysis by emission spectrometry have been demonstrated. Several methods for the preparation of biological material were developed during our participation in the Coordinated Research Programme. In these studies, direct procedures (i.e. use of diluted urine as a samples without chemical preparation) or rapid isolation methods were favoured. Within the scope of the Analytical Quality Control Service (AQCS) enriched stable isotope reference materials for medical and biological studies were prepared and are now available through the International Atomic Energy Agency. The materials are of special importance as the increasing application of stable isotopes as tracers in medical, biological and agricultural studies has focused interest on reliable measurements of biological material of different origin. 24 refs

  17. Measurement of C and N isotopes of geological samples using Delta V Plus Stable Isotope Ratio Mass Spectrometer via different preparatory systems

    Digital Repository Service at National Institute of Oceanography (India)

    Karapurkar, S.; Methar, A.; Agnihotri, R.

    standardization of newly acquired IRMS (Delta V Plus; Thermo) dedicated for measurements of C & N isotopes in a variety of geological solid samples. Results were calibrated against each other using different preparatory systems such as on-line combustion...

  18. Stable isotopes in Lithuanian bioarcheological material

    Science.gov (United States)

    Skipityte, Raminta; Jankauskas, Rimantas; Remeikis, Vidmantas

    2015-04-01

    Investigation of bioarcheological material of ancient human populations allows us to understand the subsistence behavior associated with various adaptations to the environment. Feeding habits are essential to the survival and growth of ancient populations. Stable isotope analysis is accepted tool in paleodiet (Schutkowski et al, 1999) and paleoenvironmental (Zernitskaya et al, 2014) studies. However, stable isotopes can be useful not only in investigating human feeding habits but also in describing social and cultural structure of the past populations (Le Huray and Schutkowski, 2005). Only few stable isotope investigations have been performed before in Lithuanian region suggesting a quite uniform diet between males and females and protein intake from freshwater fish and animal protein. Previously, stable isotope analysis has only been used to study a Stone Age population however, more recently studies have been conducted on Iron Age and Late medieval samples (Jacobs et al, 2009). Anyway, there was a need for more precise examination. Stable isotope analysis were performed on human bone collagen and apatite samples in this study. Data represented various ages (from 5-7th cent. to 18th cent.). Stable carbon and nitrogen isotope analysis on medieval populations indicated that individuals in studied sites in Lithuania were almost exclusively consuming C3 plants, C3 fed terrestrial animals, and some freshwater resources. Current investigation demonstrated social differences between elites and country people and is promising in paleodietary and daily life reconstruction. Acknowledgement I thank prof. dr. G. Grupe, Director of the Anthropological and Palaeoanatomical State Collection in Munich for providing the opportunity to work in her laboratory. The part of this work was funded by DAAD. Antanaitis-Jacobs, Indre, et al. "Diet in early Lithuanian prehistory and the new stable isotope evidence." Archaeologia Baltica 12 (2009): 12-30. Le Huray, Jonathan D., and Holger

  19. petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    PROF EKWUEME

    Subsurface samples of the predominantly carbonate Ewekoro Formation, obtained from Ibese core hole within the Dahomey basin were used in this study. Investigations entail petrographic, elemental composition as well as stable isotopes (carbon and oxygen) geochemistry in order to deduce the different microfacies and ...

  20. Organic synthesis with stable isotopes

    International Nuclear Information System (INIS)

    Daub, G.H.; Kerr, V.N.; Williams, D.L.; Whaley, T.W.

    1978-01-01

    Some general considerations concerning organic synthesis with stable isotopes are presented. Illustrative examples are described and discussed. The examples include DL-2-amino-3-methyl- 13 C-butanoic-3,4- 13 C 2 acid (DL-valine- 13 C 3 ); methyl oleate-1- 13 C; thymine-2,6- 13 C 2 ; 2-aminoethanesulfonic- 13 C acid (taurine- 13 C); D-glucose-6- 13 C; DL-2-amino-3-methylpentanoic-3,4- 13 C 2 acid (DL-isoleucine- 13 C 2 ); benzidine- 15 N 2 ; and 4-ethylsulfonyl-1-naphthalene-sulfonamide- 15 N

  1. Stable isotopes and biomarkers in microbial ecology

    NARCIS (Netherlands)

    Boschker, H.T.S.; Middelburg, J.J.

    2002-01-01

    The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope

  2. Uses of stable isotopes in fish ecology

    Science.gov (United States)

    Analyses of fish tissues (other than otoliths) for stable isotope ratios can provide substantial information on fish ecology, including physiological ecology. Stable isotopes of nitrogen and carbon frequently are used to determine the mix of diet sources for consumers. Stable i...

  3. Periodicity of the stable isotopes

    CERN Document Server

    Boeyens, J C A

    2003-01-01

    It is demonstrated that all stable (non-radioactive) isotopes are formally interrelated as the products of systematically adding alpha particles to four elementary units. The region of stability against radioactive decay is shown to obey a general trend based on number theory and contains the periodic law of the elements as a special case. This general law restricts the number of what may be considered as natural elements to 100 and is based on a proton:neutron ratio that matches the golden ratio, characteristic of biological and crystal growth structures. Different forms of the periodic table inferred at other proton:neutron ratios indicate that the electronic configuration of atoms is variable and may be a function of environmental pressure. Cosmic consequences of this postulate are examined. (author)

  4. Correlation between the synthetic origin of methamphetamine samples and their {sup 15}N and {sup 13}C stable isotope ratios

    Energy Technology Data Exchange (ETDEWEB)

    Billault, Isabelle [Laboratoire d' Analyse Isotopique et Electrochimique de Metabolismes, CNRS UMR6006, University of Nantes, BP 92208, 44322 Nantes (France)]. E-mail: Isabelle.Billault@univ-nantes.fr; Courant, Frederique [Laboratoire d' Analyse Isotopique et Electrochimique de Metabolismes, CNRS UMR6006, University of Nantes, BP 92208, 44322 Nantes (France); Pasquereau, Leo [Laboratoire d' Analyse Isotopique et Electrochimique de Metabolismes, CNRS UMR6006, University of Nantes, BP 92208, 44322 Nantes (France); Derrien, Solene [Laboratoire d' Analyse Isotopique et Electrochimique de Metabolismes, CNRS UMR6006, University of Nantes, BP 92208, 44322 Nantes (France); Robins, Richard J. [Laboratoire d' Analyse Isotopique et Electrochimique de Metabolismes, CNRS UMR6006, University of Nantes, BP 92208, 44322 Nantes (France); Naulet, Norbert [Laboratoire d' Analyse Isotopique et Electrochimique de Metabolismes, CNRS UMR6006, University of Nantes, BP 92208, 44322 Nantes (France)

    2007-06-12

    The active ingredient of ecstasy, N-methyl-3,4-methyldioxyphenylisopropylamine (MDMA) can be manufactured by a number of easy routes from simple precursors. We have synthesised 45 samples of MDMA following the five most common routes using N-precursors from 12 different origins and three different precursors for the aromatic moiety. The {sup 13}C and {sup 15}N contents of both the precursors and the MDMA samples derived therefrom were measured by isotope ratio mass spectrometry coupled to an elemental analyser (EA-IRMS). We show that within-pathway correlation between the {sup 15}N content of the precursor and that of the derived MDMA can be strong but that no general pattern of correlation can be defined. Rather, it is evident that the {delta} {sup 15}N values of MDMA are strongly influenced by a combination of the {delta} {sup 15}N values of the source of nitrogen used, the route by which the MDMA is synthesised, and the experimental conditions employed. Multivariate analysis (PCA) based on the {delta} {sup 15}N values of the synthetic MDMA and of the {delta} {sup 15}N and {delta} {sup 13}C values of the N-precursors leads to good discrimination between the majority of the reaction conditions tested.

  5. Substitution of stable isotopes in Chlorella

    Science.gov (United States)

    Flaumenhaft, E.; Katz, J. J.; Uphaus, R. A.

    1969-01-01

    Replacement of biologically important isotopes in the alga Chlorella by corresponding heavier stable isotopes produces increasingly greater deviations from the normal cell size and changes the quality and distribution of certain cellular components. The usefulness of isotopically altered organisms increases interest in the study of such permuted organisms.

  6. Tungsten Stable Isotope Compositions of Ferromanganese Crusts

    Science.gov (United States)

    Abraham, K.; Barling, J.; Hein, J. R.; Schauble, E. A.; Halliday, A. N.

    2014-12-01

    We report the first accurate and precise data for mass-dependent fractionation of tungsten (W) stable isotopes, using a double spike technique and MC-ICPMS. Results are expressed relative to the NIST 3136 W isotope standard as per mil deviations in 186W/184W (δ186W). Although heavy element mass-dependent fractionations are expected to be small, Tl and U both display significant low temperature isotopic fractionations. Theoretical calculations indicate that W nuclear volume isotopic effects should be smaller than mass-dependent fractionations at low temperatures. Hydrogenetic ferromanganese (Fe-Mn) crusts precipitate directly from seawater and have been used as paleoceanographic recorders of temporal changes in seawater chemistry. Crusts are strongly enriched in W and other metals, and are a promising medium for exploring W isotopic variability. Tungsten has a relatively long residence time in seawater of ~61,000 years, mainly as the tungstate ion (WO42-). Water depth profiles show conservative behaviour. During adsorption on Fe-Mn crusts, W species form inner-sphere complexes in the hexavalent (W6+) state. The major host phase is thought to be Mn oxides and the lighter W isotope is expected to be absorbed preferentially. Surface scrapings of 13 globally distributed hydrogenetic Fe-Mn crusts display δ186W from -0.08 to -0.22‰ (±0.03‰, 2sd). A trend toward lighter W isotope composition exists with increasing water depth (~1500 to ~5200m) and W concentration. One hydrothermal Mn-oxide sample is anomalously light and Mn nodules are both heavy and light relative to Fe-Mn crusts. Tungsten speciation depends on concentration, pH, and time in solution and is not well understood because of the extremely slow kinetics of the reactions. In addition, speciation of aqueous and/or adsorbed species might be sensitive to pressure, showing similar thermodynamic stability but different effective volumes. Thus, W stable isotopes might be used as a water-depth barometer in

  7. Modelling stable water isotopes: Status and perspectives

    Directory of Open Access Journals (Sweden)

    Werner M.

    2010-12-01

    Full Text Available Modelling of stable water isotopes H2 18O and HDO within various parts of the Earth’s hydrological cycle has clearly improved our understanding of the interplay between climatic variations and related isotope fractionation processes. In this article key principles and major research results of stable water isotope modelling studies are described. Emphasis is put on research work using explicit isotope diagnostics within general circulation models as this highly complex model setup bears many resemblances with studies using simpler isotope modelling approaches.

  8. Gas phase thermal diffusion of stable isotopes

    International Nuclear Information System (INIS)

    Eck, C.F.

    1979-01-01

    The separation of stable isotopes at Mound Facility is reviewed from a historical perspective. The historical development of thermal diffusion from a laboratory process to a separation facility that handles all the noble gases is described. In addition, elementary thermal diffusion theory and elementary cascade theory are presented along with a brief review of the uses of stable isotopes

  9. physico-chemical and stable isotopes

    African Journals Online (AJOL)

    This paper details the mineralogical, chemical and stable isotope abundances of calcrete in the Letlhakeng fossil valley. The stable isotope abundances (O and C) of calcretes yielded some values which were tested against the nature of the calcretes – pedogenic or groundwater type. The Kgalagadi (Kalahari) is a vast ...

  10. Stable isotope labeling strategy based on coding theory

    International Nuclear Information System (INIS)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori

    2015-01-01

    We describe a strategy for stable isotope-aided protein nuclear magnetic resonance (NMR) analysis, called stable isotope encoding. The basic idea of this strategy is that amino-acid selective labeling can be considered as “encoding and decoding” processes, in which the information of amino acid type is encoded by the stable isotope labeling ratio of the corresponding residue and it is decoded by analyzing NMR spectra. According to the idea, the strategy can diminish the required number of labelled samples by increasing information content per sample, enabling discrimination of 19 kinds of non-proline amino acids with only three labeled samples. The idea also enables this strategy to combine with information technologies, such as error detection by check digit, to improve the robustness of analyses with low quality data. Stable isotope encoding will facilitate NMR analyses of proteins under non-ideal conditions, such as those in large complex systems, with low-solubility, and in living cells

  11. Accurate Determination of Amino Acids in Serum Samples by Liquid Chromatography-Tandem Mass Spectrometry Using a Stable Isotope Labeling Strategy.

    Science.gov (United States)

    Song, Cuihua; Zhang, Shijuan; Ji, Zhongyin; Li, Yipeng; You, Jinmao

    2015-10-01

    An accurate and sensitive liquid chromatography-tandem mass spectrometry method was developed for the analysis of amino acids (isoleucine, leucine, valine, tyrosine, phenylalanine and tryptophan) in serum samples using a stable isotope labeling strategy. Amino acid samples and standards were, respectively, derivatized by 10-methyl-acridone-2-sulfonyl chloride (d0-MASC) and its deuterated counterpart d3-MASC to form isotopic pairs which co-eluted and were detected by an MS detector at the same time. Accurate internal standard-based quantification was thereby achieved without the use of any internal standard analogy. The labeling reaction of MASC with amino acids is fast, simple and robust. Besides, derivatization increased the molecular weight of amino acids, and therefore they were shifted out of the background noise which was often observed in low mass region. The instrument LODs were in the range of 1.0-2.5 nmol/L. Linearities calculated by comparing theoretical peak area ratios of d0-/d3-MASC derivatives with the experimental peak area ratios were excellent with correlation coefficients of >0.995. The proposed method was successfully applied to the analysis of amino acids in serum samples with high sensitivity and accuracy. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. High-precision dual-inlet IRMS measurements of the stable isotopes of CO2 and the N2O / CO2 ratio from polar ice core samples

    Directory of Open Access Journals (Sweden)

    T. K. Bauska

    2014-11-01

    Full Text Available An important constraint on mechanisms of past carbon cycle variability is provided by the stable isotopic composition of carbon in atmospheric carbon dioxide (δ13C-CO2 trapped in polar ice cores, but obtaining very precise measurements has proven to be a significant analytical challenge. Here we describe a new technique to determine the δ13C of CO2 at very high precision, as well as measuring the CO2 and N2O mixing ratios. In this method, ancient air is extracted from relatively large ice samples (~400 g with a dry-extraction "ice grater" device. The liberated air is cryogenically purified to a CO2 and N2O mixture and analyzed with a microvolume-equipped dual-inlet IRMS (Thermo MAT 253. The reproducibility of the method, based on replicate analysis of ice core samples, is 0.02‰ for δ13C-CO2 and 2 ppm and 4 ppb for the CO2 and N2O mixing ratios, respectively (1σ pooled standard deviation. Our experiments show that minimizing water vapor pressure in the extraction vessel by housing the grating apparatus in a ultralow-temperature freezer (−60 °C improves the precision and decreases the experimental blank of the method to −0.07 ± 0.04‰. We describe techniques for accurate calibration of small samples and the application of a mass-spectrometric method based on source fragmentation for reconstructing the N2O history of the atmosphere. The oxygen isotopic composition of CO2 is also investigated, confirming previous observations of oxygen exchange between gaseous CO2 and solid H2O within the ice archive. These data offer a possible constraint on oxygen isotopic fractionation during H2O and CO2 exchange below the H2O bulk melting temperature.

  13. Allan Hills Stable Water Isotopes, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes stable water isotope values at 10 m resolution along an approximately 5 km transect through the main icefield of the Allan Hills Blue Ice...

  14. Applications of stable isotopes in clinical pharmacology

    Science.gov (United States)

    Schellekens, Reinout C A; Stellaard, Frans; Woerdenbag, Herman J; Frijlink, Henderik W; Kosterink, Jos G W

    2011-01-01

    This review aims to present an overview of the application of stable isotope technology in clinical pharmacology. Three main categories of stable isotope technology can be distinguished in clinical pharmacology. Firstly, it is applied in the assessment of drug pharmacology to determine the pharmacokinetic profile or mode of action of a drug substance. Secondly, stable isotopes may be used for the assessment of drug products or drug delivery systems by determination of parameters such as the bioavailability or the release profile. Thirdly, patients may be assessed in relation to patient-specific drug treatment; this concept is often called personalized medicine. In this article, the application of stable isotope technology in the aforementioned three areas is reviewed, with emphasis on developments over the past 25 years. The applications are illustrated with examples from clinical studies in humans. PMID:21801197

  15. Introducing fecal stable isotope analysis in primate weaning studies.

    Science.gov (United States)

    Reitsema, Laurie J

    2012-10-01

    This research investigates the potential of a new, noninvasive method for determining age of weaning among primates using stable carbon and nitrogen isotope ratios in feces. Analysis of stable isotope ratios in body tissues is a well-established method in archeology and ecology for reconstructing diet. This is the first study to investigate weaning in primates using fecal stable isotope ratios. Diets of a single François' langur (Trachypithecus francoisi) mother-infant pair at the Toledo Zoo are reconstructed using this technique to track changes in infant suckling behavior over the weaning period. Stable isotope ratios in feces are sampled instead of more traditional samples such as bone or hair to enable daily, noninvasive snapshots of weaning status. Isotopic assessments of weaning status are compared to visual assessments to identify any discordance between the two. Three measurements documented the transition from breast milk to solid foods: stable carbon isotope ratios (δ(13)C), stable nitrogen isotope ratios (δ(15)N), and nitrogen content of feces (%N). It appears that solid foods were introduced at approximately 2 months of infant age, but that nursing continued into the 12th month, when sample collection ceased. Stable isotope data exposed a much longer weaning period than what was expected based on previously published data for captive langurs, and clarified visual estimates of weaning status. This reflects the method's sensitivity to suckling at night and ability to distinguish actual nursing from comfort nursing. After testing this method with zoo animals, it can readily be applied among wild populations. An isotopic approach to weaning provides a new, accurate, and biologically meaningful assessment of interbirth intervals, and facilitates a better understanding of mother-infant interactions. Both of these outcomes are critical for developing successful conservation strategies for captive and wild primates. © 2012 Wiley Periodicals, Inc.

  16. A biomarker based on the stable isotopes of nickel

    Science.gov (United States)

    Cameron, Vyllinniskii; Vance, Derek; Archer, Corey; House, Christopher H.

    2009-01-01

    The new stable isotope systems of transition metals are increasingly used to understand and quantify the impact of primitive microbial metabolisms on the modern and ancient Earth. To date, little effort has been expended on nickel (Ni) isotopes but there are good reasons to believe that this system may be more straightforward, and useful in this respect, than some others. Here, we present Ni stable isotope data for abiotic terrestrial samples and pure cultures of methanogens. The dataset for rocks reveals little isotopic variability and provides a lithologic baseline for terrestrial Ni isotope studies. In contrast, methanogens assimilate the light isotopes, yielding residual media with a complementary heavy isotopic enrichment. Methanogenesis may have evolved during or before the Archean, when methane could have been key to Earth's early systems. Our data suggest significant potential in Ni stable isotopes for identifying and quantifying methanogenesis on the early planet. Additionally, Ni stable isotope fractionation may well prove to be the fundamental unambiguous trace metal biomarker for methanogens. PMID:19553218

  17. Stable isotopes as tracers for radionuclides

    International Nuclear Information System (INIS)

    Giussani, A.; Bartolo, D. de; Cantone, M.C.; Zilker, T.; Greim, H.; Roth, P.; Werner, E.

    2000-01-01

    The assessment of internal dose after incorporation of radionuclides requires as input data the knowledge of the uptake into the systemic circulation, the distribution and retention in selected organs, the excretion pathways. Realistic biokinetic models are needed for reliable estimates, correct interpretation of bioassay measurements, appropriate decision-making in radiological emergencies. For many radionuclides, however, the biokinetic models currently recommended are often generic, with very few specific parameters, due to the lack of experimental human data. The use of stable isotopes as tracers enables to determine important biokinetic parameters such as the fractional uptake, the clearance from the transfer compartment, the excretion patterns under experimentally controlled conditions. The subjects investigated are not exposed to any radiation risk, so this technique enables to obtain biokinetic information also for sensitive groups of the population, such as children or pregnant women, and to determine age- and gender-specific model parameters. Sophisticated analytical method, able to discriminate and quantitate different isotopes of the same element in complex matrices such as biological fluids, have to be purposely developed and optimized. Activation analysis and mass spectrometry are the most proper techniques of choice. Experiments were conducted with molybdenum, tellurium, ruthenium and zirconium. Activation analysis with protons, thermal ionization mass spectrometry and inductively coupled mass spectrometry were employed for the determination of stable isotopes of these elements in blood plasma and urine samples. Several deviations from the predictions of the ICRP models were observed. For example, modifications to the current model for molybdenum have been suggested on the basis of these results. The dose coefficients to the target regions calculated with this proposed model are even of one order of magnitude different than the ICRP estimates

  18. Innovative method for carbon dioxide determination in human postmortem cardiac gas samples using headspace-gas chromatography–mass spectrometry and stable labeled isotope as internal standard

    International Nuclear Information System (INIS)

    Varlet, V.; Smith, F.; Froidmont, S. de; Dominguez, A.; Rinaldi, A.; Augsburger, M.; Mangin, P.; Grabherr, S.

    2013-01-01

    Graphical abstract: -- Highlights: •We developed a method for CO 2 analysis in cardiac samples and quantification by 13 CO 2 . •This method was fully validated by accuracy profile. •We have applied this method to perform CO 2 precise quantification for forensic applications. •Context of the death could be documented following CO 2 concentrations. -- Abstract: A novel approach to measure carbon dioxide (CO 2 ) in gaseous samples, based on a precise and accurate quantification by 13 CO 2 internal standard generated in situ is presented. The main goal of this study was to provide an innovative headspace-gas chromatography–mass spectrometry (HS-GC–MS) method applicable in the routine determination of CO 2 . The main drawback of the GC methods discussed in the literature for CO 2 measurement is the lack of a specific internal standard necessary to perform quantification. CO 2 measurement is still quantified by external calibration without taking into account analytical problems which can often occur considering gaseous samples. To avoid the manipulation of a stable isotope-labeled gas, we have chosen to generate in situ an internal labeled standard gas ( 13 CO 2 ) on the basis of the stoichiometric formation of CO 2 by the reaction of hydrochloric acid (HCl) with sodium hydrogen carbonate (NaH 13 CO 3 ). This method allows a precise measurement of CO 2 concentration and was validated on various human postmortem gas samples in order to study its efficiency

  19. Stable Oxygen-18 and Deuterium Isotopes

    DEFF Research Database (Denmark)

    Müller, Sascha

    The application of stable Oxygen-18 (18O) and Deuterium (2H) isotopes, as a tracer for fluxes between different compartments of the water cycle was subject of the present PhD-thesis. During a three year period, temporal data from a wide range of water cycle constituents was collected from...... the Skjern River catchment, Denmark. The presented applications focused on studying the isotopic 'input signal' to the hydrosphere in the form of precipitation, the isotopic 'output signal' with its related dynamic processes at a coastal saltwater-freshwater interface (groundwater isotopes) and the temporal...... development within a given lowland headwater catchment (stream water isotopes). Based on our investigations on the precipitation isotopic composition a local meteoric water line (LMWL) was constructed and expressed as: δ2H=7.4 δ18O + 5.36‰. Moreover, we showed that under maritime temperature climate influence...

  20. Analysis of thyroid hormones in biological samples using stable isotope dilution liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    This poster presentation will describe analytical chemistry methods for measuring thyroid hormones and related precursors and metabolites in very small tissue or plasma samples. These methods are amenable to measure thyroid hormones in amphibian tadpoles or small mammals used as ...

  1. Stable Isotope Group 1984 progress report

    International Nuclear Information System (INIS)

    Lyon, G.L.

    1985-04-01

    The work of the group in 1984 is described and includes studies in isotope geology, isotope hydrology, geochronology, isotope biology and mass spectrometer instrumentation. Geothermal studies have decreased compared to other years, but major data summaries were made for Wairakei and Ngawha. The hydrology of Whakarewarewa and Rotorua is being elucidated using water isotopes. Models of the subsurface flows at Kawerau and Ngawha are being made to relate fluid to mineral isotope compositions. A study of the δ 13 C and δ 34 S compositions of New Zealand oils has been started. Groups of oils of related origin are being defined, and compositions will be compared with those of potential source rocks. A method was developed for isotope analysis of sulphur in rocks. The isotopic composition of water is being used to identify and characterise groundwater aquifers in the Wairarapa and at Poverty Bay. Stable carbon isotopes have been used to identify food sources for invertebrates, and to show biochemical pathways in lactation by cows. The geochronology group is involved in major studies in Antarctica, using U-Pb, Rb-Sr and K-Ar methods. Rocks from North Victoria Land, Marie Byrd Land and the USARP mountains are being compared with possible correlatives in New Zealand and Argentina. Strontium isotope data is being applied to the origin of magmas in several regions of New Zealand. The K-Ar data is being stored on computer files. Fission track measurements are being applied to unravel uplift histories in Westland and Taranaki

  2. Stable Chlorine Isotope Study: Application to Early Solar System Materials

    Science.gov (United States)

    Mala,ira. M/; Nyquist, L. E.; Reese, Y.; Shih, C-Y; Fujitani, T.; Okano, O.

    2010-01-01

    A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the Cl-37/Cl-35 ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For example, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each

  3. Availability of enriched stable isotopes: present status and future prospects

    International Nuclear Information System (INIS)

    Hoff, R.W.

    1986-01-01

    The Electromagnetic Isotope Enrichment Facility (EMIEF) is currently used to produce 225 enriched stable isotopes of 50 elements. Among these are included most of the known elements with stable isotopes except for the noble gases, certain light elements, monisotopic elements, etc. The EMIEF can also be used to produce enriched samples of radioactive species, most notably the isotopes of uranium and plutonium. These enriched materials are placed in either the Sales Inventory of in the Research Materials Collection (RMC). The materials in the Sales Inventory are for sale to anyone on a first come, first served basis. Prices in the most recent catalog range from $0.05/mg for 99.8% 140 Ce to $1,267/mg for 98.5% 176 Lu. The materials in the RMC are made available to US researchers (or groups that include a US investigator) on a loan basis for use in non-destructive experiments and applications. In addition, certain samples have been provided to European investigators for cross-section studies through the auspices of EURATOM and the European-American Nuclear Data Committee. The status of the enriched isotopes included in the Sales Inventory is tabulated where isotopes are listed that are either not available or are in insufficient quantity or quality to meet current requests, as of 6/30/86. These can be summarized in the following subcategories: isotopes with zero inventory (22), Isotopes of insufficient quantity (17), and isotopes with insufficient enrichment quality (10). Of these 49 species, the supplies of 10 will be replenished by the scheduled FY86 enrichments in process (isotopes of bromine, calcium, nickel, potassium, rubidium, and strontium). In Table 3 are listed isotopes where the current inventory is less than the average annual sales level for the past five years. There are 47 isotopes listed, representing 25 different elements. Thus, there exists considerable potential for a substantial increase in the number of isotopes with zero inventory

  4. Stable isotope analysis of dynamic lipidomics.

    Science.gov (United States)

    Brandsma, Joost; Bailey, Andrew P; Koster, Grielof; Gould, Alex P; Postle, Anthony D

    2017-08-01

    Metabolic pathway flux is a fundamental element of biological activity, which can be quantified using a variety of mass spectrometric techniques to monitor incorporation of stable isotope-labelled substrates into metabolic products. This article contrasts developments in electrospray ionisation mass spectrometry (ESI-MS) for the measurement of lipid metabolism with more established gas chromatography mass spectrometry and isotope ratio mass spectrometry methodologies. ESI-MS combined with diagnostic tandem MS/MS scans permits the sensitive and specific analysis of stable isotope-labelled substrates into intact lipid molecular species without the requirement for lipid hydrolysis and derivatisation. Such dynamic lipidomic methodologies using non-toxic stable isotopes can be readily applied to quantify lipid metabolic fluxes in clinical and metabolic studies in vivo. However, a significant current limitation is the absence of appropriate software to generate kinetic models of substrate incorporation into multiple products in the time domain. Finally, we discuss the future potential of stable isotope-mass spectrometry imaging to quantify the location as well as the extent of lipid synthesis. This article is part of a Special Issue entitled: BBALIP_Lipidomics Opinion Articles edited by Sepp Kohlwein. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Membrane inlet laser spectroscopy to measure H and O stable isotope compositions of soil and sediment pore water with high sample throughput.

    Science.gov (United States)

    Oerter, Erik J; Perelet, Alexei; Pardyjak, Eric; Bowen, Gabriel

    2017-01-15

    The fast and accurate measurement of H and O stable isotope compositions (δ 2 H and δ 18 O values) of soil and sediment pore water remains an impediment to scaling-up the application of these isotopes in soil and vadose hydrology. Here we describe a method and its calibration to measuring soil and sediment pore water δ 2 H and δ 18 O values using a water vapor-permeable probe coupled to an isotope ratio infrared spectroscopy analyzer. We compare the water vapor probe method with a vapor direct equilibration method, and vacuum extraction with liquid water analysis. At a series of four study sites in a managed desert agroecosystem in the eastern Great Basin of North America, we use the water vapor probe to measure soil depth profiles of δ 2 H and δ 18 O values. We demonstrate the accuracy of the method to be equivalent to direct headspace equilibration and vacuum extraction techniques, with increased ease of use in its application, and with analysis throughput rates greater than 7 h -1 . The soil depth H and O stable isotope profiles show that soil properties such as contrasting soil texture and pedogenic soil horizons control the shape of the isotope profiles, which are reflective of local evaporation conditions within the soils. We conclude that this water vapor probe method has potential to yield large numbers of H and O stable isotope analyses of soil and sediment waters within shorter timeframes and with increased ease than with currently existing methods. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Strontium stable isotope behaviour accompanying basalt weathering

    Science.gov (United States)

    Burton, K. W.; Parkinson, I. J.; Gíslason, S. G. R.

    2016-12-01

    The strontium (Sr) stable isotope composition of rivers is strongly controlled by the balance of carbonate to silicate weathering (Krabbenhöft et al. 2010; Pearce et al. 2015). However, rivers draining silicate catchments possess distinctly heavier Sr stable isotope values than their bedrock compositions, pointing to significant fractionation during weathering. Some have argued for preferential release of heavy Sr from primary phases during chemical weathering, others for the formation of secondary weathering minerals that incorporate light isotopes. This study presents high-precision double-spike Sr stable isotope data for soils, rivers, ground waters and estuarine waters from Iceland, reflecting both natural weathering and societal impacts on those environments. The bedrock in Iceland is dominantly basaltic, d88/86Sr ≈ +0.27, extending to lighter values for rhyolites. Geothermal waters range from basaltic Sr stable compositions to those akin to seawater. Soil pore waters reflect a balance of input from primary mineral weathering, precipitation and litter recycling and removal into secondary phases and vegetation. Rivers and ground waters possess a wide range of d88/86Sr compositions from +0.101 to +0.858. Elemental and isotope data indicate that this fractionation primarily results from the formation or dissolution of secondary zeolite (d88/86Sr ≈ +0.10), but also carbonate (d88/86Sr ≈ +0.22) and sometimes anhydrite (d88/86Sr ≈ -0.73), driving the residual waters to heavier or lighter values, respectively. Estuarine waters largely reflect mixing with seawater, but are also be affected by adsorption onto particulates, again driving water to heavy values. Overall, these data indicate that the stability and nature of secondary weathering phases, exerts a strong control on the Sr stable isotope composition of silicate rivers. [1] Krabbenhöft et al. (2010) Geochim. Cosmochim. Acta 74, 4097-4109. [2] Pearce et al. (2015) Geochim. Cosmochim. Acta 157, 125-146.

  7. Petrography, compositional characteristics and stable isotope ...

    African Journals Online (AJOL)

    Petrography, compositional characteristics and stable isotope geochemistry of the Ewekoro formation from Ibese Corehole, eastern Dahomey basin, southwestern Nigeria. ME Nton, MO ... Preserved pore types such as; intercrystaline, moldic and vuggy pores were observed as predominant conduits for fluids. The major ...

  8. Facies, dissolution seams and stable isotope compositions

    Indian Academy of Sciences (India)

    Stable isotope analysis of the limestone shows that 13C and 18O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution ...

  9. The production of stable isotopes in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-07-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs.

  10. The production of stable isotopes in Spain

    International Nuclear Information System (INIS)

    Urgel, M.; Iglesias, J.; Casas, J.; Saviron, J. M.; Quintanilla, M.

    1965-01-01

    The activities developed in the field of the production of stable isotopes by means of ion-exchange chromatography and thermal diffusion techniques are reported. The first method was used to study the separation of the nitrogen and boron isotopes, whereby the separation factor was determined by the break through method. Values ranging from 1,028 to 1,022 were obtained for the separation factor of nitrogen by using ammonium hydroxide solutions while the corresponding values as obtained for boron amounted to 1,035-1,027 using boric acid solutions. Using ammonium chloride or acetate and sodium borate, respectively, resulted in the obtention of values for the separation factor approaching unity. The isotopic separation has been carried out according to the method of development by displacement. The separation of the isotopes of the noble gases, oxygen, nitrogen and carbon has been accomplished resorting to the method of thermal diffusion. (Author) 16 refs

  11. Discrimination of ginseng cultivation regions using light stable isotope analysis.

    Science.gov (United States)

    Kim, Kiwook; Song, Joo-Hyun; Heo, Sang-Cheol; Lee, Jin-Hee; Jung, In-Woo; Min, Ji-Sook

    2015-10-01

    Korean ginseng is considered to be a precious health food in Asia. Today, thieves frequently compromise ginseng farms by pervasive theft. Thus, studies regarding the characteristics of ginseng according to growth region are required in order to deter ginseng thieves and prevent theft. In this study, 6 regions were selected on the basis of Korea regional criteria (si, gun, gu), and two ginseng-farms were randomly selected from each of the 6 regions. Then 4-6 samples of ginseng were acquired from each ginseng farm. The stable isotopic compositions of H, O, C, and N of the collected ginseng samples were analyzed. As a result, differences in the hydrogen isotope ratios could be used to distinguish regional differences, and differences in the nitrogen isotope ratios yielded characteristic information regarding the farms from which the samples were obtained. Thus, stable isotope values could be used to differentiate samples according to regional differences. Therefore, stable isotope analysis serves as a powerful tool to discriminate the regional origin of Korean ginseng samples from across Korea. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Stable isotope composition of human fingernails from Slovakia

    Energy Technology Data Exchange (ETDEWEB)

    Grolmusová, Zuzana, E-mail: zuzana.grolmusova@geology.sk [Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Experimental Physics, Mlynská dolina F2, 842 48 Bratislava (Slovakia); State Geological Institute of Dionýz Štúr, Laboratory of Isotope Geology, Mlynská dolina 1, 817 04 Bratislava (Slovakia); Rapčanová, Anna [Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Experimental Physics, Mlynská dolina F2, 842 48 Bratislava (Slovakia); Michalko, Juraj; Čech, Peter [State Geological Institute of Dionýz Štúr, Laboratory of Isotope Geology, Mlynská dolina 1, 817 04 Bratislava (Slovakia); Veis, Pavel [Comenius University in Bratislava, Faculty of Mathematics, Physics and Informatics, Department of Experimental Physics, Mlynská dolina F2, 842 48 Bratislava (Slovakia); State Geological Institute of Dionýz Štúr, Laboratory of Isotope Geology, Mlynská dolina 1, 817 04 Bratislava (Slovakia)

    2014-10-15

    Stable isotope composition of human fingernails has proven to be useful for documenting human dietary information and geographical patterns in archeological, forensic, anthropological and biological studies. Therefore, it is of interest to detect all factors influencing the stable isotopic composition in the certain regions in the world. Carbon and nitrogen isotope data of human fingernail keratin from 52 individuals from Slovakia were reported in this study. The online combustion and continuous flow isotope-ratio mass spectrometer Delta V Advantage was used for δ{sup 13}C and δ{sup 15}N analysis of fingernail keratin samples from 24 vegetarian and 28 omnivorous individuals. A group of people with frequent meat consumption showed enrichment in {sup 13}C and {sup 15}N isotopes in fingernails. A similar trend was observed with increasing seafood in an individual's diet. Moreover a significant difference was revealed between smokers and nonsmokers for both δ{sup 13}C and δ{sup 15}N values. These data were compared to previously published δ{sup 13}C and δ{sup 15}N fingernail values from across the globe. This study brings new information on the stable isotope signature of individuals from Slovakia and characterizes the Central European region for the first time. The stable isotope composition of fingernails is influenced by the frequency of meat and seafood consumption as well as smoking. - Highlights: • This study deals with stable isotope analyses of fingernails from Slovak volunteers. • δ{sup 13}C and δ{sup 15}N values of vegetarian and omnivore fingernails were compared. • Influence of sex, diet and smoking was studied.

  13. Stable isotope composition of human fingernails from Slovakia

    International Nuclear Information System (INIS)

    Grolmusová, Zuzana; Rapčanová, Anna; Michalko, Juraj; Čech, Peter; Veis, Pavel

    2014-01-01

    Stable isotope composition of human fingernails has proven to be useful for documenting human dietary information and geographical patterns in archeological, forensic, anthropological and biological studies. Therefore, it is of interest to detect all factors influencing the stable isotopic composition in the certain regions in the world. Carbon and nitrogen isotope data of human fingernail keratin from 52 individuals from Slovakia were reported in this study. The online combustion and continuous flow isotope-ratio mass spectrometer Delta V Advantage was used for δ 13 C and δ 15 N analysis of fingernail keratin samples from 24 vegetarian and 28 omnivorous individuals. A group of people with frequent meat consumption showed enrichment in 13 C and 15 N isotopes in fingernails. A similar trend was observed with increasing seafood in an individual's diet. Moreover a significant difference was revealed between smokers and nonsmokers for both δ 13 C and δ 15 N values. These data were compared to previously published δ 13 C and δ 15 N fingernail values from across the globe. This study brings new information on the stable isotope signature of individuals from Slovakia and characterizes the Central European region for the first time. The stable isotope composition of fingernails is influenced by the frequency of meat and seafood consumption as well as smoking. - Highlights: • This study deals with stable isotope analyses of fingernails from Slovak volunteers. • δ 13 C and δ 15 N values of vegetarian and omnivore fingernails were compared. • Influence of sex, diet and smoking was studied

  14. Application of stable isotope to breath test

    International Nuclear Information System (INIS)

    Sasaki, Yasuto

    1988-01-01

    Needles to say, radioisotopes have good characteristics as a tracer for examining biological functions. In fact, scyntigraphy is widely used over Japan. It is true, however, that there are some difficulties in applying radioisotopes to humans. Thus, greater attention began to be attracted to stable isotopes in the late 1960s, because these substances can be used for infants and pregnant women. They can be stored for a long period of time since they do not suffer damping as in the case of radioisotopes. In addition to serving as a tracer, stable isotopes can provide structural-chemical information including the position of isotope labels, and the mass and atomic composition of fragment ions. Such techniques as NMR spectroscopy is employed for this purpose. The method is currently used to perform examinations of congenital metabolic disorders. The carbon isotopes of 13 C and 14 C are used for breath test. Compounds labeled with these isotopes are administered and their ratio to the total CO 2 in breath is measured to diagnose diseases. In the early 1970s, 13 C has come into use for breath test. Similar breath test is applied to diagnosis of the bacterial overgrowth syndrome and ileal dysfunction syndrome. (Nogami, K.)

  15. Incorporating stable isotopes into a multidisciplinary framework to ...

    African Journals Online (AJOL)

    Through its ability to address complex ecological questions and the possibility of analysing large sample sizes to understand population-level processes, the use of stable isotope analysis (δ13C and δ15N) has grown rapidly in recent years. Importantly, it is now becoming an accepted tool to derive data for conservation and ...

  16. Apparatus and method for monitoring of gas having stable isotopes

    Science.gov (United States)

    Clegg, Samuel M; Fessenden-Rahn, Julianna E

    2013-03-05

    Gas having stable isotopes is monitored continuously by using a system that sends a modulated laser beam to the gas and collects and transmits the light not absorbed by the gas to a detector. Gas from geological storage, or from the atmosphere can be monitored continuously without collecting samples and transporting them to a lab.

  17. Unit of stable isotopic N15 analysis

    International Nuclear Information System (INIS)

    Cabrera de Bisbal, Evelin; Paredes U, Maria

    1997-01-01

    active roots. The location of areas with higher density of absorbent roots and the way as they vary with the stations. The inorganic fertilizers can be substituted, in certain measure, by other sources of nutriments that are available in the town or that are less expensive. As well as the leguminous and other families, in symbiosis with the appropriate microorganisms can use the atmospheric N 2 directly. The N 1 5 isotopic techniques are really reliable to obtain quantitative and integrated fixed nitrogen values, either in natural or agricultural systems. Besides the supply of nutriments, the water is one of the main restrictive factors for the domestic agricultural production. The application of radiation techniques using neutron probe and gamma densitometers allows the development of methods to handle rain waters under agricultural drought conditions or to improve the efficiency of the irrigation use of water. The Stable Isotopes N 1 5 Analysis Laboratory, of the Laboratory Unit of the Agroecologic Resources Investigations Institute (IIRA), of CENIAP, provides from its foundation, a valuable service support to the investigation of nitrogen fertilization, aswell as alternative nitrogen sources (biological fixation), and in the development of water handling methods. The laboratory was installed in 1989, with the collaboration of the International Atomic Energy Agency. This laboratory is in capacity to analyze N 1 5 in water, land and vegetable tissue. The number of samples analyzed through these eight years of activities is 2000, being beneficiaries of this service diverse national agricultural research institutions (UCV, IVIC, LUZ and FONAIAP). The projects that have been assisted by the laboratory cover the areas previously mentioned, promoting the generation and deepening of knowledge, which helps to obtain a maximum efficiency in the use of nitrogen fertilizers and water, in the main domestic cropping systems [es

  18. Utilization of stable isotopes in medicine

    International Nuclear Information System (INIS)

    1980-11-01

    The ten lectures given at this round table are presented together with a discussion. Five lectures, relating to studies in which deuterium oxide was employed as a tracer of body water, dealt with pulmonary water measurements in man and animals, the total water pool in adipose subjects, and liquid compartments in children undergoing hemodyalisis. The heavy water is analysed by infrared spectrometry and a new double spectrodoser is described. Two studies using 13 C as tracer, described the diagnosis of liver troubles and diabetes respectively. A general review of the perspectives of the application of stable isotopes in clinical medicine is followed by a comparison of the use of stable and radioactive isotopes in France [fr

  19. Stable isotope analysis in primatology: a critical review.

    Science.gov (United States)

    Sandberg, Paul A; Loudon, James E; Sponheimer, Matt

    2012-11-01

    Stable isotope analysis has become an important tool in ecology over the last 25 years. A wealth of ecological information is stored in animal tissues in the relative abundances of the stable isotopes of several elements, particularly carbon and nitrogen, because these isotopes navigate through ecological processes in predictable ways. Stable carbon and nitrogen isotopes have been measured in most primate taxonomic groups and have yielded information about dietary content, dietary variability, and habitat use. Stable isotopes have recently proven useful for addressing more fine-grained questions about niche dynamics and anthropogenic effects on feeding ecology. Here, we discuss stable carbon and nitrogen isotope systematics and critically review the published stable carbon and nitrogen isotope data for modern primates with a focus on the problems and prospects for future stable isotope applications in primatology. © 2012 Wiley Periodicals, Inc.

  20. Determination of trace element concentrations and stable lead, uranium and thorium isotope ratios by quadrupole-ICP-MS in NORM and NORM-polluted sample leachates

    International Nuclear Information System (INIS)

    Mas, J.L.; Villa, M.; Hurtado, S.; García-Tenorio, R.

    2012-01-01

    Highlights: ► Polluted sediment and NORM samples. ► An efficient yet fast process allowing multi-parametric determinations in 206 Pb/ 207 Pb/ 208 Pb, 238 U/ 234 U and 232 Th/ 230 Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA ® extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area.

  1. Determination of trace element concentrations and stable lead, uranium and thorium isotope ratios by quadrupole-ICP-MS in NORM and NORM-polluted sample leachates

    Energy Technology Data Exchange (ETDEWEB)

    Mas, J.L., E-mail: ppmasb@us.es [Dpto. Fisica Aplicada I, EPS, Universidad de Sevilla, 41012 Sevilla (Spain); Villa, M. [Servicio de Radioisotopos, Centro de Investigacion, Tecnologia e Innovacion (CITIUS), Universidad de Sevilla, Avda. Reina Mercedes 4b, 41012 Sevilla (Spain); Dpto. Fisica Aplicada II, ETS de Arquitectura, Universidad de Sevilla, Avda. Reina Mercedes 2, 41012 Sevilla (Spain); Hurtado, S. [Servicio de Radioisotopos, Centro de Investigacion, Tecnologia e Innovacion (CITIUS), Universidad de Sevilla, Avda. Reina Mercedes 4b, 41012 Sevilla (Spain); Garcia-Tenorio, R. [Dpto. Fisica Aplicada II, ETS de Arquitectura, Universidad de Sevilla, Avda. Reina Mercedes 2, 41012 Sevilla (Spain)

    2012-02-29

    Highlights: Black-Right-Pointing-Pointer Polluted sediment and NORM samples. Black-Right-Pointing-Pointer An efficient yet fast process allowing multi-parametric determinations in <3 days. Black-Right-Pointing-Pointer Trace element concentrations, Pb, Th and U isotope ratios with a single instrument. - Abstract: This work focuses on the monitoring of the potential pollution in scenarios that involve NORM-related industrial activities (environmental or in-door scenarios). The objective was to develop a method to determine extent and origin of the contamination, suitable for monitoring (i.e. simple, fast and economical) and avoiding the use of too many different instruments. It is presented a radiochemical method that allows the determination of trace element concentrations and {sup 206}Pb/{sup 207}Pb/{sup 208}Pb, {sup 238}U/{sup 234}U and {sup 232}Th/{sup 230}Th isotope ratios using a single sample aliquot and a single instrument (ICP-QMS). Eichrom UTEVA{sup Registered-Sign} extraction chromatography minicolumns were used to separate uranium and thorium in sample leachates. Independent ICP-MS determinations of uranium and thorium isotope ratios were carried out afterwards. Previously a small aliquot of the leachate was used for the determination of trace element concentrations and lead isotope ratios. Several radiochemical arrangements were tested to get maximum performances and simplicity of the method. The performances of the method were studied in terms of chemical yields of uranium and thorium and removal of the potentially interfering elements. The established method was applied to samples from a chemical industry and sediments collected in a NORM-polluted scenario. The results obtained from our method allowed us to infer not only the extent, but also the sources of the contamination in the area.

  2. Stable Isotope Mapping of Alaskan Grasses and Marijuana

    Science.gov (United States)

    Booth, A. L.; Wooller, M. J.

    2008-12-01

    The spatial variation of isotope signatures in organic material is a useful forensic tool, particularly when applied to the task of tracking the production and distribution of plant-derived illicit drugs. In order to identify the likely grow-locations of drugs such as marijuana from unknown locations (i.e., confiscated during trafficking), base isotope maps are needed that include measurements of plants from known grow-locations. This task is logistically challenging in remote, large regions such as Alaska. We are therefore investigating the potential of supplementing our base (marijuana) isotope maps with data derived from other plants from known locations and with greater spatial coverage in Alaska. These currently include >150 samples of modern C3 grasses (Poaceae) as well as marijuana samples (n = 18) from known grow-locations across the state. We conducted oxygen, carbon and nitrogen stable isotope analyses of marijuana and grasses (Poaceae). Poaceae samples were obtained from the University of Alaska Fairbanks (UAF) Museum of the North herbarium collection, originally collected by field botanists from around Alaska. Results indicate that the oxygen isotopic composition of these grasses range from 10‰ to 30‰, and broadly mirror the spatial pattern of water isotopes in Alaska. Our marijuana samples were confiscated around the state of Alaska and supplied to us by the UAF Police Department. δ13C, δ15N and δ18O values exhibit geographic patterns similar to the modern grasses, but carbon and nitrogen isotopes of some marijuana plants appear to be influenced by additional factors related to indoor growing conditions (supplementary CO2 sources and the application of organic fertilizer). As well as providing a potential forensic resource, our Poaceae isotope maps could serve additional value by providing resources for studying ecosystem nutrient cycling, for tracing natural ecological processes (i.e., animal migration and food web dynamics) and providing

  3. Stable carbon isotope analysis of coprocessing materials

    Energy Technology Data Exchange (ETDEWEB)

    Burke, F. P.; Winschel, R. A.; Lancet, M. S.

    1989-06-01

    The program is designed to address a substantial, demonstrated need of the coprocessing community (both exploratory and development) for a technique to quantitatively distinguish the contributions of the individual coprocessing feedstocks to the various products. The carbon isotope technique is currently in routine use for other applications. Results achieved this quarter include: Feed and product fractions from a Kentucky 9 coal/Kentucky tar sand bitumen coprocessing bench unit run at the Kentucky Center for Applied Energy Research (CAER) were analyzed for carbon isotope ratios. Corrections were made to the coal carbon recoveries and selectivities from the products of HRI Run 227-53. Feeds (Westerholt coal/Cold Lake VSB) and products from two periods of HRI coprocessing Run 238-1 were analyzed. Three petroleum samples and three coal samples were pyrolyzed at 800{degree}F for 30 min to determine the effect of pyrolysis on the isotopic homogeneity of each petroleum and coal sample. Products from each pyrolysis test were separated into five fractions; an additional set of coprocessing samples and a set of two-stage coal liquefaction samples were obtained from HRI for future work; work performed by the Pennsylvania State University show that microscopy is a promising method for distinguishing coal and petroleum products in residual coprocessing materials; and coal and petroleums that have large differences in carbon isotope ratios were identified for Auburn University. 7 refs., 2 figs., 12 tabs.

  4. Stable isotopes of captive cetaceans (killer whales and bottlenose dolphins).

    Science.gov (United States)

    Caut, Stéphane; Laran, Sophie; Garcia-Hartmann, Emmanuel; Das, Krishna

    2011-02-15

    There is currently a great deal of interest in using stable isotope methods to investigate diet, trophic level and migration in wild cetaceans. In order to correctly interpret the results stemming from these methods, it is crucial to understand how diet isotopic values are reflected in consumer tissues. In this study, we investigated patterns of isotopic discrimination between diet and blood constituents of two species of cetaceans (killer whale, Orcinus orca, and bottlenose dolphin, Tursiops truncatus) fed controlled diets over 308 and 312 days, respectively. Diet discrimination factors (Δ; mean ± s.d.) for plasma were estimated to Δ(13)C=2.3±0.6‰ and Δ(15)N=1.8±0.3‰, respectively, for both species and to Δ(13)C=2.7±0.3‰ and Δ(15)N=0.5±0.1‰ for red blood cells. Delipidation did not have a significant effect on carbon and nitrogen isotopic values of blood constituents, confirming that cetacean blood does not serve as a reservoir of lipids. In contrast, carbon isotopic values were higher in delipidated samples of blubber, liver and muscle from killer whales. The potential for conflict between fisheries and cetaceans has heightened the need for trophic information about these taxa. These results provide the first published stable isotope incorporation data for cetaceans, which are essential if conclusions are to be drawn on issues concerning trophic structures, carbon sources and diet reconstruction.

  5. Divergence of stable isotopes in tap water across China

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Sihan; Hu, Hongchang; Tian, Fuqiang; Tie, Qiang; Wang, Lixin; Liu, Yaling; Shi, Chunxiang

    2017-03-02

    Stable isotopes in water (e.g., δ2H and δ18O) are important indicators of hydrological and ecological patterns and processes. Tap water can reflect integrated features of regional hydrological processes and human activities. China is a large country with significant meteorological and geographical variations. This report presents the first national-scale survey of Stable Isotopes in Tap Water (SITW) across China. 780 tap water samples have been collected from 95 cities across China from December 2014 to December 2015. (1) Results yielded the Tap Water Line in China is δ2H = 7.72 δ18O + 6.57 (r2 = 0.95). (2) SITW spatial distribution presents typical "continental effect". (3) SITW seasonal variations indicate clearly regional patterns but no trends at the national level. (4) SITW can be correlated in some parts with geographic or meteorological factors. This work presents the first SITW map in China, which sets up a benchmark for further stable isotopes research across China. This is a critical step toward monitoring and investigating water resources in climate-sensitive regions, so the human-hydrological system. These findings could be used in the future to establish water management strategies at a national or regional scale. Title: Divergence of stable isotopes in tap water across China Authors: Zhao, SH; Hu, HC; Tian, FQ; Tie, Q; Wang, LX; Liu, YL; Shi, CX Source: SCIENTIFIC REPORTS, 7 10.1038/srep43653 MAR 2 2017

  6. Lipid Extraction and the Fugacity of Stable Isotope Values

    Science.gov (United States)

    Padula, V.; Causey, D.; Wolf, N.; Welker, J. M.

    2013-12-01

    Stable isotope analysis of blood, feathers, and other tissues are often used to infer migration patterns, diet composition and trophic status of seabirds. Tissues contain variable amounts of lipids that are depleted in the heavy carbon isotope (13C) and may introduce a bias in these values. There is evidence that lipid extraction may affect other stable isotope ratios, such as δ15N. Consequently, correction factors need to be applied to appropriately interpret δ13C and δ15N values for individual species and tissue type. In this study, we collected seven species of seabirds from the Near Islands, the western most group of islands in the Aleutian Island archipelago. We sampled kidney, liver, heart and muscle samples from each bird and after freeze drying, individual tissue samples were divided into two subsamples. We left one subsample unaltered and extracted lipids from the other subsample using a 2:1 chloroform-methanol solution. We found that the change in δ13C values after lipid extraction (Δδ13C) varied widely among categories (eg., species, tissue type) from 0 - 4 ‰, while Δδ15N values ranged from 0 to 2‰. Notably, within category variation was nonsignificant and the Δδ values were linear against the covariant C:N ratio of the isotopic data, which allows us to use arithmetic corrections for categorical values. Our data strongly indicate that the effects of lipid extraction on stable isotopic values, while linear within category, vary widely by species, tissue, geographic area, year of collection, and isotope. Fugacity is usually employed as a thermodynamic quantity related to the chemical potential or activity that characterizes the escaping tendency from a phase (eg. Mackay & Paterson 1982). Here we use fugacity in the earlier, broader sense of fleeting, transitory, or instable states (eg., S. Johnson 1751), and its measure may be approximated by the higher order variance of Δδ13C and Δδ15N among data categories. Clearly, understanding the

  7. Trophic interactions of the endangered Southern river otter ( Lontra provocax) in a Chilean Ramsar wetland inferred from prey sampling, fecal analysis, and stable isotopes

    Science.gov (United States)

    Franco, Marcela; Guevara, Giovany; Correa, Loreto; Soto-Gamboa, Mauricio

    2013-04-01

    Non-invasive methodological approaches are highly recommended and commonly used to study the feeding ecology of elusive and threatened mammals. In this study, we use multiple lines of evidence to assess the feeding strategies of the endangered Southern river otter, by determining seasonal prey availability (electrofishing), analysis of undigested prey remains (spraints), and the use of stable isotopes (δ15N and δ13C) in otter spraints ( n = 262) and prey in a wetland ecosystem of southern Chile (39°49'S, 73°15'W). Fecal and isotopic analyses suggest that the otter diet is restricted to a few prey items, particularly the less-mobile, bottom-living, and larger prey such as crayfish ( Samastacus spinifrons, 86.11 %) and crabs ( Aegla spp., 32.45 %), supplemented opportunistically by cyprinids ( Cyprinus carpio, 9.55 %) and catfish ( Diplomystes camposensis, 5.66 %). The results suggest that the river otter is highly specialized in bottom foraging. Isotopic signatures of food sources and feces revealed a mid-upper trophic position for the Southern river otter, with either higher or lower δ15N values than their potential prey items. δ13C values for river otters were less enriched than their potential food resources. We suggest that due to their narrow trophic niche and possible dependence on only a few food items, this species may be highly vulnerable to the reduction in its prey populations. Finally, maintaining the ecological interactions between Southern river otters and their prey is considered a central priority for the survival of this endangered carnivore mammal.

  8. Stable Isotope Systematics of Coalbed Gas during Desorption and Production

    Directory of Open Access Journals (Sweden)

    Martin Niemann

    2017-06-01

    Full Text Available The stable carbon isotope ratios of coalbed methane (CBM demonstrate diagnostic changes that systematically vary with production and desorption times. These shifts can provide decisive, predictive information on the behaviour and potential performance of CBM operations. Samples from producing CBM wells show a general depletion in 13C-methane with increasing production times and corresponding shifts in δ13C-CH4 up to 35.8‰. Samples from canister desorption experiments show mostly enrichment in 13C for methane with increasing desorption time and isotope shifts of up to 43.4‰. Also, 13C-depletion was observed in some samples with isotope shifts of up to 32.1‰. Overall, the magnitudes of the observed isotope shifts vary considerably between different sample sets, but also within samples from the same source. The δ13C-CH4 values do not have the anticipated signature of methane generated from coal. This indicates that secondary processes, including desorption and diffusion, can influence the values. It is also challenging to deconvolute these various secondary processes because their molecular and isotope effects can have similar directions and/or magnitudes. In some instances, significant alteration of CBM gases has to be considered as a combination of secondary alteration effects.

  9. Patterns in Stable Isotope Values of Nitrogen and Carbon in ...

    Science.gov (United States)

    Stable isotope measurements of nitrogen and carbon (15N, 13ddC) are often used to characterize estuarine, nearshore, and open ocean ecosystems. Reliable information about the spatial distribution of base-level stable isotope values, often represented by primary producers, is critical to interpreting values in these ecosystems. While base-level isotope data are generally readily available for estuaries, nearshore coastal waters, and the open ocean, the continental shelf is less studied. To address this, and as a first step toward developing a surrogate for base-level isotopic signature in this region, we collected surface and deep water samples from the United States’ eastern continental shelf in the Western Atlantic Ocean, from the Gulf of Maine to Cape Hatteras, periodically between 2000 and 2013. During the study, particulate matter 15dN values ranged from 0.8 to 17.4‰, and 13dC values from −26.4 to −15.6‰over the region. We used spatial autocorrelation analysis and random forest modeling to examine the spatial trends and potential environmental drivers of the stable isotope values. We observed general trends toward lower values for both nitrogen and carbon isotopes at the seaward edge of the shelf. Conversely, higher 15dN and 13dC values were observed on the landward edge of the shelf, in particular in the southern portion of the sampling area. Across all sites, the magnitude of the difference between the 15dN of subsurface and surface particulate m

  10. Embryotoxicity of stable isotopes and use of stable isotopes in studies of teratogenetic mechanisms

    International Nuclear Information System (INIS)

    Spielmann, H.; Nau, H.

    1986-01-01

    Experiments on teratogenic effects of stable isotopes from our own and other laboratories are evaluated. In the first series of investigations, the enrichment of the stable isotope 13 C derived from U- 13 C-glucose was studied in mouse embryos at various stages of development, including limb buds in organ culture. Preimplantation mouse embryos incubated in vitro in 13 C-enriched medium for 48 hours showed normal development during subsequent differentiation in vitro and also in vivo after embryo transfer to faster mothers. These embryos were 15% to 20% enriched in 13 C. Administration of U-13-C-glucose to pregnant mice during organogenesis led to an increase of the absolute 13 C content of the embryo for several days after the end of isotope administration, whereas the enrichment in maternal tissue decreased. No alterations of embryonic development were detected due to stable isotope enrichment. Development of cultured mouse limb buds was unaffected by incubation with 82 mol% U- 13 C-glucose as judged from morphologic and biochemical criteria. The second part of the article describes the value of deuterium-labeled drugs as probes into the mechanism of activation of teratogenic metabolites. A comparison of the pharmacokinetics as well as the teratogenicity between cyclophosphamide and some specific deuterium-labeled analogues showed that the isotope effect observed can be related to a particular metabolic pathway crucial for teratogenic activation by this drug

  11. Tracing anthropogenic thallium in soil using stable isotope compositions.

    Science.gov (United States)

    Kersten, Michael; Xiao, Tangfu; Kreissig, Katharina; Brett, Alex; Coles, Barry J; Rehkämper, Mark

    2014-08-19

    Thallium stable isotope data are used in this study, for the first time, to apportion Tl contamination in soils. In the late 1970s, a cement plant near Lengerich, Germany, emitted cement kiln dust (CKD) with high Tl contents, due to cocombustion of Tl-enriched pyrite roasting waste. Locally contaminated soil profiles were obtained down to 1 m depth and the samples are in accord with a binary mixing relationship in a diagram of Tl isotope compositions (expressed as ε(205)Tl, the deviation of the (205)Tl/(203)Tl ratio of a sample from the NIST SRM 997 Tl isotope standard in parts per 10(4)) versus 1/[Tl]. The inferred mixing endmembers are the geogenic background, as defined by isotopically light soils at depth (ε(205)Tl ≈ -4), and the Tl emissions, which produce Tl-enriched topsoils with ε(205)Tl as high as ±0. The latter interpretation is supported by analyses of the CKD, which is also characterized by ε(205)Tl ≈ ± 0, and the same ε(205)Tl value was found for a pyrite from the deposit that produced the cocombusted pyrite roasting waste. Additional measurements for samples from a locality in China, with outcrops of Tl sulfide mineralization and associated high natural Tl backgrounds, reveal significant isotope fractionation between soils (ε(205)Tl ≈ +0.4) and locally grown green cabbage (ε(205)Tl between -2.5 and -5.4). This demonstrates that biological isotope fractionation cannot explain the isotopically heavy Tl in the Lengerich topsoils and the latter are therefore clearly due to anthropogenic Tl emissions from cement processing. Our results thus establish that isotopic data can reinforce receptor modeling for the toxic trace metal Tl.

  12. Quantification of stable isotope label in metabolites via mass spectrometry.

    Science.gov (United States)

    Huege, Jan; Goetze, Jan; Dethloff, Frederik; Junker, Bjoern; Kopka, Joachim

    2014-01-01

    Isotope labelling experiments with stable or radioactive isotopes have long been an integral part of biological and medical research. Labelling experiments led to the discovery of new metabolic pathways and made it possible to calculate the fluxes responsible for a metabolic phenotype, i.e., the qualitative and quantitative composition of metabolites in a biological system. Prerequisite for efficient isotope labelling experiments is a reliable and precise method to analyze the redistribution of isotope label in a metabolic network. Here we describe the use of the CORRECTOR program, which utilizes matrix calculations to correct mass spectral data from stable isotope labelling experiments for the distorting effect of naturally occurring stable isotopes (NOIs). CORRECTOR facilitates and speeds up the routine quantification of experimentally introduced isotope label from multiple mass spectral readouts, which are generated by routine metabolite profiling when combined with stable isotope labelling experiments.

  13. STABLE ISOTOPES IN ECOLOGICAL STUDIES: NEW DEVELOPMENTS IN MIXING MODELS

    Science.gov (United States)

    Stable isotopes are increasingly being used as tracers in ecological studies. One application uses isotopic ratios to quantify the proportional contributions of multiple sources to a mixture. Examples include food sources for animals, water sources for plants, pollution sources...

  14. Do stable carbon isotopes of brown coal woods record changes in Lower Miocene palaeoecology?

    NARCIS (Netherlands)

    Poole, I.J.; Dolezych, M.; Kool, J.; Burgh, J. van der; Bergen, P.F. van

    2006-01-01

    Stable carbon isotope ratios of fossil wood from the Miocene brown coal deposits in former East Germany are compared with palaeobotanical and sedimentological data to test the use of stable isotopes in determining palaeoenvironment. Significant differences in the chemical composition of samples

  15. Hg stable isotope analysis by the double-spike method.

    Science.gov (United States)

    Mead, Chris; Johnson, Thomas M

    2010-06-01

    Recent publications suggest great potential for analysis of Hg stable isotope abundances to elucidate sources and/or chemical processes that control the environmental impact of mercury. We have developed a new MC-ICP-MS method for analysis of mercury isotope ratios using the double-spike approach, in which a solution containing enriched (196)Hg and (204)Hg is mixed with samples and provides a means to correct for instrumental mass bias and most isotopic fractionation that may occur during sample preparation and introduction into the instrument. Large amounts of isotopic fractionation induced by sample preparation and introduction into the instrument (e.g., by batch reactors) are corrected for. This may greatly enhance various Hg pre-concentration methods by correcting for minor fractionation that may occur during preparation and removing the need to demonstrate 100% recovery. Current precision, when ratios are normalized to the daily average, is 0.06 per thousand, 0.06 per thousand, 0.05 per thousand, and 0.05 per thousand (2sigma) for (202)Hg/(198)Hg, (201)Hg/(198)Hg, (200)Hg/(198)Hg, and (199)Hg/(198)Hg, respectively. This is slightly better than previously published methods. Additionally, this precision was attained despite the presence of large amounts of other Hg isotopes (e.g., 5.0% atom percent (198)Hg) in the spike solution; substantially better precision could be achieved if purer (196)Hg were used.

  16. [Fractionation of hydrogen stable isotopes in the human body].

    Science.gov (United States)

    Siniak, Iu E; Grigor'ev, A I; Skuratov, V M; Ivanova, S M; Pokrovskiĭ, B G

    2006-01-01

    Fractionation of hydrogen stable isotopes was studied in 9 human subjects in a chamber with normal air pressure imitating a space cabin. Mass-spectrometry of isotopes in blood, urine, saliva, and potable water evidenced increases in the contents of heavy H isotope (deuterium) in the body liquids as compared with water. These results support one of the theories according to which the human organism eliminates heavy stable isotopes of biogenous chemical elements.

  17. Trophic position of coexisting krill species: a stable isotope approach

    DEFF Research Database (Denmark)

    Agersted, Mette Dalgaard; Bode, Antonio; Nielsen, Torkel Gissel

    2014-01-01

    .2) indicating carnivory, while T. inermis (TP = 2.4 ± 0.3) had a more omnivorous diet. In turn, T. longicaudata and T. raschii (TP = 2.2 ± 0.2) were herbivorous. Along the fjord, nutrient and plankton composition affected trophic position. Thysanoessa longicaudata was more omnivorous offshore than inshore where......Four krill species with overlapping functional biology coexist in Greenland waters. Here, we used stable isotopes to investigate and discuss their trophic role and mode of coexistence. Bulk carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of Thysanoessa longicaudata, T. inermis, T. raschii...... and Meganyctiphanes norvegica sampled in June 2010 in the Godthåbsfjord, SW Greenland revealed new insight into their trophic roles and positions. There was a general positive correlation between body length and trophic position. The largest species M. norvegica had the highest trophic position (TP = 2.8 ± 0...

  18. Neutron inelastic scattering measurements on the stable isotopes of titanium

    Science.gov (United States)

    Olacel, A.; Belloni, F.; Borcea, C.; Boromiza, M.; Dessagne, P.; Henning, G.; Kerveno, M.; Negret, A.; Nyman, M.; Pirovano, E.; Plompen, A. J. M.

    2017-07-01

    The results of a neutron inelastic scattering experiment performed at the Geel Electron Linear Accelerator pulsed white neutron source of the European Commission Joint Research Centre are reported. The neutrons with energies up to 18 MeV interacted with a natTi sample and the γ rays resulting from inelastic scattering reactions on the stable isotopes were detected using the Gamma Array for Inelastic Neutron Scattering (GAINS) spectrometer. We were able to measure the γ -production cross sections for 21 transitions in the five stable Ti isotopes. From these, the level cross sections and the total inelastic cross sections were determined. Our experimental results are compared with theoretical calculations performed using the talys 1.8 code, evaluated nuclear data libraries, and also with previously reported results.

  19. Automated determination of the stable carbon isotopic composition (δ13C) of total dissolved inorganic carbon (DIC) and total nonpurgeable dissolved organic carbon (DOC) in aqueous samples: RSIL lab codes 1851 and 1852

    Science.gov (United States)

    Révész, Kinga M.; Doctor, Daniel H.

    2014-01-01

    The purposes of the Reston Stable Isotope Laboratory (RSIL) lab codes 1851 and 1852 are to determine the total carbon mass and the ratio of the stable isotopes of carbon (δ13C) for total dissolved inorganic carbon (DIC, lab code 1851) and total nonpurgeable dissolved organic carbon (DOC, lab code 1852) in aqueous samples. The analysis procedure is automated according to a method that utilizes a total carbon analyzer as a peripheral sample preparation device for analysis of carbon dioxide (CO2) gas by a continuous-flow isotope ratio mass spectrometer (CF-IRMS). The carbon analyzer produces CO2 and determines the carbon mass in parts per million (ppm) of DIC and DOC in each sample separately, and the CF-IRMS determines the carbon isotope ratio of the produced CO2. This configuration provides a fully automated analysis of total carbon mass and δ13C with no operator intervention, additional sample preparation, or other manual analysis. To determine the DIC, the carbon analyzer transfers a specified sample volume to a heated (70 °C) reaction vessel with a preprogrammed volume of 10% phosphoric acid (H3PO4), which allows the carbonate and bicarbonate species in the sample to dissociate to CO2. The CO2 from the reacted sample is subsequently purged with a flow of helium gas that sweeps the CO2 through an infrared CO2 detector and quantifies the CO2. The CO2 is then carried through a high-temperature (650 °C) scrubber reactor, a series of water traps, and ultimately to the inlet of the mass spectrometer. For the analysis of total dissolved organic carbon, the carbon analyzer performs a second step on the sample in the heated reaction vessel during which a preprogrammed volume of sodium persulfate (Na2S2O8) is added, and the hydroxyl radicals oxidize the organics to CO2. Samples containing 2 ppm to 30,000 ppm of carbon are analyzed. The precision of the carbon isotope analysis is within 0.3 per mill for DIC, and within 0.5 per mill for DOC.

  20. Estimation of evapotranspiration rate in irrigated lands using stable isotopes

    Science.gov (United States)

    Umirzakov, Gulomjon; Windhorst, David; Forkutsa, Irina; Brauer, Lutz; Frede, Hans-Georg

    2013-04-01

    Agriculture in the Aral Sea basin is the main consumer of water resources and due to the current agricultural management practices inefficient water usage causes huge losses of freshwater resources. There is huge potential to save water resources in order to reach a more efficient water use in irrigated areas. Therefore, research is required to reveal the mechanisms of hydrological fluxes in irrigated areas. This paper focuses on estimation of evapotranspiration which is one of the crucial components in the water balance of irrigated lands. Our main objective is to estimate the rate of evapotranspiration on irrigated lands and partitioning of evaporation into transpiration using stable isotopes measurements. Experiments has done in 2 different soil types (sandy and sandy loam) irrigated areas in Ferghana Valley (Uzbekistan). Soil samples were collected during the vegetation period. The soil water from these samples was extracted via a cryogenic extraction method and analyzed for the isotopic ratio of the water isotopes (2H and 18O) based on a laser spectroscopy method (DLT 100, Los Gatos USA). Evapotranspiration rates were estimated with Isotope Mass Balance method. The results of evapotranspiration obtained using isotope mass balance method is compared with the results of Catchment Modeling Framework -1D model results which has done in the same area and the same time.

  1. STABLE ISOTOPE GEOCHEMISTRY OF MASSIVE ICE

    Directory of Open Access Journals (Sweden)

    Yurij K. Vasil’chuk

    2016-01-01

    Full Text Available The paper summarises stable-isotope research on massive ice in the Russian and North American Arctic, and includes the latest understanding of massive-ice formation. A new classification of massive-ice complexes is proposed, encompassing the range and variabilityof massive ice. It distinguishes two new categories of massive-ice complexes: homogeneousmassive-ice complexes have a similar structure, properties and genesis throughout, whereasheterogeneous massive-ice complexes vary spatially (in their structure and properties andgenetically within a locality and consist of two or more homogeneous massive-ice bodies.Analysis of pollen and spores in massive ice from Subarctic regions and from ice and snow cover of Arctic ice caps assists with interpretation of the origin of massive ice. Radiocarbon ages of massive ice and host sediments are considered together with isotope values of heavy oxygen and deuterium from massive ice plotted at a uniform scale in order to assist interpretation and correlation of the ice.

  2. A rapid, accurate and sensitive method with the new stable isotopic tags based on microwave-assisted dispersive liquid-liquid microextraction and its application to the determination of hydroxyl UV filters in environmental water samples.

    Science.gov (United States)

    Li, Xiu; Chen, Guang; Liu, Jianjun; Liu, Yuxia; Zhao, Xianen; Cao, Ziping; Xia, Lian; Li, Guoliang; Sun, Zhiwei; Zhang, Shijuan; Wang, Hua; You, Jinmao

    2017-05-15

    A rapid, accurate and sensitive method, using the stable isotope labeling (SIL), microwave-assisted dispersive liquid-liquid micro extraction (MADLLME) and the ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), was developed and validated for the determination of hydroxyl UV Filters in environmental water samples. A pair of new isotopic tags D 0 -/D 3 -1-methylindole-3-acetic acid (D 0 -/D 3 -MIAA) is synthesized, with which a simple yet efficient pretreatment MADLLME-SIL is developed. Under the optimized conditions (80℃, 240W, 180s), the sample pretreatment including analyte extraction, pre-concentration and isotope labeling can be finished conveniently in only 9min. D 0 -/D 3 -MIAA labeling improves the chromatographic retention by strengthening the hydrophobicity and enhances the MS response for 3-4 orders of magnitude. Excellent linearity is established by the H/D ratios of 1/10-10/1 with the correlation coefficients >0.9990. The quite low detection limits (0.54-1.79ng/L) are achieved, ensuring the trace detection. This method is successfully applied to a series of environmental water samples. The recoveries (93.2%~103.5%) are significantly improved and the analysis time is largely reduced (UV filters in water samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. A timeline of stable isotopes and mass spectrometry in the life sciences.

    Science.gov (United States)

    Lehmann, Wolf D

    2017-01-01

    This review retraces the role of stable isotopes and mass spectrometry in the life sciences. The timeline is divided into four segments covering the years 1920-1950, 1950-1980, 1980-2000, and 2000 until today. For each period methodic progress and typical applications are discussed. Application of stable isotopes is driven by improvements of mass spectrometry, chromatography, and related fields in sensitivity, mass accuracy, structural specificity, complex sample handling ability, data output, and data evaluation. We currently experience the vision of omics-type analyses, that is, the comprehensive identification and quantification of a complete compound class within one or a few analytical runs. This development is driven by stable isotopes without competition by radioisotopes. In metabolic studies as classic field of isotopic tracer experiments, stable isotopes and radioisotopes were competing solutions, with stable isotopes as the long-term junior partner. Since the 1990s the number of metabolic studies with radioisotopes decreases, whereas stable isotope studies retain their slow but stable upward tendency. Unique fields of stable isotopes are metabolic tests in newborns, metabolic experiments in healthy controls, newborn screening for inborn errors, quantification of drugs and drug metabolites in doping control, natural isotope fractionation in geology, ecology, food authentication, or doping control, and more recently the field of quantitative omics-type analyses. There, cells or whole organisms are systematically labeled with stable isotopes to study proteomic differences or specific responses to stimuli or genetic manipulation. The duo of stable isotopes and mass spectrometry will probably continue to grow in the life sciences, since it delivers reference-quality quantitative data with molecular specificity, often combined with informative isotope effects. © 2016 Wiley Periodicals, Inc. Mass Spec Rev 36:58-85, 2017. © 2016 Wiley Periodicals, Inc.

  4. The use of stable isotopes in drug metabolism studies.

    Science.gov (United States)

    Abramson, F P

    2001-06-01

    Although there is a long history of stable isotopes use in drug metabolism research, it is appropriate to evaluate them in pregnancy drug studies in which safety takes highest priority. It is well established through a number of human and animal experiments that stable isotopes themselves rarely generate additional toxicities beyond the molecules to which they are attached. For the analysis of stable isotopes involved in metabolism studies, mass spectrometry plays the predominant role. Several mass spectrometry-based techniques now exist that enable the selective quantitative detection of stable isotopes with better sensitivity and better retention of chromatographic resolution than do in-line radioactivity monitors for 14C. Even mass balance studies can be performed by using stable isotopes, a type of experiment that still predominantly uses radioisotopes. Some of the newest developments in the use of stable isotopes involve biopolymers, in which fully isotope-labeled species can be generated from cells grown in isotopically labeled growth media. Having shown safety, sensitivity, specificity, and versatility, stable isotopes should play an important role in drug metabolism studies in pregnancy.

  5. Magnesium stable isotope ecology using mammal tooth enamel.

    Science.gov (United States)

    Martin, Jeremy E; Vance, Derek; Balter, Vincent

    2015-01-13

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (δ(13)C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (δ(44)Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (δ(26)Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for δ(26)Mg, δ(13)C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that δ(26)Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this (26)Mg enrichment up the trophic chain is due to a (26)Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using δ(26)Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel δ(26)Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages.

  6. Magnesium stable isotope ecology using mammal tooth enamel

    Science.gov (United States)

    Martin, Jeremy E.; Vance, Derek; Balter, Vincent

    2015-01-01

    Geochemical inferences on ancient diet using bone and enamel apatite rely mainly on carbon isotope ratios (δ13C) and to a lesser extent on strontium/calcium (Sr/Ca) and barium/calcium (Ba/Ca) elemental ratios. Recent developments in nontraditional stable isotopes provide an unprecedented opportunity to use additional paleodietary proxies to disentangle complex diets such as omnivory. Of particular relevance for paleodietary reconstruction are metals present in large quantity in bone and enamel apatite, providing that biologically mediated fractionation processes are constrained. Calcium isotope ratios (δ44Ca) meet these criteria but exhibit complex ecological patterning. Stable magnesium isotope ratios (δ26Mg) also meet these criteria but a comprehensive understanding of its variability awaits new isotopic data. Here, 11 extant mammal species of known ecology from a single locality in equatorial Africa were sampled for tooth enamel and, together with vegetation and feces, analyzed for δ26Mg, δ13C, Sr/Ca, and Ba/Ca ratios. The results demonstrate that δ26Mg incorporated in tooth enamel becomes heavier from strict herbivores to omnivores/faunivores. Using data from experimentally raised sheep, we suggest that this 26Mg enrichment up the trophic chain is due to a 26Mg enrichment in muscle relative to bone. Notably, it is possible to distinguish omnivores from herbivores, using δ26Mg coupled to Ba/Ca ratios. The potential effects of metabolic and dietary changes on the enamel δ26Mg composition remain to be explored but, in the future, multiproxy approaches would permit a substantial refinement of dietary behaviors or enable accurate trophic reconstruction despite specimen-limited sampling, as is often the case for fossil assemblages. PMID:25535375

  7. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2005-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. (author). 52 refs., 11 figs., 2 tabs

  8. Stable isotope customer list and summary of shipments - FY 1983

    International Nuclear Information System (INIS)

    Davis, W.C.

    1983-12-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: (1) alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; (2) alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; (3) alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and (4) tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope

  9. Stable isotope customer list and summary of shipments: FY 1984

    International Nuclear Information System (INIS)

    Tracy, J.G.

    1984-12-01

    This compilation is published as an aid to those concerned with the separation and sale of stable isotopes. The information is divided into four sections: (1) alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; (2) alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; (3) alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and (4) tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope

  10. Stable isotope methodology and its application to nutrition and gastroenterology

    International Nuclear Information System (INIS)

    Klein, P.D.; Hachey, D.L.; Wong, W.W.; Abrams, S.A.

    1993-01-01

    This report describes the activities of the Stable Isotope Laboratory in its function as a core resource facility for stable isotope applications in human nutrition research. Three aspects are covered: Training of visitors, assessment of new instrumentation, and development of new methodology. The research achievements of the laboratory are indicated in the publications that appeared during this period. (author). 23 refs

  11. Stable isotope geochemistry. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Hoefs, J.

    1987-01-01

    Stable Isotope Geochemistry is an authoritative book comprising theoretical and experimental principles; surveying important fractionation mechanisms affecting the most important elements; discussing the natural variations of geologically important reservoirs. This updated 3rd edition, with a completely rewritten and extended main part, contains two new chapters on stable isotope composition of mantle material and on changes of the ocean during the geological past. (orig.)

  12. Stable isotope methods in biological and ecological studies of arthropods

    NARCIS (Netherlands)

    Hood-Nowotny, R.C.; Knols, B.G.J.

    2007-01-01

    This is an eclectic review and analysis of contemporary and promising stable isotope methodologies to study the biology and ecology of arthropods. It is augmented with literature from other disciplines, indicative of the potential for knowledge transfer. It is demonstrated that stable isotopes can

  13. Forensic Applications of Light-Element Stable Isotope Ratios of Ricinus communis Seeds and Ricin Preparations

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzer, Helen W.; West, Jason B.; Ehleringer, James

    2013-01-01

    Seeds of the castor plant Ricinus communis, also known as castor beans, are of forensic interest because they are the source of the poison ricin. We have tested whether stable isotope ratios of castor seeds and ricin prepared by various methods can be used as a forensic signature. We collected over 300 castor seed samples from locations around the world and measured the C, N, O, and H stable isotope ratios of the whole seeds, oil, and three types of ricin preparations. Our results demonstrate that N isotope ratios can be used to correlate ricin prepared by any of these methods to source seeds. Further, stable isotope ratios distinguished >99% of crude and purified ricin protein samples in pair-wise comparison tests. Stable isotope ratios therefore constitute a valuable forensic signature for ricin preparations.

  14. Tellurium Stable Isotopes as a Paleoredox Proxy

    Science.gov (United States)

    Wasserman, N.; Johnson, T. M.

    2017-12-01

    Despite arguments for variably-oxygenated shallow waters and anoxic deep marine waters, which delayed animal development until the Neoproterozoic Oxidation Event, the magnitude of atmospheric oxygen during the Proterozoic is still uncertain [1]. The evidence for low pO2 (biologic reduction of Te(VI) or Te(IV) to elemental Te(0) [3, 4]. Utilizing hydride generation MC-ICP-MS, we are able to obtain high precision (2σ 0.04‰) measurements of δ128Te/125Te for natural samples containing < 10 ng of Te. A suite of Phanerozoic and Proterozoic ironstones show significant variation in δ128Te/125Te (<0.5‰), suggesting that the Te redox cycle was active during the Proterozoic. Future directions will include Te isotope measurements of Precambrian paleosols to determine natural isotope variation before the Great Oxidation Event and experiments to determine fractionation during adsorption to Fe-oxyhydroxides. [1] Planavsky et al. (2014) Science 346 (6209), pp. 635-638 [2] Qin et al. (2017) Environmental Science and Technology 51 (11), pp 6027-6035 [3] Baesman et al. (2007) Applied Environmental Microbiology 73 (7), pp 2135-2143 [4] Smithers and Krause (1968) Canadian Journal of Chemistry 46(4): pp 583-591

  15. Stable isotope deltas: tiny, yet robust signatures in nature.

    Science.gov (United States)

    Brand, Willi A; Coplen, Tyler B

    2012-09-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including (14)C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. (13)C, (2)H, and (18)O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as-25 per mil can be written as-25 mUr (or-2.5 cUr or-0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg 'units' are easily included (e.g. either+0.015 ‰ or+15 per meg

  16. Stable isotope deltas: Tiny, yet robust signatures in nature

    Science.gov (United States)

    Brand, Willi A.; Coplen, Tyler B.

    2012-01-01

    Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including 14C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. 13C, 2H, and 18O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as−25 per mil can be written as−25 mUr (or−2.5 cUr or−0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg ‘units’ are easily included (e.g. either+0.015 ‰ or+15 per meg

  17. LBA-ECO CD-02 Carbon, Nitrogen, Oxygen Stable Isotopes in Organic Material, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports the measurement of stable carbon, nitrogen, and oxygen isotope ratios in organic material (plant, litter and soil samples) in forest canopy...

  18. LBA-ECO CD-02 Carbon, Nitrogen, Oxygen Stable Isotopes in Organic Material, Brazil

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports the measurement of stable carbon, nitrogen, and oxygen isotope ratios in organic material (plant, litter and soil samples) in forest...

  19. Stable isotope ratios in hair and teeth reflect biologic rhythms.

    Directory of Open Access Journals (Sweden)

    Otto Appenzeller

    Full Text Available Biologic rhythms give insight into normal physiology and disease. They can be used as biomarkers for neuronal degenerations. We present a diverse data set to show that hair and teeth contain an extended record of biologic rhythms, and that analysis of these tissues could yield signals of neurodegenerations. We examined hair from mummified humans from South America, extinct mammals and modern animals and people, both healthy and diseased, and teeth of hominins. We also monitored heart-rate variability, a measure of a biologic rhythm, in some living subjects and analyzed it using power spectra. The samples were examined to determine variations in stable isotope ratios along the length of the hair and across growth-lines of the enamel in teeth. We found recurring circa-annual periods of slow and fast rhythms in hydrogen isotope ratios in hair and carbon and oxygen isotope ratios in teeth. The power spectra contained slow and fast frequency power, matching, in terms of normalized frequency, the spectra of heart rate variability found in our living subjects. Analysis of the power spectra of hydrogen isotope ratios in hair from a patient with neurodegeneration revealed the same spectral features seen in the patient's heart-rate variability. Our study shows that spectral analysis of stable isotope ratios in readily available tissues such as hair could become a powerful diagnostic tool when effective treatments and neuroprotective drugs for neurodegenerative diseases become available. It also suggests that similar analyses of archaeological specimens could give insight into the physiology of ancient people and animals.

  20. Stable water isotope patterns in a climate change hotspot: the isotope hydrology framework of Corsica (western Mediterranean).

    Science.gov (United States)

    van Geldern, Robert; Kuhlemann, Joachim; Schiebel, Ralf; Taubald, Heinrich; Barth, Johannes A C

    2014-06-01

    The Mediterranean is regarded as a region of intense climate change. To better understand future climate change, this area has been the target of several palaeoclimate studies which also studied stable isotope proxies that are directly linked to the stable isotope composition of water, such as tree rings, tooth enamel or speleothems. For such work, it is also essential to establish an isotope hydrology framework of the region of interest. Surface waters from streams and lakes as well as groundwater from springs on the island of Corsica were sampled between 2003 and 2009 for their oxygen and hydrogen isotope compositions. Isotope values from lake waters were enriched in heavier isotopes and define a local evaporation line (LEL). On the other hand, stream and spring waters reflect the isotope composition of local precipitation in the catchment. The intersection of the LEL and the linear fit of the spring and stream waters reflect the mean isotope composition of the annual precipitation (δP) with values of-8.6(± 0.2) ‰ for δ(18)O and-58(± 2) ‰ for δ(2)H. This value is also a good indicator of the average isotope composition of the local groundwater in the island. Surface water samples reflect the altitude isotope effect with a value of-0.17(± 0.02) ‰ per 100 m elevation for oxygen isotopes. At Vizzavona Pass in central Corsica, water samples from two catchments within a lateral distance of only a few hundred metres showed unexpected but systematic differences in their stable isotope composition. At this specific location, the direction of exposure seems to be an important factor. The differences were likely caused by isotopic enrichment during recharge in warm weather conditions in south-exposed valley flanks compared to the opposite, north-exposed valley flanks.

  1. Stable isotope-based diet reconstructions of Turkana Basin hominins

    OpenAIRE

    Cerling, Thure E.; Manthi, Fredrick Kyalo; Mbua, Emma N.; Leakey, Louise N.; Leakey, Meave G.; Leakey, Richard E.; Brown, Francis H.; Grine, Frederick E.; Hart, John A.; Kaleme, Prince; Roche, Hélène; Uno, Kevin T.; Wood, Bernard A.

    2013-01-01

    Hominin fossil evidence in the Turkana Basin in Kenya from ca. 4.1 to 1.4 Ma samples two archaic early hominin genera and records some of the early evolutionary history of Paranthropus and Homo. Stable carbon isotopes in fossil tooth enamel are used to estimate the fraction of diet derived from C3 or C4 resources in these hominin taxa. The earliest hominin species in the Turkana Basin, Australopithecus anamensis, derived nearly all of its diet from C3 resources. Subsequently, by ca. 3.3 Ma, t...

  2. Using stable isotopes to determine seabird trophic relationships

    Science.gov (United States)

    Hobson, Keith A.; Piatt, John F.; Pitocchelli, Jay

    1994-01-01

    1. The stable isotopes of nitrogen (δ15N) and carbon (δ13C) were analysed in 22 species of marine birds from coastal waters of the northeast Pacific Ocean. Analyses confirm that stable nitrogen isotopes can predict seabird trophic positions.2. Based on δ15N analyses, seabird trophic-level inferences generally agree with those of conventional dietary studies, but suggest that lower trophic-level organisms are more important to several seabirds than was recognized previously.3. Stable-carbon isotope analysis may be a good indicator of inshore vs. offshore feeding preference.4. In general, stable-isotope analysis to determine trophic level offers many advantages over conventional dietary approaches since trophic inferences are based on time-integrated estimates of assimilated and not just ingested foods, and isotopic abundance represents a continuous variable that is amenable to statistical analysis.

  3. Stable isotope views on ecosystem function: challenging or challenged?

    Science.gov (United States)

    Resco, Víctor; Querejeta, José I.; Ogle, Kiona; Voltas, Jordi; Sebastià, Maria-Teresa; Serrano-Ortiz, Penélope; Linares, Juan C.; Moreno-Gutiérrez, Cristina; Herrero, Asier; Carreira, José A.; Torres-Cañabate, Patricia; Valladares, Fernando

    2010-01-01

    Stable isotopes and their potential for detecting various and complex ecosystem processes are attracting an increasing number of scientists. Progress is challenging, particularly under global change scenarios, but some established views have been challenged. The IX meeting of the Spanish Association of Terrestrial Ecology (AAET, Úbeda, 18–22 October 2009) hosted a symposium on the ecology of stable isotopes where the linear mixing model approach of partitioning sinks and sources of carbon and water fluxes within an ecosystem was challenged, and new applications of stable isotopes for the study of plant interactions were evaluated. Discussion was also centred on the need for networks that monitor ecological processes using stable isotopes and key ideas for fostering future research with isotopes. PMID:20015858

  4. Thermal Neutron Capture onto the Stable Tungsten Isotopes

    Directory of Open Access Journals (Sweden)

    Nichols A.

    2012-02-01

    Full Text Available Thermal neutron-capture measurements of the stable tungsten isotopes have been carried out using the guided thermal-neutron beam at the Budapest Reactor. Prompt singles spectra were collected and analyzed using the HYPERMET γ-ray analysis software package for the compound tungsten systems 183W, 184W, and 187W, prepared from isotopically-enriched samples of 182W, 183W, and 186W, respectively. These new data provide both confirmation and new insights into the decay schemes and structure of the tungsten isotopes reported in the Evaluated Gamma-ray Activation File based upon previous elemental analysis. The experimental data have also been compared to Monte Carlo simulations of γ-ray emission following the thermal neutron-capture process using the statistical-decay code DICEBOX. Together, the experimental cross sections and modeledfeeding contribution from the quasi continuum, have been used to determine the total radiative thermal neutron-capture cross sections for the tungsten isotopes and provide improved decay-scheme information for the structural- and neutron-data libraries.

  5. Stable isotopes for improving human nutrition

    International Nuclear Information System (INIS)

    Uauy, Ricardo

    2001-01-01

    recent FAO review of nutrition programs in 19 Latin American countries found that over 20 percent of the population - approximately 83 million people out of an estimated 414 million in the study countries - receives some level of benefits in nutrition-related programs. The allocation of limited national and international assistance resources for these activities in the region is on the order of several billion dollars annually. Undoubtedly these programs are influencing child growth. Significant reductions in underweight and wasting have occurred; but stunting has been more resistant to change. In this setting providing food supplements may be beneficial for some while it may be detrimental for others. The definition of who should benefit from the programs and what is the right combination of nutrients/foods, education, and lifestyle interventions that is required to optimise nutrition and health at each stage of the life cycle is a truly complex problem. This demands the use of the best scientific tools to define who should benefit, what should done and measured as an outcome, how programs should be evaluated, when programs should be expanded, and when they should be stopped. Isotopic and nuclear techniques are tools, not solutions. This presentation will serve to demonstrate how isotopes can contribute to refining nutrition interventions and their impact on public health. Isotopic methods can shorten the time needed to evaluate impact, because they provide sensitive measurements of biological effects. They are faster than traditional methods such as anthropometry for detecting changes in growth and body composition. Micronutrient malnutrition, and especially the bioavailability of vitamins and minerals from traditional foods, are not well evaluated using routine biochemical methods. Radioisotopes have been used successfully in the past. But recent developments in stable isotope techniques offer unique advantages for the design and evaluation of programmes that address

  6. Use of stable isotopes in human nutrition in Senegal

    International Nuclear Information System (INIS)

    2016-01-01

    In Senegal, the Laboratory of Nutrition of the Department of Animal Biology of the Faculty of Science and Technology of UCAD has been using stable isotopic techniques for nearly twenty years. Stable isotopes were applied to different target populations to measure milk production, exclusive breastfeeding, body composition, micronutrient bioavailability and total energy expenditure.The application of stable isotopic techniques in nutrition has contributed to advocacy for exclusive breastfeeding for up to 6 months in Senegal. It enabled government decision-makers to obtain essential information on the quality of foods needed for optimal effect during pregnancy and for infant growth and the results were reflected in the national policy on micronutrient supplementation.

  7. What can Fe stable isotopes tell us about magmas?

    DEFF Research Database (Denmark)

    Stausberg, Niklas

    The majority of the Earth’s crust is formed by magmas, and understanding their production and differentiation is important to interpret the geologic rock record. A powerful tool to investigate magmatic processes is the distribution of the stable isotopes of the major redox-sensitive element...... the differentiation of magmas from the perspective of Fe stable isotopes, integrated with petrology, by studying igneous rocks and their constituent phases (minerals and glasses) from the Bushveld Complex, South Africa, Thingmuli, Iceland, Pantelleria, Italy, and the Bishop Tuff, USA. The findings are interpreted...... and for more quantitative model of the magmatic processes producing enigmatic stable isotope compositions of rhyolitic and granite magmas....

  8. Simultaneous determination of stable carbon, oxygen, and hydrogen isotopes in cellulose.

    Science.gov (United States)

    Loader, N J; Street-Perrott, F A; Daley, T J; Hughes, P D M; Kimak, A; Levanič, T; Mallon, G; Mauquoy, D; Robertson, I; Roland, T P; van Bellen, S; Ziehmer, M M; Leuenberger, M

    2015-01-06

    A technological development is described through which the stable carbon-, oxygen-, and nonexchangeable hydrogen-isotopic ratios (δ(13)C, δ(18)O, δ(2)H) are determined on a single carbohydrate (cellulose) sample with precision equivalent to conventional techniques (δ(13)C 0.15‰, δ(18)O 0.30‰, δ(2)H 3.0‰). This triple-isotope approach offers significant new research opportunities, most notably in physiology and medicine, isotope biogeochemistry, forensic science, and palaeoclimatology, when isotopic analysis of a common sample is desirable or when sample material is limited.

  9. Methodology for the Validation of Isotopic Analyses by Mass Spectrometry in Stable-Isotope Labeling Experiments.

    Science.gov (United States)

    Heuillet, Maud; Bellvert, Floriant; Cahoreau, Edern; Letisse, Fabien; Millard, Pierre; Portais, Jean-Charles

    2018-02-06

    Stable-isotope labeling experiments (ILEs) are widely used to investigate the topology and operation of metabolic networks. The quality of isotopic data collected in ILEs is of utmost importance to ensure reliable biological interpretations, but current evaluation approaches are limited due to a lack of suitable reference material and relevant evaluation criteria. In this work, we present a complete methodology to evaluate mass spectrometry (MS) methods used for quantitative isotopic studies of metabolic systems. This methodology, based on a biological sample containing metabolites with controlled labeling patterns, exploits different quality metrics specific to isotopic analyses (accuracy and precision of isotopologue masses, abundances, and mass shifts and isotopic working range). We applied this methodology to evaluate a novel LC-MS method for the analysis of amino acids, which was tested on high resolution (Orbitrap operating in full scan mode) and low resolution (triple quadrupole operating in multiple reaction monitoring mode) mass spectrometers. Results show excellent accuracy and precision over a large working range and revealed matrix-specific as well as mode-specific characteristics. The proposed methodology can identify reliable (and unreliable) isotopic data in an easy and straightforward way and efficiently supports the identification of sources of systematic biases as well as of the main factors that influence the overall accuracy and precision of measurements. This approach is generic and can be used to validate isotopic analyses on different matrices, analytical platforms, labeled elements, or classes of metabolites. It is expected to strengthen the reliability of isotopic measurements and thereby the biological value of ILEs.

  10. Metal stable isotope signatures as tracers in environmental geochemistry.

    Science.gov (United States)

    Wiederhold, Jan G

    2015-03-03

    The biogeochemical cycling of metals in natural systems is often accompanied by stable isotope fractionation which can now be measured due to recent analytical advances. In consequence, a new research field has emerged over the last two decades, complementing the traditional stable isotope systems (H, C, O, N, S) with many more elements across the periodic table (Li, B, Mg, Si, Cl, Ca, Ti, V, Cr, Fe, Ni, Cu, Zn, Ge, Se, Br, Sr, Mo, Ag, Cd, Sn, Sb, Te, Ba, W, Pt, Hg, Tl, U) which are being explored and potentially applicable as novel geochemical tracers. This review presents the application of metal stable isotopes as source and process tracers in environmental studies, in particular by using mixing and Rayleigh model approaches. The most important concepts of mass-dependent and mass-independent metal stable isotope fractionation are introduced, and the extent of natural isotopic variations for different elements is compared. A particular focus lies on a discussion of processes (redox transformations, complexation, sorption, precipitation, dissolution, evaporation, diffusion, biological cycling) which are able to induce metal stable isotope fractionation in environmental systems. Additionally, the usefulness and limitations of metal stable isotope signatures as tracers in environmental geochemistry are discussed and future perspectives presented.

  11. Stable water isotopes suggest sub-canopy water recycling in a northern forested catchment

    Science.gov (United States)

    Mark B. Green; Bethany K. Laursen; John L. Campbell; Kevin J. McGuire; Eric P. Kelsey

    2015-01-01

    Stable water isotopes provide a means of tracing many hydrologic processes, including poorly understood dynamics like soil water interactions with the atmosphere. We present a four-year dataset of biweekly water isotope samples from eight fluxes and stores in a headwater catchment at the Hubbard Brook Experimental Forest, New Hampshire, USA. We use Dansgaard's...

  12. Inferring the source of evaporated waters using stable H and O isotopes

    Science.gov (United States)

    Stable isotope ratios of H and O are widely used to identify the source of water, e.g., in aquifers, river runoff, soils, plant xylem, and plant-based beverages. In situations where the sampled water is partially evaporated, its isotope values will have evolved along an evaporati...

  13. Multiple stable isotope fronts during non-isothermal fluid flow

    Science.gov (United States)

    Fekete, Szandra; Weis, Philipp; Scott, Samuel; Driesner, Thomas

    2018-02-01

    Stable isotope signatures of oxygen, hydrogen and other elements in minerals from hydrothermal veins and metasomatized host rocks are widely used to investigate fluid sources and paths. Previous theoretical studies mostly focused on analyzing stable isotope fronts developing during single-phase, isothermal fluid flow. In this study, numerical simulations were performed to assess how temperature changes, transport phenomena, kinetic vs. equilibrium isotope exchange, and isotopic source signals determine mineral oxygen isotopic compositions during fluid-rock interaction. The simulations focus on one-dimensional scenarios, with non-isothermal single- and two-phase fluid flow, and include the effects of quartz precipitation and dissolution. If isotope exchange between fluid and mineral is fast, a previously unrecognized, significant enrichment in heavy oxygen isotopes of fluids and minerals occurs at the thermal front. The maximum enrichment depends on the initial isotopic composition of fluid and mineral, the fluid-rock ratio and the maximum change in temperature, but is independent of the isotopic composition of the incoming fluid. This thermally induced isotope front propagates faster than the signal related to the initial isotopic composition of the incoming fluid, which forms a trailing front behind the zone of transient heavy oxygen isotope enrichment. Temperature-dependent kinetic rates of isotope exchange between fluid and rock strongly influence the degree of enrichment at the thermal front. In systems where initial isotope values of fluids and rocks are far from equilibrium and isotope fractionation is controlled by kinetics, the temperature increase accelerates the approach of the fluid to equilibrium conditions with the host rock. Consequently, the increase at the thermal front can be less dominant and can even generate fluid values below the initial isotopic composition of the input fluid. As kinetics limit the degree of isotope exchange, a third front may

  14. Laser ablation isotope ratio mass spectrometry for enhanced sensitivity and spatial resolution in stable isotope analysis.

    Science.gov (United States)

    Moran, James J; Newburn, Matt K; Alexander, M Lizabeth; Sams, Robert L; Kelly, James F; Kreuzer, Helen W

    2011-05-15

    Stable isotope analysis permits the tracking of physical, chemical, and biological reactions and source materials at a wide variety of spatial scales. We present a laser ablation isotope ratio mass spectrometry (LA-IRMS) method that enables δ(13)C measurement of solid samples at 50 µm spatial resolution. The method does not require sample pre-treatment to physically separate spatial zones. We use laser ablation of solid samples followed by quantitative combustion of the ablated particulates to convert sample carbon into CO(2). Cryofocusing of the resulting CO(2) coupled with modulation in the carrier flow rate permits coherent peak introduction into an isotope ratio mass spectrometer, with only 65 ng carbon required per measurement. We conclusively demonstrate that the measured CO(2) is produced by combustion of laser-ablated aerosols from the sample surface. We measured δ(13)C for a series of solid compounds using laser ablation and traditional solid sample analysis techniques. Both techniques produced consistent isotopic results but the laser ablation method required over two orders of magnitude less sample. We demonstrated that LA-IRMS sensitivity coupled with its 50 µm spatial resolution could be used to measure δ(13) C values along a length of hair, making multiple sample measurements over distances corresponding to a single day's growth. This method will be highly valuable in cases where the δ(13)C analysis of small samples over prescribed spatial distances is required. Suitable applications include forensic analysis of hair samples, investigations of tightly woven microbial systems, and cases of surface analysis where there is a sharp delineation between different components of a sample. Copyright © 2011 John Wiley & Sons, Ltd.

  15. The Global Network of Isotopes in Rivers (GNIR): Integration of Stable Water Isotopes in Riverine Research and Management

    International Nuclear Information System (INIS)

    Halder, J.; Terzer, S.; Wassenaar, L.; Araguas, L.; Aggarwal, P.

    2015-01-01

    Rivers play a crucial role in the global water cycle as watershed-integrating hydrological conduits for returning terrestrial precipitation, runoff, surface and groundwater, as well as melting snow and ice back to the world’s oceans. The IAEA Global Network of Isotopes in Rivers (GNIR) is the coherent extension of the IAEA Global Network for Isotopes in Precipitation (GNIP) and aims to fill the informational data gaps between rainfall and river discharge. Whereas the GNIP has been surveying the stable hydrogen and oxygen isotopes, and tritium composition in precipitation, the objective of GNIR is to accumulate and disseminate riverine isotope data. We introduce the new global database of riverine water isotopes and evaluate its current long-term data holdings with the objective to improve the application of water isotopes and to inform water managers and researchers. An evaluation of current GNIR database holdings confirmed that seasonal variations of the stable water isotope composition in rivers are closely coupled to precipitation and snow-melt water run-off on a global scale. Rivers could be clustered on the basis of seasonal variations in their isotope composition and latitude. Results showed furthermore, that there were periodic phases within each of these groupings and additional modelling exercises allowed a priori prediction of the seasonal variability as well as the isotopic composition of stable water isotopes in rivers. This predictive capacity will help to improve existing and new sampling strategies, help to validate and interpret riverine isotope data, and identify important catchment processes. Hence, the IAEA promulgates and supports longterm hydrological isotope observation networks and the application of isotope studies complementary with conventional hydrological, water quality, and ecological studies. (author)

  16. US ITASE Stable Isotope Data, Antarctica, Version 1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set includes stable isotope measurements from snow pits, firn, and ice cores collected by the the US component of the International Trans-Antarctic...

  17. A stable isotopic study of the diet of Potamonautes sidneyi ...

    African Journals Online (AJOL)

    Natal, South Africa. Recent flood events in the iSimangaliso Wetland Park have allowed a substantial range expansion of this species, including previously hypersaline and desiccated areas. A stable isotope study was conducted to examine ...

  18. Stable isotopes: essential tools in biological and medical research

    Energy Technology Data Exchange (ETDEWEB)

    Klein, P. D.; Hachey, D. L.; Kreek, M. J.; Schoeller, D. A.

    1977-01-01

    Recent developments in the use of the stable isotopes, /sup 13/C, /sup 15/N, /sup 17/O, and /sup 18/O, as tracers in research studies in the fields of biology, medicine, pharmacology, and agriculture are briefly reviewed. (CH)

  19. Isotopes in geobiochemistry: tracing metabolic pathways in microorganisms of environmental relevance with stable isotopes.

    Science.gov (United States)

    Adrian, Lorenz; Marco-Urrea, Ernest

    2016-10-01

    Stable isotopes are flexibly used as tracers to investigate environmental processes, microorganisms responsible for environmental transformations, syntrophic relationships in consortia, and metabolic pathways. With the advent of widely accessible high-resolution, highly accurate and sensitive mass spectrometers connected to liquid chromatography (LC-MS/MS) and the explosion of microbial genome sequence information the options to apply stable isotope tracers to geobiochemical topics have multiplied. With methods at hand to analyze biochemical pathways and enzymatic functions of yet-uncultivated microorganisms even in mixed cultures, a wide field of new discoveries can be expected. Applications rely both on the high sensitivity to detect trace amounts of biological material in slow or non-growing cultures and on the high multi-dimensional resolution of LC-MS/MS to allow the separation of complex samples and to retrieve phylogenetic information. Challenges and examples of stable isotope applications to describe geobiochemical processes are reviewed. Overall, the potential is not yet sufficiently deployed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Stable carbon isotope time series from tropical tree rings indicate a precipitation signal

    OpenAIRE

    E. Fichtler; Gerhard Helle; M. Worbes

    2010-01-01

    Although studies on stable-carbon isotopes in trees from temperate zones provide abundant paleoclimatic data, tropical trees are still understudied in this context. Therefore this study examined the variability of intra- and inter-annual stable-carbon isotopic pattern in several tree species from various tropical climates. The delta C-13 Values of samples of 12 broadleaved trees (seven species) from various paleotropical and neotropical sites along a climatic moisture gradient were investigat...

  1. Stable carbon and oxygen isotope study on benthic foraminifera ...

    Indian Academy of Sciences (India)

    Ajoy K Bhaumik

    2017-07-24

    Jul 24, 2017 ... Stable isotopes of benthic foraminifera have widely been applied in micropalaeontological research to understand vital effects in foraminifera. Isotopic fractionations are mainly controlled by ontogeny, bottom/pore water chemistry, habitat preference, kinetic effect and respiration. Discontinuous abundance.

  2. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2009-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs.

  3. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2014-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author)

  4. Stable isotope geochemistry: definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2015-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author).

  5. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2012-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 89 refs., 12 figs., 2 tabs.

  6. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2008-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs

  7. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2009-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeolimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteroic waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 56 refs., 11 figs., 2 tabs

  8. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2016-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author).

  9. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2013-01-01

    In 1936, Alfred Nier produced the first precise measurement of isotope abundance ratios and his design still remains the basis of stable isotope mass spectrometry. With this gift from the physicists for routine measurement of isotope ratios, earth scientists began to explore the natural variations of isotopes. Thus began a new era in geoscience research with the hydrological cycle and marine palaeoclimatic research being the first topics to be investigated. Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: 1. Thermometry: Formation temperatures of rock and mineral systems are determined on the basis of temperature-dependent fractionations of the isotopic ratios between two or more cogenetic phases. 2. Tracers: Reservoirs like the ocean, the mantle, meteoric waters and organic matter have distinct stable isotope signatures that can be used to trace the origin of rocks, fluids, contaminants etc. 3. Reaction mechanism: Distinctions can be made between diffusion and recrystallization, open and closed systems and bacterial and thermogenic processes. 4. Chemostratigraphy: Abrupt changes (excursions) in the stable isotope ratios of ocean sediments and certain terrestrial materials can be used as stratigraphic markers. (author). 91 refs., 12 figs., 2 tabs.

  10. Stable isotope customer list and summary of shipments, FY 1977

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.C.

    1978-04-01

    The compilation of stable isotope customers and shipments is divided into four parts. There are alphabetical lists of domestic and foreign customers, alphabetical list of isotopes with cross-references to customers, alphabetical list of states and customers with cross-reference to customers, and tabulation of shipments, quantities, and dollars. (JSR)

  11. Variation in carbon and nitrogen stable isotope ratios in flight ...

    African Journals Online (AJOL)

    bellied Sunbird to assess the value of using stable isotopes of feathers in avian dietary studies. Significant variation in δ13C and δ15N isotope values of flight feathers (range = 3.1‰ and 2.7‰, respectively) indicated that the source of carbon (i.e. ...

  12. Stable isotopes in pharmacology studies: present and future

    International Nuclear Information System (INIS)

    Browne, T.R.

    1986-01-01

    Stable-isotope techniques offer advantages over older methods in safety, sensitivity, specificity, and reduction in numbers of subjects required and analytic determinations for some types of pharmacology studies. In addition to their use as internal standards in gas chromatography-mass spectrometry analytic methods, stable isotopes have been successfully employed in studies of absorption, bioavailability, distribution, biotransformation, excretion, metabolite identification, time-dependent and dose-dependent pharmacokinetic changes, drug interactions, pharmacologic changes during pregnancy, mutagenicity, and teratogenicity. 32 references

  13. Biogeochemistry of the stable hydrogen isotopes

    International Nuclear Information System (INIS)

    Estep, M.F.; Hoering, T.C.

    1980-01-01

    The fractionation of H isotopes between the water in the growth medium and the organically bonded H from microalgae cultured under conditions, where light intensity and wavelength, temperature, nutrient availability, and the H isotope ratio of the water were controlled, is reproducible and light dependent. All studies were based either on the H isotope ratios of the total organic H or on the lipids, where most of the H is firmly bonded to C. H bonded into other macromolecules, proteins, carbohydrates and nucleic acids, does not exchange with water, when algae are incubated in water enriched with deuterium. Only after the destruction of quaternary H bonds are labile hydrogens in macromolecules free to exchange with water. By growing algae (18 strains), including blue-green algae, green algae and diatoms, in continuous light, the isotope fractionations in photosynthesis were reproducibly -93 to -178 per thousand, depending on the organism tested. This fractionation was not temperature dependent. Microalgae grown in total darkness with an organic substrate did not show the isotope fractionation seen in cells grown in light. In both light- and dark-grown algae, however, additional depletion of deuterium (-30 to -60 per thousand) in cellular organic matter occurs during the metabolism of carbohydrates to form lipids. Plants from several natural populations also fractionated isotopes during photosynthesis by an average of -90 to -110 per thousand. In addition, the organically bonded H in nonsaponifiable lipids was further fractionated by -80 per thousand from that in saponifiable lipids, isolated from two geographically distinct populations of marsh plants. This difference between H isotope ratios of these two groups of lipids provides an endogenous isotopic marker. (author)

  14. Stable isotope analysis of white paints and likelihood ratios.

    Science.gov (United States)

    Farmer, N; Meier-Augenstein, W; Lucy, D

    2009-06-01

    Architectural paints are commonly found as trace evidence at scenes of crime. Currently the most widely used technique for the analysis of architectural paints is Fourier Transformed Infra-Red Spectroscopy (FTIR). There are, however, limitations to the forensic analysis of white paints, and the ability to discriminate between samples. Isotope ratio mass spectrometry (IRMS) has been investigated as a potential tool for the analysis of architectural white paints, where no preparation of samples prior to analysis is required. When stable isotope profiles (SIPs) are compared, there appears to be no relationship between paints from the same manufacturer, or between paints of the same type. Unlike existing techniques, IRMS does not differentiate resin samples solely on the basis of modifier or oil-type, but exploits additional factors linked to samples such as geo-location where oils added to alkyd formulations were grown. In combination with the use of likelihood ratios, IRMS shows potential, with a false positive rate of 2.6% from a total of 1275 comparisons.

  15. The stable Cr isotopic compositions of chondrites and silicate planetary reservoirs

    Science.gov (United States)

    Schoenberg, Ronny; Merdian, Alexandra; Holmden, Chris; Kleinhanns, Ilka C.; Haßler, Kathrin; Wille, Martin; Reitter, Elmar

    2016-06-01

    The depletion of chromium in Earth's mantle (∼2700 ppm) in comparison to chondrites (∼4400 ppm) indicates significant incorporation of chromium into the core during our planet's metal-silicate differentiation, assuming that there was no significant escape of the moderately volatile element chromium during the accretionary phase of Earth. Stable Cr isotope compositions - expressed as the ‰-difference in 53Cr/52Cr from the terrestrial reference material SRM979 (δ53/52CrSRM979 values) - of planetary silicate reservoirs might thus yield information about the conditions of planetary metal segregation processes when compared to chondrites. The stable Cr isotopic compositions of 7 carbonaceous chondrites, 11 ordinary chondrites, 5 HED achondrites and 2 martian meteorites determined by a double spike MC-ICP-MS method are within uncertainties indistinguishable from each other and from the previously determined δ53/52CrSRM979 value of -0.124 ± 0.101‰ for the igneous silicate Earth. Extensive quality tests support the accuracy of the stable Cr isotope determinations of various meteorites and terrestrial silicates reported here. The uniformity in stable Cr isotope compositions of samples from planetary silicate mantles and undifferentiated meteorites indicates that metal-silicate differentiation of Earth, Mars and the HED parent body did not cause measurable stable Cr isotope fractionation between these two reservoirs. Our results also imply that the accretionary disc, at least in the inner solar system, was homogeneous in its stable Cr isotopic composition and that potential volatility loss of chromium during accretion of the terrestrial planets was not accompanied by measurable stable isotopic fractionation. Small but reproducible variations in δ53/52CrSRM979 values of terrestrial magmatic rocks point to natural stable Cr isotope variations within Earth's silicate reservoirs. Further and more detailed studies are required to investigate whether silicate

  16. Expanding the isotopic toolbox: Applications of hydrogen and oxygen stable isotope ratios to food web studies

    OpenAIRE

    Hannah B Vander Zanden; David X Soto; Gabriel J Bowen; Keith A Hobson; Keith A Hobson

    2016-01-01

    The measurement of stable carbon (δ13C) and nitrogen (δ15N) isotopes in tissues of organisms has formed the foundation of isotopic food web reconstructions, as these values directly reflect assimilated diet. In contrast, stable hydrogen (δ2H) and oxygen (δ18O) isotope measurements have typically been reserved for studies of migratory origin and paleoclimate reconstruction based on systematic relationships between organismal tissue and local environmental water. Recently, innovative applicat...

  17. Expanding the Isotopic Toolbox: Applications of Hydrogen and Oxygen Stable Isotope Ratios to Food Web Studies

    OpenAIRE

    Vander Zanden, Hannah B.; Soto, David X.; Bowen, Gabriel J.; Hobson, Keith A.

    2016-01-01

    The measurement of stable carbon (δ13C) and nitrogen (δ15N) isotopes in tissues of organisms has formed the foundation of isotopic food web reconstructions, as these values directly reflect assimilated diet. In contrast, stable hydrogen (δ2H) and oxygen (δ18O) isotope measurements have typically been reserved for studies of migratory origin and paleoclimate reconstruction based on systematic relationships between organismal tissue and local environmental water. Recently, innovative applicatio...

  18. The status of applying stable isotope in the studies of environmental science

    International Nuclear Information System (INIS)

    Bai Zhipeng; Zhang Liwen; Zhu Tan; Feng Yinchang

    2007-01-01

    The stable isotope composition is characteristic in the pollution source, and it is relatively fixed in the process of transferring and reaction. At present the precise analysis result of stable isotope ratio can be obtained easily. So the stable isotopes can be applied to the pollution affair arbitration and source study. The concept and analytical method of stable isotopes are introduced. The research status of the stable isotopes in the field of environmental science and the isotope fractionation is reviewed. (authors)

  19. Application of Stable Isotope Signatures in Food Traceability

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Roslanzairi Mostapha; Zainon Othman; Nor Afiqah Harun; Mohd Suhaimi Hamzah; Shamsiah Abdul Rahman; Md Suhaimi Elias; Salmah Moosa

    2015-01-01

    Stable isotope analysis has widely been used to trace the origin of organic materials in various fields, such as geochemistry, biochemistry, archaeology and petroleum. In past a decade, it has also become an important tool for food traceability study. The globalization of food markets and the relative ease with which food commodities are transported through and between countries and continents, means that consumers are increasingly concerned about the origin of the foods they eat. The natural abundance isotope variation such as carbon, nitrogen, hydrogen and oxygen are use as geographic tracers or marker to determine the geographic origin of fruits, crop, vegetables and food products from animal. The isotopic compositions of plant materials reflect various factors such as isotopic compositions of source materials and their assimilation processes as well as growth environments. This paper will discuss on stable carbon and nitrogen isotopic compositions in rice, advantages, limitations and potential of other analysis applications that can be incorporated in food traceability system. (author)

  20. Development of O-18 stable isotope separation technology using membrane

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Woo; Kim, Taek Soo; Choi, Hwa Rim; Park, Sung Hee; Lee, Ki Tae; Chang, Dae Shik

    2006-06-15

    The ultimate goal of this investigation is to develop the separation technology for O-18 oxygen stable isotope used in a cyclotron as a target for production of radioisotope F-18. F-18 is a base material for synthesis of [F-18]FDG radio-pharmaceutical, which is one of the most important tumor diagnostic agent used in PET (Positron Emission Tomography). More specifically, this investigation is focused on three categories as follow, 1) development of the membrane distillation isotope separation process to re-enrich O-18 stable isotope whose isotopic concentration is reduced after used in a cyclotron, 2) development of organic impurity purification technology to remove acetone, methanol, ethanol, and acetonitrile contained in a used cyclotron O-18 enriched target water, and 3) development of a laser absorption spectroscopic system for analyzing oxygen isotopic concentration in water.

  1. Stable Isotope Ratios as Biomarkers of Diet for Health Research.

    Science.gov (United States)

    O'Brien, Diane M

    2015-01-01

    Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently, there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short- and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general US population. Approaches to improve specificity for specific foods are needed; for example, by modeling intake using multiple stable isotope ratios or by isolating and measuring specific molecules linked to foods of interest.

  2. Source Partitioning Using Stable Isotopes: Coping with Too Much Variation

    Science.gov (United States)

    Parnell, Andrew C.; Inger, Richard; Bearhop, Stuart; Jackson, Andrew L.

    2010-01-01

    Background Stable isotope analysis is increasingly being utilised across broad areas of ecology and biology. Key to much of this work is the use of mixing models to estimate the proportion of sources contributing to a mixture such as in diet estimation. Methodology By accurately reflecting natural variation and uncertainty to generate robust probability estimates of source proportions, the application of Bayesian methods to stable isotope mixing models promises to enable researchers to address an array of new questions, and approach current questions with greater insight and honesty. Conclusions We outline a framework that builds on recently published Bayesian isotopic mixing models and present a new open source R package, SIAR. The formulation in R will allow for continued and rapid development of this core model into an all-encompassing single analysis suite for stable isotope research. PMID:20300637

  3. Stable Isotope Ratios as Biomarkers of Diet for Health Research

    Science.gov (United States)

    O’Brien, Diane M.

    2016-01-01

    Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in self-reported methods of diet assessment. Consequently there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general United States population. Approaches to improve specificity for specific foods are needed, for example, by modeling intake using multiple stable isotope ratios, or by isolating and measuring specific molecules linked to foods of interest. PMID:26048703

  4. Application of enriched stable isotopes as tracers in biological systems

    DEFF Research Database (Denmark)

    Stürup, Stefan; Hansen, Helle Rüsz; Gammelgaard, Bente

    2008-01-01

    The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry...... (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments......, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched...

  5. Leaf water stable isotopes and water transport outside the xylem.

    Science.gov (United States)

    Barbour, M M; Farquhar, G D; Buckley, T N

    2017-06-01

    How water moves through leaves, and where the phase change from liquid to vapour occurs within leaves, remain largely mysterious. Some time ago, we suggested that the stable isotope composition of leaf water may contain information on transport pathways beyond the xylem, through differences in the development of gradients in enrichment within the various pathways. Subsequent testing of this suggestion provided ambiguous results and even questioned the existence of gradients in enrichment within the mesophyll. In this review, we bring together recent theoretical developments in understanding leaf water transport pathways and stable isotope theory to map a path for future work into understanding pathways of water transport and leaf water stable isotope composition. We emphasize the need for a spatially, anatomically and isotopically explicit model of leaf water transport. © 2016 John Wiley & Sons Ltd.

  6. Stable isotope paleoaltimetry of the Mount Everest region

    Science.gov (United States)

    Gebelin, A.; Mulch, A.; Teyssier, C.; Jessup, M. J.; Law, R. D.; Brunel, M.

    2012-12-01

    Long-term climatic evolution and atmospheric circulation patterns are influenced to a first order by the topography of the largest mountain ranges. Reconstructing the Neogene elevation history of the Mount Everest region is of particular interest for understanding the tectonic history of the Himalaya-Tibet orogen as well as global scale atmospheric circulation and biotic changes through time. Stable isotope paleoaltimetry uses the isotopic lapse rate of precipitations preserved in the near-surface record. In the absence of surface deposits such as paleosols, volcanic ashes, or lacustrine limestone that record the stable isotopic composition of early to mid-Miocene water preserved in the highly erosive Himalayan range, we conduct stable-isotope paleoaltimetry based on the hydrogen isotopic composition (δD) of hydrous minerals that crystallized in the South Tibetan detachment (STD) shear zone at ~17 Ma. For paleoaltimetry reconstruction we compare stable isotope records from the STD mylonitic footwall to age-equivalent oxygen isotope ratios (δ18O) measured within pedogenic carbonate from Siwalik foreland paleosols that developed near Miocene sea level. The relative differences between meteoric water compositions in the foreland basin and the δ18Owater calculated from the hydrogen isotope composition of syntectonic minerals suggest that by ~17 Ma the central Himalaya was at an elevation similar to what it is today, and that a rain shadow likely existed at that time. Our results demonstrate the power of shear-zone based paleoaltimetry in eroded mountain belts, call for caution in interpreting basin-based stable isotope paleoaltimetry in the rain shadow of the mid-Miocene Himalayan range and suggest that strengthening of the South Asian monsoon may have occurred in early to mid-Miocene, earlier than previously thought.

  7. Stable isotope 'vital effects' in coccolith calcite

    NARCIS (Netherlands)

    Ziveri, P.; Stoll, H.; Probert, I.; Klaas, C.; Geisen, M.; Ganssen, G.M.; Young, J.

    2003-01-01

    Uncertainties about the origin of the many disequilibrium or 'vital effects' in a variety of calcifying organisms, and whether these effects are constant or variable, have hampered paleoceanographic application of carbon and oxygen isotopic ratios. Unraveling the source of these effects will improve

  8. Interpretation of stable isotope, denitrification, and groundwater age data for samples collected from Sandia National Laboratories /New Mexico (SNL/NM) Burn Site Groundwater Area of Concern

    Energy Technology Data Exchange (ETDEWEB)

    Madrid, V. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Singleton, M. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Visser, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Esser, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-06-02

    This report combines and summarizes results for two groundwater-sampling events (October 2012 and October/November 2015) from the Sandia National Laboratories/New Mexico (SNL/NM) Burn Site Groundwater (BSG) Area of Concern (AOC) located in the Lurance Canyon Arroyo southeast of Albuquerque, NM in the Manzanita Mountains. The first phase of groundwater sampling occurred in October 2012 including samples from 19 wells at three separate sites that were analyzed by the Environmental Radiochemistry Laboratory at Lawrence Livermore National Laboratory as part of a nitrate Monitored Natural Attenuation (MNA) evaluation. The three sites (BSG, Technical Area-V, and Tijeras Arroyo) are shown on the regional hydrogeologic map and described in the Sandia Annual Groundwater Monitoring Report. The first phase of groundwater sampling included six monitoring wells at the Burn Site, eight monitoring wells at Technical Area-V, and five monitoring wells at Tijeras Arroyo. Each groundwater sample was analyzed using the two specialized analytical methods, age-dating and denitrification suites. In September 2015, a second phase of groundwater sampling took place at the Burn Site including 10 wells sampled and analyzed by the same two analytical suites. Five of the six wells sampled in 2012 were resampled in 2015. This report summarizes results from two sampling events in order to evaluate evidence for in situ denitrification, the average age of the groundwater, and the extent of recent recharge of the bedrock fracture system beneath the BSG AOC.

  9. Stable isotope ratio method for the characterisation of the poultry house environment.

    Science.gov (United States)

    Skipitytė, Raminta; Mašalaitė, Agnė; Garbaras, Andrius; Mickienė, Rūta; Ragažinskienė, Ona; Baliukonienė, Violeta; Bakutis, Bronius; Šiugždaitė, Jūratė; Petkevičius, Saulius; Maruška, Audrius Sigitas; Remeikis, Vidmantas

    2017-06-01

    Stable isotope analysis was applied to describe the poultry house environment. The poultry house indoor environment was selected for this study due to the relevant health problems in animals and their caretakers. Air quality parameters including temperature, relative humidity, airflow rate, NH 3 , CO 2 and total suspended particles, as well as mean levels of total airborne bacteria and fungi count, were measured. Carbon isotope ratios ( 13 C/ 12 C) were obtained in size-segregated aerosol particles. The carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) isotope ratios were measured in feed, litter, scrapings from the ventilation system, feathers and eggs. Additionally, the distribution of δ 13 C and δ 15 N values in different tissues of the chicken was examined. The airborne bacteria and fungi extracted from the air filters collected from poultry farms were grown in the laboratory in media with known isotope values and measured for stable isotope ratios. Analysis of isotope fractionation between microorganisms and their media indicated the applicability of stable isotope analysis in bulk samples for the identification of source material. The analysed examples imply that stable isotope analysis can be used to examine the indoor environment along with its biology and ecology, and serve as an informative bioanalytical tool.

  10. Role of stable isotope mass spectroscopy in hydrological sciences

    International Nuclear Information System (INIS)

    Keesari, Tirumalesh

    2017-01-01

    Isotope Ratio Mass Spectrometry (IRMS) is a specialized technique used to provide information about a given sample about its geographic, chemical, physical and biological origin. The ability to determine the source of water molecule stems from the relative isotopic abundances of its constituent elements, viz., hydrogen and oxygen or sometimes through its dissolved elements such as carbon, nitrogen and sulphur etc. Since the isotope ratios of carbon, hydrogen, oxygen, sulfur, and nitrogen can become locally enriched or depleted through a variety of kinetic and thermodynamic factors, measurement of the isotope ratios can be used to unravel the processes and differentiate water samples which otherwise exhibit similar chemical signatures. For brevity, this article focuses mainly on measurement of water isotopes, common notation for expressing isotope data and standards, theory of isotope hydrology, field applications and advances

  11. Multivariate Stable Isotope Analysis to Determine Linkages between Benzocaine Seizures

    Science.gov (United States)

    Kemp, H. F.; Meier-Augenstein, W.; Collins, M.; Salouros, H.; Cunningham, A.; Harrison, M.

    2012-04-01

    distribution network. More than 40 Benzocaine samples comprising both seized and control samples were analysed by two stable isotope forensic laboratories in two different countries (Australia and Scotland) to assess intra-lab reproducibility as well as inter-lab repeatability of measured stable isotope abundance values.

  12. Applications of Stable Isotopes in Nutrition

    International Nuclear Information System (INIS)

    Mwangi, C.

    2006-01-01

    This is an IAEA sponsored project No. RAF/7/006 using Isotopes Techniques to assess Nutritional Intervention Programs related to people living with HIV/AIDS in Africa. The report indicates that, improved nutrition is a global objective and development co-operation priority not only in the fight against nutrition but also for poverty eradication, reproductive health, children's rights and elimination of hunger. The role of the IAEA in the global objective is to support nations in achieving the most and best outcomes of food interventions through the reliable biological tools of efficacy, effective and impact, using isotope based techniques by transferring nuclear technology and knowledge in a sustainable manner to it's member states

  13. Trends in the use of stable isotopes in biochemistry and pharmacology

    International Nuclear Information System (INIS)

    Matwiyoff, N.A.; Walker, T.E.

    1977-01-01

    Recent trends in the use of the stable isotopes 13 C, 15 N and 18 O in biochemistry and pharmacology are reviewed with emphasis on the studies that have employed nuclear magnetic resonance (nmr) spectroscopy and mass spectrometry as analytical techniques. Pharmacological studies with drugs and other compounds labelled with stable isotopes have developed in parallel with the rapid progress in the enhancement of sensitivity and selectivity of gas chromatography - mass spectrometric analyses, and have been directed largely to an evaluation of pharmako-kinetics and drug metabolic pathways. In these studies, illustrated with selected samples, isotopically labelled compounds have been used to advantage as internal standards for the mass spectrometric analyses and as in vivo tracers for metabolites. In the broader discipline of biochemistry, stable isotopes and isotopically labelled compounds have been used increasingly in conjuction with both nmr spectroscopy and mass spectrometry in tracer and structural studies. The more recent trends in the use of stable isotopes in these biochemical studies are discussed in the context of the improvements in analytical techniques. Specific examples will be drawn from investigations of the biosynthesis of natural products by micro-organisms; the protein, fat and carbohydrate fluxes in humans; and the structure and function of enzymes, membranes and other macro-molecular assemblages. The potential for the future development of stable isotopes in biochemistry and pharmacology are considered briefly, together with some of the problems that must be solved if their considerable potential is to be realized. (author)

  14. Stable isotopes (carbon, nitrogen, sulfur), diet, and anthropometry in urban Colombian women: investigating socioeconomic differences.

    Science.gov (United States)

    Bender, Richard L; Dufour, Darna L; Valenzuela, Luciano O; Cerling, Thure E; Sponheimer, Matt; Reina, Julio C; Ehleringer, James R

    2015-01-01

    We conducted stable isotope and dietary analyses of women from higher and lower socioeconomic status (SES) groups in Cali, Colombia. The objectives were to test between-group differences in stable isotope, dietary, and anthropometric characteristics, and to evaluate relationships between diet and stable isotope values. Hair samples from 38 women (mean age 33.4) from higher and lower SES groups were analyzed for δ(13) C, δ(15) N, and δ(34) S values. Dietary intake was assessed via 24-h recalls. Anthropometric variables measured were body mass index, five body circumferences, and six skinfold thicknesses. Mean δ(13) C and δ(15) N values of the higher SES group (-16.4 and 10.3‰) were significantly greater than those of the lower SES group (-17.2 and 9.6‰; P stable isotope values (P Stable isotope values revealed a difference between SES groups that was not explained by the dietary data. The relationship between diet and stable isotope composition is complex. © 2014 Wiley Periodicals, Inc.

  15. The relationship between carbon stable isotope ratios of hatchling down and egg yolk in Black-headed Gulls

    NARCIS (Netherlands)

    Klaassen, M.R.J.; Baarspul, T.; Dekkers, T.; Van Tienen, P.

    2004-01-01

    We reconstructed the nutrient source for egg synthesis by sampling Black-headed Gull (Larus ridibundus) eggs for yolk, analyzing their carbon stable isotope ratio, and comparing that to hatchling down. Most of the variation in carbon stable isotope ratio was explained by differences between nests,

  16. Stable isotope analyses - an innovative technique to monitor biodegradation of petroleum hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kelley, C. A.; Coffin, R. B.; Mueller, J. G.

    1998-09-01

    Results of studies to examine variations in stable isotope ratios of compounds upon degradation and transport through soil and ground water are discussed. These studies were undertaken as part of a study on the usefulness of stable carbon isotopes in bioremediation programs. The assumption was that stable isotope values can be used to fingerprint contaminant sources by measuring the stable isotope values of polycyclic aromatic hydrocarbons (PAHs) extracted from soil slurries with and without the occurrence of bacterial degradation. Creosote-contaminated soil samples were obtained from a respirometry study in Pensacola, Florida. Liquid-liquid extraction methods were used to extract PAHs from the groundwater. The PAH-containing organic phase was separated from the aqueous phase, dried with anhydrous sodium sulfate and concentrated. Concentration was determined by gas chromatography using external standard curve. Results showed that only four PAH compounds (acenapthene, fluorene, phenanthrene, and fluoranthene) had high enough concentrations to measure the {delta}{sup 1}3 C values for both the killed bacterial cell control (no degradation) and the degraded sample. Of these four, phenanthrene was the most degraded (69 per cent removed after seven days) and fluoranthene was the least degraded (25 per cent removed). The isotopic composition of the PAHs measured along the source site dilution transect remained consistent. It appears that neither dilution nor degradation significantly altered the stable isotopic composition of these compounds. 6 refs., 5 figs.

  17. Titanium stable isotope investigation of magmatic processes on the Earth and Moon

    Science.gov (United States)

    Millet, Marc-Alban; Dauphas, Nicolas; Greber, Nicolas D.; Burton, Kevin W.; Dale, Chris W.; Debret, Baptiste; Macpherson, Colin G.; Nowell, Geoffrey M.; Williams, Helen M.

    2016-09-01

    We present titanium stable isotope measurements of terrestrial magmatic samples and lunar mare basalts with the aims of constraining the composition of the lunar and terrestrial mantles and evaluating the potential of Ti stable isotopes for understanding magmatic processes. Relative to the OL-Ti isotope standard, the δ49Ti values of terrestrial samples vary from -0.05 to +0.55‰, whereas those of lunar mare basalts vary from -0.01 to +0.03‰ (the precisions of the double spike Ti isotope measurements are ca. ±0.02‰ at 95% confidence). The Ti stable isotope compositions of differentiated terrestrial magmas define a well-defined positive correlation with SiO2 content, which appears to result from the fractional crystallisation of Ti-bearing oxides with an inferred isotope fractionation factor of ΔTi49oxide-melt = - 0.23 ‰ ×106 /T2. Primitive terrestrial basalts show no resolvable Ti isotope variations and display similar values to mantle-derived samples (peridotite and serpentinites), indicating that partial melting does not fractionate Ti stable isotopes and that the Earth's mantle has a homogeneous δ49Ti composition of +0.005 ± 0.005 (95% c.i., n = 29). Eclogites also display similar Ti stable isotope compositions, suggesting that Ti is immobile during dehydration of subducted oceanic lithosphere. Lunar basalts have variable δ49Ti values; low-Ti mare basalts have δ49Ti values similar to that of the bulk silicate Earth (BSE) while high-Ti lunar basalts display small enrichment in the heavy Ti isotopes. This is best interpreted in terms of source heterogeneity resulting from Ti stable isotope fractionation associated with ilmenite-melt equilibrium during the generation of the mantle source of high-Ti lunar mare basalts. The similarity in δ49Ti between terrestrial samples and low-Ti lunar basalts provides strong evidence that the Earth and Moon have identical stable Ti isotope compositions.

  18. Stable platinum isotope measurements in presolar nanodiamonds by TEAMS

    Energy Technology Data Exchange (ETDEWEB)

    Wallner, A., E-mail: anton.wallner@univie.ac.at [University of Vienna, Faculty of Physics, VERA Laboratory, Waehringer Strasse 17, A-1090 Vienna (Austria); Department of Nuclear Physics, Research School of Physics and Engineering, Australian National University, Canberra (Australia); Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights (Australia); Melber, K. [University of Vienna, Faculty of Physics, VERA Laboratory, Waehringer Strasse 17, A-1090 Vienna (Austria); Merchel, S. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), D-01314 Dresden (Germany); Ott, U. [Max-Planck-Institut fuer Chemie, Joh.-J.-Becherweg 27, D-55128 Mainz (Germany); Forstner, O.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P. [University of Vienna, Faculty of Physics, VERA Laboratory, Waehringer Strasse 17, A-1090 Vienna (Austria)

    2013-01-15

    Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued previous attempts to search for stable Pt isotope anomalies in nanodiamonds via trace element accelerator mass spectrometry (TEAMS). The installation of a new injector beam line at the VERA facility allowed studying low traces of stable elements in different materials. Moreover, recent experiments showed that VERA provides the required measurement precision together with a low Pt machine background. Here, we observed for the first time an indication for enhancements of {sup 198}Pt/{sup 195}Pt isotope ratios in two diamond residues prepared by different chemical separation techniques from the Allende meteorite. Variations in other isotopic ratios were within analytical uncertainty, and no anomaly was identified in a third diamond fraction.

  19. Stable platinum isotope measurements in presolar nanodiamonds by TEAMS

    International Nuclear Information System (INIS)

    Wallner, A.; Melber, K.; Merchel, S.; Ott, U.; Forstner, O.; Golser, R.; Kutschera, W.; Priller, A.; Steier, P.

    2013-01-01

    Nanodiamonds are stardust grains commonly found in primitive meteorites. They survived the formation of the solar system and kept their own individuality. Measurements of trace-element isotopic signatures in these grains will help understanding heavy element nucleosynthesis in massive stars and dust formation from their ejecta. We have continued previous attempts to search for stable Pt isotope anomalies in nanodiamonds via trace element accelerator mass spectrometry (TEAMS). The installation of a new injector beam line at the VERA facility allowed studying low traces of stable elements in different materials. Moreover, recent experiments showed that VERA provides the required measurement precision together with a low Pt machine background. Here, we observed for the first time an indication for enhancements of 198 Pt/ 195 Pt isotope ratios in two diamond residues prepared by different chemical separation techniques from the Allende meteorite. Variations in other isotopic ratios were within analytical uncertainty, and no anomaly was identified in a third diamond fraction.

  20. Stable isotope utilization for research on human nutrition

    International Nuclear Information System (INIS)

    Desjeux, J.F.

    1994-01-01

    In the framework of nutritional molecule metabolism research, this paper presents the various stable isotopes used as labels for biological molecules, the reasons for their application in human nutritional study (mainly because of their non toxicity) and the various analysis methods (isotope ratio mass spectrometry, coupled gaseous chromatography and mass spectrometry, nuclear magnetic resonance). Several application examples in nutrition research are then discussed: metabolic conversion measurement for a molecule into its different metabolites, energetic losses. 23 refs

  1. Application of Stable Isotope Signatures in Food Traceability

    International Nuclear Information System (INIS)

    Nazaratul Ashifa Abdullah Salim; Roslanzairi Mostapha; Zainon Othman

    2016-01-01

    Stable isotope analysis has widely been used to trace the origin of organic materials in various fields, such as geochemistry, biochemistry, archaeology and petroleum. In past a decade, it has also become an important tool for food traceability study. The globalisation of food markets and the relative ease which food commodities are transported through and between countries and continents means that consumers are increasingly concerned about the origin of the foods they eat. The natural abundance of stable isotope variation such as carbon, nitrogen, hydrogen and oxygen are used as geographic tracers or marker to determine the geographic origin of fruits, crop, vegetables and food products from animal. The isotopic compositions of plant materials reflect various factors such as isotopic compositions of source materials and their assimilation processes as well as growth environments. This paper will discuss on stable carbon and nitrogen isotopic compositions in rice that been determined by Isotope Ratio Mass Spectrometry, advantages, limitations and potential of other analysis applications that can be incorporated in food traceability system. (author)

  2. Stable isotope tracers and exercise physiology: past, present and future.

    Science.gov (United States)

    Wilkinson, Daniel J; Brook, Matthew S; Smith, Kenneth; Atherton, Philip J

    2017-05-01

    Stable isotope tracers have been invaluable assets in physiological research for over 80 years. The application of substrate-specific stable isotope tracers has permitted exquisite insight into amino acid, fatty-acid and carbohydrate metabolic regulation (i.e. incorporation, flux, and oxidation, in a tissue-specific and whole-body fashion) in health, disease and response to acute and chronic exercise. Yet, despite many breakthroughs, there are limitations to 'substrate-specific' stable isotope tracers, which limit physiological insight, e.g. the need for intravenous infusions and restriction to short-term studies (hours) in controlled laboratory settings. In recent years significant interest has developed in alternative stable isotope tracer techniques that overcome these limitations, in particular deuterium oxide (D 2 O or heavy water). The unique properties of this tracer mean that through oral administration, the turnover and flux through a number of different substrates (muscle proteins, lipids, glucose, DNA (satellite cells)) can be monitored simultaneously and flexibly (hours/weeks/months) without the need for restrictive experimental control. This makes it uniquely suited for the study of 'real world' human exercise physiology (amongst many other applications). Moreover, using D 2 O permits evaluation of turnover of plasma and muscle proteins (e.g. dynamic proteomics) in addition to metabolomics (e.g. fluxomics) to seek molecular underpinnings, e.g. of exercise adaptation. Here, we provide insight into the role of stable isotope tracers, from substrate-specific to novel D 2 O approaches, in facilitating our understanding of metabolism. Further novel potential applications of stable isotope tracers are also discussed in the context of integration with the snowballing field of 'omic' technologies. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

  3. Recent applications of stable isotopes in environmental medicine in germany

    International Nuclear Information System (INIS)

    Krumbiegel, P.; Herbarth, O.

    2000-01-01

    In the last few years, a new quality in the application of stable isotopes became manifest. It is the establishment of stable isotopes as a tool in medical routine diagnosis - a novel field of nuclear medicine - and in environmental-medical epidemiological surveys. Owing to missing suitable radioactive isotopes of the bio elements carbon and nitrogen and because of ethical problems in the human use of some radionuclides, the stable isotopes 13 C and 1% N play a key role in this new field. A review is given about four new stable isotope-aided methods for in vivo organ function test. Three of them were developed in Leipzig, germany, and one in houston/Texas. We have validated the tests and then introduced into medical and environmental routine diagnostic use: ( 15 N Methacetin and ( 13 C) methacetin liver function tests to characterize the detoxification capacity of the human liver; ( 15 N) Urea and ( 13 C) urea tests to detect the colonization of the human stomach by the bacterium helicobacter pylori. This bacterium is, as known, responsible for gastritis and ulcer of the gastrointestinal tract. The transmission ways of H. Pylori are under investigation world-wide

  4. [Stable Isotopes Characters of Soil Water Movement in Shijiazhuang City].

    Science.gov (United States)

    Chen, Tong-tong; Chen, Hui; Han, Lu; Xing, Xing; Fu, Yang-yang

    2015-10-01

    In this study, we analyzed the stable hydrogen and oxygen isotope values of precipitation, soil water, irrigation water that collected in Shijiazhuang City from April 2013 to May 2014 to investigate the changing rule of the stable isotopes in different soil profiles and the process of soil water movement according to using the isotope tracer technique. The results showed that the mean excess deuterium of the local precipitation was -6.188 5 per thousand. Those reflected that the precipitation in Shijiazhuang City mainly brought by the monsoon from the ocean surface moisture, and also to some extent by the local evaporation. Precipitation was the main source of the soil water and the irrigation water played the supplementary role. In the rainy season, precipitation was enough to supply the soil water. The stable oxygen isotopes at 10-100 cm depth decreased with the increase of depth, the maximum depth of evaporation in the rainy season reached 40 cm. The peak of stable oxygen isotopes of soil water pushed down along the profile, which was infected by the interaction of the precipitation infiltration, evaporation and the mixing water.

  5. Copper stable isotopes to trace copper behavior in wetland systems.

    Science.gov (United States)

    Babcsányi, Izabella; Imfeld, Gwenaël; Granet, Mathieu; Chabaux, François

    2014-05-20

    Wetlands are reactive zones of the landscape that can sequester metals released by industrial and agricultural activities. Copper (Cu) stable isotope ratios (δ(65)Cu) have recently been used as tracers of transport and transformation processes in polluted environments. Here, we used Cu stable isotopes to trace the behavior of Cu in a stormwater wetland receiving runoff from a vineyard catchment (Alsace, France). The Cu loads and stable isotope ratios were determined in the dissolved phase, suspended particulate matter (SPM), wetland sediments, and vegetation. The wetland retained >68% of the dissolved Cu and >92% of the SPM-bound Cu, which represented 84.4% of the total Cu in the runoff. The dissolved Cu became depleted in (65)Cu when passing through the wetland (Δ(65)Cuinlet-outlet from 0.03‰ to 0.77‰), which reflects Cu adsorption to aluminum minerals and organic matter. The δ(65)Cu values varied little in the wetland sediments (0.04 ± 0.10‰), which stored >96% of the total Cu mass within the wetland. During high-flow conditions, the Cu flowing out of the wetland became isotopically lighter, indicating the mobilization of reduced Cu(I) species from the sediments and Cu reduction within the sediments. Our results demonstrate that the Cu stable isotope ratios may help trace Cu behavior in redox-dynamic environments such as wetlands.

  6. Stable nitrogen isotopes in coastal macroalgae: Geographic and anthropogenic variability

    Energy Technology Data Exchange (ETDEWEB)

    Viana, Inés G., E-mail: ines.gonzalez@co.ieo.es; Bode, Antonio

    2013-01-15

    Growing human population adds to the natural nitrogen loads to coastal waters. Both anthropogenic and natural nitrogen is readily incorporated in new biomass, and these different nitrogen sources may be traced by the measurement of the ratio of stable nitrogen isotopes (δ{sup 15}N). In this study δ{sup 15}N was determined in two species of macroalgae (Ascophyllum nodosum and Fucus vesiculosus), and in nitrate and ammonium to determine the relative importance of anthropogenic versus natural sources of nitrogen along the coast of NW Spain. Both algal species and nitrogen sources showed similar isotopic enrichment for a given site, but algal δ{sup 15}N was not related to either inorganic nitrogen concentrations or δ{sup 15}N in the water samples. The latter suggests that inorganic nitrogen inputs are variable and do not always leave an isotopic trace in macroalgae. However, a significant linear decrease in macroalgal δ{sup 15}N along the coast is consistent with the differential effect of upwelling. Besides this geographic variability, the influence of anthropogenic nitrogen sources is evidenced by higher δ{sup 15}N in macroalgae from rias and estuaries compared to those from open coastal areas and in areas with more than 15 × 10{sup 3} inhabitants in the watershed. These results indicate that, in contrast with other studies, macroalgal δ{sup 15}N is not simply related to either inorganic nitrogen concentrations or human population size but depends on other factors as the upwelling or the efficiency of local waste treatment systems. - Highlights: ► Anthropogenic versus upwelling nitrogen effect on macroalgal δ{sup 15}N was studied. ► The influence of populations and upwelling has not been made before on macroalgal δ{sup 15}N. ► Natural variability has not been taken into account in most biomonitoring studies. ► Upwelling explains most of the variability in δ{sup 15}N in macroalgae.

  7. Exploring cancer metabolism using stable isotope-resolved metabolomics (SIRM).

    Science.gov (United States)

    Bruntz, Ronald C; Lane, Andrew N; Higashi, Richard M; Fan, Teresa W-M

    2017-07-14

    Metabolic reprogramming is a hallmark of cancer. The changes in metabolism are adaptive to permit proliferation, survival, and eventually metastasis in a harsh environment. Stable isotope-resolved metabolomics (SIRM) is an approach that uses advanced approaches of NMR and mass spectrometry to analyze the fate of individual atoms from stable isotope-enriched precursors to products to deduce metabolic pathways and networks. The approach can be applied to a wide range of biological systems, including human subjects. This review focuses on the applications of SIRM to cancer metabolism and its use in understanding drug actions. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  8. Stable Isotope Values of Nitrogen and Carbon in Particulate ...

    Science.gov (United States)

    Data set from “Patterns in stable isotope values of nitrogen and carbon in particulate matter from the Northwest Atlantic Continental Shelf, from the Gulf of Maine to Cape Hatteras” by Oczkowski et al. These are the data upon which all results and conclusion are made. Publishing the data allow for use by wider audience. Stable isotope dynamics on the shelf can inform both nearshore and open ocean research efforts, providing an important link along the marine continuum. To our knowledge, this data set is unique in its spatial coverage and variables measured.

  9. Stable isotope ratio mass spectrometry in forensic science and food adulteration research

    International Nuclear Information System (INIS)

    Kumar, B.

    2009-01-01

    Stable Isotope Ratio Mass Spectrometry (SIRMS) is an established technique for the determination of origin of geological, biological, chemical and physio-chemical samples/materials. With the development of highly precise mass spectrometers, the stable isotope ratio determination of hydrogen, carbon, nitrogen and oxygen have gained considerable interest in the fields of forensic science and food authentication. Natural variations in the isotopic composition of lighter elements occur due to fractionation effects, resulting in the finger printing of specific isotope ratio values that are characteristic of the origin, purity, and manufacturing processes of the products and their constituents. Forensic science uses scientific and technical methods to investigate traceable evidence of criminal acts. Stable isotope ratio mass spectrometry has been applied to numerous aspects of the forensic science. The analysis of explosives such as ammonium nitrate, gun powder and tri-nitro-toluene (TNT), cases of murder, armed robbery, drug smuggling, terrorism, arson and hit and run traffic accidents are a few of them. The main types of geological evidences in such cases are mud, soil, rocks, sand, gravel, dust particles, biological materials, organic particles and anthropogenic components. Stable isotopes are used as tools to corroborate and confirm the evidential leads in the investigation of such crimes. The variation in natural abundances of carbon and nitrogen and their isotopic ratios δ 13 C and δ 15 N can identify links between items found at crime scene with those of suspect. The paper discusses the applications of SIRMS in the field of forensic science and food adulteration research

  10. Characterization of bile acid metabolism in man using bile acids labeled with stable isotopes. [/sup 13/C

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, A.F. Klein, P.D.

    1977-01-01

    Bile acids labeled with stable isotopes in the steroid moiety can be used to characterize bile acid metabolism in man. Isotope dilution studies give information on pool size and input. Biotransformations are easily characterized. Stable isotopically labeled bile acids offer the advantage of freedom from radiation hazard, and also offer the possibility of monitoring all pools simultaneously, since all bile acids are separated by gas chromatography before isotope measurements are made. Further, since the proportion of the pool labeled with stable isotopes is greater than that achieved when radioactive isotopes are used, stable isotopes may permit isotope dilution studies to be done on serum samples in which the absolute concentration of bile acids is very low. A major disadvantage is the complex technology required for stable isotope measurement which often makes remote processing necessary. Bile acid labeled with /sup 13/C in the amino acid moiety, e.g. cholylglycine-1-/sup 13/C can be used for detection of increased bile acid deconjugation by intestinal bacteria, since the glycine-/sup 13/C, when liberated, is rapidly converted to /sup 13/CO/sub 2/, which is expired in breath. Bile acids labeled with stable isotopes may also be used for quantitation by inverse isotope dilution, but the technique is still in the development stage and seems unlikely to compete successfully with radioimmunoassay.

  11. Using Stable Isotopes of Carbon and Nitrogen to Evaluate Trophic Interactions in Aquatic Environments

    Science.gov (United States)

    Christensen, David R.; LaRoche, Andrew

    2012-01-01

    This paper describes a series of laboratory exercises for upper level biology courses, independent research and/or honors programs. Students sampled fish from a local water body with the assistance of a local fish and wildlife agency. Tissue samples from collected fish were utilized to obtain estimates of the stable isotopes delta[superscript 13]C…

  12. Stable isotope methodology in the pharmacokinetic studies of androgenic steroids in humans

    International Nuclear Information System (INIS)

    Shinohara, Y.; Baba, S.

    1990-01-01

    The use of stable isotopically labeled steroids combined with gas chromatography/mass spectrometry (GC/MS) has found a broad application in pharmacologic studies. Initially, stable isotopically labeled steroids served as the ideal analytic internal standard for GC/MS analysis; however, their in vivo use has expanded and has proven to be a powerful pharmacokinetic tool. We have successfully used stable isotope methodology to study the pharmacokinetic/bioavailability of androgens. The primary advantage of the technique is that endogenous and exogenous steroids with the same basic structure can be differentiated by using stable isotopically labeled analogs. The method was used to examine the pharmacokinetics of testosterone and testosterone propionate, and to clarify the influence of endogenous testosterone. Another advantage of the isotope methods is that steroidal drugs can be administered concomitantly in two formulations (e.g., solution and solid dosage). A single set of blood samples serves to describe the time course of the formulations being compared. This stable isotope coadministration technique was used to estimate the relative bioavailability of 17 alpha-methyltestosterone. 35 references

  13. The carbon stable isotope biogeochemistry of streams, Taylor Valley, Antarctica

    International Nuclear Information System (INIS)

    Lyons, W.B.; Leslie, D.L.; Harmon, R.S.; Neumann, K.; Welch, K.A.; Bisson, K.M.; McKnight, D.M.

    2013-01-01

    Highlights: ► δ 13 C-DIC reported from McMurdo Dry Valleys, Antarctica, streams. ► Stream water δ 13 C PDB values range −9.4‰ to +5.1‰, largely inorganic in character. ► Atmospheric exchange is the dominant control on δ 13 C-DIC. - Abstract: The McMurdo Dry Valleys region of Antarctica is the largest ice-free region on the continent. This study reports the first C stable isotope measurements for dissolved inorganic C present in ephemeral streams in four dry valleys that flow for four to twelve weeks during the austral summer. One of these valleys, Taylor Valley, has been the focus of the McMurdo Dry Valleys Long-Term Ecological Research (MCM-LTER) program since 1993. Within Taylor Valley, numerous ephemeral streams deliver water to three perennially ice-covered, closed-basin lakes: Lake Fryxell, Lake Hoare, and Lake Bonney. The Onyx River in the Wright Valley, the longest river in Antarctica, flows for 40 km from the Wright Lower Glacier and Lake Brownworth at the foot of the glacier to Lake Vanda. Streamflow in the McMurdo Dry Valley streams is produced primarily from glacial melt, as there is no overland flow. However, hyporheic zone exchange can be a major hydrogeochemical process in these streams. Depending on landscape position, these streams vary in gradient, channel substrate, biomass abundance, and hyporheic zone extent. This study sampled streams from Taylor, Wright, Garwood, and Miers Valleys and conducted diurnal sampling of two streams of different character in Taylor Valley. In addition, transect sampling was undertaken of the Onyx River in Wright Valley. The δ 13 C PDB values from these streams span a range of greater than 14‰, from −9.4‰ to +5.1‰, with the majority of samples falling between −3‰ and +2‰, suggesting that the C stable isotope composition of dissolved C in McMurdo Dry Valley streams is largely inorganic in character. Because there are no vascular plants on this landscape and no groundwater input to these

  14. The iron stable isotope fingerprint of the human diet.

    Science.gov (United States)

    von Blanckenburg, Friedhelm; Noordmann, Janine; Guelke-Stelling, Monika

    2013-12-11

    The stable isotopes of iron disclose the metabolic pathways of iron within the human food chain. We have measured with precise multicollector ICP-MS the iron concentrations and stable isotope composition of 60 food products that are representative of the average German diet. We find that vegetables fall within the range typical of strategy I plants (-0.1 to -1.4‰ in δ(56)Fe), crop products and processed crop foods into the range typical of strategy II plants (-0.6 to +0.4‰), and animal products into the (54)Fe-enriched range known for animal tissue and blood (-1.1 to -2.7‰). Weighting these isotope compositions by the average iron dietary sources, we find a representative composition of European vegetarian diet of -0.45‰, whereas that of omnivores is -0.82‰. For human blood, known to be enriched in light iron isotopes, we find fractionation factors for iron absorption of -2.0 and -2.3‰ for vegetarians (female and male, respectively) and -1.3 and -1.5‰ for omnivores (female and male, respectively). Knowing these fractionation factors is a prerequisite for using stable iron isotope ratios in blood as monitors of intestinal iron uptake regulation.

  15. Use of Blood-soaked Cellulose Filter Paper for Measuring Carbon and Nitrogen Stable Isotopes.

    Science.gov (United States)

    O'Hara, Todd M; Templeton, Megan; Castellini, J Margaret; Wells, Randall; Beckmen, Kimberlee; Berner, James

    2018-04-01

      We explored the use of filter paper soaked in whole blood for measuring carbon (C) and nitrogen (N) stable isotopes, often used in feeding ecology or diet studies, to better understand drivers of exposure to contaminants. Our results showed no statistically or biologically relevant differences in C and N stable isotope measures between our gold standard (whole blood with anticoagulant) and eluates from processed, blood-soaked filter paper. Our data supported the effectiveness of using filter paper for assessing C and N stable isotopes in blood to address feeding ecology and other uses. The ease of sampling and processing should allow blood-soaked filter paper to be used in sampling of live (e.g., captured, stranded) and lethally taken (e.g., hunter-killed) wild vertebrates.

  16. Investigating Unsaturated Zone Travel Times with Tritium and Stable Isotopes

    Science.gov (United States)

    Visser, A.; Thaw, M.; Van der Velde, Y.

    2017-12-01

    Travel times in the unsaturated zone are notoriously difficult to assess. Travel time tracers relying on the conservative transport of dissolved (noble) gases (tritium-helium, CFCs or SF6) are not applicable. Large water volume requirements of other cosmogenic radioactive isotopes (sulfur-35, sodium-22) preclude application in the unsaturated zone. Prior investigations have relied on models, introduced tracers, profiles of stable isotopes or tritium, or a combination of these techniques. Significant unsaturated zone travel times (UZTT) complicate the interpretation of stream water travel time tracers by ranked StorAge Selection (rSAS) functions. Close examination of rSAS functions in a sloping soil lysimeter[1] show the effect of the UZTT on the shape of the rSAS cumulative distribution function. We studied the UZTT at the Southern Sierra Critical Zone Observatory (SS-CZO) using profiles of tritium and stable isotopes (18O and 2H) in the unsaturated zone, supported by soil water content data. Tritium analyses require 100-500 mL of soil water and therefore large soil samples (1-5L), and elaborate laboratory procedures (oven drying, degassing and noble gas mass spectrometry). The high seasonal and interannual variability in precipitation of the Mediterranean climate, variable snow pack and high annual ET/P ratios lead to a dynamic hydrology in the deep unsaturated soils and regolith and highly variable travel time distributions. Variability of the tritium concentration in precipitation further complicates direct age estimates. Observed tritium profiles (>3 m deep) are interpreted in terms of advective and dispersive vertical transport of the input variability and radioactive decay of tritium. Significant unsaturated zone travel times corroborate previously observed low activities of short-lived cosmogenic radioactive nuclides in stream water. Under these conditions, incorporating the UZTT is critical to adequately reconstruct stream water travel time distributions. 1

  17. Aberrant water homeostasis detected by stable isotope analysis.

    Directory of Open Access Journals (Sweden)

    Shannon P O'Grady

    Full Text Available While isotopes are frequently used as tracers in investigations of disease physiology (i.e., 14C labeled glucose, few studies have examined the impact that disease, and disease-related alterations in metabolism, may have on stable isotope ratios at natural abundance levels. The isotopic composition of body water is heavily influenced by water metabolism and dietary patterns and may provide a platform for disease detection. By utilizing a model of streptozotocin (STZ-induced diabetes as an index case of aberrant water homeostasis, we demonstrate that untreated diabetes mellitus results in distinct combinations, or signatures, of the hydrogen (delta2H and oxygen (delta18O isotope ratios in body water. Additionally, we show that the delta2H and delta18O values of body water are correlated with increased water flux, suggesting altered blood osmolality, due to hyperglycemia, as the mechanism behind this correlation. Further, we present a mathematical model describing the impact of water flux on the isotopic composition of body water and compare model predicted values with actual values. These data highlight the importance of factors such as water flux and energy expenditure on predictive models of body water and additionally provide a framework for using naturally occurring stable isotope ratios to monitor diseases that impact water homeostasis.

  18. Production of stable isotopes at Urenco. 10 years of progress

    International Nuclear Information System (INIS)

    Mol, C.A.; Rakhorst, H.

    2003-01-01

    In the last ten years, Urenco has built its spin-off activity of stable isotopes in a multi-million dollar business. It is a high quality, ISO certified, client oriented and profitable European business with further growth potential. (author)

  19. Production and use of stable isotopes in France

    International Nuclear Information System (INIS)

    Roth, E.; Letolle, R.

    1991-01-01

    This paper can not cover the field of production and use of stable isotopes in France exhaustively within six pages. We have chosen to concentrate on highlights of the subject and on recent work, and to give references for further reading. 26 refs

  20. Stable isotope compositions of organic carbon and contents of ...

    African Journals Online (AJOL)

    The stable isotope compositions of organic carbon (OC), and contents of OC and nitrogen for four sediment cores recovered from lakes Makat (located in the Ngorongoro Crater), Ndutu and Masek (located in the Serengeti Plains) are used to document sources of organic matter (OM) and climatic changes in sub-arid ...

  1. Using stable isotope analysis to study the diet of Gilchristella ...

    African Journals Online (AJOL)

    Using stable isotope analysis to study the diet of Gilchristella aestuaria larvae: preliminary insights into the foodwebs of six South African estuaries. ... We found a high similarity among the Kariega, Gamtoos, Great Fish and Sundays estuaries in terms of consumers and potential sources for both δ13C and δ15N signatures.

  2. Stable isotope geochemistry : definitions, terminology, measurement and some applications

    International Nuclear Information System (INIS)

    Faure, K.

    2004-01-01

    Stable isotope measurements have been applied to many fundamental problems in geochemistry, petrology, and paleoclimatology, as well as related fields in archaeology, anthropology, physical chemistry, biology and forensic sciences. These applications can be broadly classified into four main types: thermometry, tracers, reaction mechanisms and chemostratigraphy. 52 refs., 11 figs., 2 tabs

  3. Stable isotopes in plant nutrition, soil fertility and environmental studies

    International Nuclear Information System (INIS)

    1991-01-01

    The individual contributions in these proceedings are indexed separately. Main topics covered include the measurement of biological nitrogen fixation, studies of soil organic matter, investigations of nutrient uptake and use by plants, studies of plant metabolism and new methodologies in the analysis of stable isotopes. Refs, figs and tabs

  4. Assessing Sources of Human Methylmercury Exposure Using Stable Mercury Isotopes

    DEFF Research Database (Denmark)

    Li, Miling; Sherman, Laura S; Blum, Joel D

    2014-01-01

    Seafood consumption is the primary route of methylmercury (MeHg) exposure for most populations. Inherent uncertainties in dietary survey data point to the need for an empirical tool to confirm exposure sources. We therefore explore the utility of Hg stable isotope ratios in human hair as a new me...

  5. COMBINING SOURCES IN STABLE ISOTOPE MIXING MODELS: ALTERNATIVE METHODS

    Science.gov (United States)

    Stable isotope mixing models are often used to quantify source contributions to a mixture. Examples include pollution source identification; trophic web studies; analysis of water sources for soils, plants, or water bodies; and many others. A common problem is having too many s...

  6. MixSIAR: advanced stable isotope mixing models in R

    Science.gov (United States)

    Background/Question/Methods The development of stable isotope mixing models has coincided with modeling products (e.g. IsoSource, MixSIR, SIAR), where methodological advances are published in parity with software packages. However, while mixing model theory has recently been ex...

  7. Using stable isotopes to examine watershed connectivity to downstream waters

    Science.gov (United States)

    Water bodies within the USA are protected by the US Clean Water Act when they have a significant nexus to downstream navigable waters. As a research scientist with the US Environmental Protection Agency, I have used water stable isotopes to examine hydrologic connectivity dynami...

  8. Facies, dissolution seams and stable isotope compositions of the ...

    Indian Academy of Sciences (India)

    Stable isotope analysis of the limestone shows that 13C and 18O values are compatible with the early Mesoproterozoic open seawater composition. The ribbon limestone facies in the Rohtas Limestone is characterized by micritic beds, each decoupled in a lower band enriched and an upper band depleted in dissolution ...

  9. Stereoselective synthesis of stable-isotope-labeled amino acids

    International Nuclear Information System (INIS)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III; Lodwig, S.N.

    1994-01-01

    For magnetic resonance and vibrational spectroscopies to reach their full potential, they must be used in combination with sophisticated site-specific stable isotope labeling of biological macromolecules. Labeled amino acids are required for the study of the structure and function of enzymes and proteins. Because there are 20 common amino acids, each with its own distinguishing chemistry, they remain a synthetic challenge. The Oppolzer chiral auxiliary provides a general tool with which to approach the synthesis of labeled amino acids. By using the Oppolzer auxiliary, amino acids can be constructed from several small molecules, which is ideal for stable isotope labeling. In addition to directing the stereochemistry at the α-carbon, the camphorsultam can be used for stereo-specific isotope labeling at prochiral centers in amino acids. By using the camphorsultam auxiliary we have the potential to synthesize virtually any isotopomer of all of the common amino acids

  10. Fractionation of Stable Isotopes in Atmospheric Aerosol Reactions

    DEFF Research Database (Denmark)

    Meusinger, Carl

    reactions and undergo complex chemical and physical changes during their lifetimes. In order to assess processes that form and alter aerosols, information provided by stable isotopes can be used to help constrain estimates on the strength of aerosol sources and sinks. This thesis studies (mass......-independent) fractionation processes of stable isotopes of C, N, O and S in order to investigate three different systems related to aerosols: 1. Post-depositional processes of nitrate in snow that obscure nitrate ice core records 2. Formation and aging of secondary organic aerosol generated by ozonolysis of X...... as required. The kndings provide important results for the studies' respective felds, including a description of the isotopic fractionation and quantum yield of nitrate photolysis in snow, equilibrium fractionation in secondary organic aerosol and fractionation constants of different oxidation pathways of SO2....

  11. Application of carbon and oxygen stable isotopes to the study of Brazilian precambrian

    International Nuclear Information System (INIS)

    Torquato, J.R.F.

    1980-01-01

    Samples of carbonated rocks of precambrian age are studied. The stable carbon and oxygen isotopes are applied to the study of terrestrial materials considering the variations of some element isotopic composition in function of the environment of sedimentation. The isotopic analysis was done using mass spectrometers. The analytical results and the description of region geology of the site of each sample are presented. The isotopic data are interpreted aiming to the environment of sedimentation. New techniques for better improvement of carbon and oxygen ratios, are proposed, such as: to use the analysis of surface trend and the isotopic logging in mapping of surface and subsurface. A new method for approximated determination of the ages of precambrian carbonated rocks, considering the limitations of their new technique, is also presented. (M.C.K.) [pt

  12. Historical and contemporary stable isotope tracer approaches to studying mammalian protein metabolism

    Science.gov (United States)

    2016-01-01

    Over a century ago, Frederick Soddy provided the first evidence for the existence of isotopes; elements that occupy the same position in the periodic table are essentially chemically identical but differ in mass due to a different number of neutrons within the atomic nucleus. Allied to the discovery of isotopes was the development of some of the first forms of mass spectrometers, driven forward by the Nobel laureates JJ Thomson and FW Aston, enabling the accurate separation, identification, and quantification of the relative abundance of these isotopes. As a result, within a few years, the number of known isotopes both stable and radioactive had greatly increased and there are now over 300 stable or radioisotopes presently known. Unknown at the time, however, was the potential utility of these isotopes within biological disciplines, it was soon discovered that these stable isotopes, particularly those of carbon (13C), nitrogen (15N), oxygen (18O), and hydrogen (2H) could be chemically introduced into organic compounds, such as fatty acids, amino acids, and sugars, and used to “trace” the metabolic fate of these compounds within biological systems. From this important breakthrough, the age of the isotope tracer was born. Over the following 80 yrs, stable isotopes would become a vital tool in not only the biological sciences, but also areas as diverse as forensics, geology, and art. This progress has been almost exclusively driven through the development of new and innovative mass spectrometry equipment from IRMS to GC‐MS to LC‐MS, which has allowed for the accurate quantitation of isotopic abundance within samples of complex matrices. This historical review details the development of stable isotope tracers as metabolic tools, with particular reference to their use in monitoring protein metabolism, highlighting the unique array of tools that are now available for the investigation of protein metabolism in vivo at a whole body down to a single protein level

  13. High frequency, realtime measurements of stable isotopes in liquid water

    Science.gov (United States)

    Weiler, M.; Herbstritt, B.; Gralher, B.

    2012-04-01

    We developed a method to measure in-situ the isotopic composition of liquid water with minimal supervision and, most important, with a temporal resolution of less than a minute. For this purpose a off-the-shelf microporous hydrophobic membrane contactor for under 200€ was combined with an isotope laser spectrometer (Picarro). The contactor, originally designed for degassing liquids, was used with nitrogen as carrier gas in order to transform a small fraction of liquid water to water vapor. The generated water vapor was then analyzed continuously by the isotope laser spectrometer. To prove the membrane's applicability we determined the specific isotope fractionation factor for the phase change through the contactor's membrane for a common temperature range and with different waters of known isotopic compositions. This fractionation factor is then used to derive the liquid water isotope ratio from the measured water vapor isotope ratios and the measured temperature at the phase change. The system was compared for breakthrough curves of isotopically enriched water and the isotope values corresponded very well with those of liquid water samples taken simultaneously and analyzed with a conventional method (CRDS). The introduced method supersedes taking liquid samples and employs only relative cheap and readily available components. This makes it a relatively inexpensive, fast, user-friendly and easily reproducible method. It can be applied in both the field and laboratory wherever a water vapor isotope analyzer can be run and whenever real-time isotope data of liquid water are required at high temporal resolution with the same accuracy as collecting individual water samples.

  14. The role of stable isotopes in understanding rainfall ...

    Science.gov (United States)

    The isotopic composition of water transmitted by the canopy as throughfall or stemflow reflects important hydrologic processes occurring in the canopy. A synthesis of the literature shows that complex spatiotemporal variations of isotopic composition are created by canopy interception. As a whole, the studies suggest a set of controlling factors including fractionation, exchange among liquid and vapor phase water, and spatiotemporal redistribution along varying canopy flowpaths. However, our limited understanding of physical processes and water routing in the canopy limits the ability to discern all details for predicting interception isotope effects. We suggest that the isotopic composition of throughfall and stemflow may be the key to improve our understanding of water storage and transport in the canopy, similar to how isotopic analysis contributed to progress in our understanding of watershed runoff processes. While interception isotope effects have largely been studied under the premise that they are a source of error, previous works also indicate a wide range of possible interactions that intercepted water may have with the canopy and airspace. We identify new research questions that may be answered by stable isotopes as a path forward in examining and generalizing small-scale interception processes that could facilitate integration of interception into watershed ecohydrological concepts. Evaporation from forest canopies (interception loss) is a prominent

  15. Application of heavy stable isotopes in forensic isotope geochemistry: A review

    Energy Technology Data Exchange (ETDEWEB)

    Aggarwal, Jugdeep [W.M. Keck Isotope Laboratory, Department of Earth Sciences, University of California, Santa Cruz, CA 95064 (United States)], E-mail: jaggarwal@pmc.ucsc.edu; Habicht-Mauche, Judith; Juarez, Chelsey [Department of Anthropology, University of California, Santa Cruz, CA 95064 (United States)

    2008-09-15

    Light stable isotopes have been used for many years to characterize the source and transport of materials. More recently heavy isotope systems such as Sr, Nd and Pb have been added to this list in order to aid source identification. With the advent of multiple collector ICP-MS, the range of isotopic tools now available has increased considerably, however, until the isotope systematics of these new non-traditional isotope systems have become better understood, they will not be as useful in characterizing material source and transportation. Applications using heavy metal stable isotopes (mostly traditional heavy isotopes) have reached most avenues in science, including earth sciences, archaeology, anthropology, animal physiology, ecology and toxicology. This field will continue to grow as new applications are developed and techniques become simpler and quicker. This paper provides a review of how this field has grown and presents two new applications using Pb and Sr isotopes in glazes to determine the source of ore used in glazes, and using Sr isotopes to determine the origin of undocumented deceased Mexican border crossers.

  16. Application of heavy stable isotopes in forensic isotope geochemistry: A review

    International Nuclear Information System (INIS)

    Aggarwal, Jugdeep; Habicht-Mauche, Judith; Juarez, Chelsey

    2008-01-01

    Light stable isotopes have been used for many years to characterize the source and transport of materials. More recently heavy isotope systems such as Sr, Nd and Pb have been added to this list in order to aid source identification. With the advent of multiple collector ICP-MS, the range of isotopic tools now available has increased considerably, however, until the isotope systematics of these new non-traditional isotope systems have become better understood, they will not be as useful in characterizing material source and transportation. Applications using heavy metal stable isotopes (mostly traditional heavy isotopes) have reached most avenues in science, including earth sciences, archaeology, anthropology, animal physiology, ecology and toxicology. This field will continue to grow as new applications are developed and techniques become simpler and quicker. This paper provides a review of how this field has grown and presents two new applications using Pb and Sr isotopes in glazes to determine the source of ore used in glazes, and using Sr isotopes to determine the origin of undocumented deceased Mexican border crossers

  17. Stable isotope methods: The effect of gut contents on isotopic ratios of zooplankton

    Science.gov (United States)

    Hill, J. M.; McQuaid, C. D.

    2011-05-01

    In the past decade there has been an increased awareness of the potential for methodological bias resulting from multiple pre-analytical procedures in foodweb interpretations based on stable isotope techniques. In the case of small organisms, this includes the effect of gut contents on whole body signatures. Although gut contents may not reflect actual assimilation, their carbon and nitrogen values will be isotopically lighter than after the same material has been assimilated. The potential skewing of isotopic ratios in whole organism samples is especially important for aquatic environments as many studies involve trophic relationships among small zooplankton. This is particularly important in pelagic waters, where herbivorous zooplankton comprise small taxa. Hence this study investigated the effect of gut contents on the δ13C and δ15N ratios of three size classes of zooplankton (1.0-2.0, 2.0-4.0 and >4.0 mm) collected using bongo net tows in the tropical waters of the south-west Indian Ocean. Animals were collected at night, when they were likely to be feeding, sieved into size classes and separated into genera. We focused on Euphausia spp which dominated zooplankton biomass. Three treatment types were processed: bulk animals, bulk animals without guts and tail muscle from each size class at 10 bongo stations. The δ15N ratios were influenced by zooplankton size class, presumably reflecting ontogenetic changes in diet. ANOVA post hoc results and correlations in δ15N signatures among treatments suggest that gut contents may not affect overall nitrogen signatures of Euphausia spp., but that δ13C signatures may be significantly altered by their presence. Carbon interpretations however, were complicated by potential effects of variation in chitin, lipids and metabolism among tissues and the possibility of opportunistic omnivory. Consequently we advocate gut evacuation before sacrifice in euphausiids if specific tissue dissection is impractical and recommend

  18. Manual for the Use of Stable Isotopes in Entomology

    International Nuclear Information System (INIS)

    2009-06-01

    result of problem driven inquisitiveness and technological advances, and are framed by the social and political environment. Although the external environment may mould the technological path, a technology will only become obsolete if there are viable substitution products or methods. Stable isotope methods are a substitute for many radionuclide methods. The progress made in stable isotope science over the past twenty years is a direct result of the interplay of the above factors. Stable isotopes are omnipresent in the environment and pose no health or environmental risks. Advances in isotope ratio mass spectrometry in terms of detection, accuracy and automation have broadened experimental possibilities immensely over the past twenty years. It was recognised that there was significant potential for answering many of the entomologist?s biological and ecological questions using stable isotopes, an expertise the Soil Science Unit of the FAO/IAEA Agriculture and Biotechnology Laboratory in Seibersdorf had long fostered; therefore collaboration with the Entomology Unit at the same Laboratory was established. A number of collaborative experiments were carried and subsequently published. It was soon recognised that stable isotopes have tremendous potential in entomological research and although there were numerous studies using stable isotopes in ecology, their use in entomology per se was limited. Thus it was felt that a publication was required to make stable isotope techniques more widely known among entomologists. This manual will attempt to provide an introduction to the use of stable isotopes in entomological research. It will strive to communicate the basic principles and techniques of stable isotope science and provide a springboard for further interest and research in this area

  19. The study of trace metal absoption using stable isotopes and mass spectrometry

    Science.gov (United States)

    Fennessey, P. V.; Lloyd-Kindstrand, L.; Hambidge, K. M.

    1991-12-01

    The absorption and excretion of zinc stable isotopes have been followed in more than 120 human subjects. The isotope enrichment determinations were made using a standard VG 7070E HF mass spectrometer. A fast atom gun (FAB) was used to form the ions from a dry residue on a pure silver probe tip. Isotope ratio measurements were found to have a precision of better than 2% (relative standard deviation) and required a sample size of 1-5 [mu]g. The average true absorption of zinc was found to be 73 ± 12% (2[sigma]) when the metal was taken in a fasting state. This absorption figure was corrected for tracer that had been absorbed and secreted into the gastrointestinal (GI) tract over the time course of the study. The average time for a majority of the stable isotope tracer to pass through the GI tract was 4.7 ± 1.9 (2[sigma]) days.

  20. Use of stable isotopes of selenium in human metabolic studies: development of analytical methodology

    International Nuclear Information System (INIS)

    Janghorbani, M.; Ting, B.T.; Young, V.R.

    1981-01-01

    Use of stable isotopes of selenium in relation to enrichment of diets for studies of selenium absorption and metabolism in human subjects is discussed. A method based on radiochemical neutron activation analysis is described which allows accurate measurement of stable isotopes 74Se, 76Se, and 80Se in matrices (feces, plasma, red blood cells, and urine) of interest in metabolic studies. We show that these isotopes can routinely be measured with analytical precision and accuracy of 10% in samples of available size. This precision and accuracy is satisfactory for conduct of many nutritional experiments concerned with gastrointestinal absorption, plasma and red cell selenium turnover, and urinary excretion of the element, using an oral dose of 74Se. Original, experimental data are presented to illustrate the degree of enrichment of 74Se in feces, plasma, and urine after a single oral ingestion of 50 micrograms of the isotope with a breakfast meal in healthy young men

  1. Laser ablation MC-ICPMS to study longitudinal stable isotopic variations in single human hair strands

    International Nuclear Information System (INIS)

    Santamaria-Fernandez, R.; Hearn, R.; Giner Martinez-Sierra, J.

    2009-01-01

    Full text: There is a need for novel approaches to measure stable isotopic variations in human tissues to provide information regarding the geographical origin and lifestyle of individuals. In this work, a method for the measurement of longitudinal sulfur isotopic variations in single hair strands has been developed. The method validation, uncertainty evaluation, in-house characterization of a horse hair sample and the potential of the method as a forensic tool to obtain information from single hair strands will be discussed. In addition, a new method for carbon isotope ratio measurements by MC-ICPMS has been developed and results will be presented. (author)

  2. Stable isotopes provide insight into population structure and segregation in eastern North Atlantic sperm whales

    DEFF Research Database (Denmark)

    Borrell, Asunción; Velásquez Vacca, Adriana; Pinela, Ana M.

    2013-01-01

    highly mobile, shows indication of structuring in the eastern North Atlantic, an ocean basin in which a single population is believed to occur. To do so, we examined stable isotope values in sequential growth layer groups of teeth from individuals sampled in Denmark and NW Spain. In each layer we...... measured oxygen-isotope ratios (delta O-18) in the inorganic component (hydroxyapatite), and nitrogen and carbon isotope ratios (delta N-15: delta C-13) in the organic component (primarily collagenous). We found significant differences between Denmark and NW Spain in delta N-15 and delta O-18 values...

  3. Grain-scale stable carbon and oxygen isotopic variations of the international reference calcite, IAEA-603.

    Science.gov (United States)

    Nishida, Kozue; Ishimura, Toyoho

    2017-11-30

    The new international reference material IAEA-603 (calcite) for stable carbon and oxygen isotopes (δ 13 C and δ 18 O values) was released in 2016 to replace the previous reference material, NBS19 (exhausted). We examined the grain-scale isotopic variations in IAEA-603 for application to microscale isotopic analysis of carbonate samples. Individual grains of IAEA-603 were analyzed with an IsoPrime100 isotope ratio mass spectrometer with a customized continuous-flow gas preparation system (MICAL3c). The individual grains of IAEA-603 were observed by optical and scanning electron microscopy, and their observational characteristics (grain color and size) were compared with their stable isotope compositions. Translucent grains (main component of IAEA-603; grain weight, 4-132 μg) had homogeneous isotopic ratios, comparable with the grain-scale isotopic homogeneity of NBS 19. Their average δ 13 C and δ 18 O values were the same as the recommended values determined by the IAEA. Opaque (whitish) grains (1-2 per 100 grains; grain weight, 8-63 μg) were significantly more depleted in 13 C and 18 O than the translucent grains. Low-abundance opaque grains (1-2 grains out of 100 grains) have lower δ 13 C and δ 18 O values, suggesting that these grains should be eliminated when using IAEA-603 for single-grain (microscale) isotope analysis. Copyright © 2017 John Wiley & Sons, Ltd.

  4. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Directory of Open Access Journals (Sweden)

    Shaena Montanari

    2017-06-01

    Full Text Available Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta, a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals.

  5. Discrimination factors of carbon and nitrogen stable isotopes in meerkat feces

    Science.gov (United States)

    2017-01-01

    Stable isotope analysis of feces can provide a non-invasive method for tracking the dietary habits of nearly any mammalian species. While fecal samples are often collected for macroscopic and genetic study, stable isotope analysis can also be applied to expand the knowledge of species-specific dietary ecology. It is somewhat unclear how digestion changes the isotope ratios of animals’ diets, so more controlled diet studies are needed. To date, most diet-to-feces controlled stable isotope experiments have been performed on herbivores, so in this study I analyzed the carbon and nitrogen stable isotope ratios in the diet and feces of the meerkat (Suricata suricatta), a small omnivorous mammal. The carbon trophic discrimination factor between diet and feces (Δ13Cfeces) is calculated to be 0.1 ± 1.5‰, which is not significantly different from zero, and in turn, not different than the dietary input. On the other hand, the nitrogen trophic discrimination factor (Δ15Nfeces) is 1.5 ± 1.1‰, which is significantly different from zero, meaning it is different than the average dietary input. Based on data generated in this experiment and a review of the published literature, carbon isotopes of feces characterize diet, while nitrogen isotope ratios of feces are consistently higher than dietary inputs, meaning a discrimination factor needs to be taken into account. The carbon and nitrogen stable isotope values of feces are an excellent snapshot of diet that can be used in concert with other analytical methods to better understand ecology, diets, and habitat use of mammals. PMID:28626611

  6. Non-traditional Stable Isotope Systematics of Seafloor Hydrothermal Systems

    Science.gov (United States)

    Rouxel, O. J.

    2009-05-01

    Seafloor hydrothermal activity at mid-ocean ridges is one of the fundamental processes controlling the chemistry of the oceans and the altered oceanic crust. Past studies have demonstrated the complexity and diversity of seafloor hydrothermal systems and have highlighted the importance of subsurface environments in controlling the composition of hydrothermal fluids and mineralization types. Traditionally, the behavior of metals in seafloor hydrothermal systems have been investigated by integrating results from laboratory studies, theoretical models, mineralogy and fluid and mineral chemistry. Isotope ratios of various metals and metalloids, such as Fe, Cu, Zn, Se, Cd and Sb have recently provided new approaches for the study of seafloor hydrothermal systems. Despite these initial investigations, the cause of the isotopic variability of these elements remains poorly constrained. We have little understanding of the isotope variations between vent types (black or white smokers) as well as the influence of source rock composition (basalt, felsic or ultrabasic rocks) and alteration types. Here, I will review and present new results of metal isotope systematics of seafloor hydrothermal systems, in particular: (1) determination of empirical isotope fractionation factors for Zn, Fe and Cu-isotopes through isotopic analysis of mono-mineralic sulfide grains lining the internal chimney wall in contact with hydrothermal fluid; (2) comparison of Fe- and Cu-isotope signatures of vent fluids from mid- oceanic and back-arc hydrothermal fields, spanning wide ranges of pH, temperature, metal concentrations and contributions of magmatic fluids enriched in SO2. Ultimately, the use of complementary non-traditional stable isotope systems may help identify and constrain the complex interactions between fluids,minerals, and organisms in seafloor hydrothermal systems.

  7. Stable hydrogen and oxygen isotope ratios of bottled waters of the world.

    Science.gov (United States)

    Bowen, Gabriel J; Winter, David A; Spero, Howard J; Zierenberg, Robert A; Reeder, Mathew D; Cerling, Thure E; Ehleringer, James R

    2005-01-01

    Bottled and packaged waters are an increasingly significant component of the human diet. These products are regulated at the regional, national, and international levels, and determining the authenticity of marketing and labeling claims represents a challenge to regulatory agencies. Here, we present a dataset of stable isotope ratios for bottled waters sampled worldwide, and consider potential applications of such data for regulatory, forensic and geochemical standardization applications. The hydrogen and oxygen isotope ratios of 234 samples of bottled water range from -147 per thousand to +15 per thousand and from -19.1 per thousand to +3.0 per thousand, respectively. These values fall within and span most of the normal range for meteoric waters, indicating that these commercially available products represent a source of waters for use as laboratory working standards in applications requiring standardization over a large range of isotope ratios. The measured values of bottled water samples cluster along the global meteoric water line, suggesting that bottled water isotope ratios preserve information about the water sources from which they were derived. Using the dataset, we demonstrate how bottled water isotope ratios provide evidence for substantial evaporative enrichment of water sources prior to bottling and for the marketing of waters derived from mountain and lowland sources under the same name. Comparison of bottled water isotope ratios with natural environmental water isotope ratios demonstrates that on average the isotopic composition of bottled water tends to be similar to the composition of naturally available local water sources, suggesting that in many cases bottled water need not be considered as an isotopically distinct component of the human diet. Our findings suggest that stable isotope ratios of bottled water have the power to distinguish ultimate (e.g., recharge) and proximal (e.g., reservoir) sources of bottled water and constitute a potential

  8. Using stable isotopes techniques in the measurement of vitamin A deficiency

    International Nuclear Information System (INIS)

    Sajet, A.S.

    2010-01-01

    Vitamin A plays an important role in strengthening the eyesight and good performance of growth and to maintain the immune system in our bodies. There is several methods to measure vitamin A deficiency. The first method is called the concentration of Retinol serum, used to determine the response to treatment given to people with symptoms clinical. The second method is known as the way to respond relative to the dose adjusted depending on the patient's oral small dose of Retinol. Despite the importance of the second method but it does not give accurate accounts of the total amount of vitamin A in the body. Scientists investigated stable isotope technique to calculate the total amount of vitamin A in the general body, which depends upon giving an oral dose of stable isotope and after enough time to allow mixing of stable isotope with vitamin A in the body , withdrawn blood sample is measured in serum. (author)

  9. Clipperton Atoll Core 3C Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  10. Clipperton Atoll Core 2B Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  11. Clipperton Atoll Core 4B Stable Isotope (delta 13C, delta 18O) Data for 1893 to 1994

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — 101 year stable isotope record from P. lobata, core 4B, Clipperton Atoll, eastern Pacific. Sampling at annual and 12/year resolution, files clipperton.4B.iso.txt and...

  12. Using stable isotopes of carbon and nitrogen as in-situ tracers for monitoring the natural attenuation of explosives

    National Research Council Canada - National Science Library

    Miyares, Paul H

    1999-01-01

    The use of carbon and nitrogen stable isotope measurements from TNT was examined as a possible tool for monitoring the natural attenuation of TNT incubation studies of spiked soil samples were conducted...

  13. Infrared Spectroscopy and Stable Isotope Geochemistry of Hydrous Silicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Stolper, Edward

    2007-03-05

    The focus of this DOE-funded project has been the study of volatile components in magmas and the atmosphere. Over the twenty-one year period of this project, we have used experimental petrology and stable isotope geochemistry to study the behavior and properties of volatile components dissolved in silicate minerals and melts and glasses. More recently, we have also studied the concentration and isotopic composition of CO2 in the atmosphere, especially in relation to air quality issues in the Los Angeles basin.

  14. Spectral analysis software improves confidence in plant and soil water stable isotope analyses performed by isotope ratio infrared spectroscopy (IRIS).

    Science.gov (United States)

    West, A G; Goldsmith, G R; Matimati, I; Dawson, T E

    2011-08-30

    Previous studies have demonstrated the potential for large errors to occur when analyzing waters containing organic contaminants using isotope ratio infrared spectroscopy (IRIS). In an attempt to address this problem, IRIS manufacturers now provide post-processing spectral analysis software capable of identifying samples with the types of spectral interference that compromises their stable isotope analysis. Here we report two independent tests of this post-processing spectral analysis software on two IRIS systems, OA-ICOS (Los Gatos Research Inc.) and WS-CRDS (Picarro Inc.). Following a similar methodology to a previous study, we cryogenically extracted plant leaf water and soil water and measured the δ(2)H and δ(18)O values of identical samples by isotope ratio mass spectrometry (IRMS) and IRIS. As an additional test, we analyzed plant stem waters and tap waters by IRMS and IRIS in an independent laboratory. For all tests we assumed that the IRMS value represented the "true" value against which we could compare the stable isotope results from the IRIS methods. Samples showing significant deviations from the IRMS value (>2σ) were considered to be contaminated and representative of spectral interference in the IRIS measurement. Over the two studies, 83% of plant species were considered contaminated on OA-ICOS and 58% on WS-CRDS. Post-analysis, spectra were analyzed using the manufacturer's spectral analysis software, in order to see if the software correctly identified contaminated samples. In our tests the software performed well, identifying all the samples with major errors. However, some false negatives indicate that user evaluation and testing of the software are necessary. Repeat sampling of plants showed considerable variation in the discrepancies between IRIS and IRMS. As such, we recommend that spectral analysis of IRIS data must be incorporated into standard post-processing routines. Furthermore, we suggest that the results from spectral analysis be

  15. Isolation and stable nitrogen isotope analysis of ammonium ions in ammonium nitrate prills using sodium tetraphenylborate.

    Science.gov (United States)

    Howa, John D; Lott, Michael J; Ehleringer, James R

    2014-07-15

    Because of the threat of bombings using improvised explosives containing ammonium nitrate (AN), law enforcement and intelligence communities have been interested in stable isotope techniques for tracking and discriminating AN sources. Separate analysis of the AN component ions ammonium and nitrate would add discriminatory power to these techniques. Ammonium ions in dissolved AN solution were isolated from samples by precipitation using sodium tetraphenylborate solution. We tested the isolation of ammonium from nitrates using solutions of ammonium and nitrate salts with different (15)N/(14)N isotope ratios. Ammonium tetraphenylborate and AN were separately analyzed for their (15)N/(14)N isotope ratios using EA-ConFlo-IRMS, and the (15)N/(14)N isotope ratios of the nitrate ions were calculated using mass balance. Ammonium and nitrate nitrogen isotope ratios were plotted as two separate variables. Isolation of ammonium precipitate from solutions containing dissolved nitrates did not influence the nitrogen isotope ratios of test ammonium salts. A survey set of 42 AN samples showed that the ammonium and nitrate (15)N/(14)N isotope ratios were not significantly correlated, and the paired mean differences were not statistically significant. Both ammonium and nitrate were depleted in (15)N relative to their theoretical atmospheric sources. Isolation of the ammonium ion from AN adds another dimension for the discrimination of forensic AN samples. This technique using sodium tetraphenylborate is robust and does not require specialized equipment. Our observations indicated that ammonium nitrogen and nitrate nitrogen have independent sources of isotopic variation. Copyright © 2014 John Wiley & Sons, Ltd.

  16. Diet of spotted bats (Euderma maculatum) in Arizona as indicated by fecal analysis and stable isotopes

    Science.gov (United States)

    We assessed diet of spotted bats (Euderma maculatum (J.A. Allen, 1891)) by visual analysis of bat feces and stable carbon (δ13C) and nitrogen (δ15N) isotope analysis of bat feces, wing, hair, and insect prey. We collected 33 fecal samples from spotted bats and trapped 3755 insect...

  17. Meteoric precipitation at Yucca Mountain, Nevada: Chemical and stable isotope analyses, 2006-09

    Science.gov (United States)

    Moscati, Richard J.; Scofield, Kevin M.

    2011-01-01

    Meteoric precipitation samples collected in 2006-09 at Yucca Mountain, Nevada, were analyzed for chemistry and stable isotope composition. Precipitation is the major source of infiltration to the unsaturated zone and of recharge to the saturated zone at Yucca Mountain.

  18. Stable Carbon and Oxygen Isotope Ratios of Otoliths Differentiate Winter Flounder (Pseudopleuonectes americanus) Habitats

    Science.gov (United States)

    Stable carbon (13C) and oxygen (18O) isotope ratios were measured in otoliths of juvenile winter flounder (Pseudopleuronectes americanus) collected from 18 nursery areas along the coast of Rhode Island, USA. Samples were obtained during June and July of 2002 from locations tha...

  19. TESTING THE USE OF STABLE ISOTOPES TO IDENTIFY FOOD WEB LINKS IN FRESHWATER RIVERINE COASTAL WETLANDS

    Science.gov (United States)

    Twenty riverine wetlands were sampled along the shores of Lake Michigan in 2001 as part of a Regional Environmental Monitoring and Assessment Program for coastal wetlands. Fish, invertebrates, periphyton, seston, and macrophytes were collected for N15 and C13 stable isotope analy...

  20. Characteristics of stable carbon isotopic composition of shale gas

    Directory of Open Access Journals (Sweden)

    Zhenya Qu

    2016-04-01

    Full Text Available A type Ⅱ kerogen with low thermal maturity was adopted to perform hydrocarbon generation pyrolysis experiments in a vacuum (Micro-Scale Sealed Vessel system at the heating rates of 2 °C/h and 20 °C/h. The stable carbon isotopic compositions of gas hydrocarbons were measured to investigate their evolving characteristics and the possible reasons for isotope reversal. The δ13C values of methane became more negative with the increasing pyrolysis temperatures until it reached the lightest point, after which they became more positive. Meanwhile, the δ13C values of ethane and propane showed a positive trend with elevating pyrolysis temperatures. The carbon isotopic compositions of shale gasses were mainly determined by the type of parent organic matter, thermal evolutionary extent, and gas migration in shale systems. Our experiments and study proved that the isotope reversal shouldn't occur in a pure thermogenic gas reservoir, it must be involved with some other geochemical process/es; although mechanisms responsible for the reversal are still vague. Carbon isotopic composition of the Fayetteville and Barnett shale gas demonstrated that the isotope reversal was likely involved with water–gas reaction and Fischer-Tropsch synthesis during its generation.

  1. Water vapor stable isotope observations from tropical Australia

    KAUST Repository

    Parkes, Stephen

    2015-04-01

    The response of the tropical hydrological cycle to anthropogenically induced changes in radiative forcing is one of the largest discrepancies between climate models. Paleoclimate archives of the stable isotopic composition of precipitation in the tropics indicate a relationship with precipitation amount that could be exploited to study past hydroclimate and improve our knowledge of how this region responds to changes in climate forcing. Recently modelling studies of convective parameterizations fitted with water isotopes and remote sensing of water vapor isotopes in the tropics have illustrated uncertainty in the assumed relationship with rainfall amount. Therefore there is a need to collect water isotope data in the tropics that can be used to evaluate these models and help identify the relationships between the isotopic composition of meteoric waters and rainfall intensity. However, data in this region is almost non-existent. Here we present in-situ water vapor isotopic measurements and the HDO retrievals from the co-located Total Column Carbon Observing Network (TCCON) site at Darwin in Tropical Australia. The Darwin site is interestingly placed within the tropical western pacific region and is impacted upon by a clear monsoonal climate, and key climate cycles including ENSO and Madden Julian Oscillations. The analysis of the data illustrated relationships between water vapor isotopes and humidity which demonstrated the role of precipitation processes in the wet season and air mass mixing during the dry season. Further the wet season observations show complex relationships between humidity and isotopes. A simple Rayleigh distillation model was not obeyed, instead the importance of rainfall re-evaporation in generating the highly depleted signatures was demonstrated. These data potentially provide a useful tool for evaluating model parameterizations in monsoonal regions as they demonstrate relationships with precipitation processes that cannot be observed with

  2. Stable isotope-based diet reconstructions of Turkana Basin hominins

    Science.gov (United States)

    Cerling, Thure E.; Kyalo Manthi, Fredrick; Mbua, Emma N.; Leakey, Louise N.; Leakey, Meave G.; Leakey, Richard E.; Brown, Francis H.; Grine, Frederick E.; Hart, John A.; Kaleme, Prince; Roche, Hélène; Uno, Kevin T.; Wood, Bernard A.

    2013-06-01

    Hominin fossil evidence in the Turkana Basin in Kenya from ca. 4.1 to 1.4 Ma samples two archaic early hominin genera and records some of the early evolutionary history of Paranthropus and Homo. Stable carbon isotopes in fossil tooth enamel are used to estimate the fraction of diet derived from C3 or C4 resources in these hominin taxa. The earliest hominin species in the Turkana Basin, Australopithecus anamensis, derived nearly all of its diet from C3 resources. Subsequently, by ca. 3.3 Ma, the later Kenyanthropus platyops had a very wide dietary range-from virtually a purely C3 resource-based diet to one dominated by C4 resources. By ca. 2 Ma, hominins in the Turkana Basin had split into two distinct groups: specimens attributable to the genus Homo provide evidence for a diet with a ca. 65/35 ratio of C3- to C4-based resources, whereas P. boisei had a higher fraction of C4-based diet (ca. 25/75 ratio). Homo sp. increased the fraction of C4-based resources in the diet through ca. 1.5 Ma, whereas P. boisei maintained its high dependency on C4-derived resources.

  3. GEOTRACES inter-calibration of the stable silicon isotope composition of dissolved silicic acid in seawater

    OpenAIRE

    Grasse, Patricia; Brzezinski, Mark A.; Cardinal, Damien; De Souza, Gregory F.; Andersson, Per; Closset, Ivia; Cao, Zhimian; Dai, Minhan; Ehlert, Claudia; Estrade, Nicolas; Francois, Roger; Frank, Martin; Jiang, Guibin; Jones, Janice L.; Kooijman, Ellen

    2017-01-01

    The first inter-calibration study of the stable silicon isotope composition of dissolved silicic acid in seawater, delta Si-30(OH)(4), is presented as a contribution to the international GEOTRACES program. Eleven laboratories from seven countries analyzed two seawater samples from the North Pacific subtropical gyre (Station ALOHA) collected at 300 m and at 1000 m water depth. Sampling depths were chosen to obtain samples with a relatively low (9 mmol L-1, 300 m) and a relatively high (113 mmo...

  4. Stable water isotopes as tracers in studies of lacustrine groundwater discharge

    Science.gov (United States)

    Lewandowski, Jörg; Pöschke, Franziska; Meinikmann, Karin; Rudnick, Sebastian; Périllon, Cécile; Elmarami, Hatem; Massmann, Gudrun; Stumpp, Christine

    2015-04-01

    Different tracers are used in ecohydrology to study transport processes across groundwater-surface water interfaces. The stable water isotopes oxygen-18 and deuterium as parts of the water molecule are close to perfect tracers since their behavior in aquifers is quite conservative. Isotopic signatures of groundwater and surface water differ due to the impact of evaporation on lake water. Stable isotope measurements are nowadays orders of magnitude cheaper, faster, and easier due to the recent development of cavity ring-down spectroscopy. Based on that analytical progress, we suggest a much broader use and highlight a number of promising ecohydrological applications in studies of lacustrine groundwater discharge. For example, they might be used to clearly distinguish between in- and exfiltration zones of lakes, to identify temporal fluctuations of in- and exfiltration, but also to identify sampling artifacts due to short circuits during sampling with lakebed piezometers.

  5. Development of stable isotope separation technology for radioisotope production

    International Nuclear Information System (INIS)

    Jeong, Do Young; Kim, Cheol Jung; Park, Kyung Bae

    2003-05-01

    The ultimate goal of this project is to construct the domestic production system of stable isotopes O-18 and Tl-203 used as target materials in accelerator for the production of medical radioisotopes F-18 and Tl-201, respectively. In order to achieve this goal, diode laser spectroscopic analytical system was constructed and automatic measurement computer software for the direct analysis of H 2 16 O/H 2 18 O ratio were developed. Distillation process, laser process, and membrane diffusion process were analyzed for the evaluation of O-18 production. And electromagnetic process, plasma process, and laser process were analyzed for the evaluation of Tl-203 production. UV laser system, IR laser system, and detailed system Tl-203 production were designed. Finally, current and future worldwide demand/supply of stable isotopes O-18 and Tl-203 were estimated

  6. Fractionation of Stable Isotopes in Atmospheric Aerosol Reactions

    DEFF Research Database (Denmark)

    Meusinger, Carl

    Aerosols - particles suspended in air - are the single largest uncertainty in our current understanding of Earth's climate. They also affect human health, infrastructure and ecosystems. Aerosols are emitted either directly into the atmosphere or are formed there for instance in response to chemical...... reactions and undergo complex chemical and physical changes during their lifetimes. In order to assess processes that form and alter aerosols, information provided by stable isotopes can be used to help constrain estimates on the strength of aerosol sources and sinks. This thesis studies (mass......-independent) fractionation processes of stable isotopes of C, N, O and S in order to investigate three different systems related to aerosols: 1. Post-depositional processes of nitrate in snow that obscure nitrate ice core records 2. Formation and aging of secondary organic aerosol generated by ozonolysis of X...

  7. Tracking Seasonal Habitats Using Carbon and Nitrogen Stable Isotopes of Osprey Primary Flight Feathers

    Science.gov (United States)

    Velinsky, D.; Zelanko, P.; Rice, N.

    2011-12-01

    The majority of bird migration studies use the latitudinal precipitation effect of hydrogen and oxygen stable isotopes of feathers to determine wintering and breeding grounds. Few studies have considered carbon and nitrogen stable isotopes to accomplish the same goal; exploiting the variation in dietary constitutes throughout yearly migration cycles. Also, there is no standard procedure of feather sampling; some use body, while others use wing feathers. This sampling discrepancy is not an issue for most migratory species since the majority of birds molt completely in one location, i.e. wintering verse breeding ground. Large birds of prey however, have a continuous molt that may last years, growing feathers on their breeding and wintering grounds. Therefore, a stable isotopic study of Osprey could not randomly sample feathers because it is impossible to know where individual feathers were grown. Here we present an in depth study of carbon and nitrogen stable isotopes from Mid-Atlantic Osprey primary flight feathers. Not only did we observe three signatures indicating the breeding ground and two distinct wintering grounds, we recorded dietary seasonality shifts within 2 to 3 year olds that remain on the wintering grounds for multiple years.

  8. Continuous in situ measurements of stable isotopes in liquid water

    Science.gov (United States)

    Herbstritt, Barbara; Gralher, Benjamin; Weiler, Markus

    2012-03-01

    We developed a method to measure in situ the isotopic composition of liquid water with minimal supervision and, most important, with a temporal resolution of less than a minute. For this purpose a microporous hydrophobic membrane contactor (Membrana) was combined with an isotope laser spectrometer (Picarro). The contactor, originally designed for degassing liquids, was used with N2 as a carrier gas in order to transform a small fraction of liquid water to water vapor. The generated water vapor was then analyzed continuously by the Picarro analyzer. To prove the membrane's applicability, we determined the specific isotope fractionation factor for the phase change through the contactor's membrane across an extended temperature range (8°C-21°C) and with different waters of known isotopic compositions. This fractionation factor is needed to subsequently derive the liquid water isotope ratio from the measured water vapor isotope ratios. The system was tested with a soil column experiment, where the isotope values derived with the new method corresponded well (R2 = 0.998 for δ18O and R2 = 0.997 for δ2H) with those of liquid water samples taken simultaneously and analyzed with a conventional method (cavity ring-down spectroscopy). The new method supersedes taking liquid samples and employs only relatively cheap and readily available components. This makes it a relatively inexpensive, fast, user-friendly, and easily reproducible method. It can be applied in both the field and laboratory wherever a water vapor isotope analyzer can be run and whenever real-time isotope data of liquid water are required at high temporal resolution.

  9. Biosynthetic effects on the stable carbon isotopic compositions of agal lipids: Implications for deciphering the carbon isotopic biomarker record

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Schouten, S.; Klein Breteler, W.C.M.; Blokker, P.; Schogt, N.; Rijpstra, W.I.C.; Grice, K.; Baas, M.

    1998-01-01

    Thirteen species of algae covering an extensive range of classes were cultured and stable carbon isotopic compositions of their lipids were analysed in order to assess carbon isotopic fractionation effects during their biosynthesis. The fatty acids were found to have similar stable carbon isotopic

  10. Global spatial distributions of nitrogen and carbon stable isotope ratios of modern human hair.

    Science.gov (United States)

    Hülsemann, Frank; Lehn, Christine; Schneider, Sabine; Jackson, Glen; Hill, Sarah; Rossmann, Andreas; Scheid, Nicole; Dunn, Philip J H; Flenker, Ulrich; Schänzer, Wilhelm

    2015-11-30

    Natural stable carbon (δ(13)C) and nitrogen isotope ratios (δ(15)N) of humans are related to individual dietary habits and environmental and physiological factors. In forensic science the stable isotope ratios of human remains such as hair and nail are used for geographical allocation. Thus, knowledge of the global spatial distribution of human δ(13)C and δ(15)N values is an essential component in the interpretation of stable isotope analytical results. No substantial global datasets of human stable isotope ratios are currently available, although the amount of available (published) data has increased within recent years. We have herein summarised the published data on human global δ(13)C andδ(15)N values (around 3600 samples) and added experimental values of more than 400 additional worldwide human hair and nail samples. In order to summarise isotope ratios for hair and nail samples correction factors were determined. The current available dataset of human stable isotope ratios is biased towards Europe and North America with only limited data for countries in Africa, Central and South America and Southeast Asia. The global spatial distribution of carbon isotopes is related to latitude and supports the fact that human δ(13)C values are dominated by the amount of C4 plants in the diet, either due to direct ingestion as plant food, or by its use as animal feed. In contrast, the global spatial distribution of human δ(15)N values is apparently not exclusively related to the amount of fish or meat ingested, but also to environmental factors that influence agricultural production. There are still a large proportion of countries, especially in Africa, where there are no available data for human carbon and nitrogen isotope ratios. Although the interpretation of modern human carbon isotope ratios at the global scale is quite possible, and correlates with the latitude, the potential influences of extrinsic and/or intrinsic factors on human nitrogen isotope ratios

  11. Development of Laser Application Technology for Stable Isotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

    2007-04-15

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed.

  12. Utility of stable isotope analysis in studying foraging ecology of herbivores: Examples from moose and caribou

    Science.gov (United States)

    Ben-David, M.; Shochat, E.; Adams, L.

    2001-01-01

    Recently, researchers emphasized that patterns of stable isotope ratios observed at the individual level are a result of an interaction between ecological, physiological, and biochemical processes. Isotopic models for herbivores provide additional complications because those mammals consume foods that have high variability in nitrogen concentrations. In addition, distribution of amino acids in plants may differ greatly from that required by a herbivore. At northern latitudes, where the growing season of vegetation is short, isotope ratios in herbivore tissues are expected to differ between seasons. Summer ratios likely reflect diet composition, whereas winter ratios would reflect diet and nutrient recycling by the animals. We tested this hypothesis using data collected from blood samples of caribou (Rangifer tarandus) and moose (Alces alces) in Denali National Park and Preserve, Alaska, USA. Stable isotope ratios of moose and caribou were significantly different from each other in late summer-autumn and winter. Also, late summer-autumn and winter ratios differed significantly between seasons in both species. Nonetheless, we were unable to evaluate whether differences in seasonal isotopic ratios were a result of diet selection or a response to nutrient recycling. We believe that additional studies on plant isotopic ratios as related to ecological factors in conjunction with investigations of diet selection by the herbivores will enhance our understanding of those interactions. Also, controlled studies investigating the relation between diet and physiological responses in herbivores will increase the utility of isotopic analysis in studying foraging ecology of herbivores.

  13. Use of stable isotopes to investigate keratin deposition in the claw tips of ducks.

    Science.gov (United States)

    Hopkins, John B; Cutting, Kyle A; Warren, Jeffrey M

    2013-01-01

    Stable isotopes derived from the claws of birds could be used to determine the migratory origins of birds if the time periods represented in excised sections of claws were known. We investigated new keratin growth in the claws of adult female Lesser Scaup (Aythya affinis) by estimating the equilibration rates of stable isotopes (δ (13)C, δ (15)N, and δ (2)H) from the breeding grounds into 1 mm claw tips. We sampled birds on their breeding ground through time and found that it took approximately 3-3.5 months for isotope values in most claw tips to equilibrate to isotope values that reflected those present in the environment on their breeding grounds. Results from this study suggest that isotopes equilibrate slowly into claw tips of Lesser Scaup, suggesting isotopes could potentially be used to determine the wintering grounds of birds. We suggest using controlled feeding experiments or longitudinal field investigations to understand claw growth and isotopic equilibration in claw tips. Such information would be valuable in ascertaining whether claw tips can be used in future studies to identify the migratory origins of birds.

  14. Regional and inter annual patterns of heavy metals, organochlorines and stable isotopes in narwhals (Monodon monoceros) from West Greenland

    DEFF Research Database (Denmark)

    Dietz, R.; Riget, F.; Hobson, K.A.

    2004-01-01

    Samples of 150 narwhals obtained in different years from two West Greenland areas, Avanersuaq and Uummannaq, were compared for concentrations of and regional differences in heavy metals and organochlorines and stable-carbon and nitrogen isotopes. Cadmium, Hg, and Se concentrations increased....../age composition of the data. PCB and DDT concentrations in West Greenland narwhals were half those found in East Greenland and Svalbard. Stable-carbon isotope ratios in muscle of 150 narwhals showed a decreasing trend in the first year when they gradually reduced their dependency on mother's milk, after which...... between stable isotope ratios and metal and OC concentrations....

  15. Realistic Fasting Does Not Affect Stable Isotope Levels of a Metabolically Efficient Salamander

    Science.gov (United States)

    Stable isotopes are commonly used to examine various aspects of animal ecology. The use of stable isotopes generally proceeds under the implicit assumption that resource use is the only factor driving variation in stable isotope levels; however, a wealth of studies demonstrate a...

  16. Production of yeastolates for uniform stable isotope labelling in eukaryotic cell culture.

    NARCIS (Netherlands)

    Egorova-Zachernyuk, T.A.; Bosman, G.J.C.G.M.; Pistorius, A.M.A.; Grip, W.J. de

    2009-01-01

    Preparation of stable isotope-labelled yeastolates opens up ways to establish more cost-effective stable isotope labelling of biomolecules in insect and mammalian cell lines and hence to employ higher eukaryotic cell lines for stable isotope labelling of complex recombinant proteins. Therefore, we

  17. High-precision mass spectrometric analysis using stable isotopes in studies of children

    NARCIS (Netherlands)

    Schierbeek, Henk; van den Akker, Chris H. P.; Fay, Laurent B.; van Goudoever, Johannes B.

    2012-01-01

    The use of stable isotopes combined with mass spectrometry (MS) provides insight into metabolic processes within the body. Herein, an overview on the relevance of stable isotope methodology in pediatric research is presented. Applications for the use of stable isotopes with MS cover carbohydrate,

  18. Stable isotope studies: Progress report, March 1985--August 1987

    International Nuclear Information System (INIS)

    Ishida, Takanobu.

    1987-01-01

    Studies have been carried out in the following areas: Stable Isotope Fractionation (1) Effects of chemical poisons and surface modifiers on polycrystalline platinum electrode surfaces have been investigated with a goal to develop a new form of heterogeneous catalyst for the hydrogen isotope exchange between dihydrogen and water. (2) A new nitrogen-15 fractionation process has been developed, based on the isotope exchange between liquid N 2 O 3 -N 2 O 4 mixture and their vapor phase at a subambient temperature and a raised pressure. (3) A closed chemical recycle process has been developed for use in connection with the refluxer in the Nitrox-type nitrogen-15 plant. Isotope Effects (1) The vapor pressure isotope effect (VPIE) study of liquid fluoromethanes have been completed. (2) The VPIE study of solid and liquid ammonia has been completed. (3) A theoretical foundation of the additivity for the vibrational zero-point energy (ZPE) has been developed. Studies of Liquid Ammonia. With an aim to study intermolecular interaction (and the inversion phenomenon, in particular) in liquid ammonia, and to further investigate various ammonia solutions, a molecular dynamics (MD) study has been initiated. An MD program has been completed, and force field functions have been developed for an ensemble of non-rigid ammonia molecules. 107 refs., 41 figs., 10 tabs

  19. Stable isotopes differentiate bottlenose dolphins off west-central Florida

    Science.gov (United States)

    Barros, Nélio B.; Ostrom, P. H.; Stricker, Craig A.; Wells, R.S.

    2010-01-01

    Distinguishing discrete population units among continuously distributed coastal small cetaceans is challenging and crucial to conservation. We evaluated the utility of stable isotopes in assessing group membership in bottlenose dolphins (Tursiops truncatus) off west-central Florida by analyzing carbon, nitrogen, and sulfur isotope values (δ13C, δ15N, and δ34S) of tooth collagen from stranded dolphins. Individuals derived from three putative general population units: Sarasota Bay (SB), nearshore Gulf of Mexico (GULF), and offshore waters (OFF). Animals of known history (SB) served to ground truth the approach against animals of unknown history from the Gulf of Mexico (GULF, OFF). Dolphin groups differed significantly for each isotope. Average δ13C values from SB dolphins (−10.6‰) utilizing sea grass ecosystems differed from those of GULF (−11.9‰) and OFF (−11.9‰). Average δ15N values of GULF (12.7‰) and OFF (13.2‰) were higher than those of SB dolphins (11.9‰), consistent with differences in prey trophic levels. δ34S values showed definitive differences among SB (7.1‰), GULF (11.3‰), and OFF (16.5‰) dolphins. This is the first application of isotopes to population assignment of bottlenose dolphins in the Gulf of Mexico and results suggest that isotopes may provide a powerful tool in the conservation of small cetaceans.

  20. Using stable isotopes to examine watershed connectivity to ...

    Science.gov (United States)

    Water bodies within the USA are protected by the US Clean Water Act when they have a significant nexus to downstream navigable waters. As a research scientist with the US Environmental Protection Agency, I have used water stable isotopes to examine hydrologic connectivity dynamics. I will share two case studies. In the first case, we used the isotopic evaporation signal in water to examine wetland-stream hydrologic connectivity within the Pipestem Creek watershed, North Dakota, a watershed dominated by prairie-pothole wetlands. Prairie-Pothole wetlands are a special case of wetlands whose protection needs to be determined under the Clean Water Rule. Pipestem Creek exhibited an evaporated-water signal that had approximately half the isotopic-enrichment signal found in most evaporatively enriched prairie-pothole wetlands. Groundwater measured at the water table adjacent to Pipestem Creek had isotopic values that indicated recharge from winter precipitation and had no significant evaporative enrichment. Using isotopic theory and discharge data, we estimated the area of surface water necessary to generate the evaporation signal found within Pipestem Creek over two years. Our results indicated that prairie-pothole wetlands were important sources of stream flow in Pipestem Creek throughout the summer, as well as during snowmelt. They also demonstrated that at the lowest flows, the stream itself became disconnected from headwater stream reaches. In the second ca

  1. Applications of stable Isotope ratios determinations in fruit juice authentication

    International Nuclear Information System (INIS)

    Magdas, Dana Alina; Dehelean, Adriana; Voica, Cezara; Puscas, Romulus

    2010-01-01

    Full text: Adulteration of a product consists in making it impure by fraudulent addition of a foreign or inferior substance. The result is either an alteration of the product and of its quality or a falsification. The falsification is a voluntary act with the intention of abuse. The falsification may be more or less sophisticated and its sophistication as well as its costs increases with the improvement of analytical methods. Vacuum concentration with aroma does not affect the chemical composition of fruit juices and therefore the determination of deuterium (D) and oxygen-18 content in waters is the most confident procedure for differentiating between a natural single strength juice and a juice rediluted from a concentrate. This technique is based on the fact that when absorbed by a plant, the rainwater or the irrigation water is fractionated by evapotranspiration, and enriched in the heavy isotopes (deuterium and oxygen-18) with respect to the light isotope (hydrogen and oxygen-16, respectively). It is known that climatic conditions affect the isotope content of rain waters and therefore that of fruit juices waters: the warmer climate, the higher the deuterium and oxygen-18 contents in water. Rainwater and tap water have nearly the same isotopic content and the water of fruit juices derived from concentrate by dilution with tap water has an isotopic content close to that of tap water. This makes it easy to distinguish diluted concentrates from the isotopically more enriched water of authentic single strength juice. In this study, single strength juice, in Romanian fruits, were investigated by mean of stable isotope measurements (oxygen, hydrogen and carbon) in order to offer a discussion basis for the authenticity of some fruit juices currently available on Romanian market. (authors)

  2. Production of stable isotopes utilizing the plasma separation process

    Science.gov (United States)

    Bigelow, T. S.; Tarallo, F. J.; Stevenson, N. R.

    2005-12-01

    A plasma separation process (PSP) is being operated at Theragenics Corporation's®, Oak Ridge, TN, facility for the enrichment of stable isotopes. The PSP utilizes ion cyclotron mass discrimination to separate isotopes on a relatively large scale. With a few exceptions, nearly any metallic element could be processed with PSP. Output isotope enrichment factor depends on natural abundance and mass separation and can be fairly high in some cases. The Theragenics™ PSP facility is believed to be the only such process currently in operation. This system was developed and formerly operated under the US Department of Energy Advanced Isotope Separation program. Theragenics™ also has a laboratory at the PSP site capable of harvesting the isotopes from the process and a mass spectrometer system for analyzing enrichment and product purity. Since becoming operational in 2002, Theragenics™ has utilized the PSP to separate isotopes of several elements including: dysprosium, erbium, gadolinium, molybdenum and nickel. Currently, Theragenics™ is using the PSP for the separation of 102Pd, which is used as precursor for the production of 103Pd. The 103Pd radioisotope is the active ingredient in TheraSeed®, which is used in the treatment of early stage prostate cancer and being investigated for other medical applications. New industrial, medical and research applications are being investigated for isotopes that can be enriched on the PSP. Pre-enrichment of accelerator or reactor targets offers improved radioisotope production. Theragenics operates 14 cyclotrons for proton activation and has access to HFIR at ORNL for neutron activation of radioisotopes.

  3. Partitioning evapotranspiration fluxes with water stable isotopic measurements: from the lab to the field

    Science.gov (United States)

    Quade, M. E.; Brueggemann, N.; Graf, A.; Rothfuss, Y.

    2017-12-01

    Water stable isotopes are powerful tools for partitioning net into raw water fluxes such as evapotranspiration (ET) into soil evaporation (E) and plant transpiration (T). The isotopic methodology for ET partitioning is based on the fact that E and T have distinct water stable isotopic compositions, which in turn relies on the fact that each flux is differently affected by isotopic kinetic effects. An important work to be performed in parallel to field measurements is to better characterize these kinetic effects in the laboratory under controlled conditions. A soil evaporation laboratory experiment was conducted to retrieve characteristic values of the kinetic fractionation factor (αK) under varying soil and atmospheric water conditions. For this we used a combined soil and atmosphere column to monitor the soil and atmospheric water isotopic composition profiles at a high temporal and vertical resolution in a nondestructive manner by combining micro-porous membranes and laser spectroscopy. αK was calculated by using a well-known isotopic evaporation model in an inverse mode with the isotopic composition of E as one input variable, which was determined using a micro-Keeling regression plot. Knowledge on αK was further used in the field (Selhausen, North Rhine-Westphalia, Germany) to partition ET of catch crops and sugar beet (Beta vulgaris) during one growing season. Soil and atmospheric water isotopic profiles were measured automatically across depths and heights following a similar modus operandi as in the laboratory experiment. Additionally, a newly developed continuously moving elevator was used to obtain water vapor isotopic composition profiles with a high vertical resolution between soil surface, plant canopy and atmosphere. Finally, soil and plant samples were collected destructively to provide a comparison with the traditional isotopic methods. Our results illustrate the changing proportions of T and E along the growing season and demonstrate the

  4. Applications of C and N stable isotopes to ecological and environmental studies in seagrass ecosystems

    Energy Technology Data Exchange (ETDEWEB)

    Lepoint, Gilles [Centre MARE, Laboratoire d' Oceanologie, Institut de Chimie, B6, Universite de Liege, B-4000 Liege (Belgium)]. E-mail: g.lepoint@ulg.ac.be; Dauby, Patrick [Centre MARE, Laboratoire d' Oceanologie, Institut de Chimie, B6, Universite de Liege, B-4000 Liege (Belgium); Institut Royal des Sciences Naturelles de Belgique, rue Vautier, B1000 Brussels (Belgium); Gobert, Sylvie [Centre MARE, Laboratoire d' Oceanologie, Institut de Chimie, B6, Universite de Liege, B-4000 Liege (Belgium)

    2004-12-01

    Stable isotopes of carbon and nitrogen are increasingly used in marine ecosystems, for ecological and environmental studies. Here, we examine some applications of stable isotopes as ecological integrators or tracers in seagrass ecosystem studies. We focus on both the use of natural isotope abundance as food web integrators or environmental tracers and on the use of stable isotopes as experimental tools. As ecosystem integrators, stable isotopes have helped to elucidate the general structure of trophic webs in temperate, Mediterranean and tropical seagrass ecosystems. As environmental tracers, stable isotopes have proven their utility in sewage impact measuring and mapping. However, to make such environmental studies more comprehensible, future works on understanding of basic reasons for variations of N and C stable isotopes in seagrasses should be encouraged. At least, as experimental tracers, stable isotopes allow the study of many aspects of N and C cycles at the scale of a plant or at the scale of the seagrass ecosystem.

  5. Assessment of renal function by the stable oxygen and hydrogen isotopes in human blood plasma.

    Directory of Open Access Journals (Sweden)

    Tai-Chih Kuo

    Full Text Available Water (H(2O is the most abundant and important molecule of life. Natural water contains small amount of heavy isotopes. Previously, few animal model studies have shown that the isotopic composition of body water could play important roles in physiology and pathophysiology. Here we study the stable isotopic ratios of hydrogen (δ(2H and oxygen (δ(18O in human blood plasma. The stable isotopic ratio is defined and determined by δ(sample = [(R(sample/R(STD-1] * 1000, where R is the molar ratio of rare to abundant, for example, (18O/(16O. We observe that the δ(2H and the δ(18O in human blood plasma are associated with the human renal functions. The water isotope ratios of the δ(2H and δ(18O in human blood plasma of the control subjects are comparable to those of the diabetes subjects (with healthy kidney, but are statistically higher than those of the end stage renal disease subjects (p<0.001 for both ANOVA and Student's t-test. In addition, our data indicate the existence of the biological homeostasis of water isotopes in all subjects, except the end stage renal disease subjects under the haemodialysis treatment. Furthermore, the unexpected water contents (δ(2H and δ(18O in blood plasma of body water may shed light on a novel assessment of renal functions.

  6. Using water stable isotopes to assess evaporation and water residence time of lakes in EPA’s National Lakes Assessment.

    Science.gov (United States)

    Stable isotopes of water (18O and 2H) can be very useful in large-scale monitoring programs because water samples are easy to collect and water isotopes integrate information about basic hydrological processes such as evaporation as a percentage of inflow (E/I), w...

  7. Provenance of Chinese Loess: Evidence from Stable Lead Isotope

    Directory of Open Access Journals (Sweden)

    Feng Wu

    2011-01-01

    Full Text Available Twenty-seven samples of typical loess and paleosol strata collected in nine different regions of the Chinese Loess Plateau (CLP were fractionated into PM1.0, PM2.5, PM10 and Total Suspended Particulates (TSP (particulate matter with aerodynamic diameters less than 1.0, 2.5, 10 and ~30 £gm, respectively by a resuspension chamber at the Desert Research Institute (DRI; Reno, NV, United States. The amounts and isotope ratios of lead (Pb were quantified in the loess samples. Our size-segregated analysis demonstrated that the Pb isotopic composition in the loess-paleosol deposits was preserved after grain-size sorting and that therefore the isotope ratio can serve as a proxy for source tracing. A similar pattern of Pb isotope ratios was observed for sediment collected from potential source regions and the loess samples suggested that the Gobi and deserts in southern Mongolia and northern China are major sources for the deposits in the CLP. No significant deviation of Pb isotope amount was found between the nine samples of loess and paleosol strata, implying the stability of loess sources during the glacial and interglacial regime.

  8. Carbon and Nitrogen Stable Isotope Values for Plants and Mammals in a Semi-Desert Region of Mongolia

    Directory of Open Access Journals (Sweden)

    Hannah Davie

    2014-12-01

    Full Text Available Little information exists on the isotopic signatures of plants and animals in Mongolia, limiting the application of stable isotope analysis to wildlife biology studies. Here we present plant and mammal carbon (δ 13 C and nitrogen (δ 15 N isotope values from a desert-steppe region of southeastern Mongolia. We analyzed 11 samples from 11 plant species and 93 samples from 24 mammal species across Ikh Nart Nature Reserve, and compared these numbers to isotope values reported from other areas of Mongolia. Our plant and mammal 13 C and 15 N values were similar to those from a similar arid steppe region and more enriched than those from less arid habitats. Habitat variation within and between study sites has an important infl uence on δ 13 C and δ 15 N variation. Our results supplement current knowledge of isotopic variation in Mongolia and provide a reference for future stable isotope research in Mongolia and similar Asian steppe ecosystems.

  9. Re-introduction of a novel approach to the use of stable isotopes in pharmacokinetic studies.

    Science.gov (United States)

    Parr, Alan; Gupta, Manish; Montague, Timothy H; Hoke, Frank

    2012-09-01

    The purpose of this investigation is to evaluate the scientific benefits of a novel approach in using stable isotopes to reduce the number of subjects needed to perform relative bioavailability and bioequivalence pharmacokinetic studies for formulations that are qualitatively and quantitatively the same and quality by design (QbD) pharmacokinetic studies. The stable isotope approach was investigated using simulations to determine the impact this approach would have on the estimation of variability and, subsequently, the sample size for a bioequivalence study. A biostudy was conducted in dogs in a two period crossover to explore the viability of the stable isotope approach. For a drug product with within-subject variability (CV(w)) of 50% and assuming a correlation of 0.95 between the enriched and non-enriched pharmacokinetics (PK), simulations showed that the variability can be reduced by 70% and the required sample size can be reduced by 90% while maintaining 90% power to demonstrate bioequivalence. The dog study showed a strong correlation (R(2), > 0.99) between the enriched and non-enriched area under the curve and maximum observed concentration, and a significant reduction in the variability (reduction in % coefficient of variation from 79.9% to 6.3%). Utilization of a stable isotope approach can markedly improve the efficiency and accuracy of bioavailability and bioequivalence studies particularly for highly variable drugs in formulations that are qualitatively and quantitatively the same and for studies designed for QbD investigations.

  10. Who is who matters-The effects of pseudoreplication in stable isotope analyses.

    Science.gov (United States)

    Mundry, Roger; Oelze, Vicky M

    2016-10-01

    Stable isotope analysis in free-ranging primates is a promising new avenue in reconstructing feeding niches and temporal dietary variation. Particularly, the large sample sizes obtained from non-invasively collected hair and fecal samples from nests of great apes offer great potential. However, analyzing repeated observations of the same individuals without controlling for potential differences among them means to "pseudoreplicate" and can lead to a greatly inflated probability of erroneous significance. We here test the effects of pseudoreplication in stable isotope data of great ape hair by means of simulations. We show that pseudoreplication can severely affect the probability of erroneous significance as well as non-significance. We suggest several strategies to avoid pseudoreplication in primate isotope ecology. First, if applicable, information on individual identity should be included in statistical analyses. Second, if samples derive from unhabituated animals, sampling at far apart locations or territories should avoid resampling of the same animal. In great apes, sampling of independent nests within nest groups can ensure that each sample derives from a different individual. Third, we encourage the combination of genetic surveys with sampling for isotope analyses to ensure the (genetic) identification of individuals. Am. J. Primatol. 78:1017-1030, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  11. Role of stable isotopes in life--testing isotopic resonance hypothesis.

    Science.gov (United States)

    Zubarev, Roman A

    2011-04-01

    Stable isotopes of most important biological elements, such as C, H, N and O, affect living organisms. In rapidly growing species, deuterium and to a lesser extent other heavy isotopes reduce the growth rate. At least for deuterium it is known that its depletion also negatively impacts the speed of biological processes. As a rule, living organisms "resist" changes in their isotopic environment, preferring natural isotopic abundances. This preference could be due to evolutionary optimization; an additional effect could be due to the presence of the "isotopic resonance". The isotopic resonance phenomenon has been linked to the choice of earliest amino acids, and thus affected the evolution of genetic code. To test the isotopic resonance hypothesis, literature data were analyzed against quantitative and qualitative predictions of the hypothesis. Four studies provided five independent datasets, each in very good quantitative agreement with the predictions. Thus, the isotopic resonance hypothesis is no longer simply plausible; it can now be deemed likely. Additional testing is needed, however, before full acceptance of this hypothesis. Copyright © 2011 Beijing Genomics Institute. Published by Elsevier Ltd. All rights reserved.

  12. Stable isotope anatomy of tropical cyclone Ita, North-Eastern Australia, April 2014.

    Science.gov (United States)

    Munksgaard, Niels C; Zwart, Costijn; Kurita, Naoyuki; Bass, Adrian; Nott, Jon; Bird, Michael I

    2015-01-01

    The isotope signatures registered in speleothems during tropical cyclones (TC) provides information about the frequency and intensity of past TCs but the precise relationship between isotopic composition and the meteorology of TCs remain uncertain. Here we present continuous δ18O and δ2H data in rainfall and water vapour, as well as in discrete rainfall samples, during the passage of TC Ita and relate the evolution in isotopic compositions to local and synoptic scale meteorological observations. High-resolution data revealed a close relationship between isotopic compositions and cyclonic features such as spiral rainbands, periods of stratiform rainfall and the arrival of subtropical and tropical air masses with changing oceanic and continental moisture sources. The isotopic compositions in discrete rainfall samples were remarkably constant along the ~450 km overland path of the cyclone when taking into account the direction and distance to the eye of the cyclone at each sampling time. Near simultaneous variations in δ18O and δ2H values in rainfall and vapour and a near-equilibrium rainfall-vapour isotope fractionation indicates strong isotopic exchange between rainfall and surface inflow of vapour during the approach of the cyclone. In contrast, after the passage of spiral rainbands close to the eye of the cyclone, different moisture sources for rainfall and vapour are reflected in diverging d-excess values. High-resolution isotope studies of modern TCs refine the interpretation of stable isotope signatures found in speleothems and other paleo archives and should aim to further investigate the influence of cyclone intensity and longevity on the isotopic composition of associated rainfall.

  13. Stable isotope-resolved metabolomics and applications for drug development

    Science.gov (United States)

    Fan, Teresa W-M.; Lorkiewicz, Pawel; Sellers, Katherine; Moseley, Hunter N.B.; Higashi, Richard M.; Lane, Andrew N.

    2012-01-01

    Advances in analytical methodologies, principally nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS), during the last decade have made large-scale analysis of the human metabolome a reality. This is leading to the reawakening of the importance of metabolism in human diseases, particularly cancer. The metabolome is the functional readout of the genome, functional genome, and proteome; it is also an integral partner in molecular regulations for homeostasis. The interrogation of the metabolome, or metabolomics, is now being applied to numerous diseases, largely by metabolite profiling for biomarker discovery, but also in pharmacology and therapeutics. Recent advances in stable isotope tracer-based metabolomic approaches enable unambiguous tracking of individual atoms through compartmentalized metabolic networks directly in human subjects, which promises to decipher the complexity of the human metabolome at an unprecedented pace. This knowledge will revolutionize our understanding of complex human diseases, clinical diagnostics, as well as individualized therapeutics and drug response. In this review, we focus on the use of stable isotope tracers with metabolomics technologies for understanding metabolic network dynamics in both model systems and in clinical applications. Atom-resolved isotope tracing via the two major analytical platforms, NMR and MS, has the power to determine novel metabolic reprogramming in diseases, discover new drug targets, and facilitates ADME studies. We also illustrate new metabolic tracer-based imaging technologies, which enable direct visualization of metabolic processes in vivo. We further outline current practices and future requirements for biochemoinformatics development, which is an integral part of translating stable isotope-resolved metabolomics into clinical reality. PMID:22212615

  14. Chromium Stable Isotope Fractionation - An Indicator of Hexavalent Chromium Reduction.

    Science.gov (United States)

    Ellis, A.; Johnson, T. M.; Bullen, T. D.

    2001-12-01

    fractionation during plating operations during up to 5 years of use. These results demonstrate that Cr stable isotope analyses should be a highly practical indicator of the critical chromate reduction reaction, and an otherwise useful geologic and oceanographic tool.

  15. "Fingerprinting" Vehicle Derived Ammonia Utilizing Nitrogen Stable Isotopes

    Science.gov (United States)

    Walters, W.; Hastings, M. G.; Colombi, N. K.

    2017-12-01

    Ammonia (NH3) is the primary alkaline molecule in the atmosphere and plays a key role in numerous atmospheric processes that have important implications for human health and climate control. While agriculture activities dominate the global NH3 budget, there are large uncertainties in the urban NH3 emission inventories. The analysis of the nitrogen stable isotope composition of NH3 (δ15N-NH3) might be a useful tool for partitioning NH3 emission sources, as different emission sources tend to emit NH3 with distinctive δ15N signatures or "fingerprints". This novel tool may help improve upon urban emission inventories, which could help to improve modeling of important atmospheric processes involving NH3. However, there is a current lack of δ15N-NH3 measurements of potentially important urban NH3 emission sources, and many of the reported NH3 collection methods have not been verified for its ability to accurately characterize δ15N-NH3. Here we present a laboratory tested method to accurately measure δ15N-NH3 using honeycomb denuders coated with a 2% citric acid solution. Based on laboratory tests, the NH3 collection device has been optimized under a variety of conditions. Near quantitative NH3 collection is found at a sampling rate of 10 SLPM for NH3 concentrations less than 2 ppmv, and δ15N-NH3 precision is found to be approximately 1.0‰. This newly developed NH3 collection device for isotopic characterization has been applied to improve our understanding of the δ15N-NH3 signatures from vehicles. Preliminary results of NH3 collected near a road-side indicate an average δ15N-NH3 of -2.1 ± 1.9‰. This work is ongoing, and plans are in place to collect NH3 directly from tailpipes and from on-road air. Our preliminary results indicate that vehicle derived NH3 has a distinctive δ15N signature compared to agricultural and waste emissions; thus, δ15N(NH3) has the potential to be used to understand urban NH3 emission sources.

  16. Analytical techniques in biomedical stable isotope applications : (isotope ratio) mass spectrometry or infrared spectrometry?

    NARCIS (Netherlands)

    Stellaard, F; Elzinga, H

    2005-01-01

    An overview is presented of biomedical applications of stable isotopes in general, but mainly focused on the activities of the Center for Liver, Digestive and Metabolic Diseases of the University Medical Center Groningen. The aims of metabolic studies in the areas of glucose, fat, cholesterol and

  17. Quantitative imaging of subcellular metabolism with stable isotopes and multi-isotope imaging mass spectrometry

    Science.gov (United States)

    Steinhauser, Matthew L.; Lechene, Claude P.

    2014-01-01

    Multi-isotope imaging mass spectrometry (MIMS) is the quantitative imaging of stable isotope labels in cells with a new type of secondary ion mass spectrometer (NanoSIMS). The power of the methodology is attributable to (i) the immense advantage of using non-toxic stable isotope labels, (ii) high resolution imaging that approaches the resolution of usual transmission electron microscopy and (iii) the precise quantification of label down to 1 part-per-million and spanning several orders of magnitude. Here we review the basic elements of MIMS and describe new applications of MIMS to the quantitative study of metabolic processes including protein and nucleic acid synthesis in model organisms ranging from microbes to humans. PMID:23660233

  18. Comparison of Meteorological Data and Stable Isotope Time Series from an Indonesian Stalagmite

    Science.gov (United States)

    Watanabe, Y.; Matsuoka, H.; Sakai, S.; Ueda, J.; Yamada, M.; Ohsawa, S.; Kiguchi, M.; Satomura, T.; Nakai, S.; Brahmantyo, B.; Maryunani, K. A.; Tagami, T.; Takemura, K.; Yoden, S.

    2007-12-01

    In the last decade, geochemical records in stalagmites have been widely recognized as a powerful tool for the elucidation of paleoclimate/environment of the terrestrial areas. The previous data are mainly reported from middle latitude. However, this study aims at reconstructing past climate variations in the Asian equatorial regions by using oxygen and carbon isotope ratios recorded in Indonesian stalagmites. Especially, we focused on the comparison of meteorological data and stable isotope time series from an Indonesia stalagmite, in order to check whether the geochemistry of stalagmite is influenced by local precipitation. We performed geological surveys in Buniayu limestone caves, Sukabumi, West Java, Indonesia, and collected a series of stalagmites/stalactites and drip water samples. A stalagmite sample was observed using thin sections to identify banding. Moreover, to construct the age model of the stalagmite, we also measured both (1) the number of bands and (2) uranium series disequilibrium ages using the MC-ICP-MS. These data suggest that each layer is annual banding dominantly. Oxygen and carbon isotope ratios were analyzed on the stalagmite for annual time scales. The carbon isotope ratio has a clear correlation with oxygen isotope ratios. Furthermore, the proxy data was compared with meteorological data set in the past 80 years, showing a good correlation between the temporal variation of oxygen/carbon isotope ratios and annual precipitation. These lines of evidence suggest that the isotopic variation is predominantly caused by kinetic mass fractionation driven by the degassing of carbon dioxide in the cave.

  19. On-line stable isotope measurements during plant and soil gas exchange

    International Nuclear Information System (INIS)

    Yakir, D.

    2001-01-01

    Recent techniques for on-line stable isotope measurements during plant and soil exchange of CO 2 and/or water vapor are briefly reviewed. For CO 2 , these techniques provide means for on-line measurements of isotopic discrimination during CO 2 exchange by leaves in the laboratory and in the field, of isotopic discrimination during soil respiration and during soil-atmosphere CO 2 exchange, and of isotopic discrimination in O 2 during plant respiration. For water vapor, these techniques provide means to measure oxygen isotopic composition of water vapor during leaf transpiration and for the analysis of sub microliter condensed water vapor samples. Most of these techniques involve on-line sampling of CO 2 and water vapor from a dynamic, intact soil or plant system. In the laboratory, these systems also allow on-line isotopic analysis by continuous-flow isotope ratio mass spectrometry. The information obtained with these on-line techniques is becoming increasingly valuable, and often critical, for ecophysiologial research and in the study of biosphere-atmosphere interactions. (author)

  20. Significance of stable carbon and bromine isotopes in the source identification of PBDEs.

    Science.gov (United States)

    Chen, Liuzhu; Shouakar-Stash, Orfan; Ma, Teng; Wang, Chunlei; Liu, Lu

    2017-11-01

    Typical brominated organic pollutants poly brominated diphenyl ethers (PBDEs) might be characterized by their stable carbon and bromine isotopic compositions. Currently, there are no published reports concerning the two-dimensional isotopic (δ 13 C and δ 81 Br) values of PBDEs. To assess the significance of carbon and bromine isotopes in the source identification of PBDEs, EA-IRMS and off-line-IRMS methods were employed to measure the δ 13 C and δ 81 Br values of the typical PBDE congeners, 2,2',4,4'-tetrabromodiphenyl ethers (BDE-47) and decabromodiphenyl ether (BDE-209) from different suppliers. The results show that individual PBDE congeners (three BDE-47 samples and three BDE-209 samples) have unique δ 13 C and δ 81 Br values, possibly due to differences in the precursors and manufacturing processes, indicating that the isotope composition is a promising probe to determine the source of PBDEs in the environment. While it is worth noting that some challenges might exist during practical application of this method, such as the similar isotopic compositions of PBDEs from different source. Thus, source identification associated with isotopic signatures should be used cautiously. This study provides a basis for further research into the source identification of PBDEs in the environment by examining their isotopic characteristics. Copyright © 2017. Published by Elsevier Ltd.

  1. Application of Stable Isotope in Detection of Veterinary Drug Residues

    International Nuclear Information System (INIS)

    Wang Wei; Liu Zhanfeng; Du Xiaoning

    2010-01-01

    In recent years, there has happened a series of significant food safety events worldwide, which lower down consumers' confidence in food safety, and they are taking increasing care about the sources of their foods. The safety problem of animal-origin foods has become a global topic for discussion. Therefore, it is a pressing task to establish a precise, sensitive and reliable method for analyzing veterinary drug residue. An introduction of the present status regarding veterinary drug residue analysis was made in the paper, and it briefly summarized the limit of detection (LOD) and quantification (LOQ) which could be reached in veterinary drug residue analysis by isotopic internal standard method domestically and abroad. The paper also made a review of the progress in applied research of stable isotope labeled compound in veterinary drug residue analysis of, such as, antibiotic medicines, furans and sulfonamides. The paper elucidated the great importance of the application of stable isotopes in the sane development of China's food safety system. (authors)

  2. Biomedical research applications of electromagnetically separated enriched stable isotopes

    International Nuclear Information System (INIS)

    Lambrecht, R.M.

    1982-01-01

    The current and projected annual requirements through 1985 for stable isotopes enriched by electromagnetic separation methods were reviewed for applications in various types of biomedical research: (1) medical radiosotope production, labeled compounds, and potential radiopharmaceuticals; (2) nutrition, food science, and pharmacology; (3) metallobiochemistry and environmental toxicology; (4) nuclear magnetic resonance, electron paramagnetic resonance, and Moessbauer spectroscopy in biochemical, biophysical, and biomedical research; and (5) miscellaneous advances in radioactive and non-radioactive tracer technology. Radioisotopes available from commercial sources or routinely used in clinical nuclear medicine were excluded. Priorities and summaries are based on statements in the references and from answers to a survey conducted in the fall of 1981. Current requirements for enriched stable isotopes in biomedical research are not being satisfied. Severe shortages exist for 26 Mg, 43 Ca, 70 Zn, 76 Se, 78 Se, 102 Pd, 111 Cd, 113 Cd, and 190 Os. Many interesting and potentially important investigations in biomedical research require small quantities of specific elements at high isotopic enrichments

  3. Isotope determination of sulfur by mass spectrometry in soil samples

    Directory of Open Access Journals (Sweden)

    Alexssandra Luiza Rodrigues Molina Rossete

    2012-12-01

    Full Text Available Sulphur plays an essential role in plants and is one of the main nutrients in several metabolic processes. It has four stable isotopes (32S, 33S, 34S, and 36S with a natural abundance of 95.00, 0.76, 4.22, and 0.014 in atom %, respectively. A method for isotopic determination of S by isotope-ratio mass spectrometry (IRMS in soil samples is proposed. The procedure involves the oxidation of organic S to sulphate (S-SO4(2-, which was determined by dry combustion with alkaline oxidizing agents. The total S-SO4(2- concentration was determined by turbidimetry and the results showed that the conversion process was adequate. To produce gaseous SO2 gas, BaSO4 was thermally decomposed in a vacuum system at 900 ºC in the presence of NaPO3. The isotope determination of S (atom % 34S atoms was carried out by isotope ratio mass spectrometry (IRMS. In this work, the labeled material (K2(34SO4 was used to validate the method of isotopic determination of S; the results were precise and accurate, showing the viability of the proposed method.

  4. Inferring foraging areas of nesting loggerhead turtles using satellite telemetry and stable isotopes.

    Science.gov (United States)

    Ceriani, Simona A; Roth, James D; Evans, Daniel R; Weishampel, John F; Ehrhart, Llewellyn M

    2012-01-01

    In recent years, the use of intrinsic markers such as stable isotopes to link breeding and foraging grounds of migratory species has increased. Nevertheless, several assumptions still must be tested to interpret isotopic patterns found in the marine realm. We used a combination of satellite telemetry and stable isotope analysis to (i) identify key foraging grounds used by female loggerheads nesting in Florida and (ii) examine the relationship between stable isotope ratios and post-nesting migration destinations. We collected tissue samples for stable isotope analysis from 14 females equipped with satellite tags and an additional 57 untracked nesting females. Telemetry identified three post-nesting migratory pathways and associated non-breeding foraging grounds: (1) a seasonal continental shelf-constrained migratory pattern along the northeast U.S. coastline, (2) a non-breeding residency in southern foraging areas and (3) a residency in the waters adjacent to the breeding area. Isotopic variability in both δ(13)C and δ(15)N among individuals allowed identification of three distinct foraging aggregations. We used discriminant function analysis to examine how well δ(13)C and δ(15)N predict female post-nesting migration destination. The discriminant analysis classified correctly the foraging ground used for all but one individual and was used to predict putative feeding areas of untracked turtles. We provide the first documentation that the continental shelf of the Mid- and South Atlantic Bights are prime foraging areas for a large number (61%) of adult female loggerheads from the largest loggerhead nesting population in the western hemisphere and the second largest in the world. Our findings offer insights for future management efforts and suggest that this technique can be used to infer foraging strategies and residence areas in lieu of more expensive satellite telemetry, enabling sample sizes that are more representative at the population level.

  5. Stable Nd isotope variations in the inner Solar System: The effect of sulfide during differentiation?

    Science.gov (United States)

    McCoy-West, A.

    2017-12-01

    Radiogenic neodymium isotopes have been widely used in studies of planetary accretion to constrain the timescales of early planetary differention [1]. Whereas stable isotope varitaions potentially provide information on the the processes that occur during planet formation. Experimental work suggests that the Earth's core contains a significant proportion of sulfide [2], and recent experimental work shows that under reducing conditions sulfide can incorporate substantial quantities of refractory lithophile elements [including Nd; 3]. If planetary embroyos also contain sulfide-rich cores, Nd stable isotopes have the potential to trace this sulfide segregation event in highly reduced environments, because there is a significant contrast in bonding environment between sulfide and silicate, where heavy isotopes should be preferentially incorporated into high force-constant bonds involving REE3+ (i.e. the silicate mantle). Here we present 146Nd/144Nd data, obtained using a double spike TIMS technique, for a range of planetary bodies formed at variable oxidation states including samples from the Moon, Mars, the asteriod 4Vesta and the Angrite and Aubrite parent bodies. Analyses of chondritic meteorites and terrestrial igneous rocks indicate that the Earth has a Nd stable isotope composition that is indistinguishable from that of chondrites [4]. Eucrites and martian meteorites also have compositons within error of the chondritic average. Significantly more variabilty is observed in the low concentration lunar samples and diogienite meteorites with Δ146Nd = 0.16‰. Preliminary results suggest that the Nd stable isotope composition of oxidised planetary bodies are homogeneous and modifications are the result of subordinate magmatic processes. [1] Boyet & Carlson, Science 309, 576 (2005) [2] Labidi et al. Nature 501, 208 (2013); [3] Wohlers &Wood, Nature 520, 337 (2015); [4] McCoy-West et al. Goldschmidt Ab. 429 (2017).

  6. Platinum stable isotope ratio measurements by double-spike multiple collector ICPMS

    DEFF Research Database (Denmark)

    Creech, John; Baker, Joel; Handler, Monica

    2013-01-01

    We present a new technique for the precise determination of platinum (Pt) stable isotope ratios by multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) using two different Pt double-spikes ( Pt-Pt and Pt-Pt). Results are expressed relative to the IRMM-010 Pt isotope standard......) can be obtained on Pt stable isotope ratios with either double-spike. Elemental doping tests reveal that double-spike corrected Pt stable isotope ratios are insensitive to the presence of relatively high (up to 10%) levels of matrix elements, although the Pt-Pt double-spike is affected by an isobaric...... interference on Pt from Os. The Pt-Pt double-spike does not use Pt in the double-spike inversion and is unaffected by Os contamination, and is our recommended double-spike for use with natural samples. As part of this study, we re-determined the natural Pt isotopic composition of IRMM-010 by MC-ICPMS using...

  7. Determination of zinc stable isotopes in biological materials using isotope dilution inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    Patterson, K.Y.; Veillon, Claude

    1992-01-01

    A method is described for using isotope dilution to determine both the amount of natural zinc and enriched isotopes of zinc in biological samples. Isotope dilution inductively coupled plasma mass spectrometry offers a way to quantify not only the natural zinc found in a sample but also the enriched isotope tracers of zinc. Accurate values for the enriched isotopes and natural zinc are obtained by adjusting the mass count rate data for measurable instrumental biases. Analytical interferences from the matrix are avoided by extracting the zinc from the sample matrix using diethylammonium diethyldithiocarbamate. The extraction technique separates the zinc from elements which form interfering molecular ions at the same nominal masses as the zinc isotopes. Accuracy of the method is verified using standard reference materials. The detection limit is 0.06 μg Zn per sample. Precision of the abundance ratios range from 0.3-0.8%. R.S.D. for natural zinc concentrations is about 200-600 μg g -1 . The accuracy and precision of the measurements make it possible to follow enriched isotopic tracers of zinc in biological samples in metabolic tracer studies. (author). 19 refs.; 1 fig., 4 tabs

  8. The Conflict between Cheetahs and Humans on Namibian Farmland Elucidated by Stable Isotope Diet Analysis

    Science.gov (United States)

    Voigt, Christian C.; Thalwitzer, Susanne; Melzheimer, Jörg; Blanc, Anne-Sophie; Jago, Mark; Wachter, Bettina

    2014-01-01

    Large areas of Namibia are covered by farmland, which is also used by game and predator species. Because it can cause conflicts with farmers when predators, such as cheetahs (Acinonyx jubatus), hunt livestock, we assessed whether livestock constitutes a significant part of the cheetah diet by analysing the stable isotope composition of blood and tissue samples of cheetahs and their potential prey species. According to isotopic similarities, we defined three isotopic categories of potential prey: members of a C4 food web with high δ15N values (gemsbok, cattle, springhare and guinea fowl) and those with low δ15N values (hartebeest, warthog), and members of a C3 food web, namely browsers (eland, kudu, springbok, steenbok and scrub hare). We quantified the trophic discrimination of heavy isotopes in cheetah muscle in 9 captive individuals and measured an enrichment for 15N (3.2‰) but not for 13C in relation to food. We captured 53 free-ranging cheetahs of which 23 were members of groups. Cheetahs of the same group were isotopically distinct from members of other groups, indicating that group members shared their prey. Solitary males (n = 21) and males in a bachelor groups (n = 11) fed mostly on hartebeest and warthogs, followed by browsers in case of solitary males, and by grazers with high δ15N values in case of bachelor groups. Female cheetahs (n = 9) predominantly fed on browsers and used also hartebeest and warthogs. Mixing models suggested that the isotopic prey category that included cattle was only important, if at all, for males living in bachelor groups. Stable isotope analysis of fur, muscle, red blood cells and blood plasma in 9 free-ranging cheetahs identified most individuals as isotopic specialists, focussing on isotopically distinct prey categories as their food. PMID:25162403

  9. The conflict between cheetahs and humans on Namibian farmland elucidated by stable isotope diet analysis.

    Directory of Open Access Journals (Sweden)

    Christian C Voigt

    Full Text Available Large areas of Namibia are covered by farmland, which is also used by game and predator species. Because it can cause conflicts with farmers when predators, such as cheetahs (Acinonyx jubatus, hunt livestock, we assessed whether livestock constitutes a significant part of the cheetah diet by analysing the stable isotope composition of blood and tissue samples of cheetahs and their potential prey species. According to isotopic similarities, we defined three isotopic categories of potential prey: members of a C4 food web with high δ15N values (gemsbok, cattle, springhare and guinea fowl and those with low δ15N values (hartebeest, warthog, and members of a C3 food web, namely browsers (eland, kudu, springbok, steenbok and scrub hare. We quantified the trophic discrimination of heavy isotopes in cheetah muscle in 9 captive individuals and measured an enrichment for 15N (3.2‰ but not for 13C in relation to food. We captured 53 free-ranging cheetahs of which 23 were members of groups. Cheetahs of the same group were isotopically distinct from members of other groups, indicating that group members shared their prey. Solitary males (n = 21 and males in a bachelor groups (n = 11 fed mostly on hartebeest and warthogs, followed by browsers in case of solitary males, and by grazers with high δ15N values in case of bachelor groups. Female cheetahs (n = 9 predominantly fed on browsers and used also hartebeest and warthogs. Mixing models suggested that the isotopic prey category that included cattle was only important, if at all, for males living in bachelor groups. Stable isotope analysis of fur, muscle, red blood cells and blood plasma in 9 free-ranging cheetahs identified most individuals as isotopic specialists, focussing on isotopically distinct prey categories as their food.

  10. Application of Stable Isotope-Assisted Metabolomics for Cell Metabolism Studies

    Directory of Open Access Journals (Sweden)

    Le You

    2014-03-01

    Full Text Available The applications of stable isotopes in metabolomics have facilitated the study of cell metabolisms. Stable isotope-assisted metabolomics requires: (1 properly designed tracer experiments; (2 stringent sampling and quenching protocols to minimize isotopic alternations; (3 efficient metabolite separations; (4 high resolution mass spectrometry to resolve overlapping peaks and background noises; and (5 data analysis methods and databases to decipher isotopic clusters over a broad m/z range (mass-to-charge ratio. This paper overviews mass spectrometry based techniques for precise determination of metabolites and their isotopologues. It also discusses applications of isotopic approaches to track substrate utilization, identify unknown metabolites and their chemical formulas, measure metabolite concentrations, determine putative metabolic pathways, and investigate microbial community populations and their carbon assimilation patterns. In addition, 13C-metabolite fingerprinting and metabolic models can be integrated to quantify carbon fluxes (enzyme reaction rates. The fluxome, in combination with other “omics” analyses, may give systems-level insights into regulatory mechanisms underlying gene functions. More importantly, 13C-tracer experiments significantly improve the potential of low-resolution gas chromatography-mass spectrometry (GC-MS for broad-scope metabolism studies. We foresee the isotope-assisted metabolomics to be an indispensable tool in industrial biotechnology, environmental microbiology, and medical research.

  11. Detecting intraannual dietary variability in wild mountain gorillas by stable isotope analysis of feces.

    Science.gov (United States)

    Blumenthal, Scott A; Chritz, Kendra L; Rothman, Jessica M; Cerling, Thure E

    2012-12-26

    We use stable isotope ratios in feces of wild mountain gorillas (Gorilla beringei) to test the hypothesis that diet shifts within a single year, as measured by dry mass intake, can be recovered. Isotopic separation of staple foods indicates that intraannual changes in the isotopic composition of feces reflect shifts in diet. Fruits are isotopically distinct compared with other staple foods, and peaks in fecal δ(13)C values are interpreted as periods of increased fruit feeding. Bayesian mixing model results demonstrate that, although the timing of these diet shifts match observational data, the modeled increase in proportional fruit feeding does not capture the full shift. Variation in the isotopic and nutritional composition of gorilla foods is largely independent, highlighting the difficulty for estimating nutritional intake with stable isotopes. Our results demonstrate the potential value of fecal sampling for quantifying short-term, intraindividual dietary variability in primates and other animals with high temporal resolution even when the diet is composed of C(3) plants.

  12. Application of Stable Isotope-Assisted Metabolomics for Cell Metabolism Studies

    Science.gov (United States)

    You, Le; Zhang, Baichen; Tang, Yinjie J.

    2014-01-01

    The applications of stable isotopes in metabolomics have facilitated the study of cell metabolisms. Stable isotope-assisted metabolomics requires: (1) properly designed tracer experiments; (2) stringent sampling and quenching protocols to minimize isotopic alternations; (3) efficient metabolite separations; (4) high resolution mass spectrometry to resolve overlapping peaks and background noises; and (5) data analysis methods and databases to decipher isotopic clusters over a broad m/z range (mass-to-charge ratio). This paper overviews mass spectrometry based techniques for precise determination of metabolites and their isotopologues. It also discusses applications of isotopic approaches to track substrate utilization, identify unknown metabolites and their chemical formulas, measure metabolite concentrations, determine putative metabolic pathways, and investigate microbial community populations and their carbon assimilation patterns. In addition, 13C-metabolite fingerprinting and metabolic models can be integrated to quantify carbon fluxes (enzyme reaction rates). The fluxome, in combination with other “omics” analyses, may give systems-level insights into regulatory mechanisms underlying gene functions. More importantly, 13C-tracer experiments significantly improve the potential of low-resolution gas chromatography-mass spectrometry (GC-MS) for broad-scope metabolism studies. We foresee the isotope-assisted metabolomics to be an indispensable tool in industrial biotechnology, environmental microbiology, and medical research. PMID:24957020

  13. Detecting intraannual dietary variability in wild mountain gorillas by stable isotope analysis of feces

    Science.gov (United States)

    Blumenthal, Scott A.; Chritz, Kendra L.; Rothman, Jessica M.; Cerling, Thure E.

    2012-01-01

    We use stable isotope ratios in feces of wild mountain gorillas (Gorilla beringei) to test the hypothesis that diet shifts within a single year, as measured by dry mass intake, can be recovered. Isotopic separation of staple foods indicates that intraannual changes in the isotopic composition of feces reflect shifts in diet. Fruits are isotopically distinct compared with other staple foods, and peaks in fecal δ13C values are interpreted as periods of increased fruit feeding. Bayesian mixing model results demonstrate that, although the timing of these diet shifts match observational data, the modeled increase in proportional fruit feeding does not capture the full shift. Variation in the isotopic and nutritional composition of gorilla foods is largely independent, highlighting the difficulty for estimating nutritional intake with stable isotopes. Our results demonstrate the potential value of fecal sampling for quantifying short-term, intraindividual dietary variability in primates and other animals with high temporal resolution even when the diet is composed of C3 plants. PMID:23236160

  14. Association between Nitrogen Stable Isotope Ratios in Human Hair and Serum Levels of Leptin.

    Science.gov (United States)

    Ahn, Song Vogue; Koh, Sang-Baek; Lee, Kwang-Sik; Bong, Yeon-Sik; Park, Jong-Ku

    2017-10-01

    Stable isotope ratios have been reported to be potential biomarkers of dietary intake and nutritional status. High serum levels of leptin, a hormone which regulates energy metabolism and food intake, are associated with insulin resistance and metabolic syndrome. However, little is known about the association between stable isotope ratios and the metabolic risk in humans. We investigated whether the carbon and nitrogen stable isotope ratios in hair are associated with serum leptin levels. Hair samples were collected from 399 healthy adults (233 men and 166 women) aged 40 to 70 years of a community-based cohort in Korea and the bulk stable isotope ratios of carbon (δ 13 C) and nitrogen (δ 15 N) were measured for all hair samples. Serum leptin levels were analyzed by radioimmunoassay. δ 15 N showed positive correlations with serum leptin levels. In multivariate models, increasing δ 15 N were associated with elevated serum leptin levels (defined as ≥ the median values), whereas δ 13 C were not significantly associated with serum leptin levels. The odds ratio (95% confidence interval) per 1‰ increase in δ 15 N for an elevated serum leptin level was 1.58 (1.11-2.26). In participants with high body mass index, δ 15 N showed positive associations with serum leptin levels, whereas these associations were not seen in participants with low body mass index. The nitrogen stable isotopic ratio in hair is positively associated with serum leptin levels. The hair δ 15 N could be used as a clinical marker to estimate metabolic risk.

  15. Stable isotope and high precision concentration measurements confirm that all humans produce and exhale methane.

    Science.gov (United States)

    Keppler, Frank; Schiller, Amanda; Ehehalt, Robert; Greule, Markus; Hartmann, Jan; Polag, Daniela

    2016-01-29

    Mammalian formation of methane (methanogenesis) is widely considered to occur exclusively by anaerobic microbial activity in the gastrointestinal tract. Approximately one third of humans, depending on colonization of the gut by methanogenic archaea, are considered methane producers based on the classification terminology of high and low emitters. In this study laser absorption spectroscopy was used to precisely measure concentrations and stable carbon isotope signatures of exhaled methane in breath samples from 112 volunteers with an age range from 1 to 80 years. Here we provide analytical evidence that volunteers exhaled methane levels were significantly above background (inhaled) air. Furthermore, stable carbon isotope values of the exhaled methane unambiguously confirmed that this gas was produced by all of the human subjects studied. Based on the emission and stable carbon isotope patterns of various age groups we hypothesize that next to microbial sources in the gastrointestinal tracts there might be other, as yet unidentified, processes involved in methane formation supporting the idea that humans might also produce methane endogenously in cells. Finally we suggest that stable isotope measurements of volatile organic compounds such as methane might become a useful tool in future medical research diagnostic programs.

  16. Stable isotope paleoaltimetry and the evolution of landscapes and life

    Science.gov (United States)

    Mulch, Andreas

    2016-01-01

    Reconstructing topography of our planet not only advances our knowledge of the geodynamic processes that shape the Earth's surface; equally important it adds a key element towards understanding long-term continental moisture transport, atmospheric circulation and the distribution of biomes and biodiversity. Stable isotope paleoaltimetry exploits systematic decreases in the oxygen (δ18O) or hydrogen (δD) isotopic composition of precipitation along a mountain front when the interaction of topography and advected moist air masses induces orographic precipitation. These changes in δ18O or δD can be recovered from the geologic record and recent geochemical and modeling advances allow a broad range of proxy materials to be evaluated. Over the last 10 yr stable isotope paleoaltimetry has witnessed rapidly expanding research activities and has produced a broad array of fascinating tectonic and geomorphologic studies many of which have concentrated on determining the elevation history of continental plateau regions. These single-site studies have greatly expanded what used to be very sparse global paleoaltimetric data. The challenge now lies in disentangling the surface uplift component from the impact of climate change on δ18O and δD in precipitation. The robustness of stable isotope paleoaltimetry can be enhanced when high-elevation δ18O or δD data are referenced against low-elevation sites that track climate-modulated sea level δ18O or δD of precipitation through time (' δ- δ approach'). Analysis of central Andean paleosols documents that differences in δ18O of soil carbonate between the Subandean foreland and the Bolivian Altiplano are small between 11 and 7 Ma but rise rapidly to ca. 2.9‰ after 7 Ma, corroborating the magnitude of late Miocene change in δ18O on the Altiplano. Future advances in stable isotope paleoaltimetry will greatly benefit from addressing four key challenges: (1) Identifying topographically-induced changes in atmospheric

  17. High-Temperature Equilibrium Isotope Fractionation of Non-Traditional Stable Isotopes: Experiments, Theory, and Applications (Invited)

    Science.gov (United States)

    Young, E. D.; Lazar, G. C.; Macris, C. A.; Manning, C. E.; Schauble, E. A.; Shahar, A.

    2013-12-01

    Experiments are crucial for validating our understanding of stable isotope fractionation at high temperatures. The three-isotope method has been applied with success in the Si, Mg, Fe, and Ni isotope systems to date. The results of these experiments can be compared with expectations from theory and measurements of natural samples. Qualitative insights into the partitioning of heavy and light isotopes between mineral phases are gained by treating the force constant for relevant bonds, Kf j, as electrostatic in origin. The ionic model, based on the mean bond strength as defined by Pauling, has obvious limitations but is useful for rationalizing structures and site occupancies in silicates and oxide minerals and is equally useful in formulating expectations for isotope fractionation between phases. In some cases, as in Fe isotopes in spinels, the expectations are contrary to predictions based on modeling but similar to observations in natural samples. Experimental verification is required. The force constant for a bond between cation i (Mg, Fe, etc.) and anion j (e.g., O) can be written in terms of mean bond strengths si and sj (as defined by Pauling) as Kf,ij = sisj e2 (1-n)/(4 π ɛο r3ij ) where ɛo is the electric constant (vacuum permittivity for simplicity), e is the charge of an electron, n is the exponent in the Born-Mayer formulation for ion repulsion (Born and Mayer 1932), and rij is the interatomic spacing. This equation shows explicitly that larger values for the force constant Kf correspond to smaller coordination numbers (via si and sj). We therefore expect an inverse relationship between isotope ratios (heavy/light) and coordination of its oxygen bond partners in silicate and oxides minerals and this is verified in mantle minerals. Our work with Fe isotope partitioning in mantle spinels suggests that coordination may be equally important as oxidation state, recognizing that these distinctions are not orthogonal. Recent work on the Mg isotopic

  18. Stable isotope composition of atmospheric carbon monoxide. A modelling study

    International Nuclear Information System (INIS)

    Gromov, Sergey S.

    2014-01-01

    This study aims at an improved understanding of the stable carbon and oxygen isotope composition of the carbon monoxide (CO) in the global atmosphere by means of numerical simulations. At first, a new kinetic chemistry tagging technique for the most complete parameterisation of isotope effects has been introduced into the Modular Earth Submodel System (MESSy) framework. Incorporated into the ECHAM/MESSy Atmospheric Chemistry (EMAC) general circulation model, an explicit treatment of the isotope effects on the global scale is now possible. The expanded model system has been applied to simulate the chemical system containing up to five isotopologues of all carbon- and oxygen-bearing species, which ultimately determine the δ 13 C, δ 18 O and Δ 17 O isotopic signatures of atmospheric CO. As model input, a new stable isotope-inclusive emission inventory for the relevant trace gases has been compiled. The uncertainties of the emission estimates and of the resulting simulated mixing and isotope ratios have been analysed. The simulated CO mixing and stable isotope ratios have been compared to in-situ measurements from ground-based observatories and from the civil-aircraft-mounted CARIBIC-1 measurement platform. The systematically underestimated 13 CO/ 12 CO ratios of earlier, simplified modelling studies can now be partly explained. The EMAC simulations do not support the inferences of those studies, which suggest for CO a reduced input of the highly depleted in 13 C methane oxidation source. In particular, a high average yield of 0.94 CO per reacted methane (CH 4 ) molecule is simulated in the troposphere, to a large extent due to the competition between the deposition and convective transport processes affecting the CH 4 to CO reaction chain intermediates. None of the other factors, assumed or disregarded in previous studies, however hypothesised to have the potential in enriching tropospheric CO in 13 C, were found significant when explicitly simulated. The

  19. Interactions between surface waters in King George Island, Antarctica - a stable isotope perspective

    Science.gov (United States)

    Perşoiu, Aurel; Bădăluşă, Carmen

    2017-04-01

    In this paper we present a first study of the isotopic composition of surface waters in the southern peninsulas (Barton, Fildes, Weaver and Potter) of King George Island, Antarctica. We have collected > 200 samples of snow and snowmelt, water (lake, river and spring), ice (glacier ice and permafrost) from the four peninsulas in February 2016 and analyzed them for their oxygen and hydrogen stable isotopic composition. Samples from lake water (50+) indicate a clear west-east depletion trend, suggesting a rain-out process as air masses are moving westward (and are progressively depleted in heavy isotopes) from their origin in the Drake Passage. In both Fildes and Barton Peninsulas, permafrost samples have the heaviest isotopic composition, most probably due to preferential incorporation of heavy isotopes in the ice during freezing (and no fractionation during melting). As permafrost melts, the resulting water mixes with isotopically lighter infiltrated snowmelt, and thus the groundwater has a lower isotopic composition. Further, lake and river (the later fed by lakes) water has the lightest isotopic composition, being derived mostly from the melting of light snow and glacier ice. It seems feasible to separate isotopically water in lakes/rivers (largely fed by melting multi-year glaciers and snow) and water from melting of snow/ground ice This preliminary study suggests that it is possible to separate various water sources in the southern peninsulas of King George Island, and this separation could be used to study permafrost degradation, as well as feeding and migration patterns in the bird fauna, with implications for protection purposes. Acknowledgments. The National Institute of Research and Development for Biological Sciences (Bucharest, Romania) and the Korean polar institute financially supported fieldwork in King George Island. We thank the personal at King Sejong (South Korea), Belingshaussen (Russia) and Carlini (Argentina) stations in King George Island for

  20. Stable isotope ratiometer-multiple ion detector (SIRMID) unit for quantitative and qualitative stable isotope studies by gas chromatography-mass spectrometry

    International Nuclear Information System (INIS)

    Klein, P.D.; Haumann, J.R.; Hachey, D.L.

    1975-01-01

    A stable isotope ratiometer-multiple ion detector (SIRMID) unit which can drive existing gas chromatograph-quadrupole or magnetic sector mass spectrometers to monitor up to six ions in turn is described. Each of the three pairs of ions can be selected for quantitation; thus three different or successive components can be analyzed in a single GC run. A background subtraction option permits the ion intensity in the absence of sample to be subtracted automatically during sample measurement. Displays of accumulated counts and isotope ratio are updated twice per second during the measurement and can be printed out at its conclusion. All six ions can be monitored in the analog mode by parallel outputs to a multipen recorder. Experience gained in the construction of this prototype indicates that SIRMID units could be commercially available for $10K, or about 1 / 3 rd to 1 / 6 th of the cost of even an inexpensive computer system. (U.S.)

  1. Environmental controls on stable isotopes of precipitation in Lanzhou, China: An enhanced network at city scale.

    Science.gov (United States)

    Chen, Fenli; Zhang, Mingjun; Wang, Shengjie; Qiu, Xue; Du, Mingxia

    2017-12-31

    Stable hydrogen and oxygen isotopes in precipitation are very sensitive to environmental changes, and can record evolution of water cycle. The Lanzhou city in northwestern China is jointly influenced by the monsoon and westerlies, which is considered as a vital platform to investigate the moisture regime for this region. Since 2011, an observation network of stable isotopes in precipitation was established across the city, and four stations were included in the network. In 2013, six more sampling stations were added, and the enhanced network might provide more meaningful information on spatial incoherence and synoptic process. This study focused on the variations of stable isotopes (δ 18 O and δD) in precipitation and the environmental controls based on the 1432 samples in this enhanced network from April 2011 to October 2014. The results showed that the precipitation isotopes had great spatial diversity, and the neighboring stations may present large difference in δD and δ 18 O. Based on the observation at ten sampling sites, an isoscape in precipitation was calculated, and the method is useful to produce isoscape for small domains. The temperature effect and amount effect was reconsidered based on the dataset. Taking meteorological parameters (temperature, precipitation amount, relative humidity, water vapor pressure and dew point temperature) as variables in a multi-linear regression, the result of coefficients for these meteorological parameters were calculated. Some cases were also involved in this study, and the isotopic characteristics during one event or continuous days were used to understand the environmental controls on precipitation isotopes. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Characterising the stable δ88/86Sr isotopic composition in rainwater, southwestern Taiwan

    Science.gov (United States)

    Chao, Hung-Chun; Hsiao, Cheng-Hung; You, Chen-Feng; Huang, Chun-Chang; Chung, Chuan-Hsiung

    2017-04-01

    Radiogenic and stable Sr isotopes provide important information on chemical wreathing. However, our knowledge on the characteristic of stable Sr isotopes of rainwater, the major source of river water, is limited. More than 300 rainwater samples were collected manually and their major, trace elements, δD, δ18O, 87Sr/86Sr, and δ88Sr were determined. Two major moisture sources are differentiated based on the seasons and d-excess value, namely polar continental air mass (Pc; winter) and equatorial maritime air mass (Em; summer). The stable Sr isotopes show large variations (0.10 to 0.39 ‰) compared to other studied materials such as rocks, river water, seawater, carbonates and so on. Pc has δ88Sr distributed between 0.10 and 0.29 ‰, distinguishable and slightly lower than Em, which is distributed between 0.18 and 0.39 ‰. The δ88Sr values of Pc samples show moderate correlations with δD, δ18O, 87Sr/86Sr, Na/Sr ratio, and Sr concentration. On the other hand, Em samples show no correlation with those factors. In summary, Em samples may be contributed by sea-salt and various local signals while Pc samples show stronger lithological signal which is contributed by long range transport dusts.

  3. Stable isotopes applied in life sciences in UNESP - Botucatu campus, SP, Brazil

    International Nuclear Information System (INIS)

    Costa, Vladimir E.; Denadai, Juliana C.; Sartori, Maria M.P.; Ducatti, Carlos

    2013-01-01

    Universities and research centers that use stable isotopes follow a worldwide trend in owning laboratories isotope ratio that serves multiple users, as well as minimize maintenance costs, operation and staff training. For this purpose it was created in 1998, the Center Stable Isotopes 'Centro de Isotopos Estaveis' - CIE, which is an auxiliary unit linked to the Institute of Biosciences (IB) of the Sao Paulo State University - UNESP Botucatu Campus, Brazil. The best way to CIE grow and achieve excellence are already disclose the methodologies employed and practice areas consolidated to find new partnerships with different applications, and also seek new methods of analysis that can expand areas. The aim of this study is to disseminate methodologies for analysis of isotope ratio and areas of the CIE. The CIE analyzes the isotopic ratios 13 C/ 12 C, 15 N/ 14 N, 2 H/ 1 H and 18 O/ 16 O (CHON), and for the carbon samples can be solid, liquid and gas (in the form of CO 2 ) for the other elements is only possible to analyze in solid or liquid form. All samples are always analyzed separately by the destructive method. The CIE addition to performing scientific partnerships with all university, complementary and auxiliaries units of UNESP Botucatu campus also have partnerships in other academic units on campus of UNESP Jaboticabal and Dracena and Sao Paulo University in Piracicaba campus and is open to new partnerships in other research units. (author)

  4. Contribution of stable isotopes to the study of pharmacokinetics of magnesium salts; Apport des isotopes stables a l'etude de la pharmacocinetique de sels de magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Benech, H

    1999-05-28

    The use of stable isotopes as labels is becoming an attractive tool for the study of magnesium behavior in humans. It has been used two stable isotopes of magnesium, {sup 25}Mg and {sup 26}Mg, to measure the absolute bioavailability of a pharmaceutical form of magnesium. (N.C.)

  5. Reassessing the stable water isotope record in understanding past climate

    International Nuclear Information System (INIS)

    Noone, D.; Simmonds, I.

    1999-01-01

    Full text: The impact of atmospheric circulation on the stable water isotope record has been examined using an atmospheric general circulation model to reassess the validity of using isotopes to reconstruct Earth's climate history. Global temperature changes are classically estimated from the variations in (polar) isotopic values assuming a simple linear relationship. Such a relationship can be justified from first order theoretical considerations given that the isotopic fractionation at the deposition (ice core) site is temperature dependent. However, it is found that the history of a given air mass is more important that local processes because of the net effect of condensation events active along the transport pathway from the source region. Modulations in the hemispheric flow are seen to be crucial to Antarctic precipitation and the isotopic signal. Similarly, both transient and stationary disturbances influence the pathways of the air masses associated with Antarctic precipitation. During different climate regimes, such as that of the Last Glacial Maximum, the properties of these types of disturbances may not be assumed to be the same. As such, we may not assume that the condensation histories are the same as under different climate conditions. Therefore, the veracity of the linear climate reconstructions becomes questionable. Notwithstanding this result, the types of changes to the circulation regime that are expected generally correspond to changes in the global temperature. This fortunate result does not disallow the use of regressional reconstruction, however, the uncertainties associated with these circulation changes are of the same magnitude as the differences suggested by conventional linear regression in climate reconstruction. This indicates that interpretation of ice core data must be accompanied by detailed examination of the atmospheric processes and quantification of the impacts of their changes. Copyright (1999) Geological Society of Australia

  6. Issues and opportunities in accelerator mass spectrometry for stable isotopes.

    Science.gov (United States)

    Matteson, Sam

    2008-01-01

    Accelerator mass spectrometry (AMS) has developed in the last 30 years many notable applications to the spectrometry of radioisotopes, particularly in radiocarbon dating. The instrumentation science of trace element AMS (TEAMS) that analyzes stable isotopes, also called Accelerator SIMS or MegaSIMS, while unique in many features, has also shared in many of these significant advances and has pushed TEAMS sensitivity to concentration levels surpassing many competing mass spectroscopic technologies. This review examines recent instrumentation developments, the capabilities of the new instrumentation and discernable trends for future development. Copyright 2008 Wiley Periodicals, Inc.

  7. Zinc absorption study using an enriched stable isotope (70Zn)

    International Nuclear Information System (INIS)

    Li Gongpan.

    1990-04-01

    A weaning food from fermented soybean was prepared for increasing the bioavailability of zinc. The zinc absorption was compared with that of a weaning food from non-fermented soybean and normal staple food. A stable isotope tracer technique ( 70 Zn) and neutron activation were used for determining the absorption of zinc. Nine children aged 7 to 18 months were tested. Zinc bioavailability of weaning food from fermented soybean is higher than that of normal weaning food. The weight increment and zinc nutrition of children having weaning food from fermented soybean are improved by this diet. 5 tabs

  8. Stable isotopes. Enriched wheat: a new chance for nutrition research

    International Nuclear Information System (INIS)

    Chagvardieff, P.

    1996-01-01

    The Department of Plant Eco-physiology (DEV) from the CEA/Life Sciences Department of Cadarache (France) has artificially produced two kg of carbon 13 labelled wheat for nutrition research. It is the first successful stable isotope labelling of complex nutriments with a 10% enrichment in carbon 13. This wheat has been used for the manufacturing of pastas to follow the assimilation of nutrients by the organism. This short paper gives some details about the experimental procedure of labelled wheat cultivation. (J.S.)

  9. Isotope dilution analysis of environmental samples

    International Nuclear Information System (INIS)

    Tolgyessy, J.; Lesny, J.; Korenova, Z.; Klas, J.; Klehr, E.H.

    1986-01-01

    Isotope dilution analysis has been used for the determination of several trace elements - especially metals - in a variety of environmental samples, including aerosols, water, soils, biological materials and geological materials. Variations of the basic concept include classical IDA, substoichiometric IDA, and more recently, sub-superequivalence IDA. Each variation has its advantages and limitations. A periodic chart has been used to identify those elements which have been measured in environmental samples using one or more of these methods. (author)

  10. Stable isotope ratio measurements in atmospheric sulfate studies

    Energy Technology Data Exchange (ETDEWEB)

    Cunningham, P.T.; Holt, B.D.

    1976-01-01

    The isotopic composition of atmospheric sulfate has been determined by a number of workers and the results interpreted in terms of contributing sources and mechanisms of origin. A correlation between the /sup 18/O enrichment of atmospheric water and airborne particulate sulfate has been observed. Laboratory preparations of sulfate made from sulfur dioxide by two sets of sequential reactions, hydrolysis followed by oxidation and oxidation followed by hydrolysis, yielded products of distinguishable oxygen-isotope composition. Oxygen isotopic analysis of simultaneously collected field samples of ambient sulfate, sulfur dioxide, and water vapor indicated seasonal trends for all of the major constituents of atmospheric sulfation processes. Some isotopic data were also obtained on precipitation and precipitation sulfates. Field results suggest that ambient sulfates collected in the area of Argonne correpond more closely in oxygen isotope composition to a sulfate molecule containing two oxygens originating from sulfur dioxide, one oxygen from air and one oxygen from condensed-phased atmospheric water, SO/sub s/O/sub s/O/sub cw/O/sup 2 -//sub a/, than to the molecule SO/sub s/O/sub s/O/sub wv/O/sup 2//sub a/ in which one oxygen originates from vapor-phase atmospheric water.

  11. Stable isotope ratio measurements in atmospheric sulfate studies

    International Nuclear Information System (INIS)

    Cunningham, P.T.; Holt, B.D.

    1976-01-01

    The isotopic composition of atmospheric sulfate has been determined by a number of workers and the results interpreted in terms of contributing sources and mechanisms of origin. A correlation between the 18 O enrichment of atmospheric water and airborne particulate sulfate has been observed. Laboratory preparations of sulfate made from sulfur dioxide by two sets of sequential reactions, hydrolysis followed by oxidation and oxidation followed by hydrolysis, yielded products of distinguishable oxygen-isotope composition. Oxygen isotopic analysis of simultaneously collected field samples of ambient sulfate, sulfur dioxide, and water vapor indicated seasonal trends for all of the major constituents of atmospheric sulfation processes. Some isotopic data were also obtained on precipitation and precipitation sulfates. Field results suggest that ambient sulfates collected in the area of Argonne correpond more closely in oxygen isotope composition to a sulfate molecule containing two oxygens originating from sulfur dioxide, one oxygen from air and one oxygen from condensed-phased atmospheric water, SO/sub s/O/sub s/O/sub cw/O 2- /sub a/, than to the molecule SO/sub s/O/sub s/O/sub wv/O 2 /sub a/ in which one oxygen originates from vapor-phase atmospheric water

  12. The use of carbon stable isotope ratios in drugs characterization

    Energy Technology Data Exchange (ETDEWEB)

    Magdas, D. A., E-mail: gabriela.cristea@itim-cj.ro; Cristea, G., E-mail: gabriela.cristea@itim-cj.ro; Bot, A., E-mail: gabriela.cristea@itim-cj.ro; Mirel, V., E-mail: gabriela.cristea@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 65-103 Donath Str., 400293 Cluj-Napoca (Romania)

    2013-11-13

    Isotopic Ratio Mass Spectrometry (IRMS) is an effective toll to be used for drug product authentication. The isotopic composition could be used to assist in the differentiation between batches of drugs and assist in the identification of counterfeit materials on the market. Only two factors affect the isotopic ratios in pharmaceutical components: the isotopic composition of the raw materials and the synthetic processes performed upon them. Counterfeiting of pharmaceutical drugs threatens consumer confidence in drug products companies' economical well-being. In this preliminary study, the analyzed samples consist in two types of commercially available analgesics, which were purchases from Romanian pharmacies. Differences in δ{sup 13}C between batches from −29.7 to −31.6% were observed, demonstrating that this method can be used to differentiate among individual drug batches and subsequently identify counterfeits on the market. On the other hand, carbon isotopic ratios differences among producers were recorded, the variations being between −31.3 to −34.9% for the same type of analgesic, but from different manufactures.

  13. The use of carbon stable isotope ratios in drugs characterization

    International Nuclear Information System (INIS)

    Magdas, D. A.; Cristea, G.; Bot, A.; Mirel, V.

    2013-01-01

    Isotopic Ratio Mass Spectrometry (IRMS) is an effective toll to be used for drug product authentication. The isotopic composition could be used to assist in the differentiation between batches of drugs and assist in the identification of counterfeit materials on the market. Only two factors affect the isotopic ratios in pharmaceutical components: the isotopic composition of the raw materials and the synthetic processes performed upon them. Counterfeiting of pharmaceutical drugs threatens consumer confidence in drug products companies' economical well-being. In this preliminary study, the analyzed samples consist in two types of commercially available analgesics, which were purchases from Romanian pharmacies. Differences in δ 13 C between batches from −29.7 to −31.6% were observed, demonstrating that this method can be used to differentiate among individual drug batches and subsequently identify counterfeits on the market. On the other hand, carbon isotopic ratios differences among producers were recorded, the variations being between −31.3 to −34.9% for the same type of analgesic, but from different manufactures

  14. High-precision mass spectrometric analysis using stable isotopes in studies of children.

    Science.gov (United States)

    Schierbeek, Henk; van den Akker, Chris H P; Fay, Laurent B; van Goudoever, Johannes B

    2012-01-01

    The use of stable isotopes combined with mass spectrometry (MS) provides insight into metabolic processes within the body. Herein, an overview on the relevance of stable isotope methodology in pediatric research is presented. Applications for the use of stable isotopes with MS cover carbohydrate, fat, and amino acid metabolism as well as body composition, energy expenditure, and the synthesis of specific peptides and proteins, such as glutathione and albumin. The main focus of these studies is on the interactions between nutrients and the endogenous metabolism within the body and how these factors affect the health of a growing infant. Considering that the early imprinting of metabolic processes hugely impacts metabolism (and thus functional outcome) later in life, research in this area is important and is advancing rapidly. The major fluxes on a metabolic level are the synthesis and breakdown rates. They can be quantified using kinetic tracer analysis and mathematical modeling. Organic MS and isotope ratio mass spectrometry (IRMS) are the two most mature techniques for the isotopic analysis of compounds. Introduction of the samples is usually done by coupling gas chromatography (GC) to either IRMS or MS because it is the most robust technique for specific isotopic analysis of volatile compounds. In addition, liquid chromatography (LC) is now being used more often as a tool for sample introduction of both volatile and non-volatile compounds into IRMS or MS for (13)C isotopic analyses at natural abundances and for (13)C-labeled enriched compounds. The availability of samples is often limited in pediatric patients. Therefore, sample size restriction is important when developing new methods. Also, the availability of stable isotope-labeled substrates is necessary for measurements of the kinetics and concentrations in metabolic studies, which can be a limiting factor. During the last decade, the availability of these substrates has increased. Furthermore, improvements

  15. Stable isotope variations in benthic primary producers along the Bosphorus (Turkey): A preliminary study

    International Nuclear Information System (INIS)

    Calizza, Edoardo; Aktan, Yelda; Costantini, Maria Letizia; Rossi, Loreto

    2015-01-01

    Highlights: • Nitrogen pollution along the Bosphorus Strait was investigated. • C and N isotopic and elemental analyses on benthic primary producers were performed. • δ 15 N decreased, while δ 13 C and N% increased from north to south along the Strait. • Ulva lactuca was more useful than epiphytes as indicator of nitrogen pollution. • Preliminary isotopic analyses on resident organisms are useful monitoring tools. - Abstract: The Bosphorus Strait is a dynamic and complex system. Recent evidences showed nitrogen and heavy metal concentrations to follow opposite patterns across the Strait, suggesting a complex spatial organisation of the anthropogenic disturbance in this system. Here, we provide isotopic information on the origin and transportation of dissolved nitrogen along the Bosphorus. C and N isotopic and elemental analyses were performed on specimens of Ulva lactuca and associated epiphytes sampled in five locations across the Strait. Variations in C and N isotopic signatures were observed in U. lactuca, pointing to a decrease in the availability of anthropogenic organic dissolved nitrogen along a north-south direction. Conversely, epiphytes did not show isotopic or elemental patterns across the Strait. These results suggest that preliminary stable isotope surveys in extended costal systems basing on U. lactuca can represent a valuable tool to focus meaningful targets and hypotheses for pollution studies in the Mediterranean region

  16. The use of stable isotopes in quantitative determinations of exogenous water and added ethanol in wines

    Science.gov (United States)

    Magdas, D. A.; Moldovan, Z.; Cristea, G.

    2012-02-01

    The application of oxygen isotope ratios analysis to wine water according to EU regulation no. 822/97 to determine wine's origin and also, the possible water addition to wines, gained great importance in wines authenticity control. In the natural cycle of water isotopic fractionation, during water evaporation process, the water vapors are depleted in heavy isotopes. On the other hand inside the plants take place an isotope enrichment of heavy stable isotopes of water compared with meteoric water due to photosynthesis and plants transpiration. This process makes possible the detection of exogenous water from wines 18O/16O ratios. Carbon isotopic ratios were used to estimate the supplementary addition of ethanol obtained from C4 plants (sugar cane or corn). This work presents the way in which the isotopic fingerprints (δ13C and δ18O) were used to determine the content of exogenous water from wines and the added supplementary ethanol coming from C4 plants. By using this method, the calculated values obtained for the degree of wine adulteration were in a good agreement with the real exogenous percent of water and ethanol from investigated samples.

  17. A stable isotope approach for the quantification of sewer infiltration.

    Science.gov (United States)

    Kracht, Oliver; Gresch, Markus; Gujert, Willi

    2007-08-15

    Extraneous flows in wastewater collection systems are conventionally evaluated solely on the consideration of discharge hydrographs, which often involves a great degree of subjectivity and oversimplification. To obtain reliable information on the material fluxes within the urban environment, the use of intrinsic tracers can be the optimal choice. We demonstrate the successful use of naturally occurring stable isotopes of water (18O/16O and D/H) to accurately quantify extraneous discharge of groundwater in a combined sewer network. Fresh water supply from a distant hydrological regime provided usable isotopic separations between drinking water (proxy for real foul sewage) and local groundwater (proxy for sewer infiltration) of 1.8 per thousand in delta18O and 11.7 per thousand in 62H. Diurnal variation of wastewater isotopic composition reflected both the varying rates of foul sewage production and irregular dispersion effects in the pipe network. The latter suggest the existence of larger cumulative backwater zone volumes, which have not been attended to yet. Infiltrating groundwater contributed 39% (95% confidence interval = +/- 2.5%) of the total daily dry weather wastewater discharge. This paper discusses all relevant aspects for practical application of the method. It presents a comprehensive framework for uncertainty analysis and details on the detection and discrimination of possibly interfering effects.

  18. New Organic Stable Isotope Reference Materials for Distribution through the USGS and the IAEA

    Science.gov (United States)

    Schimmelmann, Arndt; Qi, Haiping

    2014-05-01

    The widespread adoption of relative stable isotope-ratio measurements in organic matter by diverse scientific disciplines is at odds with the dearth of international organic stable isotopic reference materials (RMs). Only two of the few carbon (C) and nitrogen (N) organic RMs, namely L-glutamic acids USGS40 and USGS41 [1], both available from the U.S. Geological Survey (USGS) and the International Atomic Energy Agency (IAEA), provide an isotopically contrasting pair of organic RMs to enable essential 2-point calibrations for δ-scale normalization [2, 3]. The supply of hydrogen (H) organic RMs is even more limited. Numerous stable isotope laboratories have resorted to questionable practices, for example by using 'CO2, N2, and H2 reference gas pulses' for isotopic calibrations, which violates the principle of identical treatment of sample and standard (i.e., organic unknowns should be calibrated directly against chemically similar organic RMs) [4], or by using only 1 anchor instead of 2 for scale calibration. The absence of international organic RMs frequently serves as an excuse for indefensible calibrations. In 2011, the U.S. National Science Foundation (NSF) funded an initiative of 10 laboratories from 7 countries to jointly develop much needed new organic RMs for future distribution by the USGS and the IAEA. The selection of targeted RMs attempts to cover various common compound classes of broad technical and scientific interest. We had to accept compromises to approach the ideal of high chemical stability, lack of toxicity, and low price of raw materials. Hazardous gases and flammable liquids were avoided in order to facilitate international shipping of future RMs. With the exception of polyethylene and vacuum pump oil, all organic RMs are individual, chemically-pure substances, which can be used for compound-specific isotopic measurements in conjunction with liquid and gas chromatographic interfaces. The compounds listed below are under isotopic calibration by

  19. Biosynthesis of stable isotope 15N labeled spirulina

    International Nuclear Information System (INIS)

    Ren Zheng; Du Xiaoning; Hou Jinghua; Zhang Jingmei

    2010-01-01

    The spirulina is a phototrophic organism. It was considered as the best of nutritional health product. The nitrogen atoms of spirulina was replaced with 15 N stable isotope by the method of biosynthesis. So 15 N labeled spirulina is a nutritional health product and stable isotope tracer product. As a tracer, 15 N labeled spirulina plays an irreplaceable part in bioscience, medicine metabolism and pathology metabolism and so on. 15 N label spirulina is cultivated only in a small scale because of expensive 15 N material. The culture temperature, shine intensity, pH for spirulina were studied. Some feasible conditions were obtained such as 25℃, 3000-4000 lux, initial pH9.0 in the room. 15 N label spirulin prescription was obtained via orthogonal experiment. The optimize prescription of spirulina was that sodium bicarbonate was 13 g · L-1, 15 N-urea was 0.2 g · L -1 , potassium phosphate dibasic was 0.6 g · L -1 , and glucose was 2 g · L -1 . The cost of 15 N material has a significant reduction. The abundance was more than 98%. (authors)

  20. Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric particulate matter

    Directory of Open Access Journals (Sweden)

    S. Moukhtar

    2011-11-01

    Full Text Available A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter is presented. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. Particulate matter was collected on quartz fibre filters using dichotomous high volume air samplers. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography and solid phase extraction. The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyltrifluoroacetamide, was added for Gas Chromatography-Mass Spectrometry analysis. The second half of the sample was stored in a refrigerator. For samples with concentrations exceeding 1 ng μl−1, the second half of the sample was used for measurement of stable carbon isotope ratios by Gas Chromatography-Isotope Ratio Mass Spectrometry.

    The procedure described in this paper provides a method for the analysis of methylnitrophenols in atmospheric particulate matter at concentrations as low as 0.3 pg m−3 and for stable isotope ratios with an accuracy of better than ±0.5‰ for concentrations exceeding 100 pg m−3.

    In all atmospheric particulate matter samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol, with concentrations ranging from the low pg m−3 range in rural areas to more than 200 pg m−3 in some samples from a suburban location.

  1. Reconstruction of trophic pathways between plankton and the North Iberian sardine (Sardina pilchardus using stable isotopes

    Directory of Open Access Journals (Sweden)

    Antonio Bode

    2004-03-01

    Full Text Available Feeding on phyto- and zooplankton by juvenile (< 1 year old and adult sardines (Sardina pilchardus was inferred from analyses of natural abundance of stable carbon and nitrogen isotopes in samples from the northwestern Iberian Peninsula (Spain collected at the beginning of the upwelling season and peak spawning period of sardine. Plankton samples were fractionated through nets of 20, 200, 500, 1000 and 2000 ?m mesh-size and the muscle protein of individual sardines was isolated before isotopic determinations. Up to six planktonic components and two sardine feeding types were identified from the modes in the frequency distributions of isotope abundance values. Also, the most probable pathways for carbon and nitrogen flows between compartments were analysed. The resulting food web revealed a relatively large degree of omnivory, both in plankton and sardine components, which confirms that complex trophic interactions could also occur in pelagic upwelling ecosystems. Young sardines had isotope abundance values clustered around a single mode in the frequency distribution, while adult sardines displayed two main modes. These modes are interpreted as representative of two extreme feeding types: one related to the individual capture of zooplankton prey and the other to unselective filter-feeding. Although both types of feeding could include micro- (20-200 ?m and mesozooplankton (200-2000 ?m prey, phytoplankton appears to be ingested mainly by filter-feeding. However, even adult sardines must be mainly zoophagous to achieve the observed isotopic abundance values, taking into account current assumptions on stable isotope enrichment through trophic levels. From the differences in the resulting pathways using either carbon or nitrogen isotopes, we interpreted that sardines acquire most of the protein nitrogen from zooplankton while a substantial fraction of their carbon would derive from phytoplankton. These interpretations agree with the information

  2. Stable isotopes in juvenile marine fishes and their invertebrate prey from the Thames Estuary, UK, and adjacent coastal regions

    Science.gov (United States)

    Leakey, Chris D. B.; Attrill, Martin J.; Jennings, Simon; Fitzsimons, Mark F.

    2008-04-01

    Estuaries are regarded as valuable nursery habitats for many commercially important marine fishes, potentially providing a thermal resource, refuge from predators and a source of abundant prey. Stable isotope analysis may be used to assess relative resource use from isotopically distinct sources. This study comprised two major components: (1) development of a spatial map and discriminant function model of stable isotope variation in selected invertebrate groups inhabiting the Thames Estuary and adjacent coastal regions; and (2) analysis of stable isotope signatures of juvenile bass ( Dicentrarchus labrax), sole ( Solea solea) and whiting ( Merlangius merlangus) for assessment of resource use and feeding strategies. The data were also used to consider anthropogenic enrichment of the estuary and potential energetic benefits of feeding in estuarine nursery habitat. Analysis of carbon (δ 13C), nitrogen (δ 15N) and sulphur (δ 34S) isotope data identified significant differences in the 'baseline' isotopic signatures between estuarine and coastal invertebrates, and discriminant function analysis allowed samples to be re-classified to estuarine and coastal regions with 98.8% accuracy. Using invertebrate signatures as source indicators, stable isotope data classified juvenile fishes to the region in which they fed. Feeding signals appear to reflect physiological (freshwater tolerance) and functional (mobility) differences between species. Juvenile sole were found to exist as two isotopically-discrete sub-populations, with no evidence of mixing between the two. An apparent energetic benefit of estuarine feeding was only found for sole.

  3. Stable isotope ratios of marijuana. I. Carbon and nitrogen stable isotopes describe growth conditions.

    Science.gov (United States)

    West, Jason B; Hurley, Janet M; Ehleringer, James R

    2009-01-01

    There remains significant uncertainty in illicit marijuana cultivation. We analyzed the delta(13)C and delta(15)N of 508 domestic samples from known U.S.A. counties, 31 seized from a single location, 5 samples grown in Mexico and Colombia, and 10 northwest border seizures. For a subset, inflorescences and leaves were analyzed separately. These data revealed a strong correspondence, with inflorescences having slightly higher delta(13)C and delta(15)N values than leaves. A framework for interpreting these results is introduced and evaluated. Samples identified as outdoor-grown by delta(13)C were generally recorded as such by the Drug Enforcement Administration (DEA). DEA-classified indoor-grown samples had the most negative delta(13)C values, consistent with indoor cultivation, although many were also in the outdoor-grown domain. Delta(15)N indicated a wide range of fertilizers across the dataset. Samples seized at the single location suggested multiple sources. Northwest border delta(13)C values suggested indoor growth, whereas for the Mexican and Colombian samples they indicated outdoor growth.

  4. Stable Isotope Analyses of water and Aqueous Solutions by Conventional Dual-inlet Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Horita, Juske [ORNL; Kendall, C. [U.S. Geological Survey, Menlo Park, CA

    2004-01-01

    The foundation of various analytical methods for the stable isotope composition of water and other aqueous samples (natural abundance, {sup 1}H : {sup 2}H (D) = 99.985 : 0.015 atom%, and {sup 16}O : {sup 17}O : {sup 18}O = 99.762 : 0.038 : 0.200 atom%) was established during the Manhatten Project in the U.S.A., when large amounts of heavy water were produced for nuclear reactors (see Kirshenbaum, 1951, for a detailed account). From early on, there was great interest in the oxygen and hydrogen isotopic compositions of water, because they are the ideal tracers of water sources and reactions. The increased analytical precisions made possible by the subsequent development of modern gas-source isotope-ratio mass spectrometers with dual-inlets and multi-collectors, have caused the proliferation of new analytical methods and applications for the oxygen and hydrogen isotopic compositions of water. These stable isotopes have found wide applications in basic as well as applied sciences (chemistry, geology, hydrology, biology, medical sciences, and food sciences). This is because water is ubiquitous, is an essential and predominant ingredient of living organisms, and is perhaps the most reactive compound in the Earth.

  5. Trophic discrimination factors of stable carbon and nitrogen isotopes in hair of corn fed wild boar.

    Directory of Open Access Journals (Sweden)

    Michaela Holá

    Full Text Available Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology of many wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet. Although trophic discrimination factors are tissue- and species-specific, researchers often rely on generalized, and fixed trophic discrimination factors that have not been experimentally derived. In this experimental study, captive wild boar (Sus scrofa were fed a controlled diet of corn (Zea mays, a popular and increasingly dominant food source for wild boar in the Czech Republic and elsewhere in Europe, and trophic discrimination factors for stable carbon (Δ13C and nitrogen (Δ15N isotopes were determined from hair samples. The mean Δ13C and Δ15N in wild boar hair were -2.3‰ and +3.5‰, respectively. Also, in order to facilitate future derivations of isotopic measurements along wild boar hair, we calculated the average hair growth rate to be 1.1 mm d(-1. Our results serve as a baseline for interpreting isotopic patterns of free-ranging wild boar in current European agricultural landscapes. However, future research is needed in order to provide a broader understanding of the processes underlying the variation in trophic discrimination factors of carbon and nitrogen across of variety of diet types.

  6. Stable isotopic analysis of fossil chironomids as an approach to environmental reconstruction: state of development and future challenges

    Directory of Open Access Journals (Sweden)

    Oliver Heiri

    2012-10-01

    Full Text Available Remains of chironomid larvae, especially their strongly sclerotized head capsules, can be found abundantly and well preserved in most lake sediment records. These remains mainly consist of chitin and proteins and, since their chemical composition does not seem to be strongly affected by decompositional processes, they can be used to develop palaeoenvironmental reconstructions based on their stable isotopic composition. Here we review available stable isotope studies based on fossil chironomids and indicate future research necessary to further develop this still relatively new research approach. Efforts to produce stable isotope records based on fossil chironomids have mainly examined the elements H, N, C, and O. They have focussed on (1 developing the methodology for preparing samples for isotopic analysis, (2 laboratory studies cultivating chironomid larvae under controlled conditions to determine the factors affecting their stable isotopic composition, (3 ecosystem-scale studies relating stable isotopic measurements of fossil chironomid assemblages to environmental conditions, and (4 developing first down-core records describing past changes in the stable isotopic composition of chironomid assemblages. These studies have shown that chemical sample pretreatment may affect the isotopic composition for some elements. Laboratory runs suggest that the diet of the larvae influences their stable isotopic composition for H, N, C and O, whereas stable isotopes in the ambient water also strongly influence their oxygen and to a lesser extent hydrogen isotopic composition. These experiments also indicate only minor offsets between the nitrogen and carbon isotopic composition of chironomid soft tissue and the fossilizing head capsules, whereas for hydrogen and oxygen this offset remains to be explored. Though few datasets have been published, the available ecosystem studies and developed down-core sediment records indicate that stable isotopes in

  7. Highly enriched stable and actinide isotopes for scientific investigation in Russian Federal Nuclear Center Arzamas-16

    International Nuclear Information System (INIS)

    Vesnovskii, S.P.; Shulzhenko, P.F.

    1997-01-01

    The paper describes the production of highly enriched isotopes of uranium and transuranium elements by electromagnetic separation and same stable isotopes for scientific and applied research in physics and environment, for reference materials and standard sources

  8. STABLE ISOTOPES IN ECOLOGICAL STUDIES: NEW DEVELOPMENTS IN MIXING MODELS (BRAZIL)

    Science.gov (United States)

    Stable isotopes are increasingly being used as tracers in ecological studies. One application uses isotopic ratios to quantify the proportional contributions of multiple sources to a mixture. Examples include pollution sources for air or water bodies, food sources for animals, ...

  9. STABLE ISOTOPES IN ECOLOGICAL STUDIES: NEW DEVELOPMENTS IN MIXING MODELS (URUGUAY)

    Science.gov (United States)

    Stable isotopes are increasingly being used as tracers in ecological studies. One application uses isotopic ratios to quantify the proportional contributions of multiple sources to a mixture. Examples include pollution sources for air or water bodies, food sources for animals, ...

  10. Stable Isotope Identification of Nitrogen Sources for United States (U.S.) Pacific Coast Estuaries

    Science.gov (United States)

    Brown, C. A.; Kaldy, J. E.; Fong, P.; Fong, C.; Mochon Collura, T.; Clinton, P.

    2016-02-01

    Nutrients are the leading cause of water quality impairments in the United States, and as a result tools are needed to identify the sources of nutrients. We used natural abundance stable isotope data to evaluate nitrogen sources to U.S. west coast estuaries. We collected macroalgae and analyzed these samples for natural abundance of stable isotopes (δ15N) and supplemented this with available data from the literature for estuaries from Mexico to Alaska. Stable isotope ratios of green macroalgae were compared to δ15N of dissolved inorganic nitrogen of oceanic and watershed end members. There was a latitudinal gradient in δ15N of macroalgae with southern estuaries being 7 per mil heavier than northern estuaries. Gradients in isotope data were compared to nitrogen sources estimated by the USGS using the SPARROW model. In California estuaries, the elevation of isotope data appeared to be related to anthropogenic nitrogen sources. In Oregon systems, the nitrogen levels of streams flowing into the estuaries are related to forest cover, rather than to developed land classes. In Oregon estuaries, the δ15N of macroalgae suggested that the ocean and nitrogen-fixing trees in the watersheds were the dominant nitrogen sources with heavier sites located near the estuary mouth. In California estuaries, the gradient was reversed with heavier sites located upriver. In some Oregon estuaries, there was an elevation an elevation of δ15N above marine end members in the vicinity of wastewater treatment facility discharge locations, suggesting isotopes may be useful for distinguishing inputs along an estuarine gradient.

  11. Defining a stable water isotope framework for isotope hydrology application in a large trans-boundary watershed (Russian Federation/Ukraine).

    Science.gov (United States)

    Vystavna, Yuliya; Diadin, Dmytro; Huneau, Frédéric

    2018-05-01

    Stable isotopes of hydrogen ( 2 H) and oxygen ( 18 O) of the water molecule were used to assess the relationship between precipitation, surface water and groundwater in a large Russia/Ukraine trans-boundary river basin. Precipitation was sampled from November 2013 to February 2015, and surface water and groundwater were sampled during high and low flow in 2014. A local meteoric water line was defined for the Ukrainian part of the basin. The isotopic seasonality in precipitation was evident with depletion in heavy isotopes in November-March and an enrichment in April-October, indicating continental and temperature effects. Surface water was enriched in stable water isotopes from upstream to downstream sites due to progressive evaporation. Stable water isotopes in groundwater indicated that recharge occurs mainly during winter and spring. A one-year data set is probably not sufficient to report the seasonality of groundwater recharge, but this survey can be used to identify the stable water isotopes framework in a weakly gauged basin for further hydrological and geochemical studies.

  12. Evaluating gull diets: A comparison of conventional methods and stable isotope analysis

    Science.gov (United States)

    Weiser, Emily L.; Powell, Abby N.

    2011-01-01

    Samples such as regurgitated pellets and food remains have traditionally been used in studies of bird diets, but these can produce biased estimates depending on the digestibility of different foods. Stable isotope analysis has been developed as a method for assessing bird diets that is not biased by digestibility. These two methods may provide complementary or conflicting information on diets of birds, but are rarely compared directly. We analyzed carbon and nitrogen stable isotope ratios of feathers of Glaucous Gull (Larus hyperboreus) chicks from eight breeding colonies in northern Alaska, and used a Bayesian mixing model to generate a probability distribution for the contribution of each food group to diets. We compared these model results with probability distributions from conventional diet samples (pellets and food remains) from the same colonies and time periods. Relative to the stable isotope estimates, conventional analysis often overestimated the contributions of birds and small mammals to gull diets and often underestimated the contributions of fish and zooplankton. Both methods gave similar estimates for the contributions of scavenged caribou, miscellaneous marine foods, and garbage to diets. Pellets and food remains therefore may be useful for assessing the importance of garbage relative to certain other foods in diets of gulls and similar birds, but are clearly inappropriate for estimating the potential impact of gulls on birds, small mammals, or fish. However, conventional samples provide more species-level information than stable isotope analysis, so a combined approach would be most useful for diet analysis and assessing a predator's impact on particular prey groups.

  13. The stable isotope fingerprinting technique for agricultural pesticide

    Science.gov (United States)

    Suto, N.; Kawashima, H.

    2014-12-01

    The compound specific isotope analysis (CSIA) is nowadays an important and powerful tool in geochemical, environmental, and forensics field. In particular, the stable isotope ratio of pesticide is applied to biological process and reaction in the soil and distribution channel as forensics science. The aim of this study is to measure the stable isotope ratios of pesticide using various analytical methodologies, GC/IRMS, EA/IRMS, and LC/IRMS under high accuracy and precision. Therefore, these methods seemed to be important knowledge as geological field. In particular case, we present the method to measure carbon isotope ratio of nine malathion emulsion pesticides using GC/IRMS with cryo-focusing system to identify the source. In December 2013, food poisoning occurred after eating frozen dumplings (i.e., pizza and chicken nuggets) in Japan. There was a very high concentration, maximum value 15,000ppm, of malathion (diethyl (dimethoxythiophosphorylthio) succinate) in products. This incident was caused by an employee of process, and threatened the food safety. We analyzed the δ13C of malathion ranged from -30.63‰ to -29.54‰ (S.D. 0.10‰), the differences less than 1.0‰. All malathion emulsion sold in Japan are imported from Cheminova India Lat., Denmark to Sumitomo Chemical Co. Ltd., Japan. After that, Japanese each manufacture buy from Sumitomo Chemical Co. Ltd. And blended malathion and organic solvent (ethylbenzene and xylene). Therefore, ethylbenzene and xylene may be important tool as source identification. We measured the δ13C of ethylbenzene and m-,p-xylene, too. As the results, the δ13C of ethylbenzene and m-,p-xylene ranged from -28.20‰ to -20.84‰ (S.D. 0.16‰), -28.69‰ to -25.15‰ (S.D. 0.13‰), respectively. The δ13C of ethylbenzene and m-,p-xylene can be identified manufacture, although the δ13C of malathion indicated same value. In addition, we measured five pesticides (acephate, acetamiprid, glufosinate, glyphosate, and oxamyl) using

  14. Preservation of terrestrial plant biomarkers from Nachukui Formation sediments and their viability for stable isotope analysis

    Science.gov (United States)

    Kahle, E.; Uno, K. T.; Polissar, P. J.; Lepre, C. J.; deMenocal, P. B.

    2013-12-01

    Plio-Pleistocene sedimentary records from the Turkana Basin in eastern Africa provide a unique opportunity to compare a high-resolution record of climate and terrestrial vegetation with important changes in the record of human evolution. Molecular biomarkers from terrestrial vegetation can yield stable isotope ratios of hydrogen and carbon that reflect ancient climate and vegetation. However, the preservation of long-chain plant wax biomarkers in these paleosol, fluvial, and lacustrine sediments is not known, and this preservation must be studied to establish their utility for molecular stable isotope studies. We investigated leaf wax biomarkers in Nachukui Formation sediments deposited between 2.3 and 1.7 Ma to assess biomarker preservation. We analyzed n alkane and n alkanoic acid concentrations and, where suitable, molecular carbon and hydrogen isotope ratios. Molecular abundance distributions show a great deal of variance in biomarker preservation and plant-type source as indicated by the carbon preference index and average chain length. This variation suggests that some samples are suitable for isotopic analysis, while other samples lack primary terrestrial plant biomarker signatures. The biomarker signal in many samples contains significant additional material from unidentified sources. For example, the n-alkane distributions contain an unresolved complex mixture underlying the short and mid-chain n-alkanes. Samples from lacustrine intervals include long-chain diacids, hydroxy acids and (ω-1) ketoacids that suggest degradation of the original acids. Degradation of poorly preserved samples and the addition of non-terrestrial plant biomarkers may originate from a number of processes including forest fire or microbial alteration. Isotopic analysis of well-preserved terrestrial plant biomarkers will be presented along with examples where the original biomarker distribution has been altered.

  15. Stable isotopic data for inferring source of groundwater recharge in the Anekal Taluk, Karnataka

    International Nuclear Information System (INIS)

    Ansari, Md. Arzoo; Deodhar, Archana; Jaryal, Ajay; Mendhekar, G.N.; Sinha, U.K.; Dash, Ashutosh; Davis, Deljo

    2015-01-01

    Occurrence of groundwater mainly depends on recharge area characteristics such as slope of the topography, surface cover characteristics, geology of the area and the permeability of top soil etc. Most of the tube wells located in the study area are in unconfined aquifer and the hydrology of them is mainly influenced by rainfall and surrounding catchments area characteristics. Isotope techniques provide a unique tool for establishing the recharge areas of groundwater. The stable Isotopes of O and H in water behave chemically conservative below 60 - 80°C and their concentrations are not affected by geochemical reactions in normal aquifers. Therefore, groundwater preserves its isotopic fingerprint, reflecting the history and origin before infiltration. This makes it an useful tool to interpret recharge mechanisms and the flow system. Therefore, an isotope hydrological technique has been applied in Anekal (12 deg 47 min 44 sec N; 77 deg 41 min 29 sec E) to identify the groundwater recharge area. Groundwater samples were collected from the study areas and analyzed for environmental Isotope (δ 2 H, δ 18 O) by a Isotope ratio mass spectrometer (IsoPrime-100) using gas equilibration method. Physico-chemical parameters (Temperature, EC, pH) were measured insitu. Electrical conductivity (EC) of the groundwater ranges from 668 to 2139 μS/cm, which is dependent on their travel path and the associated rock-water interaction (dissolution of rock minerals)

  16. Trends and problems on the studies by stable isotope ratio mass spectrometry for verifying the geographical origin of foods

    International Nuclear Information System (INIS)

    Korenaga, Takashi

    2013-01-01

    The multi-stable isotopic analysis method has employed to solve food authenticity problems. Stable isotope ratio of the light elements such as H, C, N, and O in food samples (e.g., rice, beef, and eel) were precisely analyzed by elemental analysis/isotope ratio mass spectrometry. Those samples were mainly taken from four different countries; Japan, United States of America, Australia, and China as comparison. All the rice samples were grown in the presence of either natural and or artificial fertilizer. The beef samples were taken from three different countries; Japan, United States of America, and Australia. Imported beef samples were also presented from the Ministry of Agriculture, Forestry and Fisheries, Japan, and compared with a correlation equation. The eel samples were taken from the three different countries and areas; Japan, China, and Taiwan. δX values showing some differences, all the Japanese food samples were clearly distinctive from the United States of America, Australia, China, and Taiwan samples. The results may be explained by the regional differences in isotope signatures of the climate, utilized nutrition, and/or quality of irrigation water among the farming countries. The statistical distinction could be one of the useful metrics to extract the food samples (rice, meat, fish, etc.) grown in Japan from those grown in the other countries. The dynamics analysis studies on stable isotopic behavior (i.e., Isotopomics) in human metabolism may be looking forward to establish a new science in near future. (author)

  17. Stable isotope ratio analysis of different European raspberries, blackberries, blueberries, currants and strawberries.

    Science.gov (United States)

    Perini, M; Giongo, L; Grisenti, M; Bontempo, L; Camin, F

    2018-01-15

    To date the stable isotope ratios of berries have never been extensively explored. In this work the H, C, N and O isotopic ratios of 190 samples of different soft fruits (strawberries, raspberries, blueberries, blackberries and currants) produced in a northern Italian region and at two sites in Romania and Poland collected over three harvest years are presented and discussed. The different soft fruits showed a typical range for one or more isotopic parameters that can be used to verify the authenticity of the fruit composition declared on the label. The δ 13 C and δ 15 N of pulp and the δ 18 O of juice can be considered effective tools for identifying the different geographical origin of fruit. A significant effect of crop cover on juice δ 18 O and fertilisation practices on pulp δ 15 N was demonstrated and must be considered with attention when evaluating data. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Tracing the Pb origin using stable Pb isotope ratios in sediments of Liaodong Bay, China

    Science.gov (United States)

    Hu, Ningjing; Huang, Peng; Zhang, Hui; Zhu, Aimei; He, Lianhua; Zhang, Jun; Liu, Jihua; Shi, Xuefa; Ma, Deyi

    2015-12-01

    A comprehensive study was carried out on the source of Pb within Liaodong Bay. Sixty surface sediment samples covering the entire Liaodong Bay were measured for total Pb, Cu, and Zn concentrations and Pb isotopic compositions (207Pb/206Pb and 208Pb/206Pb). Pb in northern (Section I) and southwestern (Section III) Liaodong Bay is impacted by anthropogenic sources, including coal combustion, vehicle emissions, and Pb ores. However, Pb in southern Liaodong Bay (Section II) is predominately from natural sources. While the Pb isotopic composition in some Section I sites suggests there are various anthropogenic sources of Pb, its enrichment factors are low. This indicates that the stable Pb isotopic composition is more sensitive to anthropogenic Pb inputs. Based on total concentration and enrichment factors, Cu and Zn in Liaodong Bay are mainly derived from natural process, except in the Jinzhou Gulf.

  19. Characterization of phenols biodegradation by compound specific stable isotope analysis

    Science.gov (United States)

    Wei, Xi; Gilevska, Tetyana; Wenzig, Felix; Hans, Richnow; Vogt, Carsten

    2015-04-01

    -cresol degradation and 2.2±0.3‰ for m-cresol degradation, respectively. The carbon isotope fractionation patterns of phenol degradation differed more profoundly. Oxygen-dependent monooxygenation of phenol by A.calcoaceticus as the initial reaction yielded ƐC values of -1.5±0.02‰. In contrast, the anaerobic degradation initiated by ATP-dependent carboxylation performed by Thauera aromatia DSM 6984, produced no detectable fractionation (ƐC 0±0.1‰). D. cetonica showed a slight inverse carbon isotope fractionation (ƐC 0.4±0.1‰). In conclusion, a validated method for compound specific stable isotope analysis was developed for phenolic compounds, and the first data set of carbon enrichment factors upon the biodegradation of phenol and cresols with different activation mechanisms has been obtained in the present study. Carbon isotope fractionation analysis is a potentially powerful tool to monitor phenolic compounds degradation in the environment.

  20. Stable isotopes can be used to infer the overwintering locations of prebreeding marine birds in the Canadian Arctic

    DEFF Research Database (Denmark)

    Steenweg, Rolanda J.; Crossin, Glenn T.; Kyser, T. Kurt

    2017-01-01

    their arrival at our breeding colony, and used a k-means cluster analysis approach to match arriving eiders to an overwintering group. Samples from the claws of eiders were most effective for determining overwinter origin, due to this tissue's slow growth rate relative to the 40-day turnover rate of blood....... Despite taking an integrative approach using multiple isotopes, k-means cluster analysis was most effective when using 13-carbon alone to assign eiders to an overwintering group. Our research demonstrates that it is possible to use stable isotope analysis to assign an overwintering location to a marine...... of individuals studied. Alternatively, stable isotope analysis in specific tissues can be used as an indirect means of determining individual overwintering areas of residency. Although increasingly used to infer the overwintering distributions of terrestrial birds, stable isotopes have been used less often...

  1. Geochemical and stable isotope characteristics of urban heavy rain in the downtown of Tokyo, Japan

    Science.gov (United States)

    Uchiyama, Ryunosuke; Okochi, Hiroshi; Ogata, Hiroko; Katsumi, Naoya; Asai, Daisuke; Nakano, Takanori

    2017-09-01

    In order to make clear the impact of air pollution on the formation of sudden and locally-distributed heavy rain in urban area (hereafter Urban Heavy Rain: UHR), we analyzed inorganic ion concentration and stable isotope ratio of water (δD and δ18O) in rainwater. Rainwater samples were collected in Shinjuku, which is a representative downtown of Tokyo, Japan, during four years from October 2012 to December 2015. The concentration and wet deposition fluxes of acidic components (H+, NH4+, NO3-, and nss-SO42 -) in UHR were especially higher than those in other types of rain events, i.e. normal rain, typhoon heavy rain, and frontal heavy rain. UHR had distinctly lower stable isotope ratios than those in other urban rains with same rainfall amount and summer precipitation systems. There was a high negative correlation between δ18O and the distances from the sampling point to the formation area of UHR within 10 km, while there were high positive correlations between δ18O and the concentration of acidic components in UHR. These findings indicate that UHR could effectively scavenge acidic substances within cloud and suggest the use of stable isotope ratios as tracers of an urban heavy rain's water and in-cloud scavenging process.

  2. Pooled versus separate measurements of tree-ring stable isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dorado Linan, Isabel, E-mail: isabel@gfz-potsdam.de [Universitat de Barcelona, Departament d' Ecologia, Diagonal 645, 08028, Barcelona (Spain); German Centre for Geosciences, Climate Dynamics and Landscape Evolution, Dendro Laboratory, Telegrafenberg, 14473, Potsdam (Germany); Gutierrez, Emilia, E-mail: emgutierrez@ub.edu [Universitat de Barcelona, Departament d' Ecologia, Diagonal 645, 08028, Barcelona (Spain); Helle, Gerhard, E-mail: ghelle@gfz-potsdam.de [German Centre for Geosciences, Climate Dynamics and Landscape Evolution, Dendro Laboratory, Telegrafenberg, 14473, Potsdam (Germany); Heinrich, Ingo, E-mail: heinrich@gfz-potsdam.de [German Centre for Geosciences, Climate Dynamics and Landscape Evolution, Dendro Laboratory, Telegrafenberg, 14473, Potsdam (Germany); Andreu-Hayles, Laia, E-mail: laiandreu@ub.edu [Universitat de Barcelona, Departament d' Ecologia, Diagonal 645, 08028, Barcelona (Spain); Tree-Ring Laboratory, Lamont-Doherty Earth Observatory of Columbia University, Palisades NY (United States); Planells, Octavi, E-mail: leocarpus@hotmail.com [Universitat de Barcelona, Departament d' Ecologia, Diagonal 645, 08028, Barcelona (Spain); Leuenberger, Markus, E-mail: leuenberger@climate.unibe.ch [Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, 3012 Bern (Switzerland); Oeschger Centre of Climate Change Research, University of Bern, Zaehringerstrasse 25, 3012 Bern (Switzerland); Buerger, Carmen, E-mail: buerger@gfz-potsdam.de [German Centre for Geosciences, Climate Dynamics and Landscape Evolution, Dendro Laboratory, Telegrafenberg, 14473, Potsdam (Germany); Schleser, Gerhard, E-mail: schleser@gfz-potsdam.de [German Centre for Geosciences, Climate Dynamics and Landscape Evolution, Dendro Laboratory, Telegrafenberg, 14473, Potsdam (Germany)

    2011-05-01

    {delta}{sup 13}C and {delta}{sup 18}O of tree rings contain time integrated information about the environmental conditions weighted by seasonal growth dynamics and are well established as sources of palaeoclimatic and ecophysiological data. Annually resolved isotope chronologies are frequently produced by pooling dated growth rings from several trees prior to the isotopic analyses. This procedure has the advantage of saving time and resources, but precludes from defining the isotopic error or statistical uncertainty related to the inter-tree variability. Up to now only a few studies have compared isotope series from pooled tree rings with isotopic measurements from individual trees. We tested whether or not the {delta}{sup 13}C and the {delta}{sup 18}O chronologies derived from pooled and from individual tree rings display significant differences at two locations from the Iberian Peninsula to assess advantages and constraints of both methodologies. The comparisons along the period 1900-2003 reveal a good agreement between pooled chronologies and the two mean master series which were created by averaging raw individual values (Mean) or by generating a mass calibrated mean (MassC). In most of the cases, pooled chronologies show high synchronicity with averaged individual samples at interannual scale but some differences also show up especially when comparing {delta}{sup 18}O decadal to multi-decadal variations. Moreover, differences in the first order autocorrelation among individuals may be obscured by pooling strategies. The lack of replication of pooled chronologies prevents detection of a bias due to a higher mass contribution of one sample but uncertainties associated with the analytical process itself, as sample inhomogeneity, seems to account for the observed differences. - Research Highlights: {yields} Pooled {delta}{sup 13}C and {delta}{sup 18}O chronologies are expected to be similar to the mean. {yields} Empirical pooled chronologies {delta}{sup 13}C and

  3. Seasonal and inter-annual dynamics in the stable oxygen isotope compositions of water pools in a temperate humid grassland ecosystem: results from MIBA sampling and MuSICA modelling

    Science.gov (United States)

    Hirl, Regina; Schnyder, Hans; Auerswald, Karl; Vetter, Sylvia; Ostler, Ulrike; Schleip, Inga; Wingate, Lisa; Ogée, Jérôme

    2015-04-01

    The oxygen isotope composition (δ18O) of water in terrestrial ecosystems usually shows strong and dynamic variations within and between the various compartments. These variations originate from changes in the δ18O of water inputs (e.g. rain or water vapour) and from 18O fractionation phenomena in the soil-plant-atmosphere continuum. Investigations of δ18O in ecosystem water pools and of their main drivers can help us understand water relations at plant, canopy or ecosystem scale and interpret δ18O signals in plant and animal tissues as paleo-climate proxies. During the vegetation periods of 2006 to 2012, soil, leaf and stem water as well as atmospheric humidity, rain water and groundwater were sampled at bi-weekly intervals in a temperate humid pasture of the Grünschwaige Grassland Research Station near Munich (Germany). The sampling was performed following standardised MIBA (Moisture Isotopes in the Biosphere and Atmosphere) protocols. Leaf water samples were prepared from a mixture of co-dominant species in the plant community in order to obtain a canopy-scale leaf water δ18O signal. All samples were then analysed for their δ18O compositions. The measured δ18O of leaf, stem and soil water were then compared with the δ18O signatures simulated by the process-based isotope-enabled ecosystem model MuSICA (Multi-layer Simulator of the Interactions between a vegetation Canopy and the Atmosphere). MuSICA integrates current mechanistic understanding of processes in the soil-plant-atmosphere continuum. Hence, the comparison of modelled and measured data allows the identification of gaps in current knowledge and of questions to be tackled in the future. Soil and plant characteristics for model parameterisation were derived from investigations at the experimental site and supplemented by values from the literature. Eddy-covariance measurements of ecosystem CO2 (GPP, NEE) and energy (H, LE) fluxes and soil temperature data were used for model evaluation. The

  4. Dietary heterogeneity among Western industrialized countries reflected in the stable isotope ratios of human hair.

    Directory of Open Access Journals (Sweden)

    Luciano O Valenzuela

    Full Text Available Although the globalization of food production is often assumed to result in a homogenization of consumption patterns with a convergence towards a Western style diet, the resources used to make global food products may still be locally produced (glocalization. Stable isotope ratios of human hair can quantify the extent to which residents of industrialized nations have converged on a standardized diet or whether there is persistent heterogeneity and glocalization among countries as a result of different dietary patterns and the use of local food products. Here we report isotopic differences among carbon, nitrogen and sulfur isotope ratios of human hair collected in thirteen Western European countries and in the USA. European hair samples had significantly lower δ(13C values (-22.7 to -18.3‰, and significantly higher δ(15N (7.8 to 10.3‰ and δ(34S (4.8 to 8.3‰ values than samples from the USA (δ(13C: -21.9 to -15.0‰, δ(15N: 6.7 to 9.9‰, δ(34S: -1.2 to 9.9‰. Within Europe, we detected differences in hair δ(13C and δ(34S values among countries and covariation of isotope ratios with latitude and longitude. This geographic structuring of isotopic data suggests heterogeneity in the food resources used by citizens of industrialized nations and supports the presence of different dietary patterns within Western Europe despite globalization trends. Here we showed the potential of stable isotope analysis as a population-wide tool for dietary screening, particularly as a complement of dietary surveys, that can provide additional information on assimilated macronutrients and independent verification of data obtained by those self-reporting instruments.

  5. Expanding the isotopic toolbox: Applications of hydrogen and oxygen stable isotope ratios to food web studies

    Directory of Open Access Journals (Sweden)

    Hannah B Vander Zanden

    2016-03-01

    Full Text Available The measurement of stable carbon (δ13C and nitrogen (δ15N isotopes in tissues of organisms has formed the foundation of isotopic food web reconstructions, as these values directly reflect assimilated diet. In contrast, stable hydrogen (δ2H and oxygen (δ18O isotope measurements have typically been reserved for studies of migratory origin and paleoclimate reconstruction based on systematic relationships between organismal tissue and local environmental water. Recently, innovative applications using δ2H and, to a lesser extent, δ18O values have demonstrated potential for these elements to provide novel insights in modern food web studies. We explore the advantages and challenges associated with three applications of δ2H and δ18O values in food web studies. First, large δ2H differences between aquatic and terrestrial ecosystem end members can permit the quantification of energy inputs and nutrient fluxes between these two sources, with potential applications for determining allochthonous vs. autochthonous nutrient sources in freshwater systems and relative aquatic habitat utilization by terrestrial organisms. Next, some studies have identified a relationship between δ2H values and trophic position, which suggests that this marker may serve as a trophic indicator, in addition to the more commonly used δ15N values. Finally, coupled measurements of δ2H and δ18O values are increasing as a result of reduced analytical challenges to measure both simultaneously and may provide additional ecological information over single element measurements. In some organisms, the isotopic ratios of these two elements are tightly coupled, whereas the isotopic disequilibrium in other organisms may offer insight into the diet and physiology of individuals. Although a coherent framework for interpreting δ2H and δ18O data in the context of food web studies is emerging, many fundamental uncertainties remain. We highlight directions for targeted research that

  6. A Way Forward to Improve Nutrition with Stable Isotopes

    International Nuclear Information System (INIS)

    Gorisek, Aleksandra Sasa

    2014-01-01

    People need food and water to survive, but nutritious food is central to healthy living. Energy-dense fat, protein and carbohydrates need to be accompanied by vitamins and minerals (micronutrients) to ensure proper nutrition. Malnutrition, an inappropriate balance of nutrients, can occur with too much or too little of food. The IAEA works with other agencies to evaluate interventions in Member States that are designed to address the problem of malnutrition. Stable isotope techniques can be used to validate the information collected through the use of questionnaires and simple measurements. Capacity building through training and the provision of equipment enables nutritionists worldwide to use these methods in community settings as they are safe, non-invasive and can be used with adults and children of all ages

  7. A New Stable Isotope Record From the Subantarctic Southeastern Pacific

    Science.gov (United States)

    Waddell, L. M.; Hendy, I. L.; Moore, T. C.; Lyle, M. W.

    2007-12-01

    Few stable isotope records exist from the southeast Pacific Ocean due to its remote location, low sedimentation rates, and shallow carbonate compensation depth (CCD). The CCD in the southeast Pacific, however, has been found to be unusually deep (~4750 m), thereby allowing for the preservation of Neogene carbonates at abyssal depths. Herein we present stable isotope results from MV0502-4JC, which was recently recovered from the subantarctic region of the Southwest Pacific (50°20S, 148°08W, 4286 m). Dating the record with radiolarian biostratigraphy, we have generated a benthic stable isotope record back to the Middle Miocene from Cibicidoides spp. and a planktic record from Globigerina bulloides into the Late Pliocene. These stable isotope records, in conjunction with carbonate contents and counts of ice-rafted debris (IRD) and manganese micronodules show the effect of global ice sheet build up on this poorly understood region. A prominent negative δ13C shift of ~1‰ (from ~1 to ~0.2‰) in the benthic record occurs at ~15.3 MBSF (Middle Miocene) as carbonate contents in the core decrease from ~80% to ~20%, and significant changes in the bottom water are indicated by changes in the dominant Cibicidoides spp. at the site from C. robertsonianus to C. wuellerstorfi. Trace amounts of IRD and abundant manganese micronodules also appear at the site at this time. A significant hiatus (from the Late Miocene to the Middle Pliocene) occurs somewhere between 11.4 and 9.8 MBSF. From 9.8 to 8 MBSF (Late Pliocene) benthic δ18O increases and δ13C decreases by ~1‰. Also, IRD increases, manganese micronodules decrease, and there is a dramatic increase in the preservation of planktic foraminifera at the site. A planktic δ13C shift of >1‰ (from 0 to 1‰) occurs at ~5 MBSF (Pleistocene) coincident with a 20% increase in carbonate concentration. After this interval, the variability in both benthic δ18O and δ13C and planktic δ18O increases significantly. We interpret the

  8. Electric Monopole Transition Strengths in the Stable Nickel Isotopes

    Science.gov (United States)

    Evitts, Lee John

    A series of measurements of stable nickel isotopes were performed at the Australian National University in Canberra. Excited states in 58,60,62Ni were populated via inelastic scattering of proton beams delivered by the 14UD Pelletron accelerator. Multiple setups were used in order to determine the structure of low-lying states. The CAESAR array of Compton-suppressed HPGe detectors was used to measure the (E2/M1) mixing ratio of transitions from angular distributions of gamma rays. The Super-e spectrometer was used to measure conversion coefficients for a number of J to J transitions. The data obtained from both devices was combined with previously measured parent lifetimes and branching ratios to determine E0 transition strengths between J-pi transitions. The E0 transition strength for the second 0+ to first 0+ transitions in 60,62Ni have been measured for the first time through internal conversion electron detection. The experimental value of 132(+59,-70) for 62Ni agrees within 2 sigma of the previous result obtained from internal pair formation. However it is likely that the previous experimental results used an outdated theoretical model for internal pair formation emission. This work also represents the first measurements of E0 transition strengths between 2+ states in Ni isotopes. There is generally large E0 strength between the 2+ states, particularly in the second 2+ to first 2+ transition, however there is also a large uncertainty in the measurements owing to the difficulties involved in measuring conversion coefficients. In 62Ni, the E0 transition strength of 172(+62,-77) for the second 2+ to first 2+ transition gives further weight to the argument against the spherical vibrator model, as an E0 transition is forbidden if there is a change of only one phonon. The large measurement also indicates the presence of shape coexistence, complementing the recent experimental work carried out in the neutron-rich Ni isotopes.

  9. Stable carbon isotope analysis of coprocessing materials: Quarterly technical progress report, October 1--December 31, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Burke, F. P. [Research and Development Department, Consolidation Coal Company, Library, PA (United States); Winschel, R. A. [Research and Development Department, Consolidation Coal Company, Library, PA (United States); Lancet, M. S. [Research and Development Department, Consolidation Coal Company, Library, PA (United States)

    1989-03-01

    Consol R and D will develop and demonstrate stable carbon isotope analysis as a method to quantitatively distinguish coal-derived and petroleum-derived carbon in products from coal/petroleum coprocessing. The approach taken will be to develop the method, then demonstrate its application on authentic continuous-unit products. The significance of selective isotopic fractionation will be determined and, if necessary, corrections will be applied to account for it. Precision, accuracy and range of applicability will be defined. The value of accessory analytical techniques will also be assessed. Results achieved this quarter include: feed and product fractions from hydroprocessing bench unit runs at the Kentucky Center for Applied Energy Research (CAER) were received, and samples from a Kentucky tar sand bitumen-only run were analyzed for carbon isotope ratios. Repeat carbon isotope analyses of seven samples from HRI Coprocessing Run 227-53 resulted in improved carbon balances for one run period. Athabasca ASB, Cold Lake ASB and Maya ASB were fractionated by distillation and solubility fractionation to determine the homogeneity of each petroleum with respect to carbon isotope ratios. 9 figs., 2 tabs.

  10. Stable isotope, site-specific mass tagging for protein identification

    Science.gov (United States)

    Chen, Xian

    2006-10-24

    Proteolytic peptide mass mapping as measured by mass spectrometry provides an important method for the identification of proteins, which are usually identified by matching the measured and calculated m/z values of the proteolytic peptides. A unique identification is, however, heavily dependent upon the mass accuracy and sequence coverage of the fragment ions generated by peptide ionization. The present invention describes a method for increasing the specificity, accuracy and efficiency of the assignments of particular proteolytic peptides and consequent protein identification, by the incorporation of selected amino acid residue(s) enriched with stable isotope(s) into the protein sequence without the need for ultrahigh instrumental accuracy. Selected amino acid(s) are labeled with .sup.13C/.sup.15N/.sup.2H and incorporated into proteins in a sequence-specific manner during cell culturing. Each of these labeled amino acids carries a defined mass change encoded in its monoisotopic distribution pattern. Through their characteristic patterns, the peptides with mass tag(s) can then be readily distinguished from other peptides in mass spectra. The present method of identifying unique proteins can also be extended to protein complexes and will significantly increase data search specificity, efficiency and accuracy for protein identifications.

  11. Calculation of turnover rates in stable-isotope studies

    International Nuclear Information System (INIS)

    Wootton, R.; Ford, G.C.; Cheng, K.N.; Halliday, D.

    1985-01-01

    In a comparison of glucose turnover measured with 2 H-glucose and with 13 C-glucose Tserng and Kalhan used five apparently different equations and obtained conflicting answers. There is, however, no difference in principle between the use of a stable isotope as a tracer and the use of a radioactive isotope, and the rate of appearance of tracee in a steady-state system (the turnover) can therefore be shown to be proportional to the equilibrium dilution of the infused tracer. Because the sensitivity of measurement of this dilution made using a gas chromatograph-mass spectrometer is lower than that made by radioactivity measurement, the contribution to the measured turnover rate due to the infusate cannot be neglected, as it usually is in radioisotope work. A convenient calibration curve to establish this dilution is the mole ratio of the pure infusate against the area ratio for the relevant ions. Tserng and Kalhan's apparently conflicting results for glucose-turnover using 13 C-glucose as the tracer can all be shown to amount to approximately 11.6 μmol min -1 kg -1 . This value is only slightly lower (0.05 2 H-glucose as the tracer and supports the use of 13 C-glucose as an alternative. (author)

  12. Changes in stable isotope composition in Lake Michigan trout ...

    Science.gov (United States)

    Researchers have frequently sought to use environmental archives of sediment, peat and glacial ice to try and assess historical trends in atmospheric mercury (Hg) deposition to aquatic ecosystems. While this information is valuable in the context of identifying temporal source trends, these types of assessments cannot account for likely changes in bioavailability of Hg sources that are tied to the formation of methylmercury (MeHg) and accumulation in fish tissues. For this study we propose the use of long-term fish archives and Hg stable isotope determination as an improved means to relate temporal changes in fish Hg levels to varying Hg sources in the Great Lakes. For this study we acquired 180 archived fish composites from Lake Michigan over a 40-year time period (1975 to 2014) from the Great Lakes Fish Monitoring and Surveillance Program, which were analyzed for their total Hg content and Hg isotope abundances. The results reveal that Hg sources to Lake Michigan trout (Salvelinus namaycush) have encountered considerable changes as well as a large shift in the food web trophic position as a result of the introduction of several invasive species, especially the recent invasion of dreissenid mussels. Total Hg concentrations span a large range (1,600 to 150 ng g-1) and exhibit large variations from 1975 to 1985. Ä199Hg signatures similarly exhibit large variation (3.2 to 6.9‰) until 1985, followed by less variation through the end of the data record in 2014.

  13. Mass dependent fractionation of stable chromium isotopes in mare basalts: Implications for the formation and the differentiation of the Moon

    Science.gov (United States)

    Bonnand, Pierre; Parkinson, Ian J.; Anand, Mahesh

    2016-02-01

    We present the first stable chromium isotopic data from mare basalts in order to investigate the similarity between the Moon and the Earth's mantle. A double spike technique coupled with MC-ICP-MS measurements was used to analyse 19 mare basalts, comprising high-Ti, low-Ti and KREEP-rich varieties. Chromium isotope ratios (δ53Cr) for mare basalts are positively correlated with indices of magmatic differentiation such as Mg# and Cr concentration which suggests that Cr isotopes were fractionated during magmatic differentiation. Modelling of the results provides evidence that spinel and pyroxene are the main phases controlling the Cr isotopic composition during fractional crystallisation. The most evolved samples have the lightest isotopic compositions, complemented by cumulates that are isotopically heavy. Two hypotheses are proposed to explain this fractionation: (i) equilibrium fractionation where heavy isotopes are preferentially incorporated into the spinel lattice and (ii) a difference in isotopic composition between Cr2+ and Cr3+ in the melt. However, both processes require magmatic temperatures below 1200 °C for appreciable Cr3+ to be present at the low oxygen fugacities found in the Moon (IW -1 to -2 log units). There is no isotopic difference between the most primitive high-Ti, low-Ti and KREEP basalts, which suggest that the sources of these basalts were homogeneous in terms of stable Cr isotopes. The least differentiated sample in our sample set is the low-Ti basalt 12016, characterised by a Cr isotopic composition of -0.222 ± 0.025‰, which is within error of the current BSE value (-0.124 ± 0.101‰). The similarity between the mantles of the Moon and Earth is consistent with a terrestrial origin for a major fraction of the lunar Cr. This similarity also suggests that Cr isotopes were not fractionated by core formation on the Moon.

  14. Detailed assessment of isotope ratio infrared spectroscopy and isotope ratio mass spectrometry for the stable isotope analysis of plant and soil waters.

    Science.gov (United States)

    Zhao, Liangju; Xiao, Honglang; Zhou, Jian; Wang, Lixin; Cheng, Guodong; Zhou, Maoxian; Yin, Li; McCabe, Matthew F

    2011-10-30

    As an alternative to isotope ratio mass spectrometry (IRMS), the isotope ratio infrared spectroscopy (IRIS) approach has the advantage of low cost, continuous measurement and the capacity for field-based application for the analysis of the stable isotopes of water. Recent studies have indicated that there are potential issues of organic contamination of the spectral signal in the IRIS method, resulting in incorrect results for leaf samples. To gain a more thorough understanding of the effects of sample type (e.g., leaf, root, stem and soil), sample species, sampling time and climatic condition (dry vs. wet) on water isotope estimates using IRIS, we collected soil samples and plant components from a number of major species at a fine temporal resolution (every 2 h for 24-48 h) across three locations with different climatic conditions in the Heihe River Basin, China. The hydrogen and oxygen isotopic compositions of the extracted water from these samples were measured using both an IRMS and an IRIS instrument. The results show that the mean discrepancies between the IRMS and IRIS approaches for δ(18) O and δD, respectively, were: -5.6‰ and -75.7‰ for leaf water; -4.0‰ and -23.3‰ for stem water; -3.4‰ and -28.2‰ for root water; -0.5‰ and -6.7‰ for xylem water; -0.06‰ and -0.3‰ for xylem flow; and -0.1‰ and 0.3‰ for soil water. The order of the discrepancy was: leaf > stem ≈ root > xylem > xylem flow ≈ soil. In general, species of the same functional types (e.g., woody vs. herbaceous) within similar habitats showed similar deviations. For different functional types, the differences were large. Sampling at nighttime did not remove the observed deviations. Copyright © 2011 John Wiley & Sons, Ltd.

  15. Marine bivalve feeding strategy, radiocarbon ages and stable isotopes in Scottish coastal waters

    Science.gov (United States)

    Lo Giudice Cappelli, Elena; Austin, William

    2017-04-01

    microhabitats, as all measured bivalve shells are the same age within the ± 2sigma error. Thus, the main conclusion that can be drawn from our results is that stable isotopes measured in marine bivalve shells can be a very useful source of palaeoenvironmental information in coastal and continental shelf waters, while radiocarbon dating of the same shells provides a reliable chronology of environmental change, regardless of vital effects and differences in microhabitats, feeding strategies and sample location.

  16. On the Effect of Planetary Stable Isotope Compositions on Growth and Survival of Terrestrial Organisms.

    Directory of Open Access Journals (Sweden)

    Xueshu Xie

    Full Text Available Isotopic compositions of reactants affect the rates of chemical and biochemical reactions. Usually it is assumed that heavy stable isotope enrichment leads to progressively slower reactions. Yet the effect of stable isotopes may be nonlinear, as exemplified by the "isotopic resonance" phenomenon. Since the isotopic compositions of other planets of Solar system, including Mars and Venus, are markedly different from terrestrial (e.g., deuterium content is ≈5 and ≈100 times higher, respectively, it is far from certain that terrestrial life will thrive in these isotopic conditions. Here we found that Martian deuterium content negatively affected survival of shrimp in semi-closed biosphere on a year-long time scale. Moreover, the bacterium Escherichia coli grows slower at Martian isotopic compositions and even slower at Venus's compositions. Thus, the biological impact of varying stable isotope compositions needs to be taken into account when planning interplanetary missions.

  17. Stable isotope composition of bulk and secondary carbonates from the Quaternary loess-paleosol sequence in Sutto, Hungary

    DEFF Research Database (Denmark)

    Koeniger, Paul; Barta, Gabriella; Thiel, Christine

    2014-01-01

    , and microscale secondary (authigenic) carbonates (calcified root cells, carbonate coatings, hypocoatings, and earthworm biospheroids) and concretions at 10 cm resolution were analysed to interpret stable isotope variations. Isotope values of bulk samples were in the range of 2.6 parts per thousand to -13.9 parts......, secondary carbonates showed more depleted values than bulk samples. Calcified root cells have the most depleted isotope composition with mean values of -16.0 parts per thousand and -11.8 parts per thousand for delta C-13 and 8180, respectively. Results indicate that loess and paleosol secondary carbonates...

  18. What climate information is recorded in stable isotope ratios of wood lignin methoxyl groups?

    Science.gov (United States)

    Greule, Markus; Keppler, Frank

    2010-05-01

    The stable isotope composition of the bioelements C, O, H and N in plant organic matter is known to be a very powerful for various environmental impacts. Particularly tree rings are suitable for this analysis because they exhibit a "climate archive" with a yearly or even biannual resolution. One of the most determined wood compounds is cellulose which amongst others is used to reconstruct the temperature due to measurement of stable hydrogen and oxygen isotopes. Therefore cellulose is converted into cellulose nitrate to eliminate the exchangeable hydroxyl hydrogen or equilibration methods are used. However, a general problem associated with the determination of the stable hydrogen values of marker compounds for the study of climate and environmental conditions is the isolation of the pure compound for analysis by isotope ratio mass spectrometry. Exploitation of components of wood as markers, in particular, has been restricted by the very labour intensive and time consuming preparation of samples (e.g. cellulose nitrate). An alternative way to record climate information from tree rings was recently proposed by Keppler et al. (2007) who measured the stable hydrogen values of methoxyl groups in wood. Lignin methoxyl groups are considered to be stable, i.e. the hydrogen atoms of the methoxyl moiety do not exchange with those of plant water during ongoing metabolic reactions in the plant. Thus the initial deuterium content of the methoxyl groups of lignin in woody tissue at formation is retained throughout the lifetime of the tree and in preserved tissue. The methoxyl content of lignin in wood is usually determined by the Zeisel method (Zeisel, 1885) - the reaction between methyl ethers and hydroiodic acid to form methyl iodide. Exploiting this reaction for the measurement of stable hydrogen values of lignin methoxyl groups ensures that during the entire analytical procedure the isotope signal is preserved since no isotopic exchange occurs between the methyl groups and

  19. The neodymium stable isotope composition of the silicate Earth and chondrites

    Science.gov (United States)

    McCoy-West, Alex J.; Millet, Marc-Alban; Burton, Kevin W.

    2017-12-01

    The non-chondritic neodymium (Nd) 142Nd/144Nd ratio of the silicate Earth potentially provides a key constraint on the accretion and early evolution of the Earth. Yet, it is debated whether this offset is due to the Earth being formed from material enriched in s-process Nd isotopes or results from an early differentiation process such as the segregation of a late sulfide matte during core formation, collisional erosion or a some combination of these processes. Neodymium stable isotopes are potentially sensitive to early sulfide segregation into Earth's core, a process that cannot be resolved using their radiogenic counterparts. This study presents the first comprehensive Nd stable isotope data for chondritic meteorites and terrestrial rocks. Stable Nd measurements were made using a double spike technique coupled with thermal ionisation mass spectrometry. All three of the major classes of chondritic meteorites, carbonaceous, enstatite and ordinary chondrites have broadly similar isotopic compositions allowing calculation of a chondritic mean of δ146/144Nd = -0.025 ± 0.025‰ (±2 s.d.; n = 39). Enstatite chondrites yield the most uniform stable isotope composition (Δ146/144Nd = 26 ppm), with considerably more variability observed within ordinary (Δ146/144Nd = 72 ppm) and carbonaceous meteorites (Δ146/144Nd = 143 ppm). Terrestrial weathering, nucleosynthetic variations and parent body thermal metamorphism appear to have little measurable effect on δ146/144Nd in chondrites. The small variations observed between ordinary chondrite groups most likely reflect inherited compositional differences between parent bodies, with the larger variations observed in carbonaceous chondrites being linked to varying modal proportions of calcium-aluminium rich inclusions. The terrestrial samples analysed here include rocks ranging from basaltic to rhyolitic in composition, MORB glasses and residual mantle lithologies. All of these terrestrial rocks possess a broadly similar Nd

  20. Tracing Water Sources of Terrestrial Animal Populations with Stable Isotopes: Laboratory Tests with Crickets and Spiders

    Science.gov (United States)

    McCluney, Kevin E.; Sabo, John L.

    2010-01-01

    Fluxes of carbon, nitrogen, and water between ecosystem components and organisms have great impacts across levels of biological organization. Although much progress has been made in tracing carbon and nitrogen, difficulty remains in tracing water sources from the ecosystem to animals and among animals (the “water web”). Naturally occurring, non-radioactive isotopes of hydrogen and oxygen in water provide a potential method for tracing water sources. However, using this approach for terrestrial animals is complicated by a change in water isotopes within the body due to differences in activity of heavy and light isotopes during cuticular and transpiratory water losses. Here we present a technique to use stable water isotopes to estimate the mean mix of water sources in a population by sampling a group of sympatric animals over time. Strong correlations between H and O isotopes in the body water of animals collected over time provide linear patterns of enrichment that can be used to predict a mean mix of water sources useful in standard mixing models to determine relative source contribution. Multiple temperature and humidity treatment levels do not greatly alter these relationships, thus having little effect on our ability to estimate this population-level mix of water sources. We show evidence for the validity of using multiple samples of animal body water, collected across time, to estimate the isotopic mix of water sources in a population and more accurately trace water sources. The ability to use isotopes to document patterns of animal water use should be a great asset to biologists globally, especially those studying drylands, droughts, streamside areas, irrigated landscapes, and the effects of climate change. PMID:21209877

  1. Normalization Methods and Selection Strategies for Reference Materials in Stable Isotope Analyses - Review

    International Nuclear Information System (INIS)

    A stable isotope analyst has to make a number of important decisions regarding how to best determine the 'true' stable isotope composition of analysed samples in reference to an international scale. It has to be decided which reference materials should be used, the number of reference materials and how many repetitions of each standard is most appropriate for a desired level of precision, and what normalization procedure should be selected. In this paper we summarise what is known about propagation of uncertainties associated with normalization procedures and propagation of uncertainties associated with reference materials used as anchors for the determination of 'true' values for δ''1''3C and δ''1''8O. Normalization methods Several normalization methods transforming the 'raw' value obtained from mass spectrometers to one of the internationally recognized scales has been developed. However, as summarised by Paul et al. different normalization transforms alone may lead to inconsistencies between laboratories. The most common normalization procedures are: single-point anchoring (versus working gas and certified reference standard), modified single-point normalization, linear shift between the measured and the true isotopic composition of two certified reference standards, two-point and multipoint linear normalization methods. The accuracy of these various normalization methods has been compared by using analytical laboratory data by Paul et al., with the single-point and normalization versus tank calibrations resulting in the largest normalization errors, and that also exceed the analytical uncertainty recommended for δ 13 C. The normalization error depends greatly on the relative differences between the stable isotope composition of the reference material and the sample. On the other hand, the normalization methods using two or more certified reference standards produces a smaller normalization error, if the reference materials are bracketing the whole range of

  2. Improved Sensitivity of Spectroscopic Quantification of Stable Isotope Content Using Capillary Absorption Spectroscopy

    Science.gov (United States)

    Moran, J.; Wilcox Freeburg, E.; Kriesel, J.; Linley, T. J.; Kelly, J.; Coleman, M. L.; Christensen, L. E.; Vance, S.

    2016-12-01

    Spectroscopy-based platforms have recently risen to the forefront for making stable isotope measurements of methane, carbon dioxide, water, or other analytes. These spectroscopy systems can be relatively straightforward to operate (versus a mass spectrometry platform), largely relieve the analyst of mass interference artifacts, and many can be used in the field. Despite these significant advantages, however, existing spectroscopy techniques suffer from a lack of measurement sensitivity that can ultimately limit select applications including spatially resolved and compound-specific measurements. Here we present a capillary absorption spectroscopy (CAS) system that is designed to mitigate sensitivity issues in spectroscopy-based stable isotope evaluation. The system uses mid-wave infrared excitation generated from a continuous wave quantum cascade laser. Importantly, the sample `chamber' is a flexible capillary with a total volume of less than one cc. Proprietary coatings on the internal surface of the fiber improve optical performance, guiding the light to a detector and facilitating high levels of interaction between the laser beam and gaseous analytes. We present data demonstrating that a tapered hollow fiber cell, with an internal diameter that broadens toward the detector, reduces optical feedback to further improve measurement sensitivity. Sensitivity of current hollow fiber / CAS systems enable measurements of only 10's of picomoles CO2 while theoretical improvements should enable measurements of as little as 10's of femtomoles. Continued optimization of sample introduction and improvements to optical feedback are being explored. Software is being designed to provide rapid integration of data and generation of processed isotope measurements using a graphical user interface. Taken together, the sensitivity improvements of the CAS system under development could, when coupled to a laser ablation sampling device, enable up to 2 µm spatial resolution (roughly the

  3. Stable Cl isotope composition of the Changjiang River water

    Science.gov (United States)

    Lang, Y.; Liu, C. Q.; LI, S. L.; Aravena, R.; Ding, H.; WANG, B.; Benjamin, C.

    2017-12-01

    To understand chemical wreathing, nutrient cycling, and the impact of human activities on eco-environments of the Changjiang River (Yangtze River) Basin, we carried out a geochemical study on water chemistry and multiple isotopes (C, N, S, Sr…...) of Changjiang River water in the summer season. Some of the research results about the water chemistry, boron isotope geochemistry and suspended matter have been published (Chetelat et al., 2008; Li et al., 2010). Ten samples were selected for the measurement of δ37Cl values, among which 7 samples were collected from main stream and 3 samples from tributaries. The range of δ37Cl values varies between 0.02‰ and 0.33‰ in the main stream and between 0.16‰ and 0.71‰ in the tributary waters. The δ37Cl values in general are negatively correlated with Cl- concentrations for both main stream and tributary waters. δ37Cl value of Wujiang, which is one of the large tributaries in the upper reach of Changjiang and dominated by carbonate rocks in lithology of the watershed, has the maximum value but minimum value of Cl- concentration in this study. The lowest δ37Cl value was measured for the water collected from the estuary of Changjiang River. The variation of δ37Cl values in the waters would be attributed to mixing of different sources of chlorine, which most likely include rain water, ground water, seawater, and pollutants. Systematic characterization of different Cl sources in terms of their chlorine isotope composition is imperative for better understanding of sources and processes of chlorine cycling. Acknowledgements: This work was financially supported by NSFC through project 41073099. (Omit references)

  4. Surface oceanographic fronts influencing deep-sea biological activity: Using fish stable isotopes as ecological tracers

    Science.gov (United States)

    Louzao, Maite; Navarro, Joan; Delgado-Huertas, Antonio; de Sola, Luis Gil; Forero, Manuela G.

    2017-06-01

    Ecotones can be described as transition zones between neighbouring ecological systems that can be shaped by environmental gradients over a range of space and time scales. In the marine environment, the detection of ecotones is complex given the highly dynamic nature of marine systems and the paucity of empirical data over ocean-basin scales. One approach to overcome these limitations is to use stable isotopes from animal tissues since they can track spatial oceanographic variability across marine systems and, in turn, can be used as ecological tracers. Here, we analysed stable isotopes of deep-sea fishes to assess the presence of ecological discontinuities across the western Mediterranean. We were specifically interested in exploring the connection between deep-sea biological activity and particular oceanographic features (i.e., surface fronts) occurring in the pelagic domain. We collected samples for three different abundant deep-sea species in May 2004 from an experimental oceanographic trawling cruise (MEDITS): the Mictophydae jewel lanternfish Lampanyctus crocodilus and two species of the Gadidae family, the silvery pout Gadiculus argenteus and the blue whiting Micromesistius poutassou. The experimental survey occurred along the Iberian continental shelf and the upper and middle slopes, from the Strait of Gibraltar in the SW to the Cape Creus in the NE. The three deep-sea species were highly abundant throughout the study area and they showed geographic variation in their isotopic values, with decreasing values from north to south disrupted by an important change point around the Vera Gulf. Isotopic latitudinal gradients were explained by pelagic oceanographic conditions along the study area and confirm the existence of an ecotone at the Vera Gulf. This area could be considered as an oceanographic boundary where waters of Atlantic origin meet Mediterranean surface waters forming important frontal structures such as the Almeria-Oran front. In fact, our results

  5. Evaluation of stable tungsten isotopes in the resolved resonance region

    Directory of Open Access Journals (Sweden)

    Schillebeeckx P.

    2013-03-01

    Full Text Available In the last decade benchmark experiments and simulations, together with newly obtained neutron cross section data, have pointed out deficiencies in evaluated data files of W isotopes. The role of W as a fundamental structural material in different nuclear applications fully justifies a new evaluation of 182, 183, 184, 186W neutron resonance parameters. In this regard transmission and capture cross section measurements on natural and enriched tungsten samples were performed at the GELINA facility of the EC-JRC-IRMM. A resonance parameter file used as input in the resonance shape analysis was prepared based on the available literature and adjusted in first instance to transmission data.

  6. Temporal diet changes recorded by stable isotopes in Asiatic black bear (Ursus thibetanus) hair.

    Science.gov (United States)

    Mizukami, R N; Goto, M; Izumiyama, S; Yoh, M; Ogura, N; Hayashi, H

    2005-03-01

    Carbon and nitrogen stable isotope ratios were measured in hair samples of the Asiatic black bear (Ursus thibetanus) inhabiting the Northern Japanese Alps (NJA) (n = 20) and the periphery of Nagano City (NC) (n = 6), in Nagano Prefecture, Japan. The hair of NJA bears, which did not have access to anthropogenic foods, showed lower values of d13C and d15N than that of NC bears which had access to garbage and corn fields, especially during the summer. These results reflect somewhat differing diets between the NJA and NC bears. We attempted to assess the feeding history during the hair growth cycle using the growth section analysis method. Each hair sample had been cut into 3?mm lengths from root to tip, labeled, and analyzed along the hair growth. We measured the carbon and nitrogen stable isotope ratios of each 3?mm length of hair sample from one NC bear which had been killed while raiding a corn field. The sections showed wide ranges of isotope ratios, from -23.2% to -14.6% for delta13C, and from 0.3% to 4.6% for delta15N. It was shown that the diet of this bear shifted dramatically from principally C3 plants to more C4 plants and to foods of animal origin. An analysis of the whole hair reflects just the average feeding habit during hair growth, but the present method can trace its diet history. This method can contribute to obtain precise ecological information of wildlife.

  7. Source tracing of natural organic matter bound mercury in boreal forest runoff with mercury stable isotopes.

    Science.gov (United States)

    Jiskra, Martin; Wiederhold, Jan G; Skyllberg, Ulf; Kronberg, Rose-Marie; Kretzschmar, Ruben

    2017-10-18

    Terrestrial runoff represents a major source of mercury (Hg) to aquatic ecosystems. In boreal forest catchments, such as the one in northern Sweden studied here, mercury bound to natural organic matter (NOM) represents a large fraction of mercury in the runoff. We present a method to measure Hg stable isotope signatures of colloidal Hg, mainly complexed by high molecular weight or colloidal natural organic matter (NOM) in natural waters based on pre-enrichment by ultrafiltration, followed by freeze-drying and combustion. We report that Hg associated with high molecular weight NOM in the boreal forest runoff has very similar Hg isotope signatures as compared to the organic soil horizons of the catchment area. The mass-independent fractionation (MIF) signatures (Δ 199 Hg and Δ 200 Hg) measured in soils and runoff were in agreement with typical values reported for atmospheric gaseous elemental mercury (Hg 0 ) and distinctly different from reported Hg isotope signatures in precipitation. We therefore suggest that most Hg in the boreal terrestrial ecosystem originated from the deposition of Hg 0 through foliar uptake rather than precipitation. Using a mixing model we calculated the contribution of soil horizons to the Hg in the runoff. At moderate to high flow runoff conditions, that prevailed during sampling, the uppermost part of the organic horizon (Oe/He) contributed 50-70% of the Hg in the runoff, while the underlying more humified organic Oa/Ha and the mineral soil horizons displayed a lower mobility of Hg. The good agreement of the Hg isotope results with other source tracing approaches using radiocarbon signatures and Hg : C ratios provides additional support for the strong coupling between Hg and NOM. The exploratory results from this study illustrate the potential of Hg stable isotopes to trace the source of Hg from atmospheric deposition through the terrestrial ecosystem to soil runoff, and provide a basis for more in-depth studies investigating the

  8. High-temperature pyrolysis/gas chromatography/isotope ratio mass spectrometry: simultaneous measurement of the stable isotopes of oxygen and carbon in cellulose.

    Science.gov (United States)

    Woodley, Ewan J; Loader, Neil J; McCarroll, Danny; Young, Giles H F; Robertson, Iain; Heaton, Timothy H E; Gagen, Mary H; Warham, Joseph O

    2012-01-30

    Stable isotope analysis of cellulose is an increasingly important aspect of ecological and palaeoenvironmental research. Since these techniques are very costly, any methodological development which can provide simultaneous measurement of stable carbon and oxygen isotope ratios in cellulose deserves further exploration. A large number (3074) of tree-ring α-cellulose samples are used to compare the stable carbon isotope ratios (δ(13)C) produced by high-temperature (1400°C) pyrolysis/gas chromatography (GC)/isotope ratio mass spectrometry (IRMS) with those produced by combustion GC/IRMS. Although the two data sets are very strongly correlated, the pyrolysis results display reduced variance and are strongly biased towards the mean. The low carbon isotope ratios of tree-ring cellulose during the last century, reflecting anthropogenic disturbance of atmospheric carbon dioxide, are thus overestimated. The likely explanation is that a proportion of the oxygen atoms are bonding with residual carbon in the reaction chamber to form carbon monoxide. The 'pyrolysis adjustment', proposed here, is based on combusting a stratified sub-sample of the pyrolysis results, across the full range of carbon isotope ratios, and using the paired results to define a regression equation that can be used to adjust all the pyrolysis measurements. In this study, subsamples of 30 combustion measurements produced adjusted chronologies statistically indistinguishable from those produced by combusting every sample. This methodology allows simultaneous measurement of the stable isotopes of carbon and oxygen using high-temperature pyrolysis, reducing the amount of sample required and the analytical costs of measuring them separately. Copyright © 2011 John Wiley & Sons, Ltd.

  9. Using stable isotopes to assess dietary changes of American black bears from 1980 to 2001.

    Science.gov (United States)

    Teunissen van Manen, Jennapher L; Muller, Lisa I; Li, Zheng-hua; Saxton, Arnold M; Pelton, Michael R

    2014-01-01

    We measured stable carbon and nitrogen isotope ratios in 117 hair samples from American black bears (Ursus americanus) in Great Smoky Mountains National Park, Tennessee, during 1980-2001 from live-trapped bears. We also collected hair from bears with known diets to compare with the wild bears. We hypothesized that biological factors (age, mass, and sex), food availability (hard mast and wild hogs (Sus scrofa)), and nuisance status would influence food selection by black bears and changes in their feeding history would be measureable using stable isotopes. We developed a set of a priori models using nine variables to examine changes in black bear stable isotope values. We found no support for changes in δ(13)C values associated with any of the nine variables we analyzed. Bears had enriched (15)N in years with low white oak mast production and depleted (15)N when white oak mast was abundant. Subadults had enriched (15)N compared with adults and older adults. Variation in δ(15)N increased from 1980-1991 to 1992-2000 when hard mast production had greater fluctuations. Bears in a better physical condition appeared more likely to access foods with higher protein content. In years of low white oak acorn production, larger bears and subadults likely turned to alternative food sources. The long-term variation detected in this study was important in identifying which bears were potentially more susceptible to changes in availability of hard mast.

  10. Tissue preservation biases in stable isotopes of fishes and molluscs from Patagonian lakes.

    Science.gov (United States)

    Correa, C

    2012-11-01

    Field work commonly involves preserving samples for later use; however, most preservation methods distort stable-isotope (SI) signatures that are of interest to ecologists. Although preservation of muscle samples with table salt and rubbing alcohol affected the SI (δ(13)C and δ(15)N) of important consumers in Patagonian lakes (molluscs and fishes), variation among individuals and lakes generally exceeded that among preservation treatments. Mathematical corrections for these preservation biases are provided, and a potentially bias-free preservation by air-drying is suggested. © 2012 The Author. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  11. Tracing metal-silicate segregation and late veneer in the Earth and the ureilite parent body with palladium stable isotopes

    Science.gov (United States)

    Creech, J. B.; Moynier, F.; Bizzarro, M.

    2017-11-01

    Stable isotope studies of highly siderophile elements (HSE) have the potential to yield valuable insights into a range of geological processes. In particular, the strong partitioning of these elements into metal over silicates may lead to stable isotope fractionation during metal-silicate segregation, making them sensitive tracers of planetary differentiation processes. We present the first techniques for the precise determination of palladium stable isotopes by MC-ICPMS using a 106Pd-110Pd double-spike to correct for instrumental mass fractionation. Results are expressed as the per mil (‰) difference in the 106Pd/105Pd ratio (δ106Pd) relative to an in-house solution standard (Pd_IPGP) in the absence of a certified Pd isotopic standard. Repeated analyses of the Pd isotopic composition of the chondrite Allende demonstrate the external reproducibility of the technique of ±0.032‰ on δ106Pd. Using these techniques, we have analysed Pd stable isotopes from a range of terrestrial and extraterrestrial samples. We find that chondrites define a mean δ106Pdchondrite = -0.19 ± 0.05‰. Ureilites reveal a weak trend towards heavier δ106Pd with decreasing Pd content, similar to recent findings based on Pt stable isotopes (Creech et al., 2017), although fractionation of Pd isotopes is significantly less than for Pt, possibly related to its weaker metal-silicate partitioning behaviour and the limited field shift effect. Terrestrial mantle samples have a mean δ106Pdmantle = -0.182 ± 0.130‰, which is consistent with a late-veneer of chondritic material after core formation.

  12. Estimating the diets of animals using stable isotopes and a comprehensive Bayesian mixing model.

    Directory of Open Access Journals (Sweden)

    John B Hopkins

    Full Text Available Using stable isotope mixing models (SIMMs as a tool to investigate the foraging ecology of animals is gaining popularity among researchers. As a result, statistical methods are rapidly evolving and numerous models have been produced to estimate the diets of animals--each with their benefits and their limitations. Deciding which SIMM to use is contingent on factors such as the consumer of interest, its food sources, sample size, the familiarity a user has with a particular framework for statistical analysis, or the level of inference the researcher desires to make (e.g., population- or individual-level. In this paper, we provide a review of commonly used SIMM models and describe a comprehensive SIMM that includes all features commonly used in SIMM analysis and two new features. We used data collected in Yosemite National Park to demonstrate IsotopeR's ability to estimate dietary parameters. We then examined the importance of each feature in the model and compared our results to inferences from commonly used SIMMs. IsotopeR's user interface (in R will provide researchers a user-friendly tool for SIMM analysis. The model is also applicable for use in paleontology, archaeology, and forensic studies as well as estimating pollution inputs.

  13. Stable chromium isotopic composition of meteorites and metal-silicate experiments: Implications for fractionation during core formation

    Science.gov (United States)

    Bonnand, P.; Williams, H. M.; Parkinson, I. J.; Wood, B. J.; Halliday, A. N.

    2016-02-01

    We present new mass independent and mass dependent Cr isotope compositions for meteorites measured by double spike thermal ionisation mass spectrometry. Small differences in both mass independent 53Cr and 54Cr relative to the Bulk Silicate Earth are reported and are very similar to previously published values. Carbonaceous chondrites are characterised by an excess in 54Cr compared to ordinary and enstatite chondrites which make mass independent Cr isotopes a useful tool for distinguishing between meteoritic groups. Mass dependent stable Cr isotope compositions for the same samples are also reported. Carbonaceous and ordinary chondrites are identical within uncertainty with average δ53 Cr values of - 0.118 ± 0.040 ‰ and - 0.143 ± 0.074 ‰ respectively. The heaviest isotope compositions are recorded by an enstatite chondrite and a CO carbonaceous chondrite, both of which have relatively reduced chemical compositions implying some stable Cr isotope fractionation related to redox processes in the circumstellar disk. The average δ53 Cr values for chondrites are within error of the estimate for the Bulk Silicate Earth (BSE) also determined by double spiking. The lack of isotopic difference between chondritic material and the BSE provides evidence that Cr isotopes were not fractionated during core formation on Earth. A series of high-pressure experiments was also carried out to investigate stable Cr isotope fractionation between metal and silicate and no demonstrable fractionation was observed, consistent with our meteorites data. Mass dependent Cr isotope data for achondrites suggest that Cr isotopes are fractionated during magmatic differentiation and therefore further work is required to constrain the Cr isotopic compositions of the mantles of Vesta and Mars.

  14. Stable Isotope Systematics in Grasshopper Assemblages Along an Elevation Gradient, Colorado

    Science.gov (United States)

    Kohn, M. J.; Evans, S.; Dean, J.; Nufio, C.

    2012-12-01

    Insects comprise over three quarters of all animal species, yet studies of body water isotopic composition are limited to only the cockroach, the hoverfly, and chironomid flies. These studies suggest that oxygen and hydrogen isotopic compositions in body water are primarily controlled by dietary water sources, with modification from respiratory and metabolic processes. In particular, outward diffusion of isotopically depleted water vapor through insect spiracles at low humidity enriches residual body water in 18O and 2H (D). Stable isotope compositions (δ18O and δD) also respond to gradients in elevation and humidity, but these influences remain poorly understood. In this study, we measured grasshopper body water and local vegetation isotopic compositions along an elevation gradient in Colorado to evaluate three hypotheses: 1) Insect body water isotopic composition is directly related to food source water composition 2) Water vapor transport alters body water isotopic compositions relative to original diet sources, and 3) Elevation gradients influence isotopic compositions in insect body water. Thirty-five species of grasshopper were collected from 14 locations in Colorado grasslands, ranging in elevation from 450 to 800 meters (n=131). Body water was distilled from previously frozen grasshopper specimens using a vacuum extraction line, furnaces (90 °C), and liquid nitrogen traps. Water samples were then analyzed for δ18O and δD on an LGR Liquid Water Isotope Analyzer, housed in the Department of Geosciences, Boise State University. Grasshopper body water isotopic compositions show wide variation, with values ranging between -76.64‰ to +42.82‰ in δD and -3.06‰ to +26.78‰ in δ18O. Precipitation δ18O values over the entire Earth excluding the poles vary by approximately 30‰, comparable to the total range measured in our single study area. Most grasshopper values deviate from the global meteoric water line relating δ18O and δD in precipitation

  15. Stable lead isotopic analyses of historic and contemporary lead contamination of San Francisco Bay estuary

    Science.gov (United States)

    Ritson, P.I.; Bouse, R.M.; Flegal, A.R.; Luoma, S.N.

    1999-01-01

    Variations in stable lead isotopic composition (240Pb, 206Pb, 207Pb, 208Pb) in three sediment cores from the San Francisco Bay estuary document temporal changes in sources of lead during the past two centuries. Sediment, with lead from natural geologic sources, and relatively homogeneous lead isotopic compositions are overlain by sediments whose isotopic compositions indicate change in the sources of lead associated with anthropogenic modification of the estuary. The first perturbations of lead isotopic composition in the cores occur in the late 1800s concordant with the beginning of industrialization around the estuary. Large isotopic shifts, toward lower 206Pb/207Pb, occur after the turn of the century in both Richardson and San Pablo Bays. A similar relationship among lead isotopic compositions and lead concentrations in both Bays suggest contamination from the same source (a lead smelter). The uppermost sediments (post 1980) of all cores also have a relatively homogenous lead isotopic composition distinct from pre-anthropogenic and recent aerosol signatures. Lead isotopic compositions of leachates from fourteen surface sediments and five marsh samples from the estuary were also analyzed. These analyses suggest that the lead isotopic signature identified in the upper horizons of the cores is spatially homogeneous among recently deposited sediments throughout the estuary. Current aerosol lead isotopic compositions [Smith, D.R., Niemeyer, S., Flegal, A.R., 1992. Lead sources to California sea otters: industrial inputs circumvent natural lead biodepletion mechanisms. Environmental Research 57, 163-175] are distinct from the isotopic compositions of the surface sediments, suggesting that the major source of lead is cycling of historically contaminated sediments back through the water column. Both the upper core sediments and surface sediments apparently derive their lead predominantly from sources internal to the estuary. These results support the idea that

  16. Stable Isotope Analysis Provides New Information on Winter Habitat Use of Declining Avian Migrants That Is Relevant to Their Conservation

    Science.gov (United States)

    Evans, Karl L.; Newton, Jason; Mallord, John W.; Markman, Shai

    2012-01-01

    Winter habitat use and the magnitude of migratory connectivity are important parameters when assessing drivers of the marked declines in avian migrants. Such information is unavailable for most species. We use a stable isotope approach to assess these factors for three declining African-Eurasian migrants whose winter ecology is poorly known: wood warbler Phylloscopus sibilatrix, house martin Delichon urbicum and common swift Apus apus. Spatially segregated breeding wood warbler populations (sampled across a 800 km transect), house martins and common swifts (sampled across a 3,500 km transect) exhibited statistically identical intra-specific carbon and nitrogen isotope ratios in winter grown feathers. Such patterns are compatible with a high degree of migratory connectivity, but could arise if species use isotopically similar resources at different locations. Wood warbler carbon isotope ratios are more depleted than typical for African-Eurasian migrants and are compatible with use of moist lowland forest. The very limited variance in these ratios indicates specialisation on isotopically restricted resources, which may drive the similarity in wood warbler populations' stable isotope ratios and increase susceptibility to environmental change within its wintering grounds. House martins were previously considered to primarily use moist montane forest during the winter, but this seems unlikely given the enriched nature of their carbon isotope ratios. House martins use a narrower isotopic range of resources than the common swift, indicative of increased specialisation or a relatively limited wintering range; both factors could increase house martins' vulnerability to environmental change. The marked variance in isotope ratios within each common swift population contributes to the lack of population specific signatures and indicates that the species is less vulnerable to environmental change in sub-Saharan Africa than our other focal species. Our findings demonstrate how

  17. Laboratory and field methods for stable isotope analysis in human biology.

    Science.gov (United States)

    Reitsema, Laurie J

    2015-01-01

    Stable isotope analysis (SIA; carbon, hydrogen, nitrogen, sulfur, and oxygen) of human tissues offers a means for assessing diet among living humans. Stable isotope ratios of broad categories of food and drink food vary systematically, and stable isotope ratios in consumer tissues represent a composite of the isotopic ratios of food and drink consumed during an individual's life. Isotopic evidence for diet is independent of errors in informant recall, and accrues during time periods when researchers are absent. Beyond diet reconstruction, tissue stable isotope ratios are sensitive to excursions from homeostasis, such as starvation and rapid growth. Because of their relationship to diet, geographic location, hydration, and nutritional status, stable isotope signatures in human tissues offer a window into human biocultural adaptations, past and present. This article describes methods for SIA that may be usefully applied in studies of living humans, with emphasis placed on carbon and nitrogen. Some of the ecological, physiological, and evolutionary applications of stable isotope data among living humans are discussed. By incorporating SIA in research, human biologists facilitate a productive dialog with bioarchaeologists, who routinely use stable isotope evidence, mingling different perspectives on human biology and behavior. © 2015 Wiley Periodicals, Inc.

  18. A Teaching Exercise to Introduce Stable Isotope Fractionation of Metals into Geochemistry Courses

    Science.gov (United States)

    Weiss, Dominik J.; Harris, Caroline; Maher, Kate; Bullen, Thomas

    2013-01-01

    Variations in the isotopic composition of elements have been widely used to study earth's climate, biosphere, and interior, and more recently to track the fate of contaminants. Within the broad range of elements that exhibit measureable isotopic variations, metal stable isotopes are increasingly applied across the biological, geological,…

  19. A guide for the laboratory information management system (LIMS) for light stable isotopes--Versions 7 and 8

    Science.gov (United States)

    Coplen, Tyler B.

    2000-01-01

    The reliability and accuracy of isotopic data can be improved by utilizing database software to (i) store information about samples, (ii) store the results of mass spectrometric isotope-ratio analyses of samples, (iii) calculate analytical results using standardized algorithms stored in a database, (iv) normalize stable isotopic data to international scales using isotopic reference materials, and (v) generate multi-sheet paper templates for convenient sample loading of automated mass-spectrometer sample preparation manifolds. Such a database program, the Laboratory Information Management System (LIMS) for Light Stable Isotopes, is presented herein. Major benefits of this system include (i) a dramatic improvement in quality assurance, (ii) an increase in laboratory efficiency, (iii) a reduction in workload due to the elimination or reduction of retyping of data by laboratory personnel, and (iv) a decrease in errors in data reported to sample submitters. Such a database provides a complete record of when and how often laboratory reference materials have been analyzed and provides a record of what correction factors have been used through time. It provides an audit trail for laboratories. LIMS for Light Stable Isotopes is available for both Microsoft Office 97 Professional and Microsoft Office 2000 Professional as versions 7 and 8, respectively. Both source code (mdb file) and precompiled executable files (mde) are available. Numerous improvements have been made for continuous flow isotopic analysis in this version (specifically 7.13 for Microsoft Access 97 and 8.13 for Microsoft Access 2000). It is much easier to import isotopic results from Finnigan ISODAT worksheets, even worksheets on which corrections for amount of sample (linearity corrections) have been added. The capability to determine blank corrections using isotope mass balance from analyses of elemental analyzer samples has been added. It is now possible to calculate and apply drift corrections to isotopic

  20. Stable isotopic characteristic of Taiwan's precipitation: A case study of western Pacific monsoon region

    Science.gov (United States)

    Peng, Tsung-Ren; Wang, Chung-Ho; Huang, Chi-Chao; Fei, Li-Yuan; Chen, Chen-Tung Arthur; Hwong, Jeen-Lian

    2010-01-01

    The stable oxygen and hydrogen isotopic features of precipitation in Taiwan, an island located at the western Pacific monsoon area, are presented from nearly 3,500 samples collected during the past decade for 20 stations. Results demonstrate that moisture sources from diverse air masses with different isotopic signals are the main parameter in controlling the precipitation's isotope characteristics. The air mass from polar continental (Pc) region contributes the precipitation with high deuterium excess values (up to 23‰) and relatively enriched isotope compositions (e.g., - 3.2‰ for δ 18O) during the winter with prevailing northeasterly monsoon. By contrast, air masses from equatorial maritime (Em) and tropical maritime (Tm) supply the precipitation with low deuterium excess values (as low as about 7‰) and more depleted isotope values (e.g., - 8.9‰ and - 6.0‰ for δ 18O of Tm and Em, respectively) during the summer with prevailing southwesterly monsoon. Thus seasonal differences in terms of δ 18O, δD, and deuterium excess values are primarily influenced by the interactions among various precipitation sources. While these various air masses travel through Taiwan, secondary evaporation effects further modify the isotope characteristics of the inland precipitation, such as raindrop evaporation (reduces the deuterium excess of winter precipitation) and moisture recycling (increases the deuterium excess of summer precipitation). The semi-quantitative estimations in terms of evaluation for changes in the deuterium excess suggest that the raindrop evaporation fractions for winter precipitation range 7% to 15% and the proportions of recycling moisture in summer precipitation are less than 5%. Additionally, the isotopic altitude gradient in terms of δ 18O for summer precipitation is - 0.22‰/100 m, greater than - 0.17‰/100 m of winter precipitation. The greater isotopic gradient in summer can be attributed to a higher temperature vs. altitude gradient

  1. Astronaut Bones: Stable Calcium Isotopes in Urine as a Biomarker of Bone Mineral Balance

    Science.gov (United States)

    Skulan, J.; Gordon, G. W.; Romaniello, S. J.; Anbar, A. D.; Smith, S. M.; Zwart, S.

    2016-12-01

    Bone loss is a common health concern, in conditions ranging from osteoporosis to cancer. Bone loss due to unloading is also an important health issue for astronauts. We demonstrate stable calcium isotopes, a tool developed in geochemistry, are capable of detecting real-time quantitative changes in net bone mineral balance (BMB) using serum and urine [1]. We validated this technique by comparing with DEXA and biomarker data in subjects during bed rest, a ground-based analog of space flight effects [2-4]. We now apply this tool to assess changes in astronauts' BMB before, during and after 4-6 month space missions. There is stable isotope fractionation asymmetry between bone formation and resorption. During bone formation there is a mass-dependent preference for "lighter" calcium isotopes to be removed from serum and incorporated into bone mineral. During bone resorption, there is no measurable isotopic discrimination between serum and bone. Hence, when bone formation rates exceed that of resorption, serum and urine become isotopically "heavy" due to the sequestration of "light" calcium in bone. Conversely, when bone resorption exceeds bone formation, serum and urine become isotopically "light" due to the release of the sequestered light calcium from bone. We measured Ca isotopes in urine of thirty International Space Station astronauts. Average Ca isotope values in astronauts' urine shift isotopically lighter during microgravity, consistent with negative net BMB. Within a month of return to Earth, astronauts returned to within error of their δ44Ca value prior to departure. Urine samples from astronauts testing bone loss countermeasures showed bisphosphonates provide a viable pharmacological countermeasure. Some, but not all, individuals appear able to resist bone loss through diet and intensive resistive exercise alone. This is a promising new technique for monitoring BMB in astronauts, and hopefully someday on the way to/from Mars, this also has important clinical

  2. 2001 uses of stable isotopes in the assessment of nutrient status and metabolism.

    Science.gov (United States)

    Schoeller, Dale A

    2003-01-01

    Stable isotopes are nonradioactive and can be safely administered to humans; yet, because of the isotopic difference, can be distinguished from the unlabeled moiety and thus trace the nutrient uptake and elimination. Stable isotope applications include measurement of nutrient absorption, determination of nutrient body stores, tracing routes of nutrient metabolism, measuring nutrient fluxes through specific pathways, and measuring nutrient elimination. The ability to assess the dynamics of nutrient metabolism in vivo has been vital in the study of nutrient requirements, nutrient metabolism, mechanisms of nutrient homeostasis, and nutrient toxicity. Stable isotopes provide a window into human metabolism that is particularly valuable to the quantitative study of human nutrition.

  3. Uses of stable isotopes in the assessment of nutrient status and metabolism.

    Science.gov (United States)

    Schoeller, Dale A

    2002-09-01

    Stable isotopes are nonradioactive and can be safely administered to humans; yet, because of the isotopic difference, can be distinguished from the unlabeled moiety and thus trace the nutrient uptake and elimination. Stable isotope applications include measurement of nutrient absorption, determination of nutrient body stores, tracing routes of nutrient metabolism, measuring nutrient fluxes through specific pathways, and measuring nutrient elimination. The ability to assess the dynamics of nutrient metabolism in vivo has been vital in the study of nutrient requirements, nutrient metabolism, mechanisms of nutrient homeostasis, and nutrient toxicity. Stable isotopes provide a window into human metabolism that is particularly valuable to the quantitative study of human nutrition.

  4. Carbon and nitrogen isotope analysis for amino acids from biological sample

    Energy Technology Data Exchange (ETDEWEB)

    Minagawa, Masao; Egawa, Saho; Kabaya, Yuko; Karasawa-Tsuru, Kyoko (Mitsubishi Kasei Inst. of Life Sciences, Machida, Tokyo (Japan))

    1992-02-01

    Evaluation was made for carbon and nitrogen stable isotope analyses of amino acids which were hydrolyzed from biological samples. Alteration of isotopic compositions during chemical preparations was studied in incorporation with organic solvent, acid hydrolysis, and ion-exchange chromatography. Based on such assessment, analyses of isotope compositions of single amino acids were made for collagen and plant protein. The carbon isotope composition of soybean showed consistent pattern with algal amino acids. Similarity was also found in the intermolecular relationship of {delta}{sup 13}C and {delta}{sup 15}N between collagen and soybean protein. (author).

  5. Uniform stable-isotope labeling in mammalian cells: formulation of a cost-effective culture medium

    NARCIS (Netherlands)

    Egorova-Zachernyuk, T.A.; Bosman, G.J.C.G.M.; Grip, W.J. de

    2011-01-01

    Uniform stable-isotope labeling of mammalian cells is achieved via a novel formulation of a serum-free cell culture medium that is based on stable-isotope-labeled autolysates and lipid extracts of various microbiological origin. Yeast autolysates allow complete replacement of individual amino acids

  6. IsoBank – Stable isotope ecology in the age of ‘Big Data’

    Science.gov (United States)

    Stable isotopes ratios provide valuable information to fish biologists working in a diverse range of fields: e.g. ecologists, population biologists and fishery managers. Ecologists take advantage of stable isotope ratios to provide information on the diet and migration history of consumers or when a...

  7. Advisory group meeting on stable isotope labelled compounds in biomedical studies

    International Nuclear Information System (INIS)

    Vera Ruiz, H.; Parr, R.M.

    1985-11-01

    The programme of the meeting was restricted to topics involving applications of stable isotopes of the lighter elements (H, C, N, O). The current status of stable isotope techniques and applications in nutritional and biomedical studies, the applicability of these techniques in developing countries and the IAEA's future programmes on this topic were discussed

  8. Contribution of stable isotopes to the study of pharmacokinetics of magnesium salts

    International Nuclear Information System (INIS)

    Benech, H.

    1999-01-01

    The use of stable isotopes as labels is becoming an attractive tool for the study of magnesium behavior in humans. It has been used two stable isotopes of magnesium, 25 Mg and 26 Mg, to measure the absolute bioavailability of a pharmaceutical form of magnesium. (N.C.)

  9. Insights into Wilson's Warbler migration from analyses of hydrogen stable-isotope ratios

    Science.gov (United States)

    Jeffrey F. Kelly; Viorel Atudorei; Zachary D. Sharp; Deborah M. Finch

    2002-01-01

    Our ability to link the breeding locations of individual passerines to migration stopover sites and wintering locations is limited. Stable isotopes of hydrogen contained in bird feathers have recently shown potential in this regard. We measured hydrogen stable-isotope ratios (deltaD) of feathers from breeding, migrating, and wintering Wilson's Warblers. Analyses...

  10. Stable isotope ratios and reforestation potential in Acacia koa populations on Hawai'i

    Science.gov (United States)

    Shaneka Lawson; Carrie Pike

    2017-01-01

    Stable carbon and nitrogen isotopes can be influenced by a multitude of factors including elevation, precipitation rate, season, and temperature. This work examined variability in foliar stable carbon (δ13C) and nitrogen (δ15N) isotope ratios of koa (Acacia koa) across 17 sites on Hawai'i Island, delineated by elevation and precipitation...

  11. Insights from stable light isotopes on enamel defects and weaning in ...

    Indian Academy of Sciences (India)

    Unknown

    reiterates the value of stable isotope analyses in determining both the behaviour of fossil animals and the environmental conditions that prevailed during tooth development. [Franz-Odendaal T A, Lee-Thorp J A and Chinsamy A 2003 Insights from stable light isotopes on enamel defects and weaning in Pliocene herbivores ...

  12. Monitoring biodegradation of hydrocarbons by stable isotope fractionation

    Science.gov (United States)

    Dorer, Conrad; Fischer, Anko; Herrmann, Steffi; Richnow, Hans-Hermann; Vogt, Carsten

    2010-05-01

    In the last decade, several studies have demonstrated that stable isotope tools are highly applicable for monitoring anaerobic biodegradation processes. An important methodological approach is to characterize distinct degradation pathways with respect to the specific mechanism of C-H-bond cleavage and to quantify the extent of biodegradation by compound specific isotope analysis (CSIA). Here, enrichment factors (ɛbulk) needed for a CSIA field site approach must be determined in laboratory reference experiments. Recent research results from different laboratories have shown that single ɛbulk values for similar degradation pathways can be highly variable; thus, the use of two-dimensional compound specific isotope analysis (2D-CSIA) has been encouraged for characterizing biodegradation pathways more precisely. 2D-CSIA for hydrocarbons can be expressed by the slope of the linear regression for hydrogen versus carbon discrimination known as lambda ≈ ɛHbulk/ɛCbulk. We determined the carbon and hydrogen isotope fractionation for the biodegradation of benzene, toluene and xylenes by various reference cultures. Specific enzymatic reactions initiating different biodegradation pathways could be distinguished by 2D-CSIA. For the aerobic di- and monohydroxylation of the benzene ring, lambda values always lower than 9 were observed. Enrichment cultures degrading benzene anaerobically produced significant different values: lambda values between 8-19 were oberved for nitrate-reducing consortia, whereas sulfate-reducing and methanogenic consortia showed always lambda values greater than 20 [1,2]. The observed variations suggest that (i) aerobic benzene biodegradation can be distinguished from anaerobic biodegradation, and (ii) that more than a single mechanism seems to exist for the activation of benzene under anoxic conditions. lambda values for anaerobic toluene degradation initiated by the enzyme benzylsuccinate synthase (BSS) ranged from 4 to 41, tested with strains using

  13. Optimization of post-run corrections for water stable isotope measurements by laser spectroscopy

    Science.gov (United States)

    van Geldern, Robert; Barth, Johannes A. C.

    2013-04-01

    Light stable isotope analyses of hydrogen and oxygen of water are used in numerous aquatic studies from various scientific fields. The advantage of using stable isotope ratios is that water molecules serve as ubiquitous and already present natural tracers. Traditionally, the samples were analyzed in the laboratory by isotope ratio mass spectrometry (IRMS). Within recent years these analyses have been revolutionized by the development of new isotope ratio laser spectroscopy (IRIS) systems that are said to be cheaper, more robust and mobile compared to IRMS. Although easier to operate, laser systems also need thorough calibration with international reference materials and raw data need correction for analytical effects. A major issue in systems that use liquid injection via a vaporizer module is the memory effect, i.e. the carry-over from the previous analyzed sample in a sequence. This study presents an optimized and simple post-run correction procedure for liquid water injection developed for a Picarro water analyzer. The Excel(TM) template will rely exclusively on standard features implemented in MS Office without the need to run macros, additional code written in Visual Basic for Applications (VBA) or to use a database-related software such as MS Access or SQL Server. These protocols will maximize precision, accuracy and sample throughput via an efficient memory correction. The number of injections per unknown sample can be reduced to 4 or less. This procedure meets the demands of faster throughput with reduced costs per analysis. Procedures were verified by an international proficiency test and traditional IRMS techniques. The template is available free for scientific use from the corresponding author or the journals web site (van Geldern and Barth, 2012). References van Geldern, R. and Barth, J.A.C. (2012) Limnol. Oceanogr. Methods 10:1024-1036 [doi: 10.4319/lom.2012.10.1024

  14. Seasonal variation in stable carbon and nitrogen isotope values of bats reflect environmental baselines.

    Directory of Open Access Journals (Sweden)

    Ana G Popa-Lisseanu

    Full Text Available The stable carbon and nitrogen isotope composition of animal tissues is commonly used to trace wildlife diets and analyze food chains. Changes in an animal's isotopic values over time are generally assumed to indicate diet shifts or, less frequently, physiological changes. Although plant isotopic values are known to correlate with climatic seasonality, only a few studies restricted to aquatic environments have investigated whether temporal isotopic variation in consumers may also reflect environmental baselines through trophic propagation. We modeled the monthly variation in carbon and nitrogen isotope values in whole blood of four insectivorous bat species occupying different foraging niches in southern Spain. We found a common pattern of isotopic variation independent of feeding habits, with an overall change as large as or larger than one trophic step. Physiological changes related to reproduction or to fat deposition prior to hibernation had no effect on isotopic variation, but juvenile bats had higher δ13C and δ15N values than adults. Aridity was the factor that best explained isotopic variation: bat blood became enriched in both 13C and 15N after hotter and/or drier periods. Our study is the first to show that consumers in terrestrial ecosystems reflect seasonal environmental dynamics in their isotope values. We highlight the danger of misinterpreting stable isotope data when not accounting for seasonal isotopic baselines in food web studies. Understanding how environmental seasonality is integrated in animals' isotope values will be crucial for developing reliable methods to use stable isotopes as dietary tracers.

  15. Estimation of microbial respiration rates in groundwater by geochemical modeling constrained with stable isotopes

    Science.gov (United States)

    Murphy, E. M.; Schramke, J. A.

    1998-11-01

    Changes in geochemistry and stable isotopes along a well-established groundwater flow path were used to estimate in situ microbial respiration rates in the Middendorf aquifer in the southeastern United States. Respiration rates were determined for individual terminal electron acceptors including O 2, MnO 2, Fe 3+, and SO 42-. The extent of biotic reactions were constrained by the fractionation of stable isotopes of carbon and sulfur. Sulfur isotopes and the presence of sulfur-oxidizing microorganisms indicated that sulfate is produced through the oxidation of reduced sulfur species in the aquifer and not by the dissolution of gypsum, as previously reported. The respiration rates varied along the flow path as the groundwater transitioned between primarily oxic to anoxic conditions. Iron-reducing microorganisms were the largest contributors to the oxidation of organic matter along the portion of the groundwater flow path investigated in this study. The transition zone between oxic and anoxic groundwater contained a wide range of terminal electron acceptors and showed the greatest diversity and numbers of culturable microorganisms and the highest respiration rates. A comparison of respiration rates measured from core samples and pumped groundwater suggests that variability in respiration rates may often reflect the measurement scales, both in the sample volume and the time-frame over which the respiration measurement is averaged. Chemical heterogeneity may create a wide range of respiration rates when the scale of the observation is below the scale of the heterogeneity.

  16. Stable carbon isotope analysis of fluvial sediment fluxes over two contrasting C(4) -C(3) semi-arid vegetation transitions.

    Science.gov (United States)

    Puttock, Alan; Dungait, Jennifer A J; Bol, Roland; Dixon, Elizabeth R; Macleod, Christopher J A; Brazier, Richard E

    2012-10-30

    Globally, many drylands are experiencing the encroachment of woody vegetation into grasslands. These changes in ecosystem structure and processes can result in increased sediment and nutrient fluxes due to fluvial erosion. As these changes are often accompanied by a shift from C(4) to C(3) vegetation with characteristic δ(13) C values, stable isotope analysis provides a promising mechanism for tracing these fluxes. Input vegetation, surface sediment and fluvially eroded sediment samples were collected across two contrasting C(4) -C(3) dryland vegetation transitions in New Mexico, USA. Isotope ratio mass spectrometric analyses were performed using a Carlo Erba NA2000 analyser interfaced to a SerCon 20-22 isotope ratio mass spectrometer to determine bulk δ(13) C values. Stable isotope analyses of contemporary input vegetation and surface sediments over the monitored transitions showed significant differences (p fluvially eroded sediment from each of the sites, with no significant variation between surface sediment and eroded sediment values. The significant differences in bulk δ(13) C values between sites were dependent on vegetation input. Importantly, these values were robustly expressed in fluvially eroded sediments, suggesting that stable isotope analysis is suitable for tracing sediment fluxes. Due to the prevalent nature of these dryland vegetation transitions in the USA and globally, further development of stable isotope ratio mass spectrometry has provided a valuable tool for enhanced understanding of functional changes in these ecosystems. Copyright © 2012 John Wiley & Sons, Ltd.

  17. On the use of stable oxygen isotope (δ (18)O) measurements for tracking avian movements in North America.

    Science.gov (United States)

    Hobson, Keith A; Koehler, Geoff

    2015-02-01

    Tracking migratory animals has benefitted using measurements of naturally occurring stable isotopes of hydrogen (δ (2)H) in keratinous tissues such as hair and feathers to link animal origins to continental patterns or isoscapes of δ (2)H in precipitation. However, for most taxa, much less information exists on the use of stable oxygen isotope ratios (δ (18)O) despite the fact that δ (2)H and δ (18)O are strongly linked in environmental waters through the meteoric relationship and the possibility of using both isotopes to infer greater information on origins and climatic conditions where tissues are grown. A fundamental requirement of using stable isotopes to assign individuals and populations to origins is the development of a rescaling function linking environmental food web signals to the tissue of interest and for birds, this has not been carried out. Here, we derived the relationship between H and O isotopes in known source feathers of 104 individuals representing 11 species of insectivorous passerines sampled across the strong precipitation isoscape of North America. We determined again a strong expected relationship between feather δ (2)H (δ (2)Hf) and long-term amount-weighted precipitation δ (2)H (δ (2)Hp; r (2) = 0.77), but the corresponding relationship between δ (18)Of and δ (18)Op was poor (r (2) = 0.32) for the same samples. This suggests that δ (2)H measurements are currently more useful for assignment of insectivorous songbirds to precipitation isoscapes but does not preclude other uses of the δ (18)Of data. Currently, mechanisms responsible for the decoupling of H and O isotopes in food webs is poorly known, and we advocate a much broader sampling of both isotopes in the same keratinous tissues across precipitation isotope gradients and across taxa to resolve this issue and to increase the power of using water isotopes to track migratory animals.

  18. Stable isotope analysis of pollen as a palaeoindicator - Methodological considerations and future challenges

    International Nuclear Information System (INIS)

    Loader, N.J.; Hemming, D.L.

    2002-01-01

    of modern pollen were analysed for their stable carbon isotope composition and compared with environmental variables to assess the potential of this method as a new quantitative terrestrial palaeoindicator. Results demonstrate a strong positive correlation (r 2 =0.68) between the temperature during a development period (approximately 4 weeks) prior to efflorescence and δ 13 C pollen . Owing to variations in the chemical composition of the pollen grains and associated post depositional diagenesis we favour the isolation of the sporopollenin exina for isotopic analysis. A broad similarity in isotopic response was observed between three European tree genera, however significant absolute differences in δ 13 C pollen preclude any meaningful interpretation or palaeoenvironmental inference based solely upon a potentially variable bulk pollen sample. Consequently, we propose the isolation and analysis of a single genus when examining samples from antiquity. Preliminary extraction methods indicate that this approach is feasible using manual separation/hand picking methods and standard combustion continuous-flow isotope ratio mass spectrometry. If these initial results are representative of wider plant response, δ 13 C pollen may be used to reconstruct environmental change during pollen development and provide an indication of variations in mean annual temperature. (author)

  19. Neutron Capture Radiography: Neutron Capture Radiography:a technique for isotopic labelling and analytical imaging with a few stable isotopes

    Directory of Open Access Journals (Sweden)

    Michel Thellier

    2006-01-01

    Full Text Available NCR (neutron capture radiography may be used successfully for the imaging of one of the stable isotopes of a few chemical elements (especially 6Li and 10B, possibly also 14N, 17O, and others and for labelling experiments using these stable isotopes. Other physical techniques compete with NCR. However, NCR can remain extremely useful in a certain number of cases, because it is usually more easily done and is less expensive than the other techniques.

  20. Neutron Capture Radiography: Neutron Capture Radiography:a technique for isotopic labelling and analytical imaging with a few stable isotopes

    OpenAIRE

    Thellier, Michel; Ripoll, Camille

    2006-01-01

    NCR (neutron capture radiography) may be used successfully for the imaging of one of the stable isotopes of a few chemical elements (especially 6Li and 10B, possibly also 14N, 17O, and others) and for labelling experiments using these stable isotopes. Other physical techniques compete with NCR. However, NCR can remain extremely useful in a certain number of cases, because it is usually more easily done and is less expensive than the other techniques.

  1. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    Science.gov (United States)

    Scott Aaron, W.; Tracy, Joe G.; Collins, Emory D.

    1997-02-01

    The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 y. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations to be conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; ISO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capablities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies.

  2. Status of stable isotope enrichment, products, and services at the Oak Ridge National Laboratory

    International Nuclear Information System (INIS)

    Aaron, W.S.; Tracy, J.G.; Collins, E.D.

    1996-01-01

    The Oak Ridge National Laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 years. Very significant changes have occurred in this effort over the past several years, and, while many of these changes have had a negative impact on the availability of enriched isotopes, more recent developments are actually improving the situation for both the users and the producers of enriched isotopes. ORNL is still a major producer and distributor of radioisotopes, but future isotope enrichment operations conducted at the Isotope Enrichment Facility (IEF) will be limited to stable isotopes. Among the positive changes in the enriched stable isotope area are a well-functioning, long-term contract program, which offers stability and pricing advantages; the resumption of calutron operations; the adoption of prorated conversion charges, which greatly improves the pricing of isotopes to small users; SIO 9002 registration of the IEF's quality management system; and a much more customer-oriented business philosophy. Efforts are also being made to restore and improve upon the extensive chemical and physical form processing capabilities that once existed in the enriched stable isotope program. Innovative ideas are being pursued in both technical and administrative areas to encourage the beneficial use of enriched stable isotopes and the development of related technologies

  3. Natural abundance variations in stable isotopes and their potential uses in animal physiological ecology.

    Science.gov (United States)

    Gannes, L Z; Martínez del Rio, C; Koch, P

    1998-03-01

    Chemical, biological, and physical processes lead to distinctive "isotopic signatures" in biological materials that allow tracing of the origins of organic substances. Isotopic variation has been extensively used by plant physiological ecologists and by paleontologists, and recently ecologists have adopted the use of stable isotopes to measure ecosystem patterns and processes. To date, animal physiological ecologists have made minimal use of naturally occurring stable isotopes as tracers. Here we provide a review of the current and potential uses of naturally occurring stable isotopes in animal physiological ecology. We outline the physical and biological processes that lead to variation in isotopic abundance in plants and animals. We summarize current uses in animal physiological ecology (diet reconstruction and animal movement patterns), and suggest areas of research where the use of stable isotopes can be fruitful (protein balance and turnover and the allocation of dietary nutrients). We argue that animal physiological ecologists can benefit from including the measurement of naturally occurring stable isotopes in their battery of techniques. We also argue that animal physiologists can make an important contribution to the emerging field of stable isotopes in biology by testing experimentally the plethora of assumptions upon which the techniques rely.

  4. Verification of Egg Farming Systems from The Netherlands and New Zealand Using Stable Isotopes.

    Science.gov (United States)

    Rogers, Karyne M; van Ruth, Saskia; Alewijn, Martin; Philips, Andy; Rogers, Pam

    2015-09-30

    Stable isotopes were used to develop authentication criteria of eggs laid under cage, barn, free range, and organic farming regimens from The Netherlands and New Zealand. A training set of commercial poultry feeds and egg albumen from 49 poultry farms across The Netherlands was used to determine the isotopic variability of organic and conventional feeds and to assess trophic effects of these corresponding feeds and barn, free range, and organic farming regimens on corresponding egg albumen. A further 52 brands of New Zealand eggs were sampled from supermarket shelves in 2008 (18), 2010 (30), and 2014 (4) to characterize and monitor changes in caged, barn, free range, and organic egg farming regimens. Stable carbon (δ(13)C) and nitrogen (δ(15)N) isotopes of 49 commercial poultry feeds and their corresponding egg albumens reveals that Dutch poultry are fed exclusively on a plant-based feed and that it is possible to discriminate between conventional and organic egg farming regimens in The Netherlands. Similarly, it is possible to discriminate between New Zealand organic and conventional egg farming regimens, although in the initial screening in 2008, results showed that some organic eggs had isotope values similar to those of conventional eggs, suggesting hens were not exclusively receiving an organic diet. Dutch and New Zealand egg regimens were shown to have a low isotopic correlation between both countries, because of different poultry feed compositions. In New Zealand, both conventional and organic egg whites have higher δ(15)N values than corresponding Dutch egg whites, due to the use of fishmeal or meat and bone meal (MBM), which is banned in European countries. This study suggests that stable isotopes (specifically nitrogen) show particular promise as a screening and authentication tool for organically farmed eggs. Criteria to assess truthfulness in labeling of organic eggs were developed, and we propose that Dutch organic egg whites should have a minimum

  5. Stable Strontium Isotope (δ88/86Sr) Fractionation in the Marine Realm: A Pilot Study

    OpenAIRE

    Krabbenhöft, André

    2011-01-01

    The determination of the isotopic composition of natural substances is an important field of research within isotope geochemistry. Especially the investigation of the alkaline earth element strontium (Sr) plays an important role in geological and geochemical research. In order to quantify the degree of natural stable Sr isotope fractionation a double spike technique was developed in the frame of this study. This technique allows the precise determination of natural Sr isotope frac...

  6. Carbon and nitrogen stable isotopes in U.S. milk: Insight into production process.

    Science.gov (United States)

    Bostic, Joshua N; Hagopian, William M; Jahren, A Hope

    2018-04-15

    Stable isotope analysis (SIA), a potential method of verifying the geographic origin and production method of dairy products, has not been applied to United States (U.S.) dairy samples on a national scale. To determine the potential of carbon and nitrogen SIA in authenticity assessment of U.S. dairy products, we analyzed a geographically representative collection of conventional milk samples to determine isotopic variations with (1) Purchase Location and (2) Macronutrient Content. A total of 136 milk samples spanning five commercially available varieties (3.25% [i.e., 'whole'], 2%, 1%, 0% [i.e., 'skim'] and 1% chocolate) were collected from randomly selected counties across the U.S. as part of the United States Department of Agriculture's (USDA's) National Food and Nutrient Analysis program. δ 13 C and δ 15 N values of bulk samples determined via elemental analysis/isotope ratio mass spectrometry (EA/IRMS) were used to assess the contribution of fat content, added sugar content and census-designated region of collection to isotopic variations within the dataset. There was a negative linear relationship between fat content and δ 13 C values, with average milk δ 13 C values decreasing by 0.33‰ for each 8.75% increase in dry weight (1% wet weight) fat content. The average δ 13 C value of flavored 1% chocolate milk samples, which contain an additional 12 g of added sugar, was 2.05‰ higher than that of 1% unflavored milk (-16.47‰ for chocolate milk vs -18.52‰ for unflavored milk). When controlling for macronutrient content, milk samples collected in West region supermarkets possessed significantly lower δ 13 C values than samples collected from Midwest, South, and Northeast regions. δ 15 N values did not vary with macronutrient content or region of collection. Carbon stable isotope ratios in U.S. milk samples varied with macronutrient content and region of purchase, suggesting that SIA can provide insight into production processes within the U.S. dairy

  7. Stable Isotope Characteristics of Akiri Vein Copper Mineralization ...

    African Journals Online (AJOL)

    The Akiri vein copper mineralization was investigated for its carbon and oxygen isotopic composition to determine the characteristics of the mineralizing fluid. Carbon and oxygen isotope analyses of Akiri siderite range between δ13C values (-1.05 to -1.71‰) and δ13O values (-14.94 to -15.18) respectively. δ 13C isotopic ...

  8. Stable isotope distribution in continental Maastrichtian vertebrates from the Haţeg Basin, South Carpathians

    Science.gov (United States)

    Bojar, Ana-Voica; Csiki, Zoltan; Grigorescu, Dan

    2010-05-01

    The oxygen isotopic compositions of biogenic apatite from crocodiles, turtles and dinosaurs, and their relationship to climate and physiology have been evidenced by several studies (Barrick and Showers, 1995; Kolodny et al., 1996; Barrick et al., 1999; Fricke and Rogers, 2000; Stoskopf et al., 2001; Straight et al., 2004; Amiot et al., 2007). To date, few attempts have been made to correlate the enamel d13C to dietary resources of dinosaurs (Bocherens et al., 1988; Stanton Thomas and Carlson, 2004; Fricke and Pearson, 2008; Fricke, et al., 2008). One additional complication is that for dinosaurs, the d18O of enamel phosphate depends on both body water and variations in body temperature. Several studies addressed the issue of endothermy vs. ectothermy of fossil vertebrates by studying inter- and intra-bone and enamel isotopic variability (Barrick and Showers, 1994, 1995; Barrick et al., 1996; 1998; Fricke and Rogers, 2000). More recent investigations provided evidence for inter-tooth temporal variations and related them to seasonality and/or changes in physiology (Straight et al., 2004; Stanton Thomas and Carlson, 2004). The main objectives of this study are to extract palaeoclimatic information considering, beside lithofacial characteristics and the isotopic distribution of carbonates formed in paleosols, the stable isotope composition of vertebrate remains from the Haţeg Basin. We also sampled several teeth along their growth axis in order to get further information about growth rates and the amplitude of isotopic variation. Located in the South Carpathians in Romania, the Haţeg Basin contains a thick sequence of Maastrichtian continental deposits yielding a rich dinosaur and mammalian fauna. Stable isotope analyses of both calcretes and dinosaur, crocodilian and turtle remains from two localities (Tuştea and Sibişel) were integrated in order to reconstruct environmental conditions during the Maastrichtian time and to gain further insights into the metabolism

  9. Stable isotope studies of nicotine kinetics and bioavailability

    International Nuclear Information System (INIS)

    Benowitz, N.L.; Jacob, P. III; Denaro, C.; Jenkins, R.

    1991-01-01

    The stable isotope-labeled compound 3',3'-dideuteronicotine was used to investigate the disposition kinetics of nicotine in smokers, the systemic absorption of nicotine from cigarette smoke, and the bioavailability of nicotine ingested as oral capsules. Blood levels of labeled nicotine could be measured for 9 hours after a 30-minute intravenous infusion. Analysis of disposition kinetics in 10 healthy men revealed a multiexponential decline after the end of an infusion, with an elimination half-life averaging 203 minutes. This half-life was longer than that previously reported, indicating the presence of a shallow elimination phase. Plasma clearance averaged 14.6 ml/min/kg. The average intake of nicotine per cigarette was 2.29 mg. A cigarette smoke-monitoring system that directly measured particulate matter in smoke was evaluated in these subjects. Total particulate matter, number of puffs on the cigarette, total puff volume, and time of puffing correlated with the intake of nicotine from smoking. The oral bioavailability of nicotine averaged 44%. This bioavailability is higher than expected based on the systemic clearance of nicotine and suggests that there may be significant extrahepatic metabolism of nicotine

  10. Stable isotope tracer marking of individual boll weevils

    International Nuclear Information System (INIS)

    James, W.D.; Showler, A.T.; Armstrong, J.S.; Westbrook, J.K.

    2006-01-01

    Stable isotope markers have been used to study animal nutrition for several decades and more recently to study the foraging and cultural habits of imported fire ants. In this work, we have extended that effort to evaluate the potential for marking boll weevils, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), with the rare earth element samarium to aid in studies of insect invasion and pest eradication protocols. Neutron activation analysis (NAA) was performed on the marked boll weevils as well as plant material from the cotton squares on which the insects were fed. Samarium levels in non-dosed insects average about 20 ng/g or about 100 pg total element per insect. Our computed average determination limit was 36 pg samarium/weevil. The determination limit for cotton plant squares and leaves averaged 3.5 ng/g and 8.2 ng/g, respectively. These initial results indicate the NAA method is capable of identifying individual marked insects which have assimilated 1 ng of samarium, a ten-fold increase in content over average blank values. (author)

  11. Small Tails Tell Tall Tales--Intra-Individual Variation in the Stable Isotope Values of Fish Fin.

    Science.gov (United States)

    Hayden, Brian; Soto, David X; Jardine, Tim D; Graham, Brittany S; Cunjak, Richard A; Romakkaniemi, Atso; Linnansaari, Tommi

    2015-01-01

    Fish fin is a widely used, non-lethal sample material in studies using stable isotopes to assess the ecology of fishes. However, fish fin is composed of two distinct tissues (ray and membrane) which may have different stable isotope values and are not homogeneously distributed within a fin. As such, estimates of the stable isotope values of a fish may vary according to the section of fin sampled. To assess the magnitude of this variation, we analysed carbon (δ13C), nitrogen (δ15N), hydrogen (δ2H) and oxygen (δ18O) stable isotopes of caudal fin from juvenile, riverine stages of Atlantic salmon (Salmo salar) and brown trout (Salmo trutta). Individual fins were sub-sectioned into tip, mid and base, of which a further subset were divided into ray and membrane. Isotope variation between fin sections, evident in all four elements, was primarily related to differences between ray and membrane. Base sections were13C depleted relative to tip (~1‰) with equivalent variation evident between ray and membrane. A similar trend was evident in δ2H, though the degree of variation was far greater (~10‰). Base and ray sections were 18O enriched (~2‰) relative to tip and membrane, respectively. Ray and membrane sections displayed longitudinal variation in 15N mirroring that of composite fin (~1‰), indicating that variation in15N values was likely related to ontogenetic variation. To account for the effects of intra-fin variability in stable isotope analyses we suggest that researchers sampling fish fin, in increasing priority, 1) also analyse muscle (or liver) tissue from a subsample of fish to calibrate their data, or 2) standardize sampling by selecting tissue only from the extreme tip of a fin, or 3) homogenize fins prior to analysis.

  12. Stable isotope evolution and paleolimnology of ancient Lake Creede

    Science.gov (United States)

    Rye, Robert O.; Bethke, Philip M.; Finkelstein, David B.

    2000-01-01

    The lacustrine carbonate and travertine (tufa) deposits of ancient Lake Creede preserve a remarkable record of the isotopic evolution of the lake. That record indicates that the δ18O of the lake water, and by analogy its salinity, evolved through evaporation. Limited and less reliable data on hydrous minerals and fluid inclusions in early diagenetic carbonates indicate that the δD of the lake waters also evolved through evaporation. The isotope data place restrictions on models of the physical limnology of the lake and its evolution.The closed-basin Lake Creede formed shortly after collapse of the 26.9 Ma Creede caldera. Throughout most of its history it occupied the northern three quarters of the moat between the resurgent dome and wall of the caldera. The Creede Formation was deposited in the basin, dominantly as lacustrine sediments. Travertine mounds interfinger with Creede Formation sediments along the inner and outer margins of the lake basin. An estimated one-half of the original thickness of the Creede Formation has been lost mainly to erosion although scattered remnants of the upper portion remain on the caldera walls. Two diamond core holes (CCM-1 and CCM-2) sampled the uneroded portion of the Creede Formation as part of the U.S. Continental Drilling Program. Volcaniclastic material, including tuff units deposited directly into the lake and ash washed in from the watershed, compose the main lithologies of the Creede Formation. These volcaniclastic strata were produced by episodic ring-fracture volcanism.Lacustrine carbonates make up about 15% of the section sampled by drill core. They occur as 1 mm to 2 cm low-Mg calcite laminae alternating with siliciclastic laminae in scattered intervals throughout the preserved section. The carbonate laminae are accumulations of 5–20 µm crystallites (microsparites) and brine shrimp fecal pellets (peloids) composed mainly of microsparite particles. Low-Mg calcite also occurs as an early diagenetic replacement of

  13. Compatibility of preparatory procedures for the analysis of cortisol concentrations and stable isotope (δ13C, δ15N) ratios: a test on brown bear hair

    Science.gov (United States)

    Sergiel, Agnieszka; Hobson, Keith A.; Janz, David M.; Cattet, Marc; Selva, Nuria; Kapronczai, Luciene; Gryba, Chantel

    2017-01-01

    Abstract The measurement of naturally occurring glucocorticoids and stable isotopes of several elements has gained importance in wildlife studies in recent decades and opened a myriad of ecological applications. Cortisol and stable isotopes equilibrate in animal tissues over periods of integration related to the growth rate of the tissue, providing information reflecting systemic cortisol secretion and dietary intake. Sample preparation shares the common step of first cleaning the sample of external contamination. However, it is not well understood how different solvents used in sample preparation affect isotopic and cortisol values, and whether it is safe to follow the same procedures for both measures to optimize analyses of the same sample. We conducted an experiment to compare different preparation protocols for the analysis of cortisol concentrations and stable carbon (δ13C) and nitrogen (δ15N) isotope ratios in hair. Hair samples from 12 brown bears (Ursus arctos) were each divided into five aliquots; two aliquots were rinsed with a 2:1 chloroform:methanol (v/v) mixture with one aliquot ground prior to cortisol analysis and the other left intact for stable isotope analyses; two aliquots were washed with methanol with one aliquot ground prior to cortisol analysis and the other left intact for stable isotope analyses; and one aliquot washed with methanol and ground prior to stable isotope analyses. The cortisol, δ13C and δ15N values remained consistent following all treatments. Our results indicate that hair samples rinsed with a 2:1 chloroform:methanol mixture or washed with methanol can be used for both types of analyses. Further, hair that has been ground in a standard hair cortisol procedure can also be used for stable isotope analysis. This information is important for improving laboratory efficiency and compatibility of procedures used for wildlife physiological ecology studies where concurrent measurements of cortisol and stable isotopes in hair are

  14. Chromium stable isotope fractionation in modern biogeochemical cycling

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie

    . In the present study, the isotopic composition of Cr is traced along this pathway to fill gaps in the understanding of the Cr-isotope system in natural environments. The thesis can be divided into three parts: The first part focuses on Cr release during oxidative weathering. Isotopically light Cr in modern...... processes (biological productivity). In the third part the potential use of the Cr-isotope system in the marine environment is discussed. Incorporation into biogenic carbonates (bivalves, gastropods, corals) is accompanied by Cr-isotope fractionation, causing negative seawater-shell offsets. None...

  15. Regional and inter annual patterns of heavy metals, organochlorines and stable isotopes in narwhals (Monodon monoceros) from West Greenland

    NARCIS (Netherlands)

    Dietz, R.; Riget, F.; Hobson, K.A.; Heide-Jorgensen, M.P.; Moller, P.; Cleemann, M.; Boer, de J.; Glasius, M.

    2004-01-01

    Samples of 150 narwhals obtained in different years from two West Greenland areas, Avanersuaq and Uummannaq, were compared for concentrations of and regional differences in heavy metals and organochlorines and stable-carbon and nitrogen isotopes. Cadmium, Hg, and Se concentrations increased in the

  16. New insights on ecosystem mercury cycling revealed by stable isotopes of mercury in water flowing from a headwater peatland catchment

    Science.gov (United States)

    Glenn E. Woerndle; Martin Tsz-Ki Tsui; Stephen D. Sebestyen; Joel D. Blum; Xiangping Nie; Randall K. Kolka

    2018-01-01

    Stable isotope compositions of mercury (Hg) were measured in the outlet stream and in soil cores at different landscape positions in a 9.7-ha boreal upland-peatland catchment. An acidic permanganate/persulfate digestion procedure was validated for water samples with high dissolved organic matter (DOM) concentrations through Hg spike addition analysis. We report a...

  17. Abraham Reef Stable Isotope Data (delta 13C, delta 18O, delta 14C) for 1635-1957

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Site: Abraham Reef, 22ó 06'S, 153ó 00'E, Porites australiensus, Radiocarbon (delta 14C) and Stable Isotope (del 18O and del 13C) results from bi-annual samples from...

  18. A preliminary investigation of silt motion with activable stable isotope tracers

    International Nuclear Information System (INIS)

    Ma Jianguo; Chai Zhifang; Mao Xueying; Ma Shulan

    1990-01-01

    A preliminary investigation of silt motion in Shantou Harbor region has been made by using neutron activation analysis of natural activable stable isotopes in silt. More than 20 elements in suspending and bed silt at different sites were determined. Data analysis and computer-based fitting calculation indicated that all of the suspending silt samples analyzed were of the same origin, i.e. Xinjinxi River outlet and about 37% of the bed silt at the Wailanjiangsha channel is composed of the deposit of suspending silt

  19. Stable isotope study of soil water, WIPP site New Mexico: estimation of recharge to Rustler aquifers

    International Nuclear Information System (INIS)

    Campbell, A.R.; Phillips, F.M.; Vanlandingham, R.J.

    1996-01-01

    Defining the hydrologic setting of the Waste Isolation Pilot Plant (WIPP) is an important step for site characterization and performance assessment. From past research there is a controversy about the timing of recharge to the aquifers in the Rustler Formation which overlies the repository. The stable isotopic composition (δD and δD 18 O) of the water has been used in this argument but with ambiguous conclusions. Soil cores from WIPP have been sampled for δD, δD 18 O, Cl - and water content. The data indicate that there is a small amount of infiltration (.2 to 2 mm/yr) through the desert soil. The δD and δD 18 O analyses suggest that meteoric water in the area can have a stable isotope composition similar to that in the Rustler Fm. Further supporting evidence come from the isotopic composition of drip and pool waters in nearby Carlsbad Caverns. This indicates that the water in the Rustler Fm. need not have been recharged in the past (>10,000 yrs.) under different climatic conditions. (author) 8 figs., 2 tabs., 16 refs

  20. Traceability of poultry viscera meal by stable isotopes in broiler feathers

    International Nuclear Information System (INIS)

    Araujo, Priscila Cavalca de; Sartori, Jose Roberto; Pezzato, Antonio Celso; Stradiotti, Ana Cristina; Pelicia, Vanessa Cristina; Ducatti, Carlos

    2011-01-01

    The objective of this work was to evaluate the presence of poultry viscera meal (VM) in the diet of broiler chickens, through the feather analyses by stable isotopes of carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) and mass spectrophotometry. Seven hundred and twenty Cobb male broiler chicks were subjected to the following treatments: vegetable diet based on corn and soybean meal, from 1 to 42 days of age; diet with 8% poultry viscera meal, from 1 to 42 days of age; vegetable diet from 1 to 21 days, and diet with VM from 22 to 42 days; vegetable diet from 1 to 35 days, and diet with VM from 36 to 42 days; diet with VM from 1 to 21 days and, and vegetable diet from 22 to 42 days; diet with VM from 1 to 35 days, and vegetable diet from 36 to 42 days. Feather samples were collected from four birds per treatment at 7, 14, 21, 28, 35 and 42 days of age, which were subjected to isotopic analysis for carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) by mass spectrometry. The use of the stable C and N isotope technique in feathers allow the VM detection in broiler chicken diet after 21 days of VM inclusion. (author)

  1. Stable isotope stratigraphy and larger benthic foraminiferal extinctions in the Melinau Limestone, Sarawak

    Science.gov (United States)

    Cotton, Laura J.; Pearson, Paul N.; Renema, Willem

    2014-01-01

    Important long-ranging groups of larger benthic foraminifera (LBF) are known to have become extinct during a period of global cooling and climate disruption at the Eocene-Oligocene transition (EOT) but the precise timing and mechanisms are uncertain. Recent study showed unexpectedly that the LBF extinction in Tanzania occurs very close to the Eocene/Oligocene boundary, as recognised by the extinction of the planktonic foraminiferal Family Hantkeninidae, rather than at the later period of maximum global ice growth and sea-level fall, as previously thought. Here we investigate the same phase of extinction in the Melinau Limestone of Sarawak, on the island of Borneo, Malaysia one of the most complete carbonate successions spanning the Eocene to Lower Miocene. Assemblages of LBF from the Melinau Limestone were studied extensively by Geoffrey Adams during the 1960s-80s, confirming a major extinction during the EOT, but the section lacked independent means of correlation. By analysing rock samples originally studied by Adams and now in the Natural History Museum, London, we provide new bulk stable isotope (δ13C and δ18O) records. This enables us to identify, albeit tentatively, the level of maximum stable isotope excursion and show that the LBF extinction event in the Melinau Limestone occurs below this isotope excursion, supporting the results from Tanzania and indicating that the extinction of LBF close to the Eocene/Oligocene boundary may be a global phenomenon.

  2. Pleistocene paleo-groundwater as a pristine fresh water resource in southern Germany – evidence from stable and radiogenic isotopes

    International Nuclear Information System (INIS)

    Geldern, Robert van; Baier, Alfons; Subert, Hannah L.; Kowol, Sigrid; Balk, Laura; Barth, Johannes A.C.

    2014-01-01

    Shallow groundwater aquifers are often influenced by anthropogenic contaminants or increased nutrient levels. In contrast, deeper aquifers hold potentially pristine paleo-waters that are not influenced by modern recharge. They thus represent important water resources, but their recharge history is often unknown. In this study groundwater from two aquifers in southern Germany were analyzed for their hydrogen and oxygen stable isotope compositions. One sampling campaign targeted the upper aquifer that is actively recharged by modern precipitation, whereas the second campaign sampled the confined, deep Benkersandstein aquifer. The groundwater samples from both aquifers were compared to the local meteoric water line to investigate sources and conditions of groundwater recharge. In addition, the deep groundwater was dated by tritium and radiocarbon analyses. Stable and radiogenic isotope data indicate that the deep-aquifer groundwater was not part of the hydrological water cycle in the recent human history. The results show that the groundwater is older than ∼20,000 years and most likely originates from isotopically depleted melt waters of the Pleistocene ice age. Today, the use of this aquifer is strictly regulated to preserve the pristine water. Clear identification of such non-renewable paleo-waters by means of isotope geochemistry will help local water authorities to enact and justify measures for conservation of these valuable resources for future generations in the context of a sustainable water management. - Highlights: • Groundwater from deep aquifer identified as paleo-water with age over 20,000 years. • Low stable isotope values indicate recharge during Pleistocene. • Shallow aquifer mirrors stable isotope signature of average modern precipitation. • Identification of non-renewable paleo-waters enhance sustainable water management. • Strict protection measures of authorities justified by isotope geochemistry

  3. Stable carbon isotope fractionation in pollen of Atlas cedar: first steps towards a new palaeoecological proxy for Northwest Africa

    Science.gov (United States)

    Bell, Benjamin; Fletcher, William; Ryan, Peter; Grant, Helen; Ilmen, Rachid

    2016-04-01

    Analysis of stable carbon isotopes can provide information on climate and the environmental conditions at different growth stages of the plant, both past and present. Carbon isotope discrimination in plant tissue is already well understood, and can be used as a drought stress indicator for semi-arid regions. Stable carbon isotope ratios measured directly on pollen provides the potential for the development of long-term environmental proxies (spanning thousands of years), as pollen is well preserved in the environment. Atlas Cedar (Cedrus atlantica Endl. Manetti ex Carrière), is an ideal test case to develop a pollen stable carbon isotope proxy. The tree grows across a wide altitudinal and climatic range and is extremely sensitive to moisture availability. The pollen is abundant, and easily identifiable to the species level in pollen analysis because different cedar species are geographically confined to different regions of the world. In 2015 we sampled 76 individual cedar trees across latitudinal, altitudinal and environmental gradients, highly focused on the Middle Atlas region of Morocco, with 25 additional samples from botanical gardens across Europe and the US to extend these gradients. Here, we report new stable carbon isotope data from pollen, leaf and stem wood from these samples with a view to assessing and quantifying species-specific fractionation effects associated with pollen production. The isotopic response of individual trees at local and wider geographical scales to altitude and climatic conditions is presented. This research forms part of an ongoing PhD project working to develop and calibrate a modern carbon isotope proxy in Atlas cedar pollen, which can ultimately be applied to fossil sequences and complement existing multi-proxy records (e.g. pollen analysis in lake sediments, tree-rings).

  4. Micro-scale novel stable isotope fractionation during weathering disclosed by femtosecond laser ablation

    Science.gov (United States)

    Schuessler, J. A.; von Blanckenburg, F.

    2012-12-01

    The stable isotope fractionation of metals and metalloids during chemical weathering and alteration of rocks at low temperature is a topic receiving increasing scientific attention. For these systems, weathering of primary minerals leads to selective partitioning of isotopes between the secondary minerals formed from them, and the dissolved phase of soil or river water. While the isotopic signatures of these processes have been mapped-out at the catchment or the soil scale, the actual isotopic fractionation is occurring at the mineral scale. To identify the processes underlying such micro-scale fractionation, the development of micro-analytical tools allows to investigate mechanisms of isotope fractionation in-situ, in combination with textural information of weathering reactions. We have developed a second-generation UV femtosecond (fs) laser system at GFZ Potsdam. The advantage of UV-fs laser ablation is the reduction of laser-induced isotopic and elemental fractionation by avoiding 'thermal effects' during ablation, such that accurate isotope ratios can be measured by standard-sample-standard bracketing using laser ablation multicollector ICP-MS; where the matrix of the bracketing standard does not need to match that of the sample [1]. Our system consists of the latest generation femtosecond solid-state laser (Newport Spectra Physics Solstice), producing an ultra short pulse width of about 100 femtoseconds at a wavelength of 196 nm. The system is combined with a custom-build computer-controlled sample stage and allows fully automated isotope analyses through synchronised operation of the laser with the Neptune MC-ICP-MS. To assess precision and accuracy of our laser ablation method, we analysed various geological reference materials. We obtained δ30Si values of -0.31 ± 0.23 (2SD, n = 13) for basalt glass BHVO-2G, and -1.25 ± 0.21 (2SD, n = 27) for pure Si IRMM17 when bracketed against NBS-28 quartz. δ56Fe and δ26Mg values obtained from non-matrix matched

  5. It takes time to see the menu from the body: an experiment on stable isotope composition in freshwater crayfishes

    Directory of Open Access Journals (Sweden)

    Jussila J.

    2015-01-01

    Full Text Available For many applications and ecological studies in which wild individuals are brought to laboratory it would be essential to know accurately how fast novel diet is reflected in composition of different tissues. To study the effects of two different diets on the stable isotope composition of freshwater crayfish muscle and hemolymph, we conducted a three month experiment on noble crayfish (Astacus astacus and signal crayfish (Pacifastacus leniusculus by feeding them sweet corn (Zea mays or Baltic herring (Clupea harengus membras as novel food. During the experiment, the crayfish were given 0.4 g of selected food daily and the amount consumed was recorded. The samples for the stable isotope analyses were taken at the commencement of the experiment (initial control and three times (hemolymph or twice (muscle tissue during the experiment. We found that stable isotope changes can be similarly, and rather slowly, detected from muscle tissue and hemolymph under studied conditions. Hemolymph sampling, being non-lethal, can be recommended as a practical sampling method. Our results confirm earlier reports according to which diet changes reflect to crayfish isotope ratios slowly implying that isotope ratios indicate long-term diet.

  6. Can We Untangle the Weather? Stable Water Isotope Controls on the Juneau Icefield

    Science.gov (United States)

    Ihle, A. C.; Keenan, E.; Yong, C.; Bridgers, S. L.; Markle, B. R.; Hamel, J.; Klein, E. S.

    2017-12-01

    Stable water isotopes in snow and ice provide a reliable proxy for past weather and climate. However, untangling weather and climate signals from water isotopes on the Juneau Icefield, Alaska, has proven difficult due to consistent summer melt and rain. The Juneau Icefield is a large glaciated region consisting of complex terrain and sharp climatic gradients. Here we study how topographic steepness and elevation influence stable water isotope ratios on the Juneau Icefield using vertical snowpit profiles collected from water year 2017's snowpack. As terrain steepens, we expect gradients in isotope ratios to intensify. In addition, we aim to determine how post-depositional metamorphism, particularly precipitation, affects water isotope ratios. We anticipate rain events to increase the proportion of heavy water isotopes. Lastly, we compare model output and remote sensing observations of storm origin to vertical stratigraphy of stable isotope ratios in the snowpack in order to determine if it is possible to use isotopes to identify past storm tracks on the Juneau Icefield. Snowpack isotope stratigraphy ratios can likely be linked to seasonal trends of storm characteristics. Given this enhanced understanding of how stable water isotopes behave on the Juneau Icefield, we contribute to the understanding of past weather and climate, both here and elsewhere, and explore the possibility for future deep ice cores on the Juneau Icefield.

  7. Stable water isotopic composition of the Antarctic subglacial Lake Vostok: implications for understanding the lake's hydrology.

    Science.gov (United States)

    Ekaykin, Alexey A; Lipenkov, Vladimir Y; Kozachek, Anna V; Vladimirova, Diana O

    2016-01-01

    We estimated the stable isotopic composition of water from the subglacial Lake Vostok using two different sets of samples: (1) water frozen on the drill bit immediately after the first lake unsealing and (2) water frozen in the borehole after the unsealing and re-drilled one year later. The most reliable values of the water isotopic composition are: -59.0 ± 0.3 ‰ for oxygen-18, -455 ± 1 ‰ for deuterium and 17 ± 1 ‰ for d-excess. This result is also confirmed by the modelling of isotopic transformations in the water which froze in the borehole, and by a laboratory experiment simulating this process. A comparison of the newly obtained water isotopic composition with that of the lake ice (-56.2 ‰ for oxygen-18, -442.4 ‰ for deuterium and 7.2 ‰ for d-excess) leads to the conclusion that the lake ice is very likely formed in isotopic equilibrium with water. In turn, this means that ice is formed by a slow freezing without formation of frazil ice crystals and/or water pockets. This conclusion agrees well with the observed physical and chemical properties of the lake's accreted ice. However, our estimate of the water's isotopic composition is only valid for the upper water layer and may not be representative for the deeper layers of the lake, so further investigations are required.

  8. Nutrient Concentrations and Stable Isotopes of Runoff from a Midwest Tile-Drained Corn Field

    Science.gov (United States)

    Wilkins, B. P.; Woo, D.; Li, J.; Michalski, G. M.; Kumar, P.; Conroy, J. L.; Keefer, D. A.; Keefer, L. L.; Hodson, T. O.

    2017-12-01

    Tile drains are a common crop drainage device used in Midwest agroecosystems. While efficient at drainage, the tiles provide a quick path for nutrient runoff, reducing the time available for microbes to use nutrients (e.g., NO3- and PO43-) and reduce export to riverine systems. Thus, understanding the effects of tile drains on nutrient runoff is critical to achieve nutrient reduction goals. Here we present isotopic and concentration data collected from tile drain runoff of a corn field located near Monticello, IL. Tile flow samples were measured for anion concentrations and stable isotopes of H2O and NO3-, while precipitation was measured for dual isotopes of H2O. Results demonstrate early tile flow from rain events have a low Cl- concentration (water isotopic values reflecting precipitation, indicating preferential flow (>60% contribution) in the beginning of the hydrograph. As flow continues H2O isotopic values reflect pre-event water (ground and soil water), and Cl- concentrations increase representing a greater influence by matrix flow (60-90% contribution). Nitrate concentrations change dramatically, especially during the growing season, and do not follow a similar trend as the conservative Cl-, often decreasing days before, which represents missing nitrate in the upper surface portion of the soil. Nitrate isotopic data shows significant changes in 15N (4‰) and 18O (4‰) during individual hydrological events, representing that in addition to plant uptake and leaching, considerate NO3- is lost through denitrification. It is notable, that throughout the season d15N and d18O of nitrate change significantly representing that seasonally, substantial denitrification occurs.

  9. Stable chlorine isotope analysis of chlorinated acetic acids using gas chromatography/quadrupole mass spectrometry.

    Science.gov (United States)

    Miska, Milena E; Shouakar-Stash, Orfan; Holmstrand, Henry

    2015-12-30

    The environmental occurrence of chlorinated acetic acids (CAAs) has been extensively studied, but the sources and transport are still not yet fully understood. A promising approach for source apportionment and process studies is the isotopic characterization of target compounds. We present the first on-line stable chlorine isotope analysis of CAAs by use of gas chromatography/quadrupole mass spectrometry (GC/qMS). Following approved procedures for concentration analysis, CAAs extracted into MTBE were methylated to GC-amenable methyl esters (mCAAs). These mCAAs were then analyzed by GC/qMS for their stable chlorine isotope composition using a sample/standard-bracketing approach (CAA standards in the range δ(37) Cl -6.3 to -0.2 ‰, Standard Mean Ocean Chloride). Cross-calibration of the herein presented method with off-line reference methods (thermal ionization and continuous-flow GC isotope ratio mass spectrometry; TI-MS and CF-GC/IRMS, respectively) shows good agreement between the methods (regression slope for GC/qMS vs reference method data sets: 0.92 ± 0.29). Sample amounts as small as 10 pmol Cl can herewith be analyzed with a precision of 0.1 to 0.4 ‰. This method should be useful for environmental studies of CAAs at ambient concentrations in precipitations (<0.06 to 100 nmol L(-1) ), surface waters (<0.2 to 5 nmol L(-1) ) and soil (<0.6 to 2000 nmol kg(-1) dry soil) where conventional off-line methods cannot be applied. Copyright © 2015 John Wiley & Sons, Ltd.

  10. Generalists or Specialists: Stable Isotope Analysis of Humpback Whales (Megapteranoveangliae) to Infer Variation in Feeding Preferences

    Science.gov (United States)

    Brownstein, A.; Boswell, K. M.

    2016-02-01

    Though humpback whales (Megapteranovaeangliae) are commonly observed in coastal waters of the Gulf of Alaska, their massive size, behavior, and weather conditionsmake it difficult to make accurate observations regarding their feeding habits. These whales can be highly abundant during feeding aggregations, and given their large energetic needs, they have the potential to impact populations of ecologically important forage such as krill and herring. Previous studies in other areas, such as the Gulf of Maine and the North Pacific Ocean, classify humpback whales as generalists that can efficiently feed on both schooling fish and large zooplankton. In Prince William Sound, scientists have observed the humpbacks feedingprimarily on herring. It is unclear if these whalesfeed exclusively on fish prior to returning to the Sound, and can therefore be considered specialists. Stable isotope analysis of carbon and nitrogen were used to determine the preferred diet of humpback whales (N=22) in 6 sampling regions along the Gulf of Alaska. Isotope analyses were conducted on humpback whale skin, as well as local forage species and basal resources to be used in Bayesian isotope mixing models to elucidate the trophic relationships between whales and their prey, and provide insight to whether location is an important driver in prey selection. This information will not only lead to a better understanding of the potential to use tissue isotopes to elucidate foraging behaviors of humpback whales, but also offer insight into individual feeding preferences and how increasing whale populations may affect the populations of local forage in the future.

  11. Effect of temperature and salinity on stable isotopic composition of shallow water benthic foraminifera: A laboratory culture study

    Digital Repository Service at National Institute of Oceanography (India)

    Kurtarkar, S.R.; Linshy, V.N.; Saraswat, R.; Nigam, R.

    Quantitative estimation of past climatic parameters from stable isotopic composition of foraminifera relies on estimating the precise relationship between stable isotopic composition of the species analyzed and the physico-chemical factors...

  12. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    Energy Technology Data Exchange (ETDEWEB)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J. [eds.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database.

  13. Stable isotope applications in biomolecular structure and mechanisms. A meeting to bring together producers and users of stable-isotope-labeled compounds to assess current and future needs

    International Nuclear Information System (INIS)

    Trewhella, J.; Cross, T.A.; Unkefer, C.J.

    1994-12-01

    Knowledge of biomolecular structure is a prerequisite for understanding biomolecular function, and stable isotopes play an increasingly important role in structure determination of biological molecules. The first Conference on Stable Isotope Applications in Biomolecular Structure and Mechanisms was held in Santa Fe, New Mexico, March 27--31, 1994. More than 120 participants from 8 countries and 44 institutions reviewed significant developments, discussed the most promising applications for stable isotopes, and addressed future needs and challenges. Participants focused on applications of stable isotopes for studies of the structure and function of proteins, peptides, RNA, and DNA. Recent advances in NMR techniques neutron scattering, EPR, and vibrational spectroscopy were highlighted in addition to the production and synthesis of labeled compounds. This volume includes invited speaker and poster presentations as well as a set of reports from discussion panels that focused on the needs of the scientific community and the potential roles of private industry, the National Stable Isotope Resource, and the National High Magnetic Field Laboratory in serving those needs. This is the leading abstract. Individual papers are processed separately for the database

  14. Assessment of mercury exposure among small-scale gold miners using mercury stable isotopes

    International Nuclear Information System (INIS)

    Sherman, Laura S.; Blum, Joel D.; Basu, Niladri; Rajaee, Mozhgon; Evers, David C.; Buck, David G.; Petrlik, Jindrich; DiGangi, Joseph

    2015-01-01

    Total mercury (Hg) concentrations in hair and urine are often used as biomarkers of exposure to fish-derived methylmercury (MeHg) and gaseous elemental Hg, respectively. We used Hg stable isotopes to assess the validity of these biomarkers among small-scale gold mining populations in Ghana and Indonesia. Urine from Ghanaian miners displayed similar Δ 199 Hg values to Hg derived from ore deposits (mean urine Δ 199 Hg=0.01‰, n=6). This suggests that urine total Hg concentrations accurately reflect exposure to inorganic Hg among this population. Hair samples from Ghanaian miners displayed low positive Δ 199 Hg values (0.23–0.55‰, n=6) and low percentages of total Hg as MeHg (7.6–29%, n=7). These data suggest that the majority of the Hg in these miners' hair samples is exogenously adsorbed inorganic Hg and not fish-derived MeHg. Hair samples from Indonesian gold miners who eat fish daily displayed a wider range of positive Δ 199 Hg values (0.21–1.32‰, n=5) and percentages of total Hg as MeHg (32–72%, n=4). This suggests that total Hg in the hair samples from Indonesian gold miners is likely a mixture of ingested fish MeHg and exogenously adsorbed inorganic Hg. Based on data from both populations, we suggest that total Hg concentrations in hair samples from small-scale gold miners likely overestimate exposure to MeHg from fish consumption. - Highlights: • Mercury isotopes were measured in hair and urine from small-scale gold miners. • Mercury isotopes indicate that Hg in urine comes from mining activity. • Mercury isotopes suggest Hg in hair is a mixture of fish MeHg and inorganic Hg. • A large percentage of Hg in miner’s hair is released during amalgam burning and adsorbed

  15. Toward a simple, repeatable, non-destructive approach to measuring stable-isotope ratios of water within tree stems

    Science.gov (United States)

    Raulerson, S.; Volkmann, T.; Pangle, L. A.

    2017-12-01

    Traditional methodologies for measuring ratios of stable isotopes within the xylem water of trees involve destructive coring of the stem. A recent approach involves permanently installed probes within the stem, and an on-site assembly of pumps, switching valves, gas lines, and climate-controlled structure for field deployment of a laser spectrometer. The former method limits the possible temporal resolution of sampling, and sample size, while the latter may not be feasible for many research groups. We present results from initial laboratory efforts towards developing a non-destructive, temporally-resolved technique for measuring stable isotope ratios within the xylem flow of trees. Researchers have used direct liquid-vapor equilibration as a method to measure isotope ratios of the water in soil pores. Typically, this is done by placing soil samples in a fixed container, and allowing the liquid water within the soil to come into isotopic equilibrium with the headspace of the container. Water can also be removed via cryogenic distillation or azeotropic distillation, with the resulting liquid tested for isotope ratios. Alternatively, the isotope ratios of the water vapor can be directly measured using a laser-based water vapor isotope analyzer. Well-established fractionation factors and the isotope ratios in the vapor phase are then used to calculate the isotope ratios in the liquid phase. We propose a setup which would install a single, removable chamber onto a tree, where vapor samples could non-destructively and repeatedly be taken. These vapor samples will be injected into a laser-based isotope analyzer by a recirculating gas conveyance system. A major part of what is presented here is in the procedure of taking vapor samples at 100% relative humidity, appropriately diluting them with completely dry N2 calibration gas, and injecting them into the gas conveyance system without inducing fractionation in the process. This methodology will be helpful in making

  16. The importance of accurately correcting for the natural abundance of stable isotopes.

    Science.gov (United States)

    Midani, Firas S; Wynn, Michelle L; Schnell, Santiago

    2017-03-01

    The use of isotopically labeled tracer substrates is an experimental approach for measuring in vivo and in vitro intracellular metabolic dynamics. Stable isotopes that alter the mass but not the chemical behavior of a molecule are commonly used in isotope tracer studies. Because stable isotopes of some atoms naturally occur at non-negligible abundances, it is important to account for the natural abundance of these isotopes when analyzing data from isotope labeling experiments. Specifically, a distinction must be made between isotopes introduced experimentally via an isotopically labeled tracer and the isotopes naturally present at the start of an experiment. In this tutorial review, we explain the underlying theory of natural abundance correction of stable isotopes, a concept not always understood by metabolic researchers. We also provide a comparison of distinct methods for performing this correction and discuss natural abundance correction in the context of steady state 13 C metabolic flux, a method increasingly used to infer intracellular metabolic flux from isotope experiments. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Quantifying inter-laboratory variability in stable isotope analysis of ancient skeletal remains.

    Science.gov (United States)

    Pestle, William J; Crowley, Brooke E; Weirauch, Matthew T

    2014-01-01

    Over the past forty years, stable isotope analysis of bone (and tooth) collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond), the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a) sample preparation, and b) analysis (instrumentation, working standards, and data calibration). Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration). These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite isotope values

  18. Quantifying inter-laboratory variability in stable isotope analysis of ancient skeletal remains.

    Directory of Open Access Journals (Sweden)

    William J Pestle

    Full Text Available Over the past forty years, stable isotope analysis of bone (and tooth collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond, the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a sample preparation, and b analysis (instrumentation, working standards, and data calibration. Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration. These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite

  19. Golan Heights Groundwater Systems: Separation By REE+Y And Stable Isotopes

    Science.gov (United States)

    Siebert, C.; Geyer, S.; Knoeller, K.; Roediger, T.; Weise, S.; Dulski, P.; Moeller, P.; Guttman, J.

    2008-12-01

    In a semi-arid to arid country like Israel, all freshwater resources are under (over-) utilization. Particularly, the Golan Heights rank as one of the most important extraction areas of groundwater of good quality and quantity. Additionally the mountain range feed to a high degree the most important freshwater reservoir of Israel, the Sea of Galilee. Hence, knowing the sources and characters of the Golan Heights groundwater systems is an instantaneous demand regarding sustainable management and protection. Within the "German-Israeli-Jordanian-Palestinian Joint Research Program for the Sustainable Utilisation of Aquifer Systems", hundreds of water samples were taken from all over the Jordan-Dead Sea rift-system to understand groundwater flow-systems and salinisation. For that purpose, each sample was analysed for major and minor ions, rare earth elements including yttrium (REY) and stable isotopes of water (d18O, d2H). The REY distribution in groundwater is established during infiltration by the first water-rock interaction and consequently reflects the leachable components of sediments and rocks of the recharge area. In well- developed flow-systems, REY are adsorbed onto pore surfaces are in equilibrium with the percolating groundwater, even if the lithology changes (e.g. inter-aquifer flow). Thus, groundwater sampled from wells and springs still show the REY distribution pattern established in the recharge area. Since high temperatures do not occur in Golan Heights, d2H and d18O are less controlled by water-rock interaction than by climatic and geomorphological factors at the time of replenishment. Applying the REY signature as a grouping criterion of groundwaters, d18O vs. d2H plots yield a new dimension in interpreting isotope data. The combined use of hydrochemical and isotopic methods enabled us to contain the areas of replenishment and the flow-paths of all investigated groundwater in the Golan Heights. Despite location, salinity or temperature of spring or

  20. Detection of Human Sewage in Urban Stormwater Using DNA Based Methods and Stable Isotope Analysis

    Science.gov (United States)

    McLellan, S. L.; Malet, N.; Sauer, E.; Mueller-Spitz, S.; Borchardt, M.

    2008-12-01

    Urban stormwater is a major source of fecal indicator bacteria in the Milwaukee River Basin, a major watershed draining to Lake Michigan. Much of the watershed is in highly urbanized areas and Escherichia coli (E. coli) levels have been found to be 20,000 CFU per 100 ml in the estuary leading to Lake Michigan. Aging infrastructure and illicit cross connections may allow sewage to infiltrate the stormwater system and could contribute both fecal indicator bacteria and human pathogens to these waters. We conducted extensive sampling of stormwater outfalls in the lower reaches of three major tributaries. Three outfalls along the heavily urbanized Kinnickinnick (KK) were found to have geometric mean E. coli and enterococci levels of 16,200 and 28,700 CFU/100 ml, respectively. Four outfalls along the Menomonee River, draining both suburban and urban areas, had geometric mean E. coli and enterococci levels of 14,700 and 12,800 CFU/100 ml, respectively. These seven outfalls had more than 60% of the samples positive for human specific Bacteroides genetic marker (n=46), suggesting the presence of human sources. In addition, two outfalls on Lincoln Creek, a smaller tributary of the Milwaukee River, had geometric mean E. coli and enterococci levels of 16,700 and 14,900 CFU per 100 ml, respectively. The human specific Bacteroides marker was positive in nearly 90% of the samples (n=24). Subsequent virus testing at one of these outfalls confirmed human pathogens were present with adenovirus detected at 1.3 x 10E3 genomic equivalents (ge)/L, enterovirus at 1.9 x 10E4 ge/L and G1 norovirus at 1.5 x 10E3 ge/L; these values are similar to concentrations found in sewage. Stable isotope studies were conducted in the three tributaries to investigate the relationship between delta C and delta N isotopic composition and microbiological quality of this urban freshwater system. This work is based on the premise that the organic matter of the stormwater will have a stable isotopic signature

  1. Progress in stable isotope analysis and new possibilities of clinical investigations

    International Nuclear Information System (INIS)

    Roth, E.

    1989-01-01

    The use of stable isotopes in medicine rests on three possibilities offered by labelling: identification of an element, a molecule, or a fragment of a molecule along its biological pathway; quantification of biological pools by isotopic dilution; measurement of metabolization rates, and more generally of clearances. Whenever a corporal function experiences a disregulation reflected either by changes in metabolic activity or modifications of the importance of pools of certain molecules, the possibility exists of making use of isotopes in diagnosis. Examples of practical applications of stable isotopes are given and analytical problems that had to be solved are underlined

  2. Phosphate stable oxygen isotope variability within a temperate agricultural soil.

    Science.gov (United States)

    Granger, Steven J; Harris, Paul; Peukert, Sabine; Guo, Rongrong; Tamburini, Federica; Blackwell, Martin S A; Howden, Nicholas J K; McGrath, Steve

    2017-01-01

    In this study, we conduct a spatial analysis of soil total phosphorus (TP), acid extractable phosphate (PO 4 ) and the stable oxygen (O) isotope ratio within the PO 4 molecule (δ 18 O PO 4 ) from an intensively managed agricultural grassland site. Total P in the soil was found to range from 736 to 1952 mg P kg - 1 , of which between 12 and 48% was extractable using a 1 M HCl (HCl PO 4 ) solution with the two variables exhibiting a strong positive correlation. The δ 18 O PO 4 of the extracted PO 4 ranged from 17.0 to 21.6‰ with a mean of 18.8‰ (± 0.8). While the spatial variability of Total P has been researched at various scales, this is the first study to assess the variability of soil δ 18 O PO 4 at a field-scale resolution. We investigate whether or not δ 18 O PO 4 variability has any significant relationship with: (i) itself with respect to spatial autocorrelation effects; and (ii) HCl PO 4 , elevation and slope - both globally and locally. Results indicate that δ 18 O PO 4 was not spatially autocorrelated; and that δ 18 O PO 4 was only weakly related to HCl PO 4 , elevation and slope, when considering the study field as a whole. Interestingly, the latter relationships appear to vary in strength locally. In particular, the δ 18 O PO 4 to HCl PO 4 relationship may depend on the underlying soil class and/or on different field managements that had operated across an historical north-south field division of the study field, a division that had been removed four years prior to this study.

  3. A Combined Stable Isotope And Machine Learning Approach To Quantify And Classify Of Nitrate Pollution Sources

    Science.gov (United States)

    Boeckx, P. F.; Xue, D.; De Baets, B.

    2011-12-01

    Stable isotope analyses of NO3- (δ15N and δ18O) are widely used to determine the sources of nitrate pollution in water. The objective of our study was (1) to quantify NO3- sources in surface water and to classify surface waters in NO3- pollution classes via a combined stable isotope and machine learning approach; and (2) to assess a decision tree model with physicochemical data for retrieving the latter classification. A logical approach has been followed: (1) 2-year monthly sampling of 30 sampling points from different river basins in Belgium, which were classified into 5 different NO3- pollution classes using experts knowledge (Agriculture (A), Agriculture with groundwater compensation (AGC), Combination of agriculture and horticulture (AH), Greenhouses in an agricultural area (G) and Households (H)); (2) estimating proportional NO3- source contribution per NO3- pollution class by applying a Bayesian isotopic mixing model (SIAR) for measured isotopic data of NO3-; (3) re-classifying the 30 sampling points into NO3- pollution classes via a k-means clustering of the SIAR outputs; and (4) building a decision tree model using physicochemical data to retrieve expert knowledge and k-means clustering classification. SIAR successfully estimated proportional contribution ranges of five potential NO3- sources: NO3- in precipitation, NO3- in fertilizer, NH4+ in fertilizer and precipitation, manure and sewage and soil N. For classes A, AGC, AH and H in winter manure and sewage were major (40 - 60%), NO3- in precipitation minor (pollution classes were optimal for both winter and summer. Thus the 30 sampling points were divided into four classes: classes A, class AGC, class G, and class H (class AH was not retained). Finally, a decision tree model built on physicochemical data using expert classification labels or k-means clustering labels could retrieve ca. 70% of the nitrate pollution classes in both cases. The later suggests that physicochemical data could be applied to

  4. Preparation of starch and other carbon fractions from higher plant leaves for stable carbon isotope analysis.

    Science.gov (United States)

    Wanek, W; Heintel, S; Richter, A

    2001-01-01

    The measurement of the carbon isotope composition of starch and cellulose still relies on chemical isolation of these water-insoluble plant constituents and subsequent elemental analysis by isotope ratio mass spectrometry (EA/IRMS) of the purified fractions, while delta(13)C values of low-molecular-weight organic compounds are now routinely measured by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Here we report a simple and reliable method for processing milligram quantities of dried plant material for the analysis of the carbon isotope composition of lipids, soluble sugars, starch and cellulose from the same sample. We evaluated three different starch preparation methods, namely (1) enzymatic hydrolysis by alpha-amylase, (2) solubilization by dimethyl sulfoxide (DMSO) followed by precipitation with ethanol, and (3) partial hydrolysis by HCl followed by precipitation of the resulting dextrins by ethanol. Starch recovery for three commercially available native starches (from potato, rice and wheat) varied from 48 to 81% for the techniques based on precipitation, whereas the enzymatic technique exhibited yields between 99 and 105%. In addition, the DMSO and HCl techniques introduced a significant (13)C fractionation of up to 1.9 per thousand, while the carbon isotope composition of native starches analyzed after enzymatic digestion did not show any significant difference from that of untreated samples. The enzymatic starch preparation method was then incorporated into a protocol for determination of delta(13)C signatures of lipids, soluble carbohydrates, starch and crude cellulose. The procedure is based on methanol/chloroform/water extraction of dried and ground leaf material. After recovery of the chloroform phase (lipid fraction), the methanol/water phase was deionized by ion exchange (soluble carbohydrate fraction) and the pellet treated with heat-stable alpha-amylase (starch fraction). The remaining insoluble material was subjected

  5. Estimating Niche Width Using Stable Isotopes in the Face of Habitat Variability: A Modelling Case Study in the Marine Environment

    Science.gov (United States)

    Cummings, David O.; Buhl, Jerome; Lee, Raymond W.; Simpson, Stephen J.; Holmes, Sebastian P.

    2012-01-01

    Distributions of stable isotopes have been used to infer an organism's trophic niche width, the ‘isotopic niche’, and examine resource partitioning. Spatial variation in the isotopic composition of prey may however confound the interpretation of isotopic signatures especially when foragers exploit resources across numerous locations. In this study the isotopic compositions from marine assemblages are modelled to determine the role of variation in the signature of prey items and the effect of dietary breadth and foraging strategies on predator signatures. Outputs from the models reveal that isotopic niche widths can be greater for populations of dietary specialists rather than for generalists, which contravenes what is generally accepted in the literature. When a range of different mixing models are applied to determine if the conversion from δ to p-space can be used to improve model accuracy, predator signature variation is increased rather than model precision. Furthermore the mixing models applied failed to correctly identify dietary specialists and/or to accurately estimate diet contributions that may identify resource partitioning. The results presented illustrate the need to collect sufficiently large sample sizes, in excess of what is collected under most current studies, across the complete distribution of a species and its prey, before attempts to use stable isotopes to make inferences about niche width can be made. PMID:22876280

  6. A Combined Radio- and Stable-Isotopic Study of a California Coastal Aquifer System

    Directory of Open Access Journals (Sweden)

    Michael Land

    2013-04-01

    Full Text Available Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were analyzed for a suite of major cations (Na+, K+, Mg2+, Ca2+ and anions (Cl−, SO42−, silica, alkalinity, select trace elements (Ba, B, Sr, dissolved oxygen, stable isotopes of hydrogen (δD, oxygen (δ18O, dissolved inorganic carbon (δ13CDIC, and radioactive isotopes (3H, 222Rn and 223,224,226,228Ra. In the study area, groundwater may consist of a complex mixture of native groundwater, intruded seawater, non-native injected water, and oil-field brine water. In some wells, Cl− concentrations attained seawater-like values and in conjunction with isotopically heavier δ18O values, these tracers provide information on the extent of seawater intrusion and/or mixing with oil-field brines. Groundwater 3H above 1 tritium unit (TU was observed only in a few select wells close to the Dominguez Gap area and most other well groundwater was aged pre-1952. Based on an initial 14C value for the study site of 90 percent modern carbon (pmc, groundwater age estimates likely extend beyond 20 kyr before present and confirm deep circulation of some native groundwater through multiple aquifers. Enriched values of groundwater δ13CDIC in the absence of SO42− imply enhanced anaerobic microbial methanogenesis. While secular equilibrium was observed for 234U/238U (activity ratios ~1 in host matrices, strong isotopic fractionation in these groundwater samples can be used to obtain information of adsorption/desorption kinetics. Calculated Ra residence times are short, and the associated desorption rate constant is about three orders of magnitude slower than that of the adsorption rate constant. Combined stable- and radio-isotopic results provide unique insights

  7. Stable carbon and oxygen isotope study on benthic foraminifera ...

    Indian Academy of Sciences (India)

    The present study is pursued on isotopic values of different pairs of benthic foraminifera from the Krishna–Godavari basin and Peru offshore to understand habitat-wise isotopic variation and ... Department of Applied Geology, Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand 826 004, India.

  8. Spatiotemporal variation of stable isotopic composition in precipitation

    DEFF Research Database (Denmark)

    Müller, Sascha; Stumpp, Christine; Sørensen, Jens Havskov

    2017-01-01

    gradient and predominant westerly winds. Data showed the local meteoric water line for this region is expressed by the equation δ2H = 7.4δ18O + 5.4‰. A significant trend correlating enriched isotopic values to humidities around 70% during dry season and more depleted isotopic values to humidities around 90...

  9. Stable Isotopes in Evaluation of Greenhouse Gas Emissions

    Science.gov (United States)

    Isotopes offer a unique way to have natural tracers present in the ecosystem to track produced greenhouse gases (GHG) through multiple scales. Isotopes are simply atoms of the same element (same number of protons) with differing number of neutrons. This differing number of neutrons leads to differen...

  10. Enzymatic synthesis and RNA interference of nucleosides incorporating stable isotopes into a base moiety.

    Science.gov (United States)

    Hatano, Akihiko; Shiraishi, Mitsuya; Terado, Nanae; Tanabe, Atsuhiro; Fukuda, Kenji

    2015-10-15

    Thymidine phosphorylase was used to catalyze the conversion of thymidine (or methyluridine) and uracil incorporating stable isotopes to deoxyuridine (or uridine) with the uracil base incorporating the stable isotope. These base-exchange reactions proceeded with high conversion rates (75-96%), and the isolated yields were also good (64-87%). The masses of all synthetic compounds incorporating stable isotopes were identical to the theoretical molecular weights via EIMS. (13)C NMR spectra showed spin-spin coupling between (13)C and (15)N in the synthetic compounds, and the signals were split, further proving incorporation of the isotopes into the compounds. The RNA interference effects of this siRNA with uridine incorporating stable isotopes were also investigated. A 25mer siRNA had a strong knockdown effect on the MARCKS protein. The insertion position and number of uridine moieties incorporating stable isotopes introduced into the siRNA had no influence on the silencing of the target protein. This incorporation of stable isotopes into RNA and DNA has the potential to function as a chemically benign tracer in cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Stable isotope estimates of evaporation: inflow and water residence time for lakes across the United States as a tool for national lake water quality assessments

    Science.gov (United States)

    Stable isotope ratios of water (delta18O and delta2H) can be very useful in large-scale monitoring programs because water samples are easy to collect and isotope ratios integrate information about basic hydrologic processes such as evaporation as a percentage of inflow (E/I) and ...

  12. Stable isotopic variation in tropical forest plants for applications in primatology.

    Science.gov (United States)

    Blumenthal, Scott A; Rothman, Jessica M; Chritz, Kendra L; Cerling, Thure E

    2016-10-01

    Stable isotope analysis is a promising tool for investigating primate ecology although nuanced ecological applications remain challenging, in part due to the complex nature of isotopic variability in plant-animal systems. The aim of this study is to investigate sources of carbon and nitrogen isotopic variation at the base of primate food webs that reflect aspects of primate ecology. The majority of primates inhabit tropical forest ecosystems, which are dominated by C3 vegetation. We used stable isotope ratios in plants from Kibale National Park, Uganda, a well-studied closed-canopy tropical forest, to investigate sources of isotopic variation among C3 plants related to canopy stratification, leaf age, and plant part. Unpredictably, our results demonstrate that vertical stratification within the canopy does not explain carbon or nitrogen isotopic variation in leaves. Leaf age can be a significant source of isotopic variation, although the direction and magnitude of this difference is not consistent across tree species. Some plant parts are clearly differentiated in carbon and nitrogen isotopic composition, particularly leaves compared to non-photosynthetic parts such as reproductive parts and woody stem parts. Overall, variation in the isotopic composition of floral communities, plant species, and plant parts demonstrates that stable isotope studies must include analysis of local plant species and parts consumed by the primates under study from within the study area. Am. J. Primatol. 78:1041-1054, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

  13. A Method to Evaluate Isotopic and Energy Turnover Rates in Larval Culex quinquefasciatus (Diptera: Culicidae) Using Stable Isotope Labeled Compounds.

    Science.gov (United States)

    Healy, Kristen

    2018-03-14

    The goal of this study was to evaluate the use of stable isotope labeled compounds to better understand factors influencing energy turnover in larval Culex quinquefasciatus (Say; Diptera: Culicidae). Three isotope labeled compounds were evaluated in this study, including 15N-labeled potassium nitrate, 13C-labeled glucose, and 13C-labeled leucine. Conditions were first optimized in the laboratory to determine the most appropriate concentration of isotope, as well as the half-life of enrichment. Once optimum conditions were established we used standard equations to predict and determine temperature and density-dependent energy turnover rates. Our results showed that higher concentrations of isotope had an impact on mosquito survivability, overall enrichment, and adult wing length. We predicted the half-life of to be around 0.614 to 0.971 d, and our observed half-lives were determined to be 0.72 to 1.44 d depending on temperature, larval density, and isotope compound. Both density and temperature had a strong influence on isotopic turnover rates in all isotopes evaluated. Our results suggest that stable isotopes can provide a useful tool in understanding how different stress factors influence energy turnover in larval Cx. quinquefasciatus. These data can also help lay a foundation on ways to improve larvicide efficacy under different biotic and abiotic conditions.

  14. Stable isotope fractionation in response to variable fluid residence time distributions

    Science.gov (United States)

    Druhan, J. L.; Maher, K.

    2013-12-01

    Hydrogeochemical processes governing groundwater quantity and quality are often inferred from fluid samples that are the flux-weighted average of a heterogeneous system. This connection has been demonstrated for solutes subject to transport and equilibrium constraints, in which the steady state concentration - discharge relationship is cast in terms of the choice of expression for residence time distribution (Maher, 2011). Here, we examine the extent to which the spatial correlation of the permeability field, which governs the fluid residence time distribution, exerts a principle control on the partitioning of stable isotopes between reactant and product species during heterogeneous reactions in groundwater systems. We demonstrate this relationship using numerical simulations of δ53Cr fractionation due to abiotic CrO42- reduction by Fe2+, implemented in the reactive transport code CrunchFlow. The chemically homogeneous redox reaction generates Cr3+ with an isotope ratio distinct from the reactant pool, and in turn this product species precipitates as a mineral phase Cr(OH)3(s) through a non-fractionating reaction. The corresponding chromate δ53Cr enrichment across a homogeneous domain varies from a maximum value set by the kinetic fractionation factor (αk) at high mean fluid residence times, to a value reaction-limited to transport-limited regimes. For physically heterogeneous flow fields, the transition in isotopic fractionation from a reaction-limited to a transport-limited regime becomes variable, and falls between the upper and lower bounds set by the homogeneous simulations at slow and fast precipitation rates, respectively. Our results show that while minimal variation occurs in the steady-state isotopic profile of the reactant species (δ53Cr of CrO42-), the combined effects of the precipitation rate and the heterogeneous structure of the porous media lead to a wide range in the steady state isotopic composition of the product species (δ53Cr of Cr3

  15. Heavy with child? Pregnancy status and stable isotope ratios as determined from biopsies of humpback whales.

    Science.gov (United States)

    Clark, Casey T; Fleming, Alyson H; Calambokidis, John; Kellar, Nicholas M; Allen, Camryn D; Catelani, Krista N; Robbins, Michelle; Beaulieu, Nicole E; Steel, Debbie; Harvey, James T

    2016-01-01

    Understanding reproductive rates of wild animal populations is crucially important for management and conservation. Assessing pregnancy status of free-ranging cetaceans has historically been difficult; however, recent advances in analytical techniques have allowed the diagnosis of pregnancy from small samples of blubber tissue. The primary objectives of this study were as follows: (i) to test the efficacy of blubber progesterone assays as a tool for diagnosing pregnancy in humpback whales ( Megaptera novaeangliae ); (ii) to estimate the pregnancy rate of humpback whales in Monterey Bay, California; and (iii) to investigate the relationship between stable isotopes and reproductive status of these whales. Progesterone concentrations of female whales fell into two distinct groups, allowing for diagnostic separation of pregnant and non-pregnant individuals. Pregnancy rate varied between years of the study (48.4%% in 2011 and 18.5% in 2012), but fell within the range of other estimates of reproductive success for this population. Stable carbon and nitrogen isotope ratios were examined to investigate the impacts of pregnancy on these values. Neither δ 15 N nor δ 13 C varied in a consistent way among animals of different sex or reproductive status. The relationship between δ 15 N and δ 13 C was strongly positive for male and non-pregnant female humpbacks; however, no relationship existed for pregnant whales. This difference may be indicative of the effects of pregnancy on δ 15 N, resulting from tissue synthesis and reduced excretion of nitrogenous waste, as well as on δ 13 C through increased mobilization of lipid stores to meet the energetic demands of pregnancy. Ultimately, our results support the use of blubber progesterone assays for diagnosing pregnancy in humpback whales and indicate that, when paired with other approaches (e.g. stable isotope analysis), pregnancy status can be an informative tool for addressing questions about animal physiology, ecology and

  16. Stable isotope signatures of gases liberated from fluid inclusions in bedrock at Olkiluoto

    International Nuclear Information System (INIS)

    Eichinger, F.; Meier, D.; Haemmerli, J.; Diamond, L.

    2010-12-01

    Fluid inclusions in quartzes of the Olkiluoto bedrock contain gaseous N 2 , CO 2 , H 2 , CH 4 , and higher hydrocarbons in varying proportions. Stable carbon and hydrogen isotope signatures of the gas phases give valuable information on their origin and the formation conditions. In previous studies, a method to liberate and quantify the gases trapped in fluid inclusions was developed. It allowed determining the carbon isotope signatures of liberated CO 2 , CH 4 and higher hydrocarbons (HHC), but no hydrogen isotope data were acquired. The method was advanced and, in this study, also stable hydrogen isotopes of CH 4 and H 2 liberated from fluid inclusions could be analysed. The stable carbon signatures of methane and higher hydrocarbons, as well as the hydrogen isotope signatures of methane indicate a predominant thermogenic provenance for those gases. (orig.)

  17. Stable-isotope studies of groundwaters in southeastern New Mexico

    International Nuclear Information System (INIS)

    Lambert, S.J.

    1987-01-01

    Oxygen-18/16 and deuterium/hydrogen ratio measurements have been made on groundwaters sampled according to specific field criteria applied during pump tests of the Rustler Formation in Nash Draw, a solution-subsidence valley west of the WIPP site in the northern Delaware Basin of southeastern New Mexico. Comparison of these data with similar measurements on other groundwaters from the northern Delaware Basin indicates two nonoverlapping populations of meteoric groundwaters. Most of the Rustler waters in Nash Draw and at the WIPP site and older waters from the eastern two-thirds of the Capitan Limestone constitute one population, while unconfined groundwaters originating as observable modern surface recharge to alluvium, the near-surface Rustler in southwestern Nash Draw, and the Capitan in the Guadalupe Mountains (Carlsbad Caverns) constitute the other. The isotopic distinction suggests that Rustler groundwater in most of Nash Draw and at the WIPP site is not receiving significant modern meteoric recharge. A likely explanation for this distinction is that meteoric recharge to most of the Rustler and Capitan took place in the geologic past under climatic conditions significantly different from the present. 25 refs., 4 figs., 2 tabs

  18. Preservation Methods Alter Carbon and Nitrogen Stable Isotope Values in Crickets (Orthoptera: Grylloidea).

    Science.gov (United States)

    Jesus, Fabiene Maria; Pereira, Marcelo Ribeiro; Rosa, Cassiano Sousa; Moreira, Marcelo Zacharias; Sperber, Carlos Frankl

    2015-01-01

    Stable isotope analysis (SIA) is an important tool for investigation of animal dietary habits for determination of feeding niche. Ideally, fresh samples should be used for isotopic analysis, but logistics frequently demands preservation of organisms for analysis at a later time. The goal of this study was to establish the best methodology for preserving forest litter-dwelling crickets for later SIA analysis without altering results. We collected two cricket species, Phoremia sp. and Mellopsis doucasae, from which we prepared 70 samples per species, divided among seven treatments: (i) freshly processed (control); preserved in fuel ethanol for (ii) 15 and (iii) 60 days; preserved in commercial ethanol for (iv) 15 and (v) 60 days; fresh material frozen for (vi) 15 and (vii) 60 days. After oven drying, samples were analyzed for δ15N, δ13C values, N(%), C(%) and C/N atomic values using continuous flow isotope ratio mass spectrometry. All preservation methods tested, significantly impacted δ13C and δ15N and C/N atomic values. Chemical preservatives caused δ13C enrichment as great as 1.5‰, and δ15N enrichment as great as 0.9‰; the one exception was M. doucasae stored in ethanol for 15 days, which had δ15N depletion up to 1.8‰. Freezing depleted δ13C and δ15N by up to 0.7 and 2.2‰, respectively. C/N atomic values decreased when stored in ethanol, and increased when frozen for 60 days for both cricket species. Our results indicate that all preservation methods tested in this study altered at least one of the tested isotope values when compared to fresh material (controls). We conclude that only freshly processed material provides adequate SIA results for litter-dwelling crickets.

  19. Preservation Methods Alter Carbon and Nitrogen Stable Isotope Values in Crickets (Orthoptera: Grylloidea.

    Directory of Open Access Journals (Sweden)

    Fabiene Maria Jesus

    Full Text Available Stable isotope analysis (SIA is an important tool for investigation of animal dietary habits for determination of feeding niche. Ideally, fresh samples should be used for isotopic analysis, but logistics frequently demands preservation of organisms for analysis at a later time. The goal of this study was to establish the best methodology for preserving forest litter-dwelling crickets for later SIA analysis without altering results. We collected two cricket species, Phoremia sp. and Mellopsis doucasae, from which we prepared 70 samples per species, divided among seven treatments: (i freshly processed (control; preserved in fuel ethanol for (ii 15 and (iii 60 days; preserved in commercial ethanol for (iv 15 and (v 60 days; fresh material frozen for (vi 15 and (vii 60 days. After oven drying, samples were analyzed for δ15N, δ13C values, N(%, C(% and C/N atomic values using continuous flow isotope ratio mass spectrometry. All preservation methods tested, significantly impacted δ13C and δ15N and C/N atomic values. Chemical preservatives caused δ13C enrichment as great as 1.5‰, and δ15N enrichment as great as 0.9‰; the one exception was M. doucasae stored in ethanol for 15 days, which had δ15N depletion up to 1.8‰. Freezing depleted δ13C and δ15N by up to 0.7 and 2.2‰, respectively. C/N atomic values decreased when stored in ethanol, and increased when frozen for 60 days for both cricket species. Our results indicate that all preservation methods tested in this study altered at least one of the tested isotope values when compared to fresh material (controls. We conclude that only freshly processed material provides adequate SIA results for litter-dwelling crickets.

  20. Testing seasonality of the Late Cretaceous Western Interior Seaway with stable isotope analysis of ammonites (Baculites)

    Science.gov (United States)

    Ellis, N.; Tobin, T. S.

    2017-12-01

    Common to the Western Interior Seaway, Baculites is a genus of ammonite with a straight-shelled morphology that serve as index fossils for the Late Cretaceous. Powdered shell samples were generated along growth sequences from several large Baculites fragments (20 - 40 cm) that preserve original aragonite. Stable isotope ratios (δ13C, δ18O) were determined for samples using standard techniques. Sine curves were fit to δ18O and δ13C signals, where the seasonal temperature differential is expressed as the amplitude of the δ18O signal. The periods of the signals represent one annual cycle, from which preliminary Baculites growth rate estimates have been established. Additionally, carbon and oxygen isotope data obtained by Fatheree et al. [1998] were re-analyzed and fit to a sine curve. All of the Baculites that produced usable data and the Fatheree et al. [1998] Baculites produced similar periods (30 - 35 cm), suggesting that Baculites likely utilized an r-type life strategy where they reach maturity rapidly, produce large amounts of offspring, and die within a few years. Understanding their life behaviors is critical to the use of Baculites as a paleoclimate proxy since potential migration, both geographic and in the water column, may influence carbon and oxygen isotope signals. The sinusoidal nature of the isotope signals observed in several Baculites suggests that seasonal inputs are most prevalent. Changes in ammonite activity and/or behavior driven by seasonal progression, seasonally mediated environmental changes, or combinations of these are hypothesized inputs that may result in the observed sinusoidal signals. Amplitudes of δ18O signals suggest seawater temperature variance that is consistent with the paleolatitudes associated with the Baculites specimens sampled. Ammonites from higher paleolatitudes yielded larger amplitude signals indicating greater seasonality at these locations. Further experimentation with Baculites aptychi is ongoing and may yield

  1. Multisample conversion of water to hydrogen by zinc for stable isotope determination

    Science.gov (United States)

    Kendall, C.; Coplen, T.B.

    1985-01-01

    Two techniques for the conversion of water to hydrogen for stable isotope ratio determination have been developed that are especially suited for automated multisample analysis. Both procedures involve reaction of zinc shot with a water sample at 450 ??C. in one method designed for water samples in bottles, the water is put in capillaries and is reduced by zinc in reaction vessels; overall savings in sample preparation labor of 75% have been realized over the standard uranium reduction technique. The second technique is for waters evolved under vacuum and is a sealed-tube method employing 9 mm o.d. quartz tubing. Problems inherent with zinc reduction include surface inhomogeneity of the zinc and exchange of hydrogen both with the zinc and with the glass walls of the vessels. For best results, water/zinc and water/glass surface area ratios of vessels should be kept as large as possible.

  2. Fractionation of stable isotopes in perchlorate and nitrate during in situ biodegradation in a sandy aquifer

    Science.gov (United States)

    Hatzinger, P.B.; Bohlke, John Karl; Sturchio, N.C.; Gu, B.; Heraty, L.J.; Borden, R.C.

    2009-01-01

    An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation. An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification. During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h. After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 8.6 h after the injection. The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (e18O/e37Cl) was 2.6, which is similar to that observed in the laboratory using pure cultures (2.5). Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~0.8 (e18O/e15N), which is within the range of values reported previously for denitrification. However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (0.2 to 0.6 times), even after adjustment for dilution. These results indicate that (1) isotope fractionation factor ratios (e18O/e37Cl, e18O/e15N) derived from homogeneous laboratory systems (e.g. pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent e values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion.

  3. Stable isotopes in fish eye lenses as potential recorders of trophic and geographic history.

    Science.gov (United States)

    Wallace, Amy A; Hollander, David J; Peebles, Ernst B

    2014-01-01

    We evaluated eye lenses as potential recorders of stable isotope histories in fish because they consist of metabolically inert optical proteins that are deposited in successive, concentric circles (laminae) much like otolith circuli and tree rings. We conducted four different tests on lenses from red snapper, red grouper, gag, and white grunt. The first test was a low-resolution screening of multiple individuals (4-5 radial groups of laminae per lens, all species except white grunt). Along the radial axis, all individuals exhibited substantial isotopic variability. Red snapper individuals separated into two groups based on δ15N and gag separated into two groups based on δ13C. Two gag with the greatest variation were chosen for high-resolution temporal analysis using individual laminae from their second eye lenses. The first-order patterns from the high-resolution analysis generally mimicked patterns from the low-resolution screening of grouped laminae, yet the high-resolution plots revealed early-life details that were not apparent in the low-resolution screenings. For the third test, left- versus right-eye variation was compared using high-resolution methods. White grunt left- and right-eye radial isotopic patterns were almost identical for both δ13C and δ15N, suggesting the variations observed among individual fish were not artifacts. The final test evaluated intra-laminar variation; multiple samples were analyzed from different parts of the same lamina. Seven laminae from three individuals of two species were analyzed in this manner; variations among laminae were found to be much higher than variations within laminae. However, nominal intra-laminar variations were comparable to nominal differences between left and right lenses, suggesting intra-laminar variation established measurement precision. Eye lens isotopes appear to be useful for reconstructing the isotopic histories of individual fish; these histories can be compared with spatially-derived isoscapes

  4. Mapping Precipitation Patterns from the Stable Isotopic Composition of Surface Waters: Olympic Peninsula, Washington State

    Science.gov (United States)

    Anders, A. M.; Brandon, M. T.

    2008-12-01

    Available data indicate that large and persistent precipitation gradients are tied to topography at scales down to a few kilometers, but precipitation patterns in the majority of mountain ranges are poorly constrained at scales less than tens of kilometers. A lack of knowledge of precipitation patterns hampers efforts to understand the processes of orographic precipitation and identify the relationships between geomorphic evolution and climate. A new method for mapping precipitation using the stable isotopic composition of surface waters is tested in the Olympic Mountains of Washington State. Measured δD and δ18O of 97 samples of surface water are linearly related and nearly inseparable from the global meteoric water line. A linear orographic precipitation model extended to include in effects of isotopic fractionation via Rayleigh distillation predicts precipitation patterns and isotopic composition of surface water. Seven parameters relating to the climate and isotopic composition of source water are used. A constrained random search identifies the best-fitting parameter set. Confidence intervals for parameter values are defined and precipitation patterns are determined. Average errors for the best-fitting model are 4.8 permil in δD. The difference between the best fitting model and other models within the 95% confidence interval was less than 20%. An independent high-resolution precipitation climatology documents precipitation gradients similar in shape and magnitude to the model derived from surface water isotopic composition. This technique could be extended to other mountain ranges, providing an economical and fast assessment of precipitation patterns requiring minimal field work.

  5. Stable isotopes in fish eye lenses as potential recorders of trophic and geographic history.

    Directory of Open Access Journals (Sweden)

    Amy A Wallace

    Full Text Available We evaluated eye lenses as potential recorders of stable isotope histories in fish because they consist of metabolically inert optical proteins that are deposited in successive, concentric circles (laminae much like otolith circuli and tree rings. We conducted four different tests on lenses from red snapper, red grouper, gag, and white grunt. The first test was a low-resolution screening of multiple individuals (4-5 radial groups of laminae per lens, all species except white grunt. Along the radial axis, all individuals exhibited substantial isotopic variability. Red snapper individuals separated into two groups based on δ15N and gag separated into two groups based on δ13C. Two gag with the greatest variation were chosen for high-resolution temporal analysis using individual laminae from their second eye lenses. The first-order patterns from the high-resolution analysis generally mimicked patterns from the low-resolution screening of grouped laminae, yet the high-resolution plots revealed early-life details that were not apparent in the low-resolution screenings. For the third test, left- versus right-eye variation was compared using high-resolution methods. White grunt left- and right-eye radial isotopic patterns were almost identical for both δ13C and δ15N, suggesting the variations observed among individual fish were not artifacts. The final test evaluated intra-laminar variation; multiple samples were analyzed from different parts of the same lamina. Seven laminae from three individuals of two species were analyzed in this manner; variations among laminae were found to be much higher than variations within laminae. However, nominal intra-laminar variations were comparable to nominal differences between left and right lenses, suggesting intra-laminar variation established measurement precision. Eye lens isotopes appear to be useful for reconstructing the isotopic histories of individual fish; these histories can be compared with spatially

  6. Fe and Cu stable isotopes in archeological human bones and their relationship to sex.

    Science.gov (United States)

    Jaouen, Klervia; Balter, Vincent; Herrscher, Estelle; Lamboux, Aline; Telouk, Philippe; Albarède, Francis

    2012-07-01

    Accurate sex assignment of ancient human remains usually relies on the availability of coxal bones or well-preserved DNA. Iron (Fe) and copper (Cu) stable isotope compositions ((56)Fe/(54)Fe and (65)Cu/(63)Cu, respectively) were recently measured in modern human blood, and an unexpected result was the discovery of a (56)Fe-depletion and a (65)Cu-enrichment in men's blood compared to women's blood. Bones, being pervasively irrigated by blood, are expected to retain the (56)Fe/(54)Fe and (65)Cu/(63)Cu signature of blood, which in turn is useful for determining the sex of ancient bones. Here, we report the (56)Fe/(54)Fe, (65)Cu/(63)Cu, and (66)Zn/(64)Zn ratios from a suite of well-preserved phalanxes (n = 43) belonging to individuals buried in the 17th and 18th centuries at the necropolis of Saint-Laurent de Grenoble, France, and for which the sex was independently estimated from pelvic bone morphology. The metals were purified from the bone matrix by liquid chromatography on ion exchange resin and the isotope compositions were measured by multiple-collector inductively coupled plasma mass spectrometry. The results show that, as expected from literature data on blood, male bone iron is depleted in (56)Fe and enriched in (65)Cu relative to female. No sex difference is found in the (66)Zn/(64)Zn ratios of bone. The concentration and isotopic data show no evidence of soil contamination. Four samples of five (77%) can be assigned their correct sex, a result comparable to sex assignment using Fe and Cu isotopes in blood (81%). Isotopic analysis of metals may therefore represent a valid method of sex assignment applicable to incomplete human remains. Copyright © 2012 Wiley Periodicals, Inc.

  7. Stable isotope tracing of Ni and Cu pollution in North-East Norway: Potentials and drawbacks.

    Science.gov (United States)

    Šillerová, Hana; Chrastný, Vladislav; Vítková, Martina; Francová, Anna; Jehlička, Jan; Gutsch, Marissa R; Kocourková, Jana; Aspholm, Paul E; Nilsson, Lars O; Berglen, Tore F; Jensen, Henning K B; Komárek, Michael

    2017-09-01

    The use of Ni and Cu isotopes for tracing contamination sources in the environment remains a challenging task due to the limited information about the influence of various biogeochemical processes influencing stable isotope fractionation. This work focuses on a relatively simple system in north-east Norway with two possible endmembers (smelter-bedrock) and various environmental samples (snow, soil, lichens, PM 10 ). In general, the whole area is enriched in heavy Ni and Cu isotopes highlighting the impact of the smelting activity. However, the environmental samples exhibit a large range of δ 60 Ni (-0.01 ± 0.03‰ to 1.71 ± 0.02‰) and δ 65 Cu (-0.06 ± 0.06‰ to -3.94 ± 0.3‰) values which exceeds the range of δ 60 Ni and δ 65 Cu values determined in the smelter, i.e. in feeding material and slag (δ 60 Ni from 0.56 ± 0.06‰ to 1.00 ± 0.06‰ and δ 65 Cu from -1.67 ± 0.04‰ to -1.68 ± 0.15‰). The shift toward heavier Ni and Cu δ values was the most significant in organic rich topsoil samples in the case of Ni (δ 60 Ni up to 1.71 ± 0.02‰) and in lichens and snow in the case of Cu (δ 65 Cu up to -0.06 ± 0.06‰ and -0.24 ± 0.04‰, respectively). These data suggest an important biological and biochemical fractionation (microorganisms and/or metal uptake by higher plants, organo-complexation etc.) of Ni and Cu isotopes, which should be quantified separately for each process and taken into account when using the stable isotopes for tracing contamination in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Laboratory investigations of stable carbon and oxygen isotope ratio data enhance monitoring of CO2 underground

    Science.gov (United States)

    Barth, Johannes A. C.; Myrttinen, Anssi; Becker, Veith; Nowak, Martin; Mayer, Bernhard

    2014-05-01

    Stable carbon and oxygen isotope data play an important role in monitoring CO2 in the subsurface, for instance during carbon capture and storage (CCS). This includes monitoring of supercritical and gaseous CO2 movement and reactions under reservoir conditions and detection of potential CO2 leakage scenarios. However, in many cases isotope data from field campaigns are either limited due to complex sample retrieval or require verification under controlled boundary conditions. Moreover, experimentally verified isotope fractionation factors are also accurately known only for temperatures and pressures lower than commonly found in CO2 reservoirs (Myrttinen et al., 2012). For this reason, several experimental series were conducted in order to investigate effects of elevated pressures, temperatures and salinities on stable carbon and oxygen isotope