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Sample records for compound-specific stable isotopes

  1. 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.

  2. Microbial degradation of alpha-cypermethrin in soil by compound-specific stable isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Zemin [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Shen, Xiaoli [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Environmental Engineering, Quzhou University, Quzhou 324000 (China); Zhang, Xi-Chang [Laboratory for Teaching in Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Liu, Weiping [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Fangxing, E-mail: fxyang@zju.edu.cn [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Effect-Directed Analysis, Helmholtz Center for Environmental Research – UFZ, Leipzig 04318 (Germany)

    2015-09-15

    Highlights: • Alpha-cypermethrin (α-CP) can be degraded by microorganisms in soil. • Biodegradation of α-CP resulted in carbon isotope fractionation. • A relationship was found between carbon isotope ratios and concentrations of α-CP. • An enrichment factor ϵ of α-CP was determined as −1.87‰. • CSIA is applicable to assess biodegradation of α-CP. - Abstract: To assess microbial degradation of alpha-cypermethrin in soil, attenuation of alpha-cypermethrin was investigated by compound-specific stable isotope analysis. The variations of the residual concentrations and stable carbon isotope ratios of alpha-cypermethrin were detected in unsterilized and sterilized soils spiked with alpha-cypermethrin. After an 80 days’ incubation, the concentrations of alpha-cypermethrin decreased to 0.47 and 3.41 mg/kg in the unsterilized soils spiked with 2 and 10 mg/kg, while those decreased to 1.43 and 6.61 mg/kg in the sterilized soils. Meanwhile, the carbon isotope ratios shifted to −29.14 ± 0.22‰ and −29.86 ± 0.33‰ in the unsterilized soils spiked with 2 and 10 mg/kg, respectively. The results revealed that microbial degradation contributed to the attenuation of alpha-cypermethrin and induced the carbon isotope fractionation. In order to quantitatively assess microbial degradation, a relationship between carbon isotope ratios and residual concentrations of alpha-cypermethrin was established according to Rayleigh equation. An enrichment factor, ϵ = −1.87‰ was obtained, which can be employed to assess microbial degradation of alpha-cypermethrin. The significant carbon isotope fractionation during microbial degradation suggests that CSIA is a proper approach to qualitatively detect and quantitatively assess the biodegradation during attenuation process of alpha-cypermethrin in the field.

  3. Assessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approach

    KAUST Repository

    Tietbohl, Matthew

    2016-12-01

    Herbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within broad functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.

  4. Assessing the functional diversity of herbivorous reef fishes using a compound-specific stable isotope approach

    KAUST Repository

    Tietbohl, Matthew

    2016-01-01

    Herbivorous coral reef fishes play an important role in helping to structure their environment directly by consuming algae and indirectly by promoting coral health and growth. These fishes are generally separated into three broad groups: browsers, grazers, and excavators/scrapers, with these groupings often thought to have a fixed general function and all fishes within a group thought to have similar ecological roles. This categorization assumes a high level of functional redundancy within herbivorous fishes. However, recent evidence questions the use of this broad classification scheme, and posits that there may actually be more resource partitioning within these functional groupings. Here, I use a compound-specific stable isotope approach (CSIA) to show there appears to be a greater diversity of functional roles than previously assumed within broad functional groups. The δ13C signatures from essential amino acids of reef end-members (coral, macroalgae, detritus, and phytoplankton) and fish muscle were analyzed to investigate differences in resource use between fishes. Most end-members displayed clear isotopic differences, and most fishes within functional groups were dissimilar in their isotopic signature, implying differences in the resources they target. No grazers closely resembled each other isotopically, implying a much lower level of functional redundancy within this group; scraping parrotfish were also distinct from excavating parrotfish and to a lesser degree distinct between scrapers. This study highlights the potential of CSIA to help distinguish fine-scale ecological differences within other groups of reef organisms as well. These results question the utility of lumping nominally herbivorous fishes into broad groups with assumed similar roles. Given the apparent functional differences between nominally herbivorous reef fishes, it is important for managers to incorporate the diversity of functional roles these fish play.

  5. Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach.

    Science.gov (United States)

    McMahon, Kelton W; Thorrold, Simon R; Houghton, Leah A; Berumen, Michael L

    2016-03-01

    Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world's oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon (C). We coupled compound-specific stable C isotope ratio (δ(13)C) analyses with Bayesian mixing models to quantify C flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ(13)C values of essential amino acids from all baseline C sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single-source end-member often dominated dietary C assimilation of a given species, even for highly mobile, generalist top predators. Microbially reworked detritus was an important secondary C source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton-based food web (72 ± 11 %) on oceanic reefs. Our work provides insights into the roles that diverse C sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.

  6. Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach

    KAUST Repository

    McMahon, Kelton

    2015-11-21

    Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world’s oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon (C). We coupled compound-specific stable C isotope ratio (δ13C) analyses with Bayesian mixing models to quantify C flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ13C values of essential amino acids from all baseline C sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single-source end-member often dominated dietary C assimilation of a given species, even for highly mobile, generalist top predators. Microbially reworked detritus was an important secondary C source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton-based food web (72 ± 11 %) on oceanic reefs. Our work provides insights into the roles that diverse C sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.

  7. A Paleoevaporation Proxy Using Compound Specific Stable Isotope Measurements from Peatland Biomarkers

    Science.gov (United States)

    Wang, J.; Nichols, J. E.; Huang, Y.

    2009-12-01

    It is important to understand how evaporation from wetlands changes with climate. To do this, we have developed a paleoevaporation proxy for use in ombrotrophic peatland sediments. Using compound specific hydrogen isotopic ratios of vascular plant and Sphagnum biomarkers, we can quantitatively reconstruct past changes in evaporation. The contrast in H isotopic ratios of water available to living Sphagnum and water in the acrotelm can be used to estimate “f”—the fraction of water remaining after evaporation. Vascular plant leaf waxes record H isotopic ratios of precipitation which is little affected by evaporation, whereas the Sphagnum biomarker, C23 n-alkane, records H isotopic ratios of the water inside its cells and between its leaves, which is strongly affected by evaporation at the bog surface. Evaporation changes can then be calculated with the H-isotopic ratios of the two types of biomarkers. We calibrated the apparent fractionation of D/H ratios from source water to C23 n-alkane with lab-grown Sphagnum. We also present several reconstructions of paleoevaporation from peatlands throughout eastern North America. By comparison with overall hydrologic balance, we are able to understand the varying role of evaporation in the hydrologic system in both time and space.

  8. 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.

  9. Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yan-Hong [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China); Luo, Xiao-Jun, E-mail: luoxiaoj@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Hua-Shan; Wu, Jiang-Ping; Chen, She-Jun; Mai, Bi-Xian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2012-05-15

    A separation and isotopic analysis method was developed to accurately measure the stable carbon isotope ratios of polybrominated diphenyl ethers (PBDEs) with three to six substituted bromine atoms in fish samples. Sample extracts were treated with concentrated sulfuric acid to remove lipids, purified using complex silica gel column chromatography, and finally processed using alumina/silica (Al/Si) gel column chromatography. The purities of extracts were verified by gas chromatography and mass spectrometry (GC-MS) in the full-scan mode. The average recoveries of all compounds across the purification method were between 60% and 110%, with the exception of BDE-154. The stable carbon isotopic compositions of PBDEs can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . No significant isotopic fraction was found during the purification of the main PBDE congeners. A significant change in the stable carbon isotope ratio of BDE-47 was observed in fish carcasses compared to the original isotopic signatures, implying that PBDE stable carbon isotopic compositions can be used to trace the biotransformation of PBDEs in biota. - Highlights: Black-Right-Pointing-Pointer A method for the purification of PBDEs for CSIA was developed. Black-Right-Pointing-Pointer The {delta}{sup 13}C of PBDE congeners can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . Black-Right-Pointing-Pointer Common carp were exposed to a PBDE mixture to investigate debromination. Black-Right-Pointing-Pointer Ratios of the {delta}{sup 13}C values can be used to trace the debromination of PBDE in fish.

  10. Novel proxies for reconstructing paleohydrology from ombrotrophic peatlands: biomarker and compound-specific H and C stable isotope ratios

    Science.gov (United States)

    Wang, J.; Nichols, J. E.; Huang, Y.

    2008-12-01

    Ombrotrophic peatlands are excellent archives for paleohydrologic information because they are hydrologically isolated from their surroundings. However, quantitative proxies for deciphering peatland archives are lacking. Here, we present development and application of novel organic geochemical methods for quantitative reconstruction of paleohydrology from the ombrotrophic sediments, and comparison of organic geochemical data with conventional paleoecological proxies. Application of these methods to the sediments of several North American and European peatlands has revealed significant changes in the hydroclimate throughout the Holocene. The plant assemblage living at the surface of the peatland is tightly controlled by surface moisture. Under wet conditions, Sphagnum mosses, with no active mechanism for drawing water from below the surface of the peatland, are dominant. During dry conditions, vascular plants are more productive relative to Sphagnum. A ratio of the abundance of two biomarkers representing Sphagnum and vascular plants sensitively records changes in hydrologic balance (Nichols et al., 2006, Org. Geochem. 37, 1505-1513). We have further developed stable isotope models to compute climate parameters from compound-specific H and C isotope ratios of biomarkers to create a more comprehensive climate reconstruction. Vascular plant leaf waxes carry the D/H ratio signature of precipitation that is little affected by evaporation, whereas the Sphagnum biomarker records isotopic ratios of the water at the peatland surface, which is strongly enriched by evaporation. Evaporation amount can be calculated using the differences between D/H ratios of the two types of biomarkers. C isotope ratios of Sphagnum biomarkers can also be used to quantify surface wetness. Methanotrophic bacteria live symbiotically with Sphagnum, providing isotopically light carbon for photosynthesis. These bacteria are more active when the Sphagnum is wet, thus providing more 13C-depleted CO2

  11. Degradation of sulfamethoxazole using ozone and chlorine dioxide - Compound-specific stable isotope analysis, transformation product analysis and mechanistic aspects.

    Science.gov (United States)

    Willach, Sarah; Lutze, Holger V; Eckey, Kevin; Löppenberg, Katja; Lüling, Michelle; Terhalle, Jens; Wolbert, Jens-Benjamin; Jochmann, Maik A; Karst, Uwe; Schmidt, Torsten C

    2017-10-01

    The sulfonamide antibiotic sulfamethoxazole (SMX) is a widely detected micropollutant in surface and groundwaters. Oxidative treatment with e.g. ozone or chlorine dioxide is regularly applied for disinfection purposes at the same time exhibiting a high potential for removal of micropollutants. Especially for nitrogen containing compounds such as SMX, the related reaction mechanisms are largely unknown. In this study, we systematically investigated reaction stoichiometry, product formation and reaction mechanisms in reactions of SMX with ozone and chlorine dioxide. To this end, the neutral and anionic SMX species, which may occur at typical pH-values of water treatment were studied. Two moles of chlorine dioxide and approximately three moles of ozone were consumed per mole SMX degraded. Oxidation of SMX with ozone and chlorine dioxide leads in both cases to six major transformation products (TPs) as revealed by high-resolution mass spectrometry (HRMS). Tentatively formulated TP structures from other studies could partly be confirmed by compound-specific stable isotope analysis (CSIA). However, for one TP, a hydroxylated SMX, it was not possible by HRMS alone to identify whether hydroxylation occurred at the aromatic ring, as suggested in literature before, or at the anilinic nitrogen. By means of CSIA and an analytical standard it was possible to identify sulfamethoxazole hydroxylamine unequivocally as one of the TPs of the reaction of SMX with ozone as well as with chlorine dioxide. H-abstraction and electron transfer at the anilinic nitrogen are suggested as likely initial reactions of ozone and chlorine dioxide, respectively, leading to its formation. Oxidation of anionic SMX with ozone did not show any significant isotopic fractionation whereas the other reactions studied resulted in a significant carbon isotope fractionation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Branched GDGTs in Lacustrine Environments: Tracing Allochthonous and Autochthonous Sources Using Compound-Specific Stable Carbon Isotope Analysis

    Science.gov (United States)

    Weber, Y.; S Sinninghe Damsté, J.; Lehmann, M. F.; Niemann, H.; Schubert, C. J.

    2015-12-01

    allochthonous (i.e., soil) source. Our data demonstrate the great potential of compound-specific C isotope analysis to constrain the origin of brGDGTs in lake sediments, possibly allowing the identification of freshwater environments that are particularly suited for brGDGT-based paleoenvironmental reconstructions.

  13. Apportioning sources of organic matter in streambed sediments: An integrated molecular and compound-specific stable isotope approach

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Richard J., E-mail: Richard.J.Cooper@uea.ac.uk [School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ (United Kingdom); Pedentchouk, Nikolai; Hiscock, Kevin M.; Disdle, Paul [School of Environmental Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ (United Kingdom); Krueger, Tobias [IRI THESys, Humboldt University, 10099 Berlin (Germany); Rawlins, Barry G. [British Geological Survey, Keyworth, Nottingham NG12 5GG (United Kingdom)

    2015-07-01

    We present a novel application for quantitatively apportioning sources of organic matter in streambed sediments via a coupled molecular and compound-specific isotope analysis (CSIA) of long-chain leaf wax n-alkane biomarkers using a Bayesian mixing model. Leaf wax extracts of 13 plant species were collected from across two environments (aquatic and terrestrial) and four plant functional types (trees, herbaceous perennials, and C{sub 3} and C{sub 4} graminoids) from the agricultural River Wensum catchment, UK. Seven isotopic (δ{sup 13}C{sub 27}, δ{sup 13}C{sub 29}, δ{sup 13}C{sub 31}, δ{sup 13}C{sub 27–31}, δ{sup 2}H{sub 27}, δ{sup 2}H{sub 29}, and δ{sup 2}H{sub 27–29}) and two n-alkane ratio (average chain length (ACL), carbon preference index (CPI)) fingerprints were derived, which successfully differentiated 93% of individual plant specimens by plant functional type. The δ{sup 2}H values were the strongest discriminators of plants originating from different functional groups, with trees (δ{sup 2}H{sub 27–29} = − 208‰ to − 164‰) and C{sub 3} graminoids (δ{sup 2}H{sub 27–29} = − 259‰ to − 221‰) providing the largest contrasts. The δ{sup 13}C values provided strong discrimination between C{sub 3} (δ{sup 13}C{sub 27–31} = − 37.5‰ to − 33.8‰) and C{sub 4} (δ{sup 13}C{sub 27–31} = − 23.5‰ to − 23.1‰) plants, but neither δ{sup 13}C nor δ{sup 2}H values could uniquely differentiate aquatic and terrestrial species, emphasizing a stronger plant physiological/biochemical rather than environmental control over isotopic differences. ACL and CPI complemented isotopic discrimination, with significantly longer chain lengths recorded for trees and terrestrial plants compared with herbaceous perennials and aquatic species, respectively. Application of a comprehensive Bayesian mixing model for 18 streambed sediments collected between September 2013 and March 2014 revealed considerable temporal variability in the

  14. Functional connectivity of coral reef fishes in a tropical seascape assessed by compound-specific stable isotope analyses

    KAUST Repository

    McMahon, Kelton W.

    2011-01-01

    The ecological integrity of tropical habitats, including mangroves, seagrass beds and coral reefs, is coming under increasing pressure from human activities. Many coral reef fish species are thought to use mangroves and seagrass beds as juvenile nurseries before migrating to coral reefs as adults. Identifying essential habitats and preserving functional linkages among these habitats is likely necessary to promote ecosystem health and sustainable fisheries on coral reefs. This necessitates quantitative assessment of functional connectivity among essential habitats at the seascape level. This thesis presents the development and first application of a method for tracking fish migration using amino acid (AA) δ13C analysis in otoliths. In a controlled feeding experiment with fish reared on isotopically distinct diets, we showed that essential AAs exhibited minimal trophic fractionation between consumer and diet, providing a δ13C record of the baseline isoscape. We explored the potential for geochemical signatures in otoliths of snapper to act as natural tags of residency in seagrass beds, mangroves and coral reefs in the Red Sea, Caribbean Sea and Eastern Pacific Ocean. The δ13C values of otolith essential AAs varied as a function of habitat type and provided a better tracer of residence in juvenile nursery habitats than conventional bulk stable isotope analyses (SIA). Using our otolith AA SIA approach, we quantified the relative contribution of coastal wetlands and reef habitats to Lutjanus ehrenbergii populations on coastal, shelf and oceanic coral reefs in the Red Sea. L. ehrenbergii made significant ontogenetic migrations, traveling more than 30 km from juvenile nurseries to coral reefs and across deep open water. Coastal wetlands were important nurseries for L. ehrenbergii; however, there was significant plasticity in L. ehrenbergii juvenile habitat requirements. Seascape configuration played an important role in determining the functional connectivity of L

  15. Complementing approaches to demonstrate chlorinated solvent biodegradation in a complex pollution plume: mass balance, PCR and compound-specific stable isotope analysis.

    OpenAIRE

    Courbet Christelle; Rivière Agnès; Jeannottat Simon; Rinaldi Sandro; Hunkeler Daniel; Bendjoudi Hocine; De Marsily Ghislain

    2011-01-01

    This work describes the use of different complementing methods (mass balance polymerase chain reaction assays and compound specific stable isotope analysis) to demonstrate the existence and effectiveness of biodegradation of chlorinated solvents in an alluvial aquifer. The solvent contaminated site is an old chemical factory located in an alluvial plain in France. As most of the chlorinated contaminants currently found in the groundwater at this site were produced by local industries at vario...

  16. Evaluation of the performance of high temperature conversion reactors for compound-specific oxygen stable isotope analysis.

    Science.gov (United States)

    Hitzfeld, Kristina L; Gehre, Matthias; Richnow, Hans-Hermann

    2017-05-01

    In this study conversion conditions for oxygen gas chromatography high temperature conversion (HTC) isotope ratio mass spectrometry (IRMS) are characterised using qualitative mass spectrometry (IonTrap). It is shown that physical and chemical properties of a given reactor design impact HTC and thus the ability to accurately measure oxygen isotope ratios. Commercially available and custom-built tube-in-tube reactors were used to elucidate (i) by-product formation (carbon dioxide, water, small organic molecules), (ii) 2nd sources of oxygen (leakage, metal oxides, ceramic material), and (iii) required reactor conditions (conditioning, reduction, stability). The suitability of the available HTC approach for compound-specific isotope analysis of oxygen in volatile organic molecules like methyl tert-butyl ether is assessed. Main problems impeding accurate analysis are non-quantitative HTC and significant carbon dioxide by-product formation. An evaluation strategy combining mass spectrometric analysis of HTC products and IRMS 18 O/ 16 O monitoring for future method development is proposed.

  17. Compound specific stable isotopes as probes for distinguishing the sources of biomolecules in terrestrial and extraterrestrial materials

    Science.gov (United States)

    Engel, M. H.; Macko, S. A.

    2003-04-01

    Life on Earth consists of orderly arrangements of several key types of organic compounds (amino acids, sugars, fatty acids, nucleic bases) that are the building blocks of proteins, carbohydrates, lipids and nucleotides. Subsequent to death, macromolecules are commonly broken down to their molecular constituents or other similar scale components. Thus, in ancient terrestrial and extraterrestrial materials, it is far more likely to expect the presence of simple compounds such as amino acids rather than the proteins from which they were possibly derived. Given that amino acids, for example, are common components of all extinct and extant organisms, the challenge has been to develop methods for distinguishing their sources. Stable isotopes are powerful probes for determining the origins of organic matter. Amino acid constituents of all organisms on Earth exhibit characteristic stable isotope compositions owing to fractionations associated with their biosynthesis. These fractionations are distinct from those observed for amino acids formed by abiotic processes. Thus it should be possible to use isotopes as probes for determining whether amino acids in ancient rocks on Earth are biotic or abiotic, based on their relative isotopic compositions. Also, owing to differences in the isotope compositions of precursors, amino acids in extraterrestrial materials such as carbonaceous meteorites are moderately to substantially enriched in the heavy isotopes of C, N and H relative to terrestrial amino acids. Assuming that the isotope compositions of the gaseous components of, for example, the Martian atmosphere were distinct from Earth at such time when organic molecules may have formed, it should be possible to distinguish these components from terrestrial contaminants by determining their isotope compositions and/or those of their respective enantiomers. Also, if life as we know it existed on another planet such as Mars, fractionations characteristic of biosynthesis should be

  18. Functional connectivity of coral reef fishes in a tropical seascape assessed by compound-specific stable isotope analyses

    KAUST Repository

    McMahon, Kelton W.

    2011-01-01

    . The compound-specific SIA approach presented in this thesis will be particularly valuable for tracking the movement of species and life-stages not amenable to conventional tagging techniques. This thesis provides quantitative scientific support for establishing

  19. The CSSIAR v.1.00 Software: A new tool based on SIAR to assess soil redistribution using Compound Specific Stable Isotopes

    Directory of Open Access Journals (Sweden)

    de los Santos-Villalobos Sergio

    2017-01-01

    Full Text Available Soil erosion is one of the biggest challenges for food production around the world. Many techniques have been used to evaluate and mitigate soil degradation. Nowadays isotopic techniques are becoming a powerful tool to assess soil apportionment. One of the innovative techniques used is the Compound Specific Stable Isotopes (CSSI analysis, which has been used to track down sediments and specify their sources by the isotopic signature of δ13C in specific fatty acids. The application of this technique on soil apportionment has been recently developed, however there is a lack of user-friendly Software for data processing and interpretation. The aim of this article is to introduce a new open source tool for working with data sets generated by the use of the CSSI technique to assess soil apportionment, called the CSSIARv1.00 Software

  20. The CSSIAR v.1.00 Software: A new tool based on SIAR to assess soil redistribution using Compound Specific Stable Isotopes

    Science.gov (United States)

    Sergio, de los Santos-Villalobos; Claudio, Bravo-Linares; dos Anjos Roberto, Meigikos; Renan, Cardoso; Max, Gibbs; Andrew, Swales; Lionel, Mabit; Gerd, Dercon

    Soil erosion is one of the biggest challenges for food production around the world. Many techniques have been used to evaluate and mitigate soil degradation. Nowadays isotopic techniques are becoming a powerful tool to assess soil apportionment. One of the innovative techniques used is the Compound Specific Stable Isotopes (CSSI) analysis, which has been used to track down sediments and specify their sources by the isotopic signature of δ13 C in specific fatty acids. The application of this technique on soil apportionment has been recently developed, however there is a lack of user-friendly Software for data processing and interpretation. The aim of this article is to introduce a new open source tool for working with data sets generated by the use of the CSSI technique to assess soil apportionment, called the CSSIARv1.00 Software

  1. Compound-specific stable carbon isotopic composition of petroleum hydrocarbons as a tool for tracing the source of oil spills

    International Nuclear Information System (INIS)

    Li Yun; Xiong Yongqiang; Yang Wanying; Xie Yueliang; Li Siyuan; Sun Yongge

    2009-01-01

    With the increasing demand for and consumption of crude oils, oil spill accidents happen frequently during the transportation of crude oils and oil products, and the environmental hazard they pose has become increasingly serious in China. The exact identification of the source of spilled oil can act as forensic evidence in the investigation and handling of oil spill accidents. In this study, a weathering simulation experiment demonstrates that the mass loss of crude oils caused by short-term weathering mainly occurs within the first 24 h after a spill, and is dominated by the depletion of low-molecular weight hydrocarbons ( 18 n-alkanes). Short-term weathering has no significant effect on δ 13 C values of individual n-alkanes (C 12 -C 33 ), suggesting that a stable carbon isotope profile of n-alkanes can be a useful tool for tracing the source of an oil spill, particularly for weathered oils or those with a relatively low concentration or absence of sterane and terpane biomarkers

  2. A protocol for pressurized liquid extraction and processing methods to isolate modern and ancient bone cholesterol for compound-specific stable isotope analysis.

    Science.gov (United States)

    Laffey, Ann O; Krigbaum, John; Zimmerman, Andrew R

    2017-02-15

    Bone lipid compound-specific isotope analysis (CSIA) and bone collagen and apatite stable isotope ratio analysis are important sources of ecological and paleodietary information. Pressurized liquid extraction (PLE) is quicker and utilizes less solvent than traditional methods of lipid extraction such as soxhlet and ultrasonication. This study facilitates dietary analysis by optimizing and testing a standardized methodology for PLE of bone cholesterol. Modern and archaeological bones were extracted by PLE using varied temperatures, solvent solutions, and sample weights. The efficiency of PLE was assessed via quantification of cholesterol yields. Stable isotopic ratio integrity was evaluated by comparing isotopic signatures (δ 13 C and δ 18 O values) of cholesterol derived from whole bone, bone collagen and bone apatite. Gas chromatography/mass spectrometry (GC/MS) and gas chromatography isotope ratio mass spectrometry (GC/IRMS) were conducted on purified collagen and lipid extracts to assess isotopic responses to PLE. Lipid yield was optimized at two PLE extraction cycles of 75 °C using dichloromethane/methanol (2:1 v/v) as a solvent with 0.25-0.75 g bone sample. Following lipid extraction, saponification combined with the derivatization of the neutral fraction using trimethylsilylation yielded nearly twice the cholesterol of non-saponified or non-derivatized samples. It was also found that lipids extracted from purified bone collagen and apatite could be used for cholesterol CSIA. There was no difference in the bulk δ 13 C values of collagen extracted from bone with or without lipid. However, there was a significant depletion in 18 O of bone apatite due to lipid presence or processing. These results should assist sample selection and provide an effective, alternative extraction method for bone cholesterol that may be used for isotopic and paleodietary analysis. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  3. Sources of variability in fatty acid (FA) biomarkers in the application of compound-specific stable isotopes (CSSIs) to soil and sediment fingerprinting and tracing: A review

    Energy Technology Data Exchange (ETDEWEB)

    Reiffarth, D.G., E-mail: Dominic.Reiffarth@unbc.ca [Natural Resources and Environmental Studies Program, University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 (Canada); Petticrew, E.L., E-mail: Ellen.Petticrew@unbc.ca [Geography Program and Quesnel River Research Centre, University of Northern British Columbia, 3333 University Way, Prince George, BC V2N 4Z9 (Canada); Owens, P.N., E-mail: Philip.Owens@unbc.ca [Environmental Science Program and Quesnel River Research Centre, University of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9 (Canada); Lobb, D.A., E-mail: David.Lobb@umanitoba.ca [Watershed Systems Research Program, University of Manitoba, 13 Freedman Crescent, Winnipeg, MB R3T 2N2 (Canada)

    2016-09-15

    Determining soil redistribution and sediment budgets in watersheds is often challenging. One of the methods for making such determinations employs soil and sediment fingerprinting techniques, using sediment properties such as geochemistry, fallout radionuclides, and mineral magnetism. These methods greatly improve the estimation of erosion and deposition within a watershed, but are limited when determining land use-based soil and sediment movement. Recently, compound-specific stable isotopes (CSSIs), which employ fatty acids naturally occurring in the vegetative cover of soils, offer the possibility of refining fingerprinting techniques based on land use, complementing other methods that are currently in use. The CSSI method has been met with some success; however, challenges still remain with respect to scale and resolution due to a potentially large degree of biological, environmental and analytical uncertainty. By better understanding the source of tracers used in CSSI work and the inherent biochemical variability in those tracers, improvement in sample design and tracer selection is possible. Furthermore, an understanding of environmental and analytical factors affecting the CSSI signal will lead to refinement of the approach and the ability to generate more robust data. This review focuses on sources of biological, environmental and analytical variability in applying CSSI to soil and sediment fingerprinting, and presents recommendations based on past work and current research in this area for improving the CSSI technique. A recommendation, based on current information available in the literature, is to use very-long chain saturated fatty acids and to avoid the use of the ubiquitous saturated fatty acids, C{sub 16} and C{sub 18}. - Highlights: • Compound-specific stable isotopes (CSSIs) of carbon may be used as soil tracers. • The variables affecting CSSI data are: biological, environmental and analytical. • Understanding sources of variability will lead

  4. Sources of variability in fatty acid (FA) biomarkers in the application of compound-specific stable isotopes (CSSIs) to soil and sediment fingerprinting and tracing: A review

    International Nuclear Information System (INIS)

    Reiffarth, D.G.; Petticrew, E.L.; Owens, P.N.; Lobb, D.A.

    2016-01-01

    Determining soil redistribution and sediment budgets in watersheds is often challenging. One of the methods for making such determinations employs soil and sediment fingerprinting techniques, using sediment properties such as geochemistry, fallout radionuclides, and mineral magnetism. These methods greatly improve the estimation of erosion and deposition within a watershed, but are limited when determining land use-based soil and sediment movement. Recently, compound-specific stable isotopes (CSSIs), which employ fatty acids naturally occurring in the vegetative cover of soils, offer the possibility of refining fingerprinting techniques based on land use, complementing other methods that are currently in use. The CSSI method has been met with some success; however, challenges still remain with respect to scale and resolution due to a potentially large degree of biological, environmental and analytical uncertainty. By better understanding the source of tracers used in CSSI work and the inherent biochemical variability in those tracers, improvement in sample design and tracer selection is possible. Furthermore, an understanding of environmental and analytical factors affecting the CSSI signal will lead to refinement of the approach and the ability to generate more robust data. This review focuses on sources of biological, environmental and analytical variability in applying CSSI to soil and sediment fingerprinting, and presents recommendations based on past work and current research in this area for improving the CSSI technique. A recommendation, based on current information available in the literature, is to use very-long chain saturated fatty acids and to avoid the use of the ubiquitous saturated fatty acids, C 16 and C 18 . - Highlights: • Compound-specific stable isotopes (CSSIs) of carbon may be used as soil tracers. • The variables affecting CSSI data are: biological, environmental and analytical. • Understanding sources of variability will lead to more

  5. Sediment Origin Determination in the Sub-Catchment of Mistelbach (Austria) using Fatty Acids Biomarkers and Compound-Specific Stable Isotope Techniques

    International Nuclear Information System (INIS)

    Mabit, L.; Chen, X.; Resch, C.; Toloza, A.; Meusburger, K.; Alewell, C.; Gibbs, M.; Klik, A.; Eder, A.; Strauss, P.

    2016-01-01

    Compound-specific stable isotope (CSSI) signatures of inherent soil organic biomarkers allow discriminating and apportioning the source of soil contribution from different land uses. Plant communities label the soil where they grow by exuding organic biomarkers. Although all plants produce the same biomarkers, the stable isotopic signature of those biomarkers is different for each plant species. For agri-environmental investigations, the CSSI technique is based on the measurement of carbon-13 ( 13 C) natural abundance signatures of specific organic compounds such as natural fatty acids (FAs) in the soil. By linking fingerprints of land use to the sediment in deposition zones, this approach has been shown to be a useful technique for determining the source of eroded soil and thereby identifying areas prone to soil degradation. The authors have used this innovative technique to investigate a 3 hectares sub-catchment of Mistelbach situated 60 km north of Vienna. Using the 137 Cs technique, Mabit et al. (2009) reported a local maximum sedimentation rate reaching 20 to 50 t ha -1 yr -1 in the lowest part of this Austrian catchment. To test the ability of the CSSI technique to discriminate different sediment sources of these deposited sediments, representative soil samples from four main agricultural fields of the site were analyzed

  6. Holocene Paleohydrological Changes in Northern Michigan: Interpretations of Biomarker Distributions and Compound Specific Stable Isotope Analysis from Peatlands

    Science.gov (United States)

    Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Huang, Y.

    2006-12-01

    Sediments of ombrotrophic peatlands are excellent archives for reconstructing past changes in precipitation/evaporation (P/E) balance. Multiproxy analysis of these sediments is critical for better understanding of climatic events experienced by these highly sensitive systems, as each proxy may respond to different climate parameters. In this study, we use distributions of n-alkanes and δD of Sphagnum biomarkers to interpret paleohydrology from sediments of Irwin Smith Bog, northern Michigan. We then integrate these data with pollen data and testate amoebae-inferred water table depth. Sphagnum moss is the dominant peat former in ombrotrophic bogs, but vascular plants become abundant when water tables are drawn down. Thus, the abundance of Sphagnum relative to vascular plants is indicative of peatland hydrology. The n-alkanes produced by Sphagnum differ from vascular plants in the relative abundance of the different homologues, with the former having excess amounts of shorter chain C23 n-alkane. We use several measures (compound ratios, PCA) to show changes in then-alkane distributions in the sediments, and thus changes in the peatland plant community. Our data provide high- resolution, quantitative paleohydrological records for the study region that are consistent with other records. We also show that the relative abundance of a newly identified Sphagnum biomarker, 2-heptacosanone, can be used to reconstruct changing plant communities. Because ombrotrophic systems lose water by evaporation, drier/warmer conditions cause hydrogen isotopic enrichment of bog water and Sphagnum biomarkers. We measured the δD of C23 n-alkane and 2-heptacosanone to provide additional paleoclimate information. Our multiproxy approach allows us to better understand the climate changes during key intervals of the Holocene. For example, a sharp decrease in the abundance of Tsuga canadensis (hemlock) pollen has been previously identified in records from many places throughout eastern North

  7. Triple-element compound-specific stable isotope analysis of 1,2-dichloroethane for characterization of the underlying dehalogenation reaction in two Dehalococcoides mccartyi strains.

    Science.gov (United States)

    Franke, Steffi; Lihl, Christina; Renpenning, Julian; Elsner, Martin; Nijenhuis, Ivonne

    2017-12-01

    Chlorinated ethanes belong to the most common groundwater and soil contaminants. Of these, 1,2-dichloroethane (1,2-DCA) is a man-made, persistent and toxic contaminant, released due to improper waste treatment at versatile production sites. This study investigated the anaerobic transformation of 1,2-DCA by Dehalococcoides mccartyi strain 195 and strain BTF08 using triple-element compound-specific stable isotope analysis of carbon, chlorine and hydrogen for the first time. Isotope fractionation patterns for carbon (εCBTF08 = -28.4 ± 3.7‰; εC195 = -30.9 ± 3.6‰) and chlorine (εClBTF08 = -4.6 ± 0.7‰; εCl195 = -4.2 ± 0.5‰) within both investigated D. mccartyi strains, as well as the dual-element analysis (ΛBTF08 = 6.9 ± 1.2; Λ195 = 7.1 ± 0.2), supported identical reaction mechanisms for dehalogenation of 1,2-DCA. Hydrogen isotope fractionation analysis revealed dihaloelimination as prevalent reaction mechanism. Vinyl chloride as major intermediate could be excluded by performing the experiment in deuterated aqueous media. Furthermore, evaluation of the derived apparent kinetic isotope effects (AKIECBTF08 = 1.029/AKIEC195 = 1.031; AKIEClBTF08 = 1.005/AKIECl195 = 1.004) pointed towards simultaneous abstraction of both involved chlorine-substituents in a concerted matter. It was shown that D. mccartyi strain BTF08 and strain 195 are capable of complete, direct dihaloelimination of 1,2-DCA to ethene. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  8. First use of a compound-specific stable isotope (CSSI) technique to trace sediment transport in upland forest catchments of Chile.

    Science.gov (United States)

    Bravo-Linares, Claudio; Schuller, Paulina; Castillo, Alejandra; Ovando-Fuentealba, Luis; Muñoz-Arcos, Enrique; Alarcón, Oscar; de Los Santos-Villalobos, Sergio; Cardoso, Renan; Muniz, Marcelo; Meigikos Dos Anjos, Roberto; Bustamante-Ortega, Ramón; Dercon, Gerd

    2018-03-15

    Land degradation is a problem affecting the sustainability of commercial forest plantations. The identification of critical areas prone to erosion can assist this activity to better target soil conservation efforts. Here we present the first use of the carbon-13 signatures of fatty acids (C14 to C24) in soil samples for spatial and temporal tracing of sediment transport in river bodies of upland commercial forest catchments in Chile. This compound-specific stable isotope (CSSI) technique was tested as a fingerprinting approach to determine the degree of soil erosion in pre-harvested forest catchments with surface areas ranging from 12 to 40ha. For soil apportionment a mixing model based on a Bayesian inference framework was used (CSSIAR v.2.0). Approximately four potential sediment sources were used for the calculations of all of the selected catchments. Unpaved forestry roads were shown to be the main source of sediment deposited at the outlet of the catchments (30-75%). Furthermore, sampling along the stream channel demonstrated that sediments were mainly comprised of sediment coming from the unpaved roads in the upper part of the catchments (74-98%). From this it was possible to identify the location and type of primary land use contributing to the sediment delivered at the outlet of the catchments. The derived information will allow management to focus efforts to control or mitigate soil erosion by improving the runoff features of the forest roads. The use of this CSSI technique has a high potential to help forestry managers and decision makers to evaluate and mitigate sources of soil erosion in upland forest catchments. It is important to highlight that this technique can also be a good complement to other soil erosion assessment and geological fingerprinting techniques, especially when attempting to quantify (sediment loads) and differentiate which type of land use most contributes to sediment accumulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Complementing approaches to demonstrate chlorinated solvent biodegradation in a complex pollution plume: Mass balance, PCR and compound-specific stable isotope analysis

    Science.gov (United States)

    Courbet, Christelle; Rivière, Agnès; Jeannottat, Simon; Rinaldi, Sandro; Hunkeler, Daniel; Bendjoudi, Hocine; de Marsily, Ghislain

    2011-11-01

    This work describes the use of different complementing methods (mass balance, polymerase chain reaction assays and compound-specific stable isotope analysis) to demonstrate the existence and effectiveness of biodegradation of chlorinated solvents in an alluvial aquifer. The solvent-contaminated site is an old chemical factory located in an alluvial plain in France. As most of the chlorinated contaminants currently found in the groundwater at this site were produced by local industries at various times in the past, it is not enough to analyze chlorinated solvent concentrations along a flow path to convincingly demonstrate biodegradation. Moreover, only a few data were initially available to characterize the geochemical conditions at this site, which were apparently complex at the source zone due to (i) the presence of a steady oxygen supply to the groundwater by irrigation canal losses and river infiltration and (ii) an alkaline pH higher than 10 due to former underground lime disposal. A demonstration of the existence of biodegradation processes was however required by the regulatory authority within a timeframe that did not allow a full geochemical characterization of such a complex site. Thus a combination of different fast methods was used to obtain a proof of the biodegradation occurrence. First, a mass balance analysis was performed which revealed the existence of a strong natural attenuation process (biodegradation, volatilization or dilution), despite the huge uncertainty on these calculations. Second, a good agreement was found between carbon isotopic measurements and PCR assays (based on 16S RNA gene sequences and functional genes), which clearly indicated reductive dechlorination of different hydrocarbons (Tetrachloroethene—PCE-, Trichloroethene—TCE-, 1,2- cisDichloroethene— cis-1,2-DCE-, 1,2- transDichloroethene— trans-1,2-DCE-, 1,1-Dichloroethene—1,1-DCE-, and Vinyl Chloride—VC) to ethene. According to these carbon isotope measurements

  10. Metabolism of Seriola lalandi during Starvation as Revealed by Fatty Acid Analysis and Compound-Specific Analysis of Stable Isotopes within Amino Acids.

    Directory of Open Access Journals (Sweden)

    Fernando Barreto-Curiel

    Full Text Available Fish starvation is defined as food deprivation for a long period of time, such that physiological processes become confined to basal metabolism. Starvation provides insights in physiological processes without interference from unknown factors in digestion and nutrient absorption occurring in fed state. Juveniles of amberjack Seriola lalandi were isotopically equilibrated to a formulated diet for 60 days. One treatment consisted of fish that continued to be fed and fish in the other treatment were not fed for 35 days. The isotopic signatures prior to the beginning of and after the starvation period, for fish in the starvation and control treatments, were analysed for lipid content, fatty acid composition and isotopic analysis of bulk (EA-IRMS and of amino acids (compound specific isotope analysis, CSIA. There were three replicates for the starvation group. Fatty acid content in muscle and liver tissue before and after starvation was determined to calculate percent change. Results showed that crude lipid was the most used source of energy in most cases; the PUFAs and LC-PUFAs were highly conserved. According to the protein signature in bulk (δ15N and per amino acid (δ13C and δ15N, in muscle tissue, protein synthesis did not appear to occur substantially during starvation, whereas in liver, increases in δ13C and δ15N indicate that protein turnover occurred, probably for metabolic routing to energy-yielding processes. As a result, isotopic values of δ15N in muscle tissue do not change, whereas CSIA net change occurred in the liver tissue. During the study period of 35 days, muscle protein was largely conserved, being neither replenished from amino acid pools in the plasma and liver nor catabolized.

  11. High Relative Abundance of Biofuel Sourced Ethanol in Precipitation in the US and Brazil Determined Using Compound Specific Stable Carbon Isotopes

    Science.gov (United States)

    Shimizu, M. S.; Felix, J. D. D.; Casas, M.; Avery, G. B., Jr.; Kieber, R. J.; Mead, R. N.; Willey, J. D.; Lane, C.

    2017-12-01

    Ethanol biofuel production and consumption have increased exponentially over the last two decades to help reduce greenhouse gas emissions. Currently, 85% of global ethanol production and consumption occurs in the US and Brazil. Increasing biofuel ethanol usage in these two countries enhances emissions of uncombusted ethanol to the atmosphere contributing to poor air quality. Although measurements of ethanol in the air and the precipitation reveal elevated ethanol concentrations in densely populated cities, other sources such as natural vegetation can contribute to emission to the atmosphere. Previous modeling studies indicated up to 12% of atmospheric ethanol is from anthropogenic emissions. Only one gas phase study in southern Florida attempted to constrain the two sources through direct isotopic measurements. The current study used a stable carbon isotope method to constrain sources of ethanol in rainwater from the US and Brazil. A method was developed using solid phase microextraction (SPME) with subsequent analysis by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Stable carbon isotope signatures (δ13C) of vehicle ethanol emission sources for both the US (-9.8‰) and Brazil (-12.7‰) represented C4 plants as feedstock (corn and sugarcane) for biofuel production. An isotope mixing model using biofuel from vehicles (C4 plants) and biogenic (C3 plants) end-members was implemented to estimate ethanol source apportionment in the rain. We found that stable carbon isotope ratio of ethanol in the rain ranged between -22.6‰ and -12.7‰. Our results suggest that the contribution of biofuel to atmospheric ethanol can be higher than previously estimated. As biofuel usage increasing globally, it is essential to determine the relative abundance of anthropogenic ethanol in other areas of the world.

  12. Tracing fresh assimilates through Larix decidua exposed to elevated CO₂ and soil warming at the alpine treeline using compound-specific stable isotope analysis.

    Science.gov (United States)

    Streit, Kathrin; Rinne, Katja T; Hagedorn, Frank; Dawes, Melissa A; Saurer, Matthias; Hoch, Günter; Werner, Roland A; Buchmann, Nina; Siegwolf, Rolf T W

    2013-02-01

    How will carbon source-sink relations of 35-yr-old larch trees (Larix decidua) at the alpine treeline respond to changes in atmospheric CO(2) and climate? We evaluated the effects of previously elevated CO(2) concentrations (9 yr, 580 ppm, ended the previous season) and ongoing soil warming (4 yr, + 4°C). Larch branches were pulse labeled (50 at% (13)CO(2)) in July 2010 to trace fresh assimilates through tissues (buds, needles, bark and wood) and non-structural carbon compounds (NCC; starch, lipids, individual sugars) using compound-specific isotope analysis. Nine years of elevated CO(2) did not lead to increased NCC concentrations, nor did soil warming increase NCC transfer velocities. By contrast, we found slower transfer velocities and higher NCC concentrations than reported in the literature for lowland larch. As a result of low dilution with older carbon, sucrose and glucose showed the highest maximum (13)C labels, whereas labels were lower for starch, lipids and pinitol. Label residence times in needles were shorter for sucrose and starch (c. 2 d) than for glucose (c. 6 d). Although our treatments showed no persistent effect on larch carbon relations, low temperature at high altitudes clearly induced a limitation of sink activities (growth, respiration, root exudation), expressed in slower carbon transfer and higher NCC concentrations. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  13. Molecular distribution and compound-specific stable carbon isotopic composition of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls in PM2.5 from Beijing, China

    Directory of Open Access Journals (Sweden)

    W. Zhao

    2018-02-01

    Full Text Available This study investigates the seasonal variation, molecular distribution and stable carbon isotopic composition of diacids, oxocarboxylic acids and α-dicarbonyls to better understand the sources and formation processes of fine aerosols (PM2.5 in Beijing. The concentrations of total dicarboxylic acids varied from 110 to 2580 ng m−3, whereas oxoacids (9.50–353 ng m−3 and dicarbonyls (1.50–85.9 ng m−3 were less abundant. Oxalic acid was found to be the most abundant individual species, followed by succinic acid or occasionally by terephthalic acid (tPh, a plastic waste burning tracer. Ambient concentrations of phthalic acid (37.9 ± 27.3 ng m−3 and tPh (48.7 ± 51.1 ng m−3 were larger in winter than in other seasons, illustrating that fossil fuel combustion and plastic waste incineration contribute more to wintertime aerosols. The year-round mass concentration ratios of malonic acid to succinic acid (C3 ∕ C4 were relatively low by comparison with those in other urban aerosols and remote marine aerosols. The values were less than or equal to unity in Beijing, implying that the degree of photochemical formation of diacids in Beijing is insignificant. Moreover, strong correlation coefficients of major oxocarboxylic acids and α-dicarbonyls with nss-K+ suggest that biomass burning contributes significantly to these organic acids and related precursors. The mean δ13C value of succinic acid is the highest among all species, with values of −17.1 ± 3.9 ‰ (winter and −17.1 ± 2.0 ‰ (spring, while malonic acid is more enriched in 13C than others in autumn (−17.6 ± 4.6 ‰ and summer (−18.7 ± 4.0 ‰. The δ13C values of major species in Beijing aerosols are generally lower than those in the western North Pacific atmosphere, the downwind region, which indicates that stable carbon isotopic compositions of diacids depend on their precursor sources in Beijing. Therefore, our

  14. Molecular distribution and compound-specific stable carbon isotopic composition of dicarboxylic acids, oxocarboxylic acids and α-dicarbonyls in PM2.5 from Beijing, China

    Science.gov (United States)

    Zhao, Wanyu; Kawamura, Kimitaka; Yue, Siyao; Wei, Lianfang; Ren, Hong; Yan, Yu; Kang, Mingjie; Li, Linjie; Ren, Lujie; Lai, Senchao; Li, Jie; Sun, Yele; Wang, Zifa; Fu, Pingqing

    2018-02-01

    This study investigates the seasonal variation, molecular distribution and stable carbon isotopic composition of diacids, oxocarboxylic acids and α-dicarbonyls to better understand the sources and formation processes of fine aerosols (PM2.5) in Beijing. The concentrations of total dicarboxylic acids varied from 110 to 2580 ng m-3, whereas oxoacids (9.50-353 ng m-3) and dicarbonyls (1.50-85.9 ng m-3) were less abundant. Oxalic acid was found to be the most abundant individual species, followed by succinic acid or occasionally by terephthalic acid (tPh), a plastic waste burning tracer. Ambient concentrations of phthalic acid (37.9 ± 27.3 ng m-3) and tPh (48.7 ± 51.1 ng m-3) were larger in winter than in other seasons, illustrating that fossil fuel combustion and plastic waste incineration contribute more to wintertime aerosols. The year-round mass concentration ratios of malonic acid to succinic acid (C3 / C4) were relatively low by comparison with those in other urban aerosols and remote marine aerosols. The values were less than or equal to unity in Beijing, implying that the degree of photochemical formation of diacids in Beijing is insignificant. Moreover, strong correlation coefficients of major oxocarboxylic acids and α-dicarbonyls with nss-K+ suggest that biomass burning contributes significantly to these organic acids and related precursors. The mean δ13C value of succinic acid is the highest among all species, with values of -17.1 ± 3.9 ‰ (winter) and -17.1 ± 2.0 ‰ (spring), while malonic acid is more enriched in 13C than others in autumn (-17.6 ± 4.6 ‰) and summer (-18.7 ± 4.0 ‰). The δ13C values of major species in Beijing aerosols are generally lower than those in the western North Pacific atmosphere, the downwind region, which indicates that stable carbon isotopic compositions of diacids depend on their precursor sources in Beijing. Therefore, our study demonstrates that in addition to photochemical oxidation, high abundances of diacids

  15. Use of compound-specific stable carbon isotope ratio measurements of asphaltene-bound polycyclic aromatic hydrocarbons (PAHs) as a novel aid to source apportionment of environmental PAHs

    Energy Technology Data Exchange (ETDEWEB)

    C. Sun; C. Snape; M. Cooper; W. Ivwurie [University of Nottingham, Nottingham (United Kingdom). Nottingham Energy & Fuel Centre

    2005-07-01

    In this study, the PAHs from hydropyrolysis of asphaltenes from different primary sources (e.g. crude oil, low and high temperature coal tars) were characterized by their molecular distributions and {sup 13}C/{sup 12}C isotope ratios. It was found that for all oil samples, the molecular and isotopic profiles for their asphaltene-derived PAHs are both similar to those observed for their contained free aromatics, with {sup 13}C-isotopic values varying from -25 to -27{per_thousand} for the Nigerian and -27 to -30{per_thousand} for North Sea oil samples. For low and high temperature coal tar samples, however, similar molecular but different isotopic profiles were observed for their asphaltene-bound PAHs. The free aromatics are significantly isotopically lighter (by nearly -3{per_thousand}) than their asphaltene-derived counterparts having isotopic values typically between -22 and -23{per_thousand} for all coal tar samples examined, and this leads to a larger isotopic difference of up to 7{per_thousand} between the two sources of PAHs than that already observed between their free aromatics (3{per_thousand}). Applying these results to samples previously examined in an area where unambiguous source apportionment could not be conducted for the PAHs due to likely biodegradation, it was found that the bound PAHs released from the asphaltenes recovered from the soil samples in this area are extremely similar to low temperature tar as the source, in terms of their both molecular (highly alkylated) and isotopic profiles. The free PAHs are much less alkyl substituted confirming that the aromatics detected in this area have been subjected to intensiveenvironmental degradation with alkylated aromatic constituents being preferentially removed from their initial matrix.

  16. 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)

  17. Transformation of chlorpyrifos in integrated recirculating constructed wetlands (IRCWs) as revealed by compound-specific stable isotope (CSIA) and microbial community structure analysis.

    Science.gov (United States)

    Tang, Xiaoyan; Yang, Yang; Huang, Wenda; McBride, Murray B; Guo, Jingjing; Tao, Ran; Dai, Yunv

    2017-06-01

    Carbon isotope analysis and 454 pyrosequencing methods were used to investigate in situ biodegradation of chlorpyrifos during its transport through three model integrated recirculating constructed wetlands (IRCWs). Results show that plant and Fe-impregnated biochar promoted degradation of chlorpyrifos and its metabolite 3,5,6-trichloro-2-pyridinol (TCP). Carbon isotope ratios in the IRCWs shifted to -31.24±0.58‰ (IRCW1, plant free), -26.82±0.60‰ (IRCW2, with plant) and -24.76±0.94‰ (IRCW3, with plant and Fe-biochar). The enrichment factors (Ɛ bulk,c ) were determined as -0.69±0.06‰ (IRCW1), -0.91±0.07‰ (IRCW2) and -1.03±0.09‰ (IRCW3). Microbial community analysis showed that IRCW3 was dominated by members of Bacillus, which can utilize and degrade chlorpyrifos. These results reveal that plant and Fe-biochar can induce carbon isotope fractionation and have a positive impact on the chlorpyrifos degradation efficiency by influencing the development of beneficial microbial communities. Copyright © 2017. Published by Elsevier Ltd.

  18. Stable isotopes

    International Nuclear Information System (INIS)

    Brazier, J.L.; Guinamant, J.L.

    1995-01-01

    According to the progress which has been realised in the technology of separating and measuring isotopes, the stable isotopes are used as preferable 'labelling elements' for big number of applications. The isotopic composition of natural products shows significant variations as a result of different reasons like the climate, the seasons, or their geographic origins. So, it was proved that the same product has a different isotopic composition of alimentary and agriculture products. It is also important in detecting the pharmacological and medical chemicals. This review article deals with the technology, like chromatography and spectrophotometry, adapted to this aim, and some important applications. 17 refs. 6 figs

  19. Pico-CSIA: Picomolar Scale Compound-Specific Isotope Analyses

    Science.gov (United States)

    Baczynski, A. A.; Polissar, P. J.; Juchelka, D.; Schwieters, J. B.; Hilkert, A.; Freeman, K. H.

    2016-12-01

    The basic approach to analyzing molecular isotopes has remained largely unchanged since the late 1990s. Conventional compound-specific isotope analyses (CSIA) are conducted using capillary gas chromatography (GC), a combustion interface, and an isotope-ratio mass spectrometer (IRMS). Commercially available GC-IRMS systems are comprised of components with inner diameters ≥0.25 mm and employ helium flow rates of 1-4 mL/min. These flow rates are an order of magnitude larger than what the IRMS can accept. Consequently, ≥90% of the sample is lost through the open split, and 1-10s of nanomoles of carbon are required for analysis. These sample requirements are prohibitive for many biomarkers, which are often present in picomolar concentrations. We utilize the resolving power and low flows of narrow-bore capillary GC to improve the sensitivity of CSIA. Narrow bore capillary columns (<0.25 mm ID) allow low helium flow rates of ≤0.5mL/min for more efficient sample transfer to the ion source of the IRMS while maintaining the high linear flow rates necessary to preserve narrow peak widths ( 250 ms). The IRMS has been fitted with collector amplifiers configured to 25 ms response times for rapid data acquisition across narrow peaks. Previous authors (e.g., Sacks et al., 2007) successfully demonstrated improved sensitivity afforded by narrow-bore GC columns. They reported an accuracy and precision of 1.4‰ for peaks with an average width at half maximum of 720 ms for 100 picomoles of carbon on column. Our method builds on their advances and further reduces peak widths ( 600 ms) and the amount of sample lost prior to isotopic analysis. Preliminary experiments with 100 picomoles of carbon on column show an accuracy and standard deviation <1‰. With further improvement, we hope to demonstrate robust isotopic analysis of 10s of picomoles of carbon, more than 2 orders of magnitude lower than commercial systems. The pico-CSIA method affords high-precision isotopic analyses for

  20. Development and validation of an universal interface for compound-specific stable isotope analysis of chlorine (37Cl/35Cl) by GC-high-temperature conversion (HTC)-MS/IRMS.

    Science.gov (United States)

    Renpenning, Julian; Hitzfeld, Kristina L; Gilevska, Tetyana; Nijenhuis, Ivonne; Gehre, Matthias; Richnow, Hans-Hermann

    2015-03-03

    A universal application of compound-specific isotope analysis of chlorine was thus far limited by the availability of suitable analysis techniques. In this study, gas chromatography in combination with a high-temperature conversion interface (GC-HTC), converting organic chlorine in the presence of H2 to gaseous HCl, was coupled to a dual-detection system, combining an ion trap mass spectrometer (MS) and isotope-ratio mass spectrometer (IRMS). The combination of the MS/IRMS detection enabled a detailed characterization, optimization, and online monitoring of the high-temperature conversion process via ion trap MS as well as a simultaneous chlorine isotope analysis by the IRMS. Using GC-HTC-MS/IRMS, chlorine isotope analysis at optimized conversion conditions resulted in very accurate isotope values (δ(37)Cl(SMOC)) for measured reference material with known isotope composition, including chlorinated ethylene, chloromethane, hexachlorocyclohexane, and trichloroacetic acids methyl ester. Respective detection limits were determined to be <15 nmol Cl on column with achieved precision of <0.3‰.

  1. Application of compound specific 13C isotope investigations of chlorinated hydrocarbons in contaminated groundwaters

    International Nuclear Information System (INIS)

    Osenbrueck, K.; Heidinger, M.; Voropaev, A.; Ertl, S.; Eichinger, L.

    2002-01-01

    the stable carbon isotopes. The isotope ratios may be used to assess and quantify the degradation of the organic compounds at the field sites. This application has gained great interest for remediation strategies including monitored natural attenuation of contaminations. In contrast to the laboratory studies, many of the field investigation show no evidence for isotope fractionation although biodegradation of the chlorinated hydrocarbons in the groundwater is significant. Here, we present the results of 21 field studies, where compound specific 13 C isotope ratios have been applied. Only in some cases isotope fractionation processes of chlorinated hydrocarbons due to biodegradation have been observed. The measured δ 13 C values agree reasonably with a Rayleigh type isotope fractionation model, where the fractionation factors are used as fitting parameters. The occurrence and the degree of significant isotope fractionation of chlorinated hydrocarbons is still an open question. Major factors that control the extend of measurable 13 C isotope fractionation of chlorinated hydrocarbons in groundwater most likely include parameters as activity and type of the microbiological species, availability of cosubstrates as well as hydrochemical and hydrogeological conditions. (author)

  2. Amino acid compositions in heated carbonaceous chondrites and their compound-specific nitrogen isotopic ratios

    Science.gov (United States)

    Chan, Queenie Hoi Shan; Chikaraishi, Yoshito; Takano, Yoshinori; Ogawa, Nanako O.; Ohkouchi, Naohiko

    2016-01-01

    A novel method has been developed for compound-specific nitrogen isotope compositions with an achiral column which was previously shown to offer high precision for nitrogen isotopic analysis. We applied the method to determine the amino acid contents and stable nitrogen isotopic compositions of individual amino acids from the thermally metamorphosed (above 500 °C) Antarctic carbonaceous chondrites Ivuna-like (CI)1 (or CI-like) Yamato (Y) 980115 and Ornans-like (CO)3.5 Allan Hills (ALH) A77003 with the use of gas chromatography/combustion/isotope ratio mass spectrometry. ALHA77003 was deprived of amino acids due to its extended thermal alteration history. Amino acids were unambiguously identified in Y-980115, and the δ15N values of selected amino acids (glycine +144.8 ‰; α-alanine +121.2 ‰) are clearly extraterrestrial. Y-980115 has experienced an extended period of aqueous alteration as indicated by the presence of hydrous mineral phases. It has also been exposed to at least one post-hydration short-lived thermal metamorphism. Glycine and alanine were possibly produced shortly after the accretion event of the asteroid parent body during the course of an extensive aqueous alteration event and have abstained from the short-term post-aqueous alteration heating due to the heterogeneity of the parent body composition and porosity. These carbonaceous chondrite samples are good analogs that offer important insights into the target asteroid Ryugu of the Hayabusa-2 mission, which is a C-type asteroid likely composed of heterogeneous materials including hydrated and dehydrated minerals.

  3. Compound-Specific Isotopic Analysis of Meteoritic Amino Acids as a Tool for Evaluating Potential Formation Pathways

    Science.gov (United States)

    Elsila, Jamie E.; Burton, Aaron S.; Callahan, Michael C.; Charnley, Steven B.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    Measurements of stable hydrogen, carbon, and nitrogen isotopic ratios (delta D, delta C-13, delta N-15) of organic compounds can reveal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may point towards the most likely of these proposed pathways. The technique of gas chromatography coupled with mass spectrometry and isotope ratio mass spectrometry provides compound-specific structural and isotopic information from a single splitless injection, enhancing the amount of information gained from small amounts of precious samples such as carbonaceous chondrites. We have applied this technique to measure the compound-specific C, N, and H isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites. We are using these measurements to evaluate predictions of expected isotopic enrichments from potential formation pathways and environments, leading to a better understanding of the origin of these compounds.

  4. 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

  5. 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

  6. Applications of compound-specific carbon isotope ratios in organic contaminant studies

    International Nuclear Information System (INIS)

    Aravena, R.; Hunkeler, D.; Bloom, Y.; Frape, S.K.; Butler, B.; Edwards, E.; Cox, E.

    1999-01-01

    In this paper results are presented on the application of compound-specific isotope ratios measurements to assess biodegradation of chlorinated solvents, in particularly on microbial dechlorination of tetrachloroethene (PCE) and trichloroethene (TCE). Analytical aspects and isotope data from laboratory and field studies are discussed. The analytical tests showed that both headspace and SPME techniques provide accurate δ 13 C values with a similar precision for a wide range of chlorinated solvents. However, the SPME method is generally more sensitive. The microcosm experiments show that a significant isotopic fractionation occurs during dechlorination of PCE and TCE to ethene. The largest fractionation factors are observed in the steps DCE-VC and VC-Ethene. In general, the δ 13 C of each dechlorination product was always more negative than the δ 13 C of the corresponding precursor. In addition, the δ 13 C values of each compound increased with time. A similar pattern was observed for dechlorination of PCE at a field site. These results show that compound-specific carbon isotope ratios technology is a very sensitive tool for evaluation of natural attenuation of chlorinated solvents in groundwater. (author)

  7. 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

  8. Compound-Specific Isotope Analysis of Diesel Fuels in a Forensic Investigation

    Science.gov (United States)

    Muhammad, Syahidah; Frew, Russell; Hayman, Alan

    2015-02-01

    Compound-specific isotope analysis (CSIA) offers great potential as a tool to provide chemical evidence in a forensic investigation. Many attempts to trace environmental oil spills were successful where isotopic values were particularly distinct. However, difficulties arise when a large data set is analyzed and the isotopic differences between samples are subtle. In the present study, discrimination of diesel oils involved in a diesel theft case was carried out to infer the relatedness of the samples to potential source samples. This discriminatory analysis used a suite of hydrocarbon diagnostic indices, alkanes, to generate carbon and hydrogen isotopic data of the compositions of the compounds which were then processed using multivariate statistical analyses to infer the relatedness of the data set. The results from this analysis were put into context by comparing the data with the δ13C and δ2H of alkanes in commercial diesel samples obtained from various locations in the South Island of New Zealand. Based on the isotopic character of the alkanes, it is suggested that diesel fuels involved in the diesel theft case were distinguishable. This manuscript shows that CSIA when used in tandem with multivariate statistical analysis provide a defensible means to differentiate and source-apportion qualitatively similar oils at the molecular level. This approach was able to overcome confounding challenges posed by the near single-point source of origin i.e. the very subtle differences in isotopic values between the samples.

  9. Compound-Specific Isotope Analysis of Diesel Fuels in a Forensic Investigation

    Directory of Open Access Journals (Sweden)

    Syahidah Akmal Muhammad

    2015-02-01

    Full Text Available Compound-specific isotope analysis (CSIA offers great potential as a tool to provide chemical evidence in a forensic investigation. Many attempts to trace environmental oil spills were successful where isotopic values were particularly distinct. However, difficulties arise when a large data set is analyzed and the isotopic differences between samples are subtle. In the present study, discrimination of diesel oils involved in a diesel theft case was carried out to infer the relatedness of the samples to potential source samples. This discriminatory analysis used a suite of hydrocarbon diagnostic indices, alkanes, to generate carbon and hydrogen isotopic data of the compositions of the compounds which were then processed using multivariate statistical analyses to infer the relatedness of the data set. The results from this analysis were put into context by comparing the data with the δ13C and δ2H of alkanes in commercial diesel samples obtained from various locations in the South Island of New Zealand. Based on the isotopic character of the alkanes, it is suggested that diesel fuels involved in the diesel theft case were distinguishable. This manuscript shows that CSIA when used in tandem with multivariate statistical analysis provide a defensible means to differentiate and source-apportion qualitatively similar oils at the molecular level. This approach was able to overcome confounding challenges posed by the near single-point source of origin i.e. the very subtle differences in isotopic values between the samples.

  10. Compound-specific isotope analysis of diesel fuels in a forensic investigation.

    Science.gov (United States)

    Muhammad, Syahidah A; Frew, Russell D; Hayman, Alan R

    2015-01-01

    Compound-specific isotope analysis (CSIA) offers great potential as a tool to provide chemical evidence in a forensic investigation. Many attempts to trace environmental oil spills were successful where isotopic values were particularly distinct. However, difficulties arise when a large data set is analyzed and the isotopic differences between samples are subtle. In the present study, discrimination of diesel oils involved in a diesel theft case was carried out to infer the relatedness of the samples to potential source samples. This discriminatory analysis used a suite of hydrocarbon diagnostic indices, alkanes, to generate carbon and hydrogen isotopic data of the compositions of the compounds which were then processed using multivariate statistical analyses to infer the relatedness of the data set. The results from this analysis were put into context by comparing the data with the δ(13)C and δ(2)H of alkanes in commercial diesel samples obtained from various locations in the South Island of New Zealand. Based on the isotopic character of the alkanes, it is suggested that diesel fuels involved in the diesel theft case were distinguishable. This manuscript shows that CSIA when used in tandem with multivariate statistical analysis provide a defensible means to differentiate and source-apportion qualitatively similar oils at the molecular level. This approach was able to overcome confounding challenges posed by the near single-point source of origin, i.e., the very subtle differences in isotopic values between the samples.

  11. Use of Shark Dental Protein to Estimate Trophic Position via Amino Acid Compound-Specific Isotope Analysis

    Science.gov (United States)

    Hayes, M.; Herbert, G.; Ellis, G.

    2017-12-01

    The diets of apex predators such as sharks are expected to change in response to overfishing of their mesopredator prey, but pre-anthropogenic baselines necessary to test for such changes are lacking. Stable isotope analysis (SIA) of soft tissues is commonly used to study diets in animals based on the bioaccumulation of heavier isotopes of carbon and nitrogen with increasing trophic level. In specimens representing pre-anthropogenic baselines, however, a modified SIA approach is needed to deal with taphonomic challenges, such as loss of soft tissues or selective loss of less stable amino acids (AAs) in other sources of organic compounds (e.g., teeth or bone) which can alter bulk isotope values. These challenges can be overcome with a compound-specific isotope analysis of individual AAs (AA-CSIA), but this first requires a thorough understanding of trophic enrichment factors for individual AAs within biomineralized tissues. In this study, we compare dental and muscle proteins of individual sharks via AA-CSIA to determine how trophic position is recorded within teeth and whether that information differs from that obtained from soft tissues. If skeletal organics reliably record information about shark ecology, then archaeological and perhaps paleontological specimens can be used to investigate pre-anthropogenic ecosystems. Preliminary experiments show that the commonly used glutamic acid/phenylalanine AA pairing may not be useful for establishing trophic position from dental proteins, but that estimated trophic position determined from alternate AA pairs are comparable to those from muscle tissue within the same species.

  12. Uses of stable isotopes

    International Nuclear Information System (INIS)

    Axente, Damian

    1998-01-01

    The most important fields of stable isotope use with examples are presented. These are: 1. Isotope dilution analysis: trace analysis, measurements of volumes and masses; 2. Stable isotopes as tracers: transport phenomena, environmental studies, agricultural research, authentication of products and objects, archaeometry, studies of reaction mechanisms, structure and function determination of complex biological entities, studies of metabolism, breath test for diagnostic; 3. Isotope equilibrium effects: measurement of equilibrium effects, investigation of equilibrium conditions, mechanism of drug action, study of natural processes, water cycle, temperature measurements; 4. Stable isotope for advanced nuclear reactors: uranium nitride with 15 N as nuclear fuel, 157 Gd for reactor control. In spite of some difficulties of stable isotope use, particularly related to the analytical techniques, which are slow and expensive, the number of papers reporting on this subject is steadily growing as well as the number of scientific meetings organized by International Isotope Section and IAEA, Gordon Conferences, and regional meeting in Germany, France, etc. Stable isotope application development on large scale is determined by improving their production technologies as well as those of labeled compound and the analytical techniques. (author)

  13. Compound-Specific Isotope Analyses to Assess TCE Biodegradation in a Fractured Dolomitic Aquifer.

    Science.gov (United States)

    Clark, Justin A; Stotler, Randy L; Frape, Shaun K; Illman, Walter A

    2017-01-01

    The potential for trichloroethene (TCE) biodegradation in a fractured dolomite aquifer at a former chemical disposal site in Smithville, Ontario, Canada, is assessed using chemical analysis and TCE and cis-DCE compound-specific isotope analysis of carbon and chlorine collected over a 16-month period. Groundwater redox conditions change from suboxic to much more reducing environments within and around the plume, indicating that oxidation of organic contaminants and degradation products is occurring at the study site. TCE and cis-DCE were observed in 13 of 14 wells sampled. VC, ethene, and/or ethane were also observed in ten wells, indicating that partial/full dechlorination has occurred. Chlorine isotopic values (δ 37 Cl) range between 1.39 to 4.69‰ SMOC for TCE, and 3.57 to 13.86‰ SMOC for cis-DCE. Carbon isotopic values range between -28.9 and -20.7‰ VPDB for TCE, and -26.5 and -11.8‰ VPDB for cis-DCE. In most wells, isotopic values remained steady over the 15-month study. Isotopic enrichment from TCE to cis-DCE varied between 0 and 13‰ for carbon and 1 and 4‰ for chlorine. Calculated chlorine-carbon isotopic enrichment ratios (ϵ Cl /ϵ C ) were 0.18 for TCE and 0.69 for cis-DCE. Combined, isotopic and chemical data indicate very little dechlorination is occurring near the source zone, but suggest bacterially mediated degradation is occurring closer to the edges of the plume. © 2016, National Ground Water Association.

  14. 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.

  15. Calcium stable isotope geochemistry

    International Nuclear Information System (INIS)

    Gausonne, Nikolaus; Schmitt, Anne-Desiree; Heuser, Alexander; Wombacher, Frank; Dietzel, Martin; Tipper, Edward; Schiller, Martin

    2016-01-01

    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.

  16. Using compound-specific isotope analysis to assess the degradation of chloroacetanilide herbicides in lab-scale wetlands.

    Science.gov (United States)

    Elsayed, O F; Maillard, E; Vuilleumier, S; Nijenhuis, I; Richnow, H H; Imfeld, G

    2014-03-01

    Compound-specific isotope analysis (CSIA) is a promising tool to study the environmental fate of a wide range of contaminants including pesticides. In this study, a novel CSIA method was developed to analyse the stable carbon isotope signatures of widely used chloroacetanilide herbicides. The developed method was applied in combination with herbicide concentration and hydrochemical analyses to investigate in situ biodegradation of metolachlor, acetochlor and alachlor during their transport in lab-scale wetlands. Two distinct redox zones were identified in the wetlands. Oxic conditions prevailed close to the inlet of the four wetlands (oxygen concentration of 212±24μM), and anoxic conditions (oxygen concentrations of 28±41μM) prevailed towards the outlet, where dissipation of herbicides mainly occurred. Removal of acetochlor and alachlor from inlet to outlet of wetlands was 56% and 51%, whereas metolachlor was more persistent (23% of load dissipation). CSIA of chloroacetanilides at the inlet and outlet of the wetlands revealed carbon isotope fractionation of alachlor (εbulk=-2.0±0.3‰) and acetochlor (εbulk=-3.4±0.5‰), indicating that biodegradation contributes to the dissipation of both herbicides. This study is a first step towards the application of CSIA to evaluate the transport and degradation of chloroacetanilide herbicides in the environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Compound-specific isotope analysis resolves the dietary origin of docosahexaenoic acid in the mouse brain.

    Science.gov (United States)

    Lacombe, R J Scott; Giuliano, Vanessa; Colombo, Stefanie M; Arts, Michael T; Bazinet, Richard P

    2017-10-01

    DHA (22:6n-3) may be derived from two dietary sources, preformed dietary DHA or through synthesis from α-linolenic acid (ALA; 18:3n-3). However, conventional methods cannot distinguish between DHA derived from either source without the use of costly labeled tracers. In the present study, we demonstrate the proof-of-concept that compound-specific isotope analysis (CSIA) by GC-isotope ratio mass spectrometry (IRMS) can differentiate between sources of brain DHA based on differences in natural 13 C enrichment. Mice were fed diets containing either purified ALA or DHA as the sole n-3 PUFA. Extracted lipids were analyzed by CSIA for natural abundance 13 C enrichment. Brain DHA from DHA-fed mice was significantly more enriched (-23.32‰ to -21.92‰) compared with mice on the ALA diet (-28.25‰ to -27.49‰). The measured 13 C enrichment of brain DHA closely resembled the dietary n-3 PUFA source, -21.86‰ and -28.22‰ for DHA and ALA, respectively. The dietary effect on DHA 13 C enrichment was similar in liver and blood fractions. Our results demonstrate the effectiveness of CSIA, at natural 13 C enrichment, to differentiate between the incorporation of preformed or synthesized DHA into the brain and other tissues without the need for tracers. Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

  18. Fingerprinting TCE in a bedrock aquifer using compound-specific isotope analysis.

    Science.gov (United States)

    Lojkasek-Lima, Paulo; Aravena, Ramon; Parker, Beth L; Cherry, John A

    2012-01-01

    A dual isotope approach based on compound-specific isotope analysis (CSIA) of carbon (C) and chlorine (Cl) was used to identify sources of persistent trichloroethylene (TCE) that caused the shut-down in 1994 of a municipal well in an extensive fractured dolostone aquifer beneath Guelph, Ontario. Several nearby industrial properties have known subsurface TCE contamination; however, only one has created a comprehensive monitoring network in the bedrock. The impacted municipal well and many monitoring wells were sampled for volatile organic compounds (VOCs), inorganic parameters, and CSIA. A wide range in isotope values was observed at the study site. The TCE varies between -35.6‰ and -21.8‰ and from 1.6‰ to 3.2‰ for δ(13) C and δ(37) Cl, respectively. In case of cis-1,2-dichloroethene, the isotope values range between -36.3‰ and -18.9‰ and from 2.4‰ to 4.7‰ for δ(13) C and δ(37) Cl, respectively. The dual isotope approach represented by a plot of δ(13) C vs. δ(37) Cl shows the municipal well samples grouped in a domain clearly separate from all other samples from the property with the comprehensive well network. The CSIA results collected under non-pumping and short-term pumping conditions thus indicate that this particular property, which has been studied intensively for several years, is not a substantial contributor of the TCE presently in the municipal well under non-pumping conditions. This case study demonstrates that CSIA signatures would have been useful much earlier in the quest to examine sources of the TCE in the municipal well if bedrock monitoring wells had been located at several depths beneath each of the potential TCE-contributing properties. Moreover, the CSIA results show that microbial reductive dechlorination of TCE occurs in some parts of the bedrock aquifer. At this site, the use of CSIA for C and Cl in combination with analyses of VOC and redox parameters proved to be important due to the complexity introduced by

  19. Compound-specific chlorine isotope ratios of TCE, PCE and DCE isomers by direct injection using CF-IRMS

    International Nuclear Information System (INIS)

    Shouakar-Stash, Orfan; Drimmie, Robert J.; Zhang Min; Frape, Shaun K.

    2006-01-01

    produced during ion bombardment in the mass spectrometer, there is no need to convert chlorinated ethenes to methyl chloride. As a result, this technique greatly enhances the efficiency for isotopic analysis by eliminating procedures for pre-concentration, off-line separation and sample preparation. In addition, it also reduces the potential for isotopic fractionation introduced during these procedures. Compound-specific Cl stable isotope analysis can be used as a tool to study the sources of organic contaminants in groundwater and their behaviour in the subsurface environments. It may also assist in understanding processes such as transport, mixing, and degradation reactions

  20. Compound-specific isotope records of late-quaternary environmental change in southeastern North Carolina

    Science.gov (United States)

    Lane, Chad S.; Taylor, Audrey K.; Spencer, Jessica; Jones, Kaylee B.

    2018-02-01

    Reconstructions of late Quaternary paleohydrology are rare from the U.S. Atlantic coastal plain (ACP). Here we present compound-specific hydrogen (δ2Halkane) and carbon (δ13Calkane) isotope analyses of terrestrially-derived n-alkanes from Jones Lake and Singletary Lake in eastern North Carolina spanning the last ∼50,000 years. Combined with pollen, charcoal, and bulk geochemical analyses, the δ2Halkane data indicate arid conditions during the late-Pleistocene, but differing edaphic conditions at the sites perhaps related to differing water table depths. The δ13Calkane data indicate a significant C4 plant component during the late Pleistocene, but other proxies indicate a sparsely-vegetated landscape. The Pleistocene-Holocene transition is marked by rapid fluctuations in δ2Halkane values that are similar to the patterns of Bølling Allerød and Younger Dryas isotope data from Greenland indicating sensitivity of the regional climate to short-lived, high-amplitude climatic events. The δ2Halkane data indicate a mesic early Holocene that supported colonization by Quercus-dominated ecosystems. Evidence of middle Holocene aridity in eastern Tennessee and western North Carolina contrasts with evidence of mesic conditions on the ACP, a geographic pattern similar to modern teleconnected precipitation responses to the Pacific Decadal Oscillation. A transition to Pinus-dominated ecosystems ∼5500 cal yr B.P. is accompanied by a large increase charcoal, but is not coincident with any large changes in δ2Halkane values, indicating that hydrologic change was likely not responsible for sustained late-Holocene dominance of Pinus. The lack of a change in middle Holocene hydrology and the spatiotemporally heterogeneous nature of the Quercus-Pinus transition on the ACP indicate prehistoric anthropogenic land management practices may represent the most parsimonious explanation for the regionally pervasive ecological change.

  1. 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.

  2. 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.

  3. Compound-Specific Isotope Analysis (CSIA Application for Source Apportionment and Natural Attenuation Assessment of Chlorinated Benzenes

    Directory of Open Access Journals (Sweden)

    Luca Alberti

    2017-11-01

    Full Text Available In light of the complex management of chlorobenzene (CB contaminated sites, at which a hydraulic barrier (HB for plumes containment is emplaced, compound-specific stable isotope analysis (CSIA has been applied for source apportionment, for investigating the relation between the upgradient and downgradient of the HB, and to target potential CB biodegradation processes. The isotope signature of all the components potentially involved in the degradation processes has been expressed using the concentration-weighted average δ13C of CBs + benzene (δ13Csum. Upgradient of the HB, the average δ13Csum of −25.6‰ and −29.4‰ were measured for plumes within the eastern and western sectors, respectively. Similar values were observed for the potential sources, with δ13Csum values of −26.5‰ for contaminated soils and −29.8‰ for the processing water pipeline in the eastern and western sectors, respectively, allowing for apportioning of these potential sources to the respective contaminant plumes. For the downgradient of the HB, similar CB concentrations but enriched δ13Csum values between −24.5‰ and −25.9‰ were measured. Moreover, contaminated soils showed a similar δ13Csum signature of −24.5‰, thus suggesting that the plumes likely originate from past activities located in the downgradient of the HB. Within the industrial property, significant δ13C enrichments were measured for 1,2,4-trichlorobenzene (TCB, 1,2-dichlorobenzene (DCB, 1,3-DCB, and 1,4-DCBs, thus suggesting an important role for anaerobic biodegradation. Further degradation of monochlorobenzene (MCB and benzene was also demonstrated. CSIA was confirmed to be an effective approach for site characterization, revealing the proper functioning of the HB and demonstrating the important role of natural attenuation processes in reducing the contamination upgradient of the HB.

  4. Origin of Xylitol in Chewing Gum: A Compound-Specific Isotope Technique for the Differentiation of Corn- and Wood-Based Xylitol by LC-IRMS.

    Science.gov (United States)

    Köster, Daniel; Wolbert, Jens-Benjamin; Schulte, Marcel S; Jochmann, Maik A; Schmidt, Torsten C

    2018-02-28

    The sugar replacement compound xylitol has gained increasing attention because of its use in many commercial food products, dental-hygiene articles, and pharmaceuticals. It can be classified by the origin of the raw material used for its production. The traditional "birch xylitol" is considered a premium product, in contrast to xylitol produced from agriculture byproducts such as corn husks or sugar-cane straw. Bulk stable-isotope analysis (BSIA) and compound-specific stable-isotope analysis (CSIA) by liquid-chromatography isotope-ratio mass spectrometry (LC-IRMS) of chewing-gum extracts were used to determine the δ 13 C isotope signatures for xylitol. These were applied to elucidate the original plant type the xylitol was produced from on the basis of differences in isotope-fractionation processes of photosynthetic CO 2 fixation. For the LC-IRMS analysis, an organic-solvent-free extraction protocol and HPLC method for the separation of xylitol from different artificial sweeteners and sugar-replacement compounds was successfully developed and applied to the analysis of 21 samples of chewing gum, from which 18 could be clearly related to the raw-material plant class.

  5. Development of Stable Isotope Technology

    International Nuclear Information System (INIS)

    Jeong, Do Young; Kim, Cheol Jung; Han, Jae Min

    2009-03-01

    KAERI has obtained an advanced technology with singular originality for laser stable isotope separation. Objectives for this project are to get production technology of Tl-203 stable isotope used for medical application and are to establish the foundation of the pilot system, while we are taking aim at 'Laser Isotope Separation Technology to make resistance to the nuclear proliferation'. And we will contribute to ensuring a nuclear transparency in the world society by taking part in a practical group of NSG and being collaboration with various international groups related to stable isotope separation technology

  6. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1980-12-01

    This report contains a listing of electromagnetically separated stable isotopes which are available for distribution within the United States for non-destructive research use from the Oak Ridge National Laboratory on a loan basis. This inventory includes all samples of stable isotopes in the Materials Research Collection and does not designate whether a sample is out on loan or in reprocessing

  7. 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

  8. French days on stable isotopes

    International Nuclear Information System (INIS)

    2000-01-01

    These first French days on stable isotopes took place in parallel with the 1. French days of environmental chemistry. Both conferences had common plenary sessions. The conference covers all aspects of the use of stable isotopes in the following domains: medicine, biology, environment, tracer techniques, agronomy, food industry, geology, petroleum geochemistry, cosmo-geochemistry, archaeology, bio-geochemistry, hydrology, climatology, nuclear and particle physics, astrophysics, isotope separations etc.. Abstracts available on CD-Rom only. (J.S.)

  9. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1982-01-01

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

  10. Compound-specific isotopic analyses: a novel tool for reconstruction of ancient biogeochemical processes

    Science.gov (United States)

    Hayes, J. M.; Freeman, K. H.; Popp, B. N.; Hoham, C. H.

    1990-01-01

    Patterns of isotopic fractionation in biogeochemical processes are reviewed and it is suggested that isotopic fractionations will be small when substrates are large. If so, isotopic compositions of biomarkers will reflect those of their biosynthetic precursors. This prediction is tested by consideration of results of analyses of geoporphyrins and geolipids from the Greenhorn Formation (Cretaceous, Western Interior Seaway of North America) and the Messel Shale (Eocene, lacustrine, southern Germany). It is shown (i) that isotopic compositions of porphyrins that are related to a common source, but which have been altered structurally, cluster tightly and (ii) that isotopic differences between geolipids and porphyrins related to a common source are equal to those observed in modern biosynthetic products. Both of these observations are consistent with preservation of biologically controlled isotopic compositions during diagenesis. Isotopic compositions of individual compounds can thus be interpreted in terms of biogeochemical processes in ancient depositional environments. In the Cretaceous samples, isotopic compositions of n-alkanes are covariant with those of total organic carbon, while delta values for pristane and phytane are covariant with those of porphyrins. In this unit representing an open marine environment, the preserved acyclic polyisoprenoids apparently derive mainly from primary material, while the extractable, n-alkanes derive mainly from lower levels of the food chain. In the Messel Shale, isotopic compositions of individual biomarkers range from -20.9 to -73.4% vs PDB. Isotopic compositions of specific compounds can be interpreted in terms of origin from methylotrophic, chemautotrophic, and chemolithotrophic microorganisms as well as from primary producers that lived in the water column and sediments of this ancient lake.

  11. Identification of chlorinated solvents degradation zones in clay till by high resolution chemical, microbial and compound specific isotope analysis

    DEFF Research Database (Denmark)

    Damgaard, Ida; Bjerg, Poul Løgstrup; Bælum, Jacob

    2013-01-01

    subsampling of the clay till cores. The study demonstrates that an integrated approach combining chemical analysis, molecular microbial tools and compound specific isotope analysis (CSIA) was required in order to document biotic and abiotic degradations in the clay till system. © 2013 Elsevier B.V.......The degradation of chlorinated ethenes and ethanes in clay till was investigated at a contaminated site (Vadsby, Denmark) by high resolution sampling of intact cores combined with groundwater sampling. Over decades of contamination, bioactive zones with degradation of trichloroethene (TCE) and 1...

  12. A field-deployable compound-specific isotope analyzer based on quantum cascade laser and hollow waveguide

    Science.gov (United States)

    Wu, Sheng; Deev, Andrei

    2013-01-01

    A field deployable Compound Specific Isotope Analyzer (CSIA) coupled with capillary chromatogrpahy based on Quantum Cascade (QC) lasers and Hollow Waveguide (HWG) with precision and chemical resolution matching mature Mass Spectroscopy has been achieved in our laboratory. The system could realize 0.3 per mil accuracy for 12C/13C for a Gas Chromatography (GC) peak lasting as short as 5 seconds with carbon molar concentration in the GC peak less than 0.5%. Spectroscopic advantages of HWG when working with QC lasers, i.e. single mode transmission, noiseless measurement and small sample volume, are compared with traditional free space and multipass spectroscopy methods.

  13. 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...

  14. 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)

  15. Compound-Specific Carbon, Nitrogen, and Hydrogen Isotopic Ratios for Amino Acids in CM and CR Chondrites and their use in Evaluating Potential Formation Pathways

    Science.gov (United States)

    Elsila, Jamie E.; Charnley, Steven B.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    Stable hydrogen, carbon, and nitrogen isotopic ratios (oD, 013C, and olSN) of organic compounds can revcal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may indicate the most likely of these pathways. We have applied gas chromatography with mass spectrometry and combustion isotope ratio mass spectrometry to measure the compound-specific C, N, and H stable isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites: CM1I2 Allan Hills (ALH) 83100, CM2 Murchison, CM2 Lewis Cliff (LEW) 90500, CM2 Lonewolf Nunataks (LON) 94101, CRZ Graves Nunataks (GRA) 95229, CRZ Elephant Moraine (EET) 92042, and CR3 Queen Alexandra Range (QUE) 99177. We compare the isotopic compositions of amino acids in these meteorites with predictions of expected isotopic enrichments from potential formation pathways. We observe trends of decreasing ODC and increasing oD with increasing carbon number in the aH, (l-NH2 amino acids that correspond to predictions made for formation via Streckercyanohydrin synthesis. We also observe light ODC signatures for -alanine, which may indicate either formation via Michael addition or via a pathway that forms primarily small, straight-chain, amine-terminal amino acids (n-ro-amino acids). Higher deuterium enrichments are observed in amethyl amino acids, indicating formation of these amino acids or their precursors in cold interstellar or nebular environments. Finally, individual amino acids are more enriched in deuterium in CR chondrites than CM chondrites, reflecting different parent-body chemistry.

  16. The application of compound-specific isotope analysis of fatty acids for traceability of sea cucumber (Apostichopus japonicus) in the coastal areas of China.

    Science.gov (United States)

    Liu, Yu; Zhang, Xufeng; Li, Ying; Wang, Haixia

    2017-11-01

    Geographical origin traceability is an important issue for controlling the quality of seafood and safeguarding the interest of consumers. In the present study, a new method of compound-specific isotope analysis (CSIA) of fatty acids was established to evaluate its applicability in establishing the origin traceability of Apostichopus japonicus in the coastal areas of China. Moreover, principal component analysis (PCA) and discriminant analysis (DA) were applied to distinguish between the origins of A. japonicus. The results show that the stable carbon isotope compositions of fatty acids of A. japonicus significantly differ in terms of both season and origin. They also indicate that the stable carbon isotope composition of fatty acids could effectively discriminate between the origins of A. japonicus, except for between Changhai Island and Zhangzi Island in the spring of 2016 because of geographical proximity or the similarity of food sources. The fatty acids that have the highest contribution to identifying the geographical origins of A. japonicus are C22:6n-3, C16:1n-7, C20:5n-3, C18:0 and C23:1n-9, when considering the fatty acid contents, the stable carbon isotope composition of fatty acids and the results of the PCA and DA. We conclude that CSIA of fatty acids, combined with multivariate statistical analysis such as PCA and DA, may be an effective tool for establishing the traceability of A. japonicus in the coastal areas of China. The relevant conclusions of the present study provide a new method for determining the traceability of seafood or other food products. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  17. Stable-isotope studies

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Structures of bacteriochlorophyll b and the Krasnovskii photoreduction products of chlorophyll a are given. All 55 13 C and 4 15 N NMR transitions in chlorophyl a and its magnesium-free derivative pheophytin a were assigned. ESR of triplet states of chlorophylls a, b, c/sub z/, and c 2 and bacteriochlorophyll a are reported. Experiments in the cultivation of 13 C-enriched morning glory plants indicated that the isotope enrichment can produce observable morphological changes. (U.S.)

  18. 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

  19. 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

  20. 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

  1. 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

  2. Stable-isotope paleoclimatology

    International Nuclear Information System (INIS)

    Deuser, W.G.

    1978-01-01

    Seasonal variations of temperature and salinity in the surface waters of large parts of the oceans are well established. Available data on seasonal distributions of planktonic foraminifera show that the abundances of different species groups peak at different times of the year with an apparent succession of abundance peaks through most of the year. This evidence suggests that a measure of seasonal contrast is recorded in the isotope ratios of oxygen, and perhaps carbon, in the tests of different foraminiferal species. The evaluation of this potential paleoclimatologic tool awaits planned experiments with recent foraminifera in well-known settings, but a variety of available data is consistent with the idea that interspecies differences in 18 O content contain a seasonal component.(auth.)

  3. Stable isotopes - separation and application

    International Nuclear Information System (INIS)

    Lockhart, I.M.

    1980-01-01

    In this review, methods used for the separation of stable isotopes ( 12 C, 13 C, 14 N, 15 N, 16 O, 17 O, 18 O, 34 S) will be described. The synthesis of labelled compounds, techniques for detection and assay, and areas of application will also be discussed. Particular attention will be paid to the isotopes of carbon, nitrogen, and oxygen; to date, sulphur isotopes have only assumed a minor role. The field of deuterium chemistry is too extensive for adequate treatment; it will therefore be essentially excluded. (author)

  4. Evaluation of ethyl tert-butyl ether biodegradation in a contaminated aquifer by compound-specific isotope analysis and in situ microcosms

    Energy Technology Data Exchange (ETDEWEB)

    Bombach, Petra, E-mail: petra.bombach@ufz.de [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Isodetect GmbH Leipzig, Deutscher Platz 5b, D-04103 Leipzig (Germany); Nägele, Norbert [Kuvier the Biotech Company S.L., Ctra. N-I, p.k. 234–P.E. INBISA 23" a, E-09001 Burgos (Spain); Rosell, Mònica [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristallografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), C/Martí i Franquès s/n, 08028 Barcelona (Spain); Richnow, Hans H. [UFZ – Helmholtz Centre for Environmental Research, Department of Isotope Biogeochemistry, Permoserstrasse 15, D-04318 Leipzig (Germany); Fischer, Anko [Isodetect GmbH Leipzig, Deutscher Platz 5b, D-04103 Leipzig (Germany)

    2015-04-09

    Highlights: • In situ biodegradation of ETBE was investigated in a fuel contaminated aquifer. • Degradation was studied by CSIA and in situ microcosms in combination with TLFA-SIP. • ETBE was degraded when ETBE was the main groundwater contaminant. • ETBE was also degraded in the presence of BTEX and MTBE. • Hydrochemical analysis indicated aerobic and anaerobic ETBE biodegradation. - Abstract: Ethyl tert-butyl ether (ETBE) is an upcoming groundwater pollutant in Europe whose environmental fate has been less investigated, thus far. In the present study, we investigated the in situ biodegradation of ETBE in a fuel-contaminated aquifer using compound-specific stable isotope analysis (CSIA), and in situ microcosms in combination with total lipid fatty acid (TLFA)-stable isotope probing (SIP). In a first field investigation, CSIA revealed insignificant carbon isotope fractionation, but low hydrogen isotope fractionation of up to +14‰ along the prevailing anoxic ETBE plume suggesting biodegradation of ETBE. Ten months later, oxygen injection was conducted to enhance the biodegradation of petroleum hydrocarbons (PH) at the field site. Within the framework of this remediation measure, in situ microcosms loaded with [{sup 13}C{sub 6}]-ETBE (BACTRAP{sup ®}s) were exposed for 119 days in selected groundwater wells to assess the biodegradation of ETBE by TLFA-SIP under the following conditions: (i) ETBE as main contaminant; (ii) ETBE as main contaminant subjected to oxygen injection; (iii) ETBE plus other PH; (iv) ETBE plus other PH subjected to oxygen injection. Under all conditions investigated, significant {sup 13}C-incorporation into microbial total lipid fatty acids extracted from the in situ microcosms was found, providing clear evidence of ETBE biodegradation.

  5. Evaluation of ethyl tert-butyl ether biodegradation in a contaminated aquifer by compound-specific isotope analysis and in situ microcosms

    International Nuclear Information System (INIS)

    Bombach, Petra; a, E-09001 Burgos (Spain))" data-affiliation=" (Kuvier the Biotech Company S.L., Ctra. N-I, p.k. 234–P.E. INBISA 23a, E-09001 Burgos (Spain))" >Nägele, Norbert; Rosell, Mònica; Richnow, Hans H.; Fischer, Anko

    2015-01-01

    Highlights: • In situ biodegradation of ETBE was investigated in a fuel contaminated aquifer. • Degradation was studied by CSIA and in situ microcosms in combination with TLFA-SIP. • ETBE was degraded when ETBE was the main groundwater contaminant. • ETBE was also degraded in the presence of BTEX and MTBE. • Hydrochemical analysis indicated aerobic and anaerobic ETBE biodegradation. - Abstract: Ethyl tert-butyl ether (ETBE) is an upcoming groundwater pollutant in Europe whose environmental fate has been less investigated, thus far. In the present study, we investigated the in situ biodegradation of ETBE in a fuel-contaminated aquifer using compound-specific stable isotope analysis (CSIA), and in situ microcosms in combination with total lipid fatty acid (TLFA)-stable isotope probing (SIP). In a first field investigation, CSIA revealed insignificant carbon isotope fractionation, but low hydrogen isotope fractionation of up to +14‰ along the prevailing anoxic ETBE plume suggesting biodegradation of ETBE. Ten months later, oxygen injection was conducted to enhance the biodegradation of petroleum hydrocarbons (PH) at the field site. Within the framework of this remediation measure, in situ microcosms loaded with [ 13 C 6 ]-ETBE (BACTRAP ® s) were exposed for 119 days in selected groundwater wells to assess the biodegradation of ETBE by TLFA-SIP under the following conditions: (i) ETBE as main contaminant; (ii) ETBE as main contaminant subjected to oxygen injection; (iii) ETBE plus other PH; (iv) ETBE plus other PH subjected to oxygen injection. Under all conditions investigated, significant 13 C-incorporation into microbial total lipid fatty acids extracted from the in situ microcosms was found, providing clear evidence of ETBE biodegradation

  6. Stable isotope research pool inventory

    International Nuclear Information System (INIS)

    1986-08-01

    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. All requests for the loan of samples should be submitted with a summary of the purpose of the loan to: Iotope Distribution Office, Oak Ridge National Laboratory, P.O. Box X, Oak Ridge, Tennessee 37831. Requests from non-DOE contractors and from foreign institutions require DOE approval

  7. Stable isotopes and the environment

    International Nuclear Information System (INIS)

    Krouse, H.R.

    1990-01-01

    Whereas traditionally, stable isotope research has been directed towards resource exploration and development, it is finding more frequent applications in helping to assess the impacts of resource utilization upon ecosystems. Among the many pursuits, two themes are evident: tracing the transport and conversions of pollutants in the environment and better understanding of the interplay among environmental receptors, e.g. food web studies. Stable isotope data are used primarily to identify the presence of pollutants in the environment and with a few exceptions, the consequence of their presence must be assessed by other techniques. Increasing attention has been given to the isotopic composition of humans with many potential applications in areas such as paleodiets, medicine, and criminology. In this brief overview examples are used from the Pacific Rim to illustrate the above concepts. 26 refs., 1 tab., 3 figs

  8. A Compound-Specific Hydrogen Isotope Record at the Onset of Ocean Anoxic Event 2, Kaiparowits Plateau, Southern Utah

    Science.gov (United States)

    Todes, J.; Jones, M. M.; Sageman, B. B.; Osburn, M. R.

    2017-12-01

    Rhythmic lithologic variations (limestone-shale couplets) interpreted to reflect Milankovitch cycles occur at the onset of Ocean Anoxic Event 2 (OAE2) in deposits of the Western Interior Seaway. These couplets have been interpreted to reflect climate cycles: however, the physical mechanism(s) through which climate cycles were translated to the sedimentary record during peak greenhouse conditions remain unsettled. Although glacioeustasy has been considered, variance in surface ocean temperature, ocean circulation, or local hydrology may be more plausible options. Compound-specific hydrogen isotope ratios (δ2H) of n-alkanes and other biomarkers may provide a means to evaluate such mechanisms. Since sedimentary alkanes are direct products of plants and membrane lipid diagenesis and are resistant to secondary hydrogen exchange during thermal maturation at low (chain length distributions suggest low thermal maturity and the possible preservation of primary δ2H values. Short and long chain ­n-alkanes are potentially sourced from planktonic biomass and terrestrial plants, respectively, enabling a comparison of climatic processes between marine and terrestrial settings. Biomarkers, including both steranes and hopanes, are also preserved and reflect putative source organisms and local paleoenvironmental conditions. Facies-specific δ2H analysis will allow for evaluation of changes in the dominant source of atmospheric moisture in the Western Interior during orbitally-forced climate cycles. Organic matter deposited during periods of northerly Boreal influence would have a depleted 2H-isotope composition relative to those deposited during periods of more southerly Tethys influence. In this model, these variations are reflected by lithology - limestone deposition would occur during warm, evaporative Tethys-dominated times, while cooler, wetter Boreal periods would promote shale deposition.

  9. Monitoring biodegradation of ethene and bioremediation of chlorinated ethenes at a contaminated site using compound-specific isotope analysis (CSIA).

    Science.gov (United States)

    Mundle, Scott O C; Johnson, Tiffany; Lacrampe-Couloume, Georges; Pérez-de-Mora, Alfredo; Duhamel, Melanie; Edwards, Elizabeth A; McMaster, Michaye L; Cox, Evan; Révész, Kinga; Sherwood Lollar, Barbara

    2012-02-07

    Chlorinated ethenes are commonly found in contaminated groundwater. Remediation strategies focus on transformation processes that will ultimately lead to nontoxic products. A major concern with these strategies is the possibility of incomplete dechlorination and accumulation of toxic daughter products (cis-1,2-dichloroethene (cDCE), vinyl chloride (VC)). Ethene mass balance can be used as a direct indicator to assess the effectiveness of dechlorination. However, the microbial processes that affect ethene are not well characterized and poor mass balance may reflect biotransformation of ethene rather than incomplete dechlorination. Microbial degradation of ethene is commonly observed in aerobic systems but fewer cases have been reported in anaerobic systems. Limited information is available on the isotope enrichment factors associated with these processes. Using compound-specific isotope analysis (CSIA) we determined the enrichment factors associated with microbial degradation of ethene in anaerobic microcosms (ε = -6.7‰ ± 0.4‰, and -4.0‰ ± 0.8‰) from cultures collected from the Twin Lakes wetland area at the Savannah River site in Georgia (United States), and in aerobic microcosms (ε = -3.0‰ ± 0.3‰) from Mycobacterium sp. strain JS60. Under anaerobic and aerobic conditions, CSIA can be used to determine whether biotransformation of ethene is occurring in addition to biodegradation of the chlorinated ethenes. Using δ(13)C values determined for ethene and for chlorinated ethenes at a contaminated field site undergoing bioremediation, this study demonstrates how CSIA of ethene can be used to reduce uncertainty and risk at a site by distinguishing between actual mass balance deficits during reductive dechlorination and apparent lack of mass balance that is related to biotransformation of ethene.

  10. pH-dependent equilibrium isotope fractionation associated with the compound specific nitrogen and carbon isotope analysis of substituted anilines by SPME-GC/IRMS.

    Science.gov (United States)

    Skarpeli-Liati, Marita; Turgeon, Aurora; Garr, Ashley N; Arnold, William A; Cramer, Christopher J; Hofstetter, Thomas B

    2011-03-01

    Solid-phase microextraction (SPME) coupled to gas chromatography/isotope ratio mass spectrometry (GC/IRMS) was used to elucidate the effects of N-atom protonation on the analysis of N and C isotope signatures of selected aromatic amines. Precise and accurate isotope ratios were measured using polydimethylsiloxane/divinylbenzene (PDMS/DVB) as the SPME fiber material at solution pH-values that exceeded the pK(a) of the substituted aniline's conjugate acid by two pH-units. Deviations of δ(15)N and δ(13)C-values from reference measurements by elemental analyzer IRMS were small (IRMS. Under these conditions, the detection limits for accurate isotope ratio measurements were between 0.64 and 2.1 mg L(-1) for δ(15)N and between 0.13 and 0.54 mg L(-1) for δ(13)C, respectively. Substantial inverse N isotope fractionation was observed by SPME-GC/IRMS as the fraction of protonated species increased with decreasing pH leading to deviations of -20‰ while the corresponding δ(13)C-values were largely invariant. From isotope ratio analysis at different solution pHs and theoretical calculations by density functional theory, we derived equilibrium isotope effects, EIEs, pertinent to aromatic amine protonation of 0.980 and 1.001 for N and C, respectively, which were very similar for all compounds investigated. Our work shows that N-atom protonation can compromise accurate compound-specific N isotope analysis of aromatic amines.

  11. Compound-Specific Hydrogen Isotope Evidence of Late Quaternary Paleohydrologic Change from the Atlantic Coastal Plain, North Carolina, USA

    Science.gov (United States)

    Lane, C.; Taylor, A. K.; Spencer, J.; Jones, K.

    2017-12-01

    Reconstructions of late Quaternary paleohydrology are rare from the U.S. Atlantic coastal plain (ACP). Here we present compound-specific hydrogen isotope analyses of terrestrially-derived n-alkanes (δ2Halkane) from Jones Lake and Singletary Lake in eastern North Carolina spanning the last 50,000 years. Combined with prior pollen, charcoal, and bulk sediment geochemical analyses, the δ2Halkane data indicate arid conditions during the late-Pleistocene, but marked differences in edaphic conditions at the two sites likely due to differing water table depths. The Pleistocene-Holocene transition is marked by rapid fluctuations in δ2Halkane values that resemble the Bølling Allerød and Younger Dryas climatic events indicating potential sensitivity of regional hydrology to rapid climate change. The δ2Halkane data indicate a generally mesic Holocene that supported colonization by Quercus-dominated ecosystems during the early to middle Holocene. Evidence of increased aridity on the in eastern Tennessee and western North Carolina contrasts with evidence of mesic conditions in eastern North Carolina during the middle to late Holocene, a geographic pattern similar to modern teleconnected precipitation responses to the Pacific Decadal Oscillation. This pattern may be indicative of a stronger Pacific basin influence on regional paleoprecipitation patterns than the distally-closer Atlantic. A transition from Quercus-to Pinus-dominated ecosystems 5500 cal yr B.P. is accompanied by a large increase in charcoal abundance, but is not coincident with any high-amplitude changes in the δ2Halkane record, indicating that precipitation variability was not likely the mechanism responsible for this ecological transition. While further development of regional paleohydrological records is necessary, the lack of a clear change in middle Holocene precipitation dynamics and the temporally-heterogeneous nature of the Quercus-Pinus transition in the region indicate prehistoric anthropogenic

  12. Compound-specific isotope analysis of light elements using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) and its application to geochemistry

    International Nuclear Information System (INIS)

    Naraoka, Hiroshi; Yamada, Keita; Matsumoto, Kohei; Ishiwatari, Ryoshi

    1997-01-01

    Compound-specific isotope analysis has been developed recently using gas chromatography/combustion/mass spectrometry (GC/C/IRMS). This paper summarizes principles and progress of GC/C/IRMS, and reviews recent some important works using this new method. GC/C/IRMS is a novel tool for (1) biomarker analysis in sediments and living matter, (2) paleoenvironment analysis including reconstruction of ancient biogeochemical processes, (3) geochemical cycle study of organic compounds in a terrestrial-marine system, (4) evaluation of maturity and diagenesis of organic matter including petroleum formation, (5) ecological analysis, (6) evaluation of anthropologenic pollution in environment, (7) detection of extraterrestrial organic compounds and the formation mechanism study, (8) tracer studies in environment. (author)

  13. 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

  14. Optimization of the solvent-based dissolution method to sample volatile organic compound vapors for compound-specific isotope analysis.

    Science.gov (United States)

    Bouchard, Daniel; Wanner, Philipp; Luo, Hong; McLoughlin, Patrick W; Henderson, James K; Pirkle, Robert J; Hunkeler, Daniel

    2017-10-20

    The methodology of the solvent-based dissolution method used to sample gas phase volatile organic compounds (VOC) for compound-specific isotope analysis (CSIA) was optimized to lower the method detection limits for TCE and benzene. The sampling methodology previously evaluated by [1] consists in pulling the air through a solvent to dissolve and accumulate the gaseous VOC. After the sampling process, the solvent can then be treated similarly as groundwater samples to perform routine CSIA by diluting an aliquot of the solvent into water to reach the required concentration of the targeted contaminant. Among solvents tested, tetraethylene glycol dimethyl ether (TGDE) showed the best aptitude for the method. TGDE has a great affinity with TCE and benzene, hence efficiently dissolving the compounds during their transition through the solvent. The method detection limit for TCE (5±1μg/m 3 ) and benzene (1.7±0.5μg/m 3 ) is lower when using TGDE compared to methanol, which was previously used (385μg/m 3 for TCE and 130μg/m 3 for benzene) [2]. The method detection limit refers to the minimal gas phase concentration in ambient air required to load sufficient VOC mass into TGDE to perform δ 13 C analysis. Due to a different analytical procedure, the method detection limit associated with δ 37 Cl analysis was found to be 156±6μg/m 3 for TCE. Furthermore, the experimental results validated the relationship between the gas phase TCE and the progressive accumulation of dissolved TCE in the solvent during the sampling process. Accordingly, based on the air-solvent partitioning coefficient, the sampling methodology (e.g. sampling rate, sampling duration, amount of solvent) and the final TCE concentration in the solvent, the concentration of TCE in the gas phase prevailing during the sampling event can be determined. Moreover, the possibility to analyse for TCE concentration in the solvent after sampling (or other targeted VOCs) allows the field deployment of the sampling

  15. Water Table Depth Reconstruction in Ombrotrophic Peatlands Using Biomarker Abundance Ratios and Compound-Specific Hydrogen Isotope Composition

    Science.gov (United States)

    Nichols, J. E.; Jackson, S. T.; Booth, R. K.; Pendall, E. G.; Huang, Y.

    2005-12-01

    Sediment cores from ombrotrophic peat bogs provide sensitive records of changes in precipitation/evaporation (P/E) balance. Various proxies have been developed to reconstruct surface moisture conditions in peat bogs, including testate amoebae, plant macrofossils, and peat humification. Studying species composition of testate amoeba assemblages is time consuming and requires specialized training. Humification index can be influenced by environmental factors other than moisture balance. The plant macrofossil proxy is less quantitative and cannot be performed on highly decomposed samples. We demonstrate that the ratio of C23 alkane to C29 alkane abundance may provide a simple alternative or complementary means of tracking peatland water-table depth. Data for this proxy can be collected quickly using a small sample (100 mg dry). Water-table depth decreases during drought, and abundance of Sphagnum, the dominant peat-forming genus, decreases as vascular plants increase. Sphagnum moss produces mainly medium chain-length alkanes (C21-C25) while vascular plants (grasses and shrubs) produce primarily longer chain-length alkanes (C27-C31). Therefore, C23:C29 n-alkane ratios quantitatively track the water table depth fluctuations in peat bogs. We compared C23:C29 n-alkane ratios in a core from Minden Bog (southeastern Michigan) with water table depth reconstructions based on testate-amoeba assemblages and humification. The 184-cm core spans the past ~3kyr of continuous peat deposition in the bog. Our results indicate that the alkane ratios closely track the water table depth variations, with C29 most abundant during droughts. We also explored the use of D/H ratios in Sphagnum biomarkers as a water-table depth proxy. Compound-specific hydrogen isotope ratio analyses were performed on Sphagnum biomarkers: C23 and C25 alkane and C24 acid. Dry periods are represented in these records by an enrichment of deuterium in these Sphagnum-specific compounds. These events also correlate

  16. 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

  17. Compound-specific nitrogen isotope analysis of D-alanine, L-alanine, and valine: application of diastereomer separation to delta15N and microbial peptidoglycan studies.

    Science.gov (United States)

    Takano, Yoshinori; Chikaraishi, Yoshito; Ogawa, Nanako O; Kitazato, Hiroshi; Ohkouchi, Naohiko

    2009-01-01

    We have developed an analytical method to determine the compound-specific nitrogen isotope compositions of individual amino acid enantiomers using gas chromatography/combustion/isotope ratio mass spectrometry. A novel derivatization of amino acid diastereomers by optically active (R)-(-)-2-butanol or (S)-(+)-2-butanol offers two advantages for nitrogen isotope analysis. First, chromatographic chiral separation can be achieved without the use of chiral stationary-phase columns. Second, the elution order of these compounds on the chromatogram can be switched by a designated esterification reaction. We applied the method to the compound-specific nitrogen isotope analysis of D- and L-alanine in a peptidoglycan derived from the cell walls of cultured bacteria (Firmicutes and Actinobacteria; Enterococcus faecalis, Staphylococcus aureus, Staphylococcus staphylolyticus, Lactobacillus acidophilus, Bacillus subtilis, Micrococcus luteus, and Streptomyces sp.), natural whole bacterial cells (Bacillus subtilis var. natto), (pseudo)-peptidoglycan from archaea (Methanobacterium sp.), and cell wall from eukaryota (Saccharomyces cerevisiae). We observed statistically significant differences in nitrogen isotopic compositions; e.g., delta15N ( per thousand vs air) in Staphylococcus staphylolyticus for d-alanine (19.2 +/- 0.5 per thousand, n = 4) and L-alanine (21.3 +/- 0.8 per thousand, n = 4) and in Bacillus subtilis for D-alanine (6.2 +/- 0.2 per thousand, n = 3) and L-alanine (8.2 +/- 0.4 per thousand, n = 3). These results suggest that enzymatic reaction pathways, including the alanine racemase reaction, produce a nitrogen isotopic difference in amino acid enantiomers, resulting in 15N-depleted D-alanine. This method is expected to facilitate compound-specific nitrogen isotope studies of amino acid stereoisomers.

  18. Combining position-specific 13C labeling with compound-specific isotope analysis: first steps towards soil fluxomics

    Science.gov (United States)

    Dippold, Michaela; Kuzyakov, Yakov

    2015-04-01

    Understanding the soil organic matter (SOM) dynamics is one of the most important challenges in soil science. Transformation of low molecular weight organic substances (LMWOS) is a key step in biogeochemical cycles because 1) all high molecular substances pass this stage during their decomposition and 2) only LMWOS will be taken up by microorganisms. Previous studies on LMWOS were focused on determining net fluxes through the LMWOS pool, but they rarely identified transformations. As LMWOS are the preferred C and energy source for microorganisms, the transformations of LMWOS are dominated by biochemical pathways of the soil microorganisms. Thus, understanding fluxes and transformations in soils requires a detailed knowledge on the biochemical pathways and its controlling factors. Tracing C fate in soil by isotopes became on of the most applied and promising biogeochemistry tools. Up to now, studies on LMWOS were nearly exclusively based on uniformly labeled organic substances i.e. all C atoms in the molecules were labeled with 13C or 14C. However, this classical approach did not allow the differentiation between use of intact initial substances in any process, or whether they were transformed to metabolites. The novel tool of position-specific labeling enables to trace molecule atoms separately and thus to determine the cleavage of molecules - a prerequisite for metabolic tracing. Position-specific labeling of LMWOS and quantification of 13CO2 and 13C in bulk soil enabled following the basic metabolic pathways of soil microorganisms. However, only the combination of position-specific 13C labeling with compound-specific isotope analysis of microbial biomarkers and metabolites allowed 1) tracing specific anabolic pathways in diverse microbial communities in soils and 2) identification of specific pathways of individual functional microbial groups. So, these are the prerequisites for soil fluxomics. Our studies combining position-specific labeled glucose with amino

  19. Stable isotope enrichment: Current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1992-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities

  20. Stable isotope enrichment - current and future potential

    International Nuclear Information System (INIS)

    Tracy, J.G.; Aaron, W.S.

    1993-01-01

    Oak Ridge National Laboratory (ORNL) operates the Isotope Enrichment Facility for the purpose of providing enriched stable isotopes, selected radioactive isotopes (including the actinides), and isotope-related materials and services for use in various research applications. ORNL is responsible for isotope enrichment and the distribution of approximately 225 nongaseous stable isotopes from 50 multi-isotopic elements. Many enriched isotope products are of prime importance in the fabrication of nuclear targets and the subsequent production of special radionuclides. State-of-the-art techniques to achieve special isotopic, chemical, and physical requirements are performed at ORNL. This report describes the status and capabilities of the Isotope Enrichment Facility and the Isotope Research Materials Laboratory as well as emphasizing potential advancements in enrichment capabilities. (orig.)

  1. Pyrolysis compound specific isotopic analysis (δ13C and δD Py-CSIA) of soil organic matter size fractions under four vegetation covers.

    Science.gov (United States)

    Jiménez-Morillo, Nicasio T.; González-Vila, Francisco J.; Almendros, Gonzalo; De la Rosa, José M.; González-Pérez, José A.

    2015-04-01

    A chemical characterization of soil organic matter (SOM) under different ground cover from a Mediterranean climate (Doñana National Park, Andalusia, Spain) is approached using bulk δ15N, δ13C, δ18O and δD isotopic analysis (C/TC-IRMS) and δ13C and δD pyrolysis compound specific isotopic analysis (Py-CSIA: Py-GC-C/TC-IRMS). Soil samples were collected in sandy soils, Arenosols (WRB 2006) from the Doñana National Park (SW Spain) under different vegetation cover: cork oak (Quercus suber, QS), eagle fern (Pteridium aquilinum, PA), pine (Pinus pinea, PP) and rockrose (Halimium halimifolium, HH). Two size fractions; coarse (C: 1-2 mm) and fine (F: studied from each soil. A complete conventional analytical pyrolysis (Py-GC/MS) of these samples have been studied in detail (Jiménez-Morillo et al., 2015). Bulk isotopic analysis of stable light elements (δ15N, δ13C, δ18O and δD) revealed particular isotopic signatures showing differences related with the main vegetation cover and the different soil size fraction. All samples had a carbon isotopic signature between -26 and -29 ‰, which indicated that the organic matter in the two fractions of each soil sample derived from C3-type plants. The bulk δD isotopic signature in whole soil sample indicate a lower deuterium fractionation occurs in SOM under arboreal than under no-arboreal vegetation, this can be caused by the occurrence of a higher water evaporation rate under bush vegetation and/or to differences due to leaf morphology as previously described (Leaney et al., 1985). A δ15N vs. δ18O chart may provide some clues about N origin in the soil and particularly about the original source of nitrates (Kendall et al., 1996). In in all sample and size fractions our values are in the chart area corresponding to NO3 in precipitation, with lighter δ18O (c. 20 ‰) values compatible with fertilizers may be from adjacent crops. In addition we were able to assign δ13C and δD values for a number of specific SOM

  2. 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)

  3. Reconstruction of past changes in ocean salinity - a compound specific stable hydrogen isotope approach

    NARCIS (Netherlands)

    Kasper, S.

    2015-01-01

    The extent of the general warming related to increasing anthropogenic CO2 emission andits implications for the global climate system are currently under heavy debate. In particular theextrapolation of long term climatic trends relies on complex climate models for the interactionbetween the

  4. Authenticity of aroma components Enantiomeric separation and compound specific stable isotope analysis

    DEFF Research Database (Denmark)

    Hansen, Anne-Mette Sølvbjerg

    of both enantiomers contrary to natural aromas where often only one of the enantiomers will be in excess. Consequently, if equal amounts of enantiomers are detected in a food product labelled “Natural” it could be an indication of adulteration. Artificial aroma compounds often have very different ratios......The word “authenticity” is increasingly used in the marketing of food products. A product can be marketed claiming its authenticity such as containing only natural ingredients or originating from a special location produced using local traditional production methods. Within the area of food...... ingredients a problem with authenticity of aroma compounds has occurred, because natural aromas are wholly or partly replaced with synthetic ones. This is a large economic problem, since natural aromas are often more expensive than artificial ones. Furthermore, the European Union has legal requirements...

  5. Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach

    KAUST Repository

    McMahon, Kelton; Thorrold, Simon R.; Houghton, Leah A.; Berumen, Michael L.

    2015-01-01

    . Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton

  6. Reconstruction of past changes in ocean salinity - a compound specific stable hydrogen isotope approach

    NARCIS (Netherlands)

    Kasper, S.

    2015-01-01

    The extent of the general warming related to increasing anthropogenic CO2 emission and its implications for the global climate system are currently under heavy debate. In particular the extrapolation of long term climatic trends relies on complex climate models for the interaction between the

  7. Modeling of isotope fractionation at the catchment scale: How promising is compound specific isotope analysis (CSIA) as a tool for analyzing diffuse pollution by agrochemicals?

    Science.gov (United States)

    Lutz, S. R.; van Meerveld, H. J.; Waterloo, M. J.; Broers, H. P.; van Breukelen, B. M.

    2012-04-01

    Concentration measurements are indispensable for the assessment of subsurface and surface water pollution by agrochemicals such as pesticides. However, monitoring data is often ambiguous and easily misinterpreted as a decrease in concentration could be caused by transformation, dilution or changes in the application of the pesticide. In this context, compound specific isotope analysis (CSIA) has recently emerged as a complementary monitoring technique. It is based on the measurement of the isotopic composition (e.g. δ13C and δ2H) of the contaminant. Since transformation processes are likely accompanied by isotope fractionation, thus a change in this composition, CSIA offers the opportunity to gain additional knowledge about transport and degradation processes as well as to track pollutants back to their sources. Isotopic techniques have not yet been applied in a comprehensive way in the analysis of catchment-wide organic pollution. We therefore incorporated fractionation processes associated with the fate of pesticides into the numerical flow and solute transport model HydroGeoSphere in order to assess the feasibility of CSIA within the context of catchment monitoring. The model was set up for a hypothetical hillslope transect which drains into a river. Reactive solute transport was driven by two pesticides applications within one year and actual data for rainfall and potential evapotranspiration from a meteorological station in the Netherlands. Degradation of the pesticide was assumed to take place at a higher rate under the prevailing oxic conditions in the topsoil than in deeper, anoxic subsurface layers. In terms of CSIA, these two degradation pathways were associated with different strengths of isotope fractionation for both hydrogen and carbon atoms. By simulating changes in δ13C and δ2H, the share of the oxic and the anoxic reaction on the overall degradation could be assessed. Model results suggest that CSIA is suitable for assessing degradation of

  8. Development of stable isotope manufacturing in Russia

    International Nuclear Information System (INIS)

    Pokidychev, A.; Pokidycheva, M.

    1999-01-01

    For the past 25 years, Russia has relied heavily on the electromagnetic separation process for the production of middle and heavy mass stable isotopes. The separation of most light isotopes had been centered in Georgia which, after the collapse of the USSR, left Russia without this capability. In the mid-1970s, development of centrifuge technology for the separation of stable isotopes was begun. Alternative techniques such as laser separation, physical-chemical methods, and ion cyclotron resonance have also been investigated. Economic considerations have played a major role in the development and current status of the stable isotope enrichment capabilities of Russia

  9. Applications of stable isotopes in clinical pharmacology

    NARCIS (Netherlands)

    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

  10. 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

  11. Rare stable isotopes in meteorites

    International Nuclear Information System (INIS)

    Wilson, G.C.

    1981-01-01

    Secondary Ion Mass Spectrometry (SIMS) using accelerators has been applied with success to cosmic ray exposure ages and terrestrial residence times of meteorites by measuring cosmogenic nuclides of Be, Cl, and I. It is proposed to complement this work with experiments on rare stable isotopes, in the hope of setting constraints on the processes of solar nebula/meteoritic formation. The relevant species can be classified as: a) daughter products of extinct nuclides (halflife less than or equal to 2 x 10 8 y) -chronology of the early solar system; b) products of high temperature astrophysical processes - different components incorporated into the solar nebula; and c) products of relatively low temperature processes, stellar winds and cosmic ray reactions - early solar system radiation history. The use of micron-scale primary ion beams will allow detailed sampling of phases within meteorites. Strategies of charge-state selection, molecular disintegration and detection should bring a new set of targets within analytical range. The developing accelerator field is compared to existing (keV energy) ion microprobes

  12. A versatile method for simultaneous stable carbon isotope analysis of DNA and RNA nucleotides by liquid chromatography/isotope ratio mass spectrometry

    NARCIS (Netherlands)

    Moerdijk-Poortvliet, T.C.W.; Brasser, J.; de Ruiter, G.; Houtekamer, M.; Bolhuis, H.; Stal, L.J.; Boschker, H.T.S.

    2014-01-01

    RATIONALELiquid chromatography/isotope ratio mass spectrometry (LC/IRMS) is currently the most accurate and precise technique for the measurement of compound-specific stable carbon isotope ratios (C-13/C-12) in biological metabolites, at their natural abundance. However, until now this technique

  13. Reconstructing hydroclimatic variations using compound-specific hydrogen isotope analysis of biomarkers from a maar lake in the Central Highlands, Vietnam

    Science.gov (United States)

    Doiron, Kelsey; Stevens, Lora; Sauer, Peter

    2017-04-01

    Monsoonal variation in Southeast Asia affects a significant portion of the global population, but knowledge regarding response of the monsoon system to changing boundary conditions is limited. The paleoclimatic tool of compound-specific isotope analysis(CSIA) provides the ability to reconstruct past precipitation using a diverse set of biomarkers preserved in the sedimentary record. Limited proxies in tropical southeast Asia and difficult site access have led to a deficit in paleoclimate records. Ia M'He (14˚ 10'45" N, 107˚ 52' E) is a shallow volcanic crater (maar) lake, approximately 57 ha, located in the Central Highlands of Vietnam. Precipitation in the Central Highlands is sensitive to reorganizations of major climatic features, such as the migration of the ITCZ and the coupled Indo-Asian monsoon, ENSO and related shifts in the Pacific Walker Circulation and typhoon frequency. To examine this complex behavior, this pilot study aims to provide a 500-year record of effective moisture inferred from CSIA of hydrogen isotopes on biomarkers. Carbon/nitrogen ratios and carbon isotope ratios indicate that bulk organic matter is a combination of algae and C3 vegetation, offering the potential to use compound-specific hydrogen isotopes of aquatic and terrestrial organic matter in tandem. Preliminary analysis of the core shows dominant alkane chain lengths of C27 and C29, associated with terrestrial plant leaf waxes. The hydrogen isotope ratios of the plant wax components provide a proxy for paleo precipitation in a region where rainfall and droughts heavily influence population dynamics and create social discord. The CSIA record is expected to correlate with records from northern Vietnam, the South China Sea and Indonesia, with greater precipitation during the Little Ice Age. The degree to which evaporative modification of lake water (i.e., seasonal drying) occurs will be estimated by comparing the terrestrial CSIA values indicative of meteoric water with aquatic CSIA

  14. Assessing microbial degradation of o-xylene at field-scale from the reduction in mass flow rate combined with compound-specific isotope analyses

    Science.gov (United States)

    Peter, A.; Steinbach, A.; Liedl, R.; Ptak, T.; Michaelis, W.; Teutsch, G.

    2004-07-01

    In recent years, natural attenuation (NA) has evolved into a possible remediation alternative, especially in the case of BTEX spills. In order to be approved by the regulators, biodegradation needs to be demonstrated which requires efficient site investigation and monitoring tools. Three methods—the Integral Groundwater Investigation method, the compound-specific isotope analysis (CSIA) and a newly developed combination of both—were used in this work to quantify at field scale the biodegradation of o-xylene at a former gasworks site which is heavily contaminated with BTEX and PAHs. First, the Integral Groundwater Investigation method [Schwarz, R., Ptak, T., Holder, T., Teutsch, G., 1998. Groundwater risk assessment at contaminated sites: a new investigation approach. In: Herbert, M. and Kovar, K. (Editors), GQ'98 Groundwater Quality: Remediation and Protection. IAHS Publication 250, pp. 68-71; COH 4 (2000) 170] was applied, which allows the determination of mass flow rates of o-xylene by integral pumping tests. Concentration time series obtained during pumping at two wells were used to calculate inversely contaminant mass flow rates at the two control planes that are defined by the diameter of the maximum isochrone. A reactive transport model was used within a Monte Carlo approach to identify biodegradation as the dominant process for reduction in the contaminant mass flow rate between the two consecutive control planes. Secondly, compound-specific carbon isotope analyses of o-xylene were performed on the basis of point-scale samples from the same two wells. The Rayleigh equation was used to quantify the degree of biodegradation that occurred between the wells. Thirdly, a combination of the Integral Groundwater Investigation method and the compound-specific isotope analysis was developed and applied. It comprises isotope measurements during the integral pumping tests and the evaluation of δ13C time series by an inversion algorithm to obtain spatially

  15. Stable-isotope analysis: a neglected tool for placing parasites in food webs.

    Science.gov (United States)

    Sabadel, A J M; Stumbo, A D; MacLeod, C D

    2018-02-28

    Parasites are often overlooked in the construction of food webs, despite their ubiquitous presence in almost every type of ecosystem. Researchers who do recognize their importance often struggle to include parasites using classical food-web theory, mainly due to the parasites' multiple hosts and life stages. A novel approach using compound-specific stable-isotope analysis promises to provide considerable insight into the energetic exchanges of parasite and host, which may solve some of the issues inherent in incorporating parasites using a classical approach. Understanding the role of parasites within food webs, and tracing the associated biomass transfers, are crucial to constructing new models that will expand our knowledge of food webs. This mini-review focuses on stable-isotope studies published in the past decade, and introduces compound-specific stable-isotope analysis as a powerful, but underutilized, newly developed tool that may answer many unresolved questions regarding the role of parasites in food webs.

  16. Trophodynamics and functional feeding groups of North Sea fauna: a combined stable isotope and fatty acid approach

    NARCIS (Netherlands)

    Kürten, B.; Frutos, I.; Struck, U.; Painting, S.J.; Polunin, N.V.C.; Middelburg, J.J.

    The trophodynamics of pelagic and benthic animals of the North Sea, North Atlantic shelf, were assessed using stable isotope analysis (SIA) of natural abundance carbon and nitrogen isotopes, lipid fingerprinting and compound-specific SIA (CSIA) of phospholipid-derived fatty acids (PLFAs).

  17. Trophodynamics and functional feeding groups of North Sea fauna: a combined stable isotope and fatty acid approach

    NARCIS (Netherlands)

    Kürten, B.; Frutos, I.; Struck, U.; Painting, S.J.; Polunin, N.V.C.; Middelburg, J.J.

    2013-01-01

    The trophodynamics of pelagic and benthic animals of the North Sea, North Atlantic shelf, were assessed using stable isotope analysis (SIA) of natural abundance carbon and nitrogen isotopes, lipid fingerprinting and compound-specific SIA (CSIA) of phospholipid-derived fatty acids (PLFAs).

  18. Stable isotope genealogy of meteorites

    International Nuclear Information System (INIS)

    Pillinger, C.T.

    1988-01-01

    One of the oldest problems in meteoritics is that of taxonomically grouping samples. In recent years the use of isotopes, particularly oxygen isotopes has proved very successful in this respect. Other light-element systematics potentially can perform the same function. For example, nitrogen in iron meteorites, and nitrogen and carbon in ureilites and SNC meteorites. These measurements will serve to extend and augment existing classification schemes and provide clues to the nature of meteorite parent bodies. They can also aid in the recognition of the isotopic signatures relating to inaccessible regions of the Earth. (author)

  19. Molecular and compound-specific hydrogen isotope analyses of insoluble organic matter from different carbonaceous chondrite groups

    Science.gov (United States)

    Wang, Yi; Huang, Yongsong; Alexander, Conel M. O.'D.; Fogel, Marilyn; Cody, George

    2005-07-01

    We have conducted the first systematic analyses of molecular distribution and δD values of individual compounds in pyrolysates of insoluble organic matter (IOM) from different carbonaceous chondrite groups, using flash pyrolysis coupled to gas chromatography-mass spectrometry and compound-specific D/H analysis. IOM samples from six meteorites of different classifications, Elephant Moraine (EET) 92042 (CR2), Orgueil (CI1), Allan Hills (ALH) 83100 (CM1/2), Murchison (CM2), ALH 85013 (CM2), and Tagish Lake (C2) were isolated and studied. Except for the pyrolysate of Tagish Lake IOM, pyrolysates of all five meteorite IOM samples were dominated by an extensive series of aromatic (C 1 to C 7 alkyl-substituted benzenes, C 0 to C 2 alkyl-substituted naphthalenes), with aliphatic (straight chain and branched C 10 to C 15 alkanes) hydrocarbons and several S- and O- containing compounds (C 1 to C 2 alkylthiophenes, benzothiophene, benzaldehyde) being also present. The strong similarity in the pyrolysates of different carbonaceous chondrites suggests certain common characteristics in the formation mechanisms of IOM from different meteorites. The Tagish Lake IOM sample is unique in that its pyrolysate lacks most of the alkyl-substituted aromatic hydrocarbons detected in other meteorite IOM samples, suggesting distinctively different formation processes. Both bulk δD values of meteorite IOMs and weighted-average δD values of individual compounds in pyrolysates show a decreasing trend: CR2 > CI1 > CM2 > C2 (Tagish Lake), with the EET 92042 (CR2) IOM having the highest δD values (˜2000‰ higher than other samples). We attribute the high D contents in the IOM to primitive interstellar organic sources.

  20. 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

  1. 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...

  2. Deciphering Complex Carbon Cycle Changes Across the K-Pg Boundary Using Compound-Specific Carbon Isotopic Analyses

    Science.gov (United States)

    Pancost, R. D.; Taylor, K. W.; Hollis, C. J.; Crouch, E. M.

    2014-12-01

    The consequences of the Cretaceous-Paleogene (K/Pg) boundary event on the Earth system have been the subject of much scrutiny. Postulated climate events include a brief (10 - 2000 yr) period of global cooling induced by sulphate aerosols (the so-called 'impact winter'), an interval of warming caused by impact-induced CO2release, as well as longer-term climatic oscillations during the subsequent 1 to 3Myr. Associated with these were putative changes in the biogeochemical cycle, manifested as carbon isotope excursions on both short- and long-term timescales. In this study we develop new biomarker-based climate and biogeochemical records for the mid-Waipara River and Branch Stream sections, NZ. At Branch Stream, a pronounced negative (ca 6 to 8 permil) carbon isotope excursion occurs at the K/Pg; the excursion is recorded by higher plant biomarkers, consistent with some terrestrial records and suggesting that the immediate aftermath of the K/Pg boundary event was characterised by the massive release of 13C-depleted reduced carbon into the ocean-atmosphere reservoir. Mixing across the K/Pg boundary at the Waipara section precludes a similar high-resolution investigation. Lower-resolution, longer-term records, however, also reveal a negative carbon istope excursion documented by both algal and higher plant biomarkers. This event appears to be distinct from that recorded at Branch Stream, being of lower magnitude and longer duration. It coincided with a transient terrestrial and marine warming and appears to have lasted at least 100 kyr and perhaps longer. We argue that this protracted negative CIE reflects a secondary and longer-term consequence of the K/Pg on the global carbon cycle. There is little evidence for an algal extinction as a range of C27 to C30 sterols continued to be deposited throughout the entire section, but changes in GDGT distributions do suggest a change in carbon export dynamics which could have impacted burial of 13C-depleted marine organic matter

  3. C, Cl and H compound-specific isotope analysis to assess natural versus Fe(0) barrier-induced degradation of chlorinated ethenes at a contaminated site

    Energy Technology Data Exchange (ETDEWEB)

    Audí-Miró, Carme, E-mail: carmeaudi@ub.edu [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona (Spain); Cretnik, Stefan [Institute of Groundwater Ecology, Helmholtz Zentrum München-National Research Center for Environmental Health, Ingolstädter Landstrasse 1, D-85764 Neuherberg (Germany); Torrentó, Clara; Rosell, Mònica [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona (Spain); Shouakar-Stash, Orfan [Department of Earth & Environmental Sciences, 200 University Ave. W, N2L 3G1 Waterloo, Ontario (Canada); Otero, Neus [Grup de Mineralogia Aplicada i Medi Ambient, Departament de Cristal.lografia, Mineralogia i Dipòsits Minerals, Facultat de Geologia, Universitat de Barcelona (UB), Martí Franquès s/n, 08028, Barcelona (Spain); Palau, Jordi [Université de Neuchâtel, CHYN - Centre d' Hydrogéologie, Rue Emile-Argand 11, CH-2000 Neuchâtel (Switzerland); and others

    2015-12-15

    Highlights: • {sup 13}C to evaluate natural chlorinated ethenes biodegradation. • {sup 13}C to evaluate the efficiency of a zero-valent iron-permeable reactive barrier. • {sup 13}C-{sup 37}Cl to discriminate biotic from abiotic degradation of cis-dichloroethene. • {sup 13}C-{sup 37}Cl-{sup 2}H of cis-DCE and TCE to elucidate different contaminant sources. - Abstract: Compound-specific isotopic analysis of multiple elements (C, Cl, H) was tested to better assess the effect of a zero-valent iron-permeable reactive barrier (ZVI-PRB) installation at a site contaminated with tetrachloroethene (PCE) and trichloroethene (TCE). The focus was on (1) using {sup 13}C to evaluate natural chlorinated ethene biodegradation and the ZVI-PRB efficiency; (2) using dual element {sup 13}C-{sup 37}Cl isotopic analysis to distinguish biotic from abiotic degradation of cis-dichloroethene (cis-DCE); and (3) using {sup 13}C-{sup 37}Cl-{sup 2}H isotopic analysis of cis-DCE and TCE to elucidate different contaminant sources. Both biodegradation and degradation by ZVI-PRB were indicated by the metabolites that were detected and the {sup 13}C data, with a quantitative estimate of the ZVI-PRB efficiency of less than 10% for PCE. Dual element {sup 13}C-{sup 37}Cl isotopic plots confirmed that biodegradation was the main process at the site including the ZVI-PRB area. Based on the carbon isotope data, approximately 45% and 71% of PCE and TCE, respectively, were estimated to be removed by biodegradation. {sup 2}H combined with {sup 13}C and {sup 37}Cl seems to have identified two discrete sources contributing to the contaminant plume, indicating the potential of δ{sup 2}H to discriminate whether a compound is of industrial origin, or whether a compound is formed as a daughter product during degradation.

  4. C, Cl and H compound-specific isotope analysis to assess natural versus Fe(0) barrier-induced degradation of chlorinated ethenes at a contaminated site

    International Nuclear Information System (INIS)

    Audí-Miró, Carme; Cretnik, Stefan; Torrentó, Clara; Rosell, Mònica; Shouakar-Stash, Orfan; Otero, Neus; Palau, Jordi

    2015-01-01

    Highlights: • 13 C to evaluate natural chlorinated ethenes biodegradation. • 13 C to evaluate the efficiency of a zero-valent iron-permeable reactive barrier. • 13 C- 37 Cl to discriminate biotic from abiotic degradation of cis-dichloroethene. • 13 C- 37 Cl- 2 H of cis-DCE and TCE to elucidate different contaminant sources. - Abstract: Compound-specific isotopic analysis of multiple elements (C, Cl, H) was tested to better assess the effect of a zero-valent iron-permeable reactive barrier (ZVI-PRB) installation at a site contaminated with tetrachloroethene (PCE) and trichloroethene (TCE). The focus was on (1) using 13 C to evaluate natural chlorinated ethene biodegradation and the ZVI-PRB efficiency; (2) using dual element 13 C- 37 Cl isotopic analysis to distinguish biotic from abiotic degradation of cis-dichloroethene (cis-DCE); and (3) using 13 C- 37 Cl- 2 H isotopic analysis of cis-DCE and TCE to elucidate different contaminant sources. Both biodegradation and degradation by ZVI-PRB were indicated by the metabolites that were detected and the 13 C data, with a quantitative estimate of the ZVI-PRB efficiency of less than 10% for PCE. Dual element 13 C- 37 Cl isotopic plots confirmed that biodegradation was the main process at the site including the ZVI-PRB area. Based on the carbon isotope data, approximately 45% and 71% of PCE and TCE, respectively, were estimated to be removed by biodegradation. 2 H combined with 13 C and 37 Cl seems to have identified two discrete sources contributing to the contaminant plume, indicating the potential of δ 2 H to discriminate whether a compound is of industrial origin, or whether a compound is formed as a daughter product during degradation.

  5. 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

  6. 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

  7. Monitoring of the aerobe biodegradation of chlorinated organic solvents by stable isotope analysis

    Science.gov (United States)

    Horváth, Anikó; Futó, István; Palcsu, László

    2014-05-01

    Our chemical-biological basic research aims to eliminate chlorinated environmental contaminants from aquifers around industrial areas in the frame of research program supported by the European Social Fund (TÁMOP-4.2.2.A-11/1/KONV-2012-0043). The most careful and simplest way includes the in situ biodegradation with the help of cultured and compound specific strains. Numerous members of Pseudomonas bacteria are famous about function of bioremediation. They can metabolism the environmental hazardous chemicals like gas oils, dyes, and organic solvents. Our research based on the Pseudomonas putida F1 strain, because its ability to degrade halogenated hydrocarbons such as trichloroethylene. Several methods were investigated to estimate the rate of biodegradation, such as the measurement of the concentration of the pollutant along the contamination pathway, the microcosm's studies or the compound specific stable isotope analysis. In this area in the Transcarpathian basin we are pioneers in the stable isotope monitoring of biodegradation. The main goal is to find stable isotope fractionation factors by stable isotope analysis, which can help us to estimate the rate and effectiveness of the biodegradation. The subsequent research period includes the investigation of the method, testing its feasibility and adaptation in the environment. Last but not least, the research gives an opportunity to identify the producer of the contaminant based on the stable isotope composition of the contaminant.

  8. Compound-specific radiocarbon analysis - Analytical challenges and applications

    Science.gov (United States)

    Mollenhauer, G.; Rethemeyer, J.

    2009-01-01

    Within the last decades, techniques have become available that allow measurement of isotopic compositions of individual organic compounds (compound-specific isotope measurements). Most often the carbon isotopic composition of these compounds is studied, including stable carbon (δ13C) and radiocarbon (Δ14C) measurements. While compound-specific stable carbon isotope measurements are fairly simple, and well-established techniques are widely available, radiocarbon analysis of specific organic compounds is a more challenging method. Analytical challenges include difficulty obtaining adequate quantities of sample, tedious and complicated laboratory separations, the lack of authentic standards for measuring realistic processing blanks, and large uncertainties in values of Δ14C at small sample sizes. The challenges associated with sample preparation for compound-specific Δ14C measurements will be discussed in this contribution. Several years of compound-specific radiocarbon analysis have revealed that in most natural samples, purified organic compounds consist of heterogeneous mixtures of the same compound. These mixtures could derive from multiple sources, each having a different initial reservoir age but mixed in the same terminal reservoir, from a single source but mixed after deposition, or from a prokaryotic organism using variable carbon sources including mobilization of ancient carbon. These processes not only represent challenges to the interpretation of compound-specific radiocarbon data, but provide unique tools for the understanding of biogeochemical and sedimentological processes influencing the preserved organic geochemical records in marine sediments. We will discuss some examples where compound-specific radiocarbon analysis has provided new insights for the understanding of carbon source utilization and carbon cycling.

  9. Reconstructing hydroclimatic variations using compound-specific hydrogen isotope analysis of biomarkers from a maar lake in the Central Highlands, Vietnam

    Science.gov (United States)

    Doiron, K. E.; Stevens, L. R.; Sauer, P. E.

    2017-12-01

    Monsoonal variation in Southeast Asia affects a significant portion of the global population, but knowledge regarding response of the monsoon system to changing boundary conditions is limited. The paleoclimatic tool of compound-specific isotope analysis(CSIA) provides the ability to reconstruct past precipitation using a diverse set of biomarkers preserved in the sedimentary record. Limited proxies in tropical southeast Asia and difficult site access have led to a deficit in paleoclimate records. Ia M'He (14°10'45" N, 107°52' E) is a shallow volcanic crater (maar) lake, approximately 57 ha, located in the Central Highlands of Vietnam. Precipitation in the Central Highlands is sensitive to reorganizations of major climatic features, such as the migration of the ITCZ and the coupled Indo-Asian monsoon, ENSO and related shifts in the Pacific Walker Circulation and typhoon frequency. To examine this complex behavior, this pilot study aims to provide a 500-year record of effective moisture inferred from CSIA of hydrogen isotopes on biomarkers. This study highlights the use of hydrogen isotopes of C28 n-alkanoic acid and dominant n-alkane chain lengths of C27 and C29, associated with terrestrial plant leaf waxes, as tracers for precipitation. The hydrogen isotope ratios of the plant wax components provide a proxy for paleo precipitation in a region where rainfall and droughts heavily influence population dynamics and create social discord. The CSIA record is expected to correlate with records from northern Vietnam, the South China Sea and Indonesia, with greater precipitation during the Little Ice Age. The CSIA data of terrestrial plant leaf waxes will be compared with secondary proxies including: diatoms, C/N and biogenic silica.

  10. Molecular and stable carbon isotopic characterization of PAH contaminants at McMurdo Station, Antarctica

    International Nuclear Information System (INIS)

    Kim, Moonkoo . E-mail moonkoo.kim@wmich.edu; Kennicutt, Mahlon C.; Qian Yaorong

    2006-01-01

    The molecular and stable carbon isotopic compositions of contaminant polycyclic aromatic hydrocarbons (PAHs) at McMurdo Station, Antarctica were analyzed in samples collected from land and sub-tidal area. PAHs in the study areas were characterized by high amounts of naphthalene and alkylated naphthalenes from petroleum products introduced by human activities in the area. Principal component analysis (PCA) of PAH composition data identified multiple sources of PAH contamination in the study area. Compositional assignments of origins were confirmed using compound specific stable carbon isotopic analysis

  11. 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.

  12. 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 ...

  13. Retroconversion is a minor contributor to increases in eicosapentaenoic acid following docosahexaenoic acid feeding as determined by compound specific isotope analysis in rat liver.

    Science.gov (United States)

    Metherel, Adam H; Chouinard-Watkins, Raphaël; Trépanier, Marc-Olivier; Lacombe, R J Scott; Bazinet, Richard P

    2017-01-01

    Dietary docosahexaenoic acid (DHA, 22:6n-3) not only increases blood and tissue levels of DHA, but also eicosapentaenoic acid (EPA, 20:5n-3). It is generally believed that this increase is due to DHA retroconversion to EPA, however, a slower conversion of α-linolenic acid (ALA, 18:3n-3) derived EPA to downstream metabolic products (i.e. slower turnover of EPA) is equally plausible. In this study, 21-day old Long Evans rats were weaned onto an ALA only or DHA + ALA diet for 12 weeks. Afterwards, livers were collected and the natural abundance 13 C-enrichment was determined by compound specific isotope analysis (CSIA) of liver EPA by isotope ratio mass-spectrometry and compared to dietary ALA and DHA 13 C-enrichment. Isotopic signatures (per mil, ‰) for liver EPA were not different ( p  > 0.05) between the ALA only diet (-25.89 ± 0.39 ‰, mean ± SEM) and the DHA + ALA diet (-26.26 ± 0.40 ‰), suggesting the relative contribution from dietary ALA and DHA to liver EPA did not change. However, with DHA feeding estimates of absolute EPA contribution from ALA increased 4.4-fold (147 ± 22 to 788 ± 153 nmol/g) compared to 3.2-fold from DHA (91 ± 14 to 382 ± 13 nmol/g), respectively. In conclusion, CSIA of liver EPA in rats following 12-weeks of dietary DHA suggests that retroconversion of DHA to EPA is a relatively small contributor to increases in EPA, and that this increase in EPA is largely coming from elongation/desaturation of ALA.

  14. 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.

  15. The Importance of Zostera marina to a Local Food Web Based on the Analysis of Compound Specific Isotopes in Maquoit Bay, Gulf of Maine

    Science.gov (United States)

    Doolittle, H. A.; Johnson, B. J.; Ambrose, W. G.; Locke, W.; Harris, C. M.

    2010-12-01

    Zostera marina (also known as eelgrass) is an important primary producer in near shore ecosystems in the Gulf of Maine, providing both habitat and nutrients for a variety of organisms (e.g., crustaceans, polychaetes, gastropods, and fish). The purpose of this study is to use compound specific δ13C analyses of essential amino acids to determine the degree to which organic matter derived from isotopically distinct primary producers (e.g., eelgrass, phytoplankton, and epiphytic algae) contribute to the diets of snails, shrimp, and fish in an eelgrass system in Casco Bay. Maquoit Bay, located in northwestern Casco Bay, in the Gulf of Maine, is a shallow estuarine system that is characterized by silt and clay sized sediments and the presence of extensive eelgrass beds. Amino acid concentrations and δ13C compositions were determined for a variety of sample-types collected in July-August, 2010, from three sites in the study area, including muscle tissue from Tautogolabrus adspersus (cunner), Gasterosteus aculeatus (3-spined stickleback), Nassarius obsoletus (snail), and Mysis spp. (shrimp), seston (i.e., phytoplankton), Z. marina, and epiphytic algae. TFAA amino acid derivatives of the total hydrolyzate were analyzed by GC-FID for amino acid concentration, and by GC-c-IRMS- for carbon isotope composition. Muscle tissue was dominated by glutamic and aspartic acids, and leucine, whereas Zostera marina was dominated by aspartic and glutamic acids, and proline. Phenylalanine and leucine in Z. marina are approximately 10 ‰ enriched in 13C relative to these same amino acids in the seston. The carbon isotope values of these essential amino acids are significantly more enriched in 13C for N. obsoletus than for T. adspersus, G. aculeatus, and Mysis spp. These data suggest that organic matter derived from Z. marina and/or epiphytic algae is more important in the diets of N. obsoletus, and organic matter derived from seston is more important for the diets of T. adspersus, G

  16. Stable isotope separation by thermal diffusion

    International Nuclear Information System (INIS)

    Vasaru, Gheorghe

    2001-01-01

    Thermal diffusion in both gaseous and liquid phase has been subject of extensive experimental and theoretical investigations, especially after the invention of K. Clusius and G. Dickel of the thermal diffusion column, sixty three years ago. This paper gives a brief overview of the most important research and developments performed during the time at the National Institute for Research and Development for Isotopic and Molecular Technology (ITIM) at Cluj - Napoca, Romania in the field of separation of stable isotopes by thermal diffusion. An retrospective analysis of the research and results concerning isotope separation by thermal diffusion entails the following conclusions: - thermal diffusion is an adequate method for hydrogen isotope separation (deuterium and tritium) and for noble gas isotope separation (He, Ne, Ar, Kr, Xe); - thermal diffusion is attractive also for 13 C enrichment using methane as raw material for separation, when annual yields of up to 100 g are envisaged; - lately, the thermal diffusion appears to be chosen as a final enrichment step for 17 O. An obvious advantage of this method is its non-specificity, i.e. the implied equipment can be utilized for isotope separation of other chemical elements too. Having in view the low investment costs for thermal diffusion cascades the method appears economically attractive for obtaining low-scale, laboratory isotope production. The paper has the following content: 1. The principle of method; 2. The method's application; 3. Research in the field of thermal diffusion at ITIM; 4. Thermal diffusion cascades for N, C, Ne, Ar and Kr isotope separation; 5. Conclusion

  17. Use of stable isotopes in agriculture

    International Nuclear Information System (INIS)

    Ali, F. K.

    2011-01-01

    Scientific research is considered to be one of the most important steps to achieve sustainable agriculture development. This paper is focused on the role of stable isotopes and their applications in agriculture for plant and animal production, and to study the relationship between soil, plant, air, water, nutrients and agricultural pests. Symbiotic N 2 fixation and efficient use of chemical and organic N fertilizers using 15 N were reported. Factors affecting 13 C values and application of carbon isotope discrimination to physiological and eco-physiological studies and selection of genotypes with improved water-use efficiency and drought tolerance and the recent progress in this field are reviewed. Moreover, the use of carbon isotope compositions in monitoring environmental changes and its various applications in food technology, animal production and entomology are discussed. (author)

  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 measurements of atmospheric CO2

    International Nuclear Information System (INIS)

    White, J.W.C.; Ferretti, D.F.; Vaughn, B.H.; Francey, R.J.; Allison, C.E.

    2002-01-01

    The measurement of stable carbon isotope ratios of atmospheric carbon dioxide, δ 13 CO 2 are useful for partitioning surface-atmospheric fluxes into terrestrial and oceanic components. δC 18 OO also has potential for segregating photosynthetic and respiratory fluxes in terrestrial ecosystems. Here we describe in detail the techniques for making these measurements. The primary challenge for all of the techniques used to measure isotopes of atmospheric CO 2 is to achieve acceptable accuracy and precision and to maintain them over the decades needed to observe carbon cycle variability. The keys to success such an approach are diligent intercalibrations of laboratories from around the world, as well as the use of multiple techniques such as dual inlet and GC-IRMS and the intercomparison of such measurements. We focus here on two laboratories, the Stable Isotope Lab at the Institute for Arctic and Alpine Research (INSTAAR) at the University of Colorado is described and the Commonwealth Scientific and Industrial Research Organisation - Atmospheric Research (CSIRO). Different approaches exist at other laboratories (e.g. programs operated by Scripps Institution of Oceanography (SIO) and The Center for Atmospheric and Oceanic Studies, Toboku University (TU)) however these are not discussed here. Finally, we also discuss the recently developed Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) technique which holds significant promise for measuring ultra-small samples of gas with good precision. (author)

  20. 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.

  1. Protein-based stable isotope probing.

    Science.gov (United States)

    Jehmlich, Nico; Schmidt, Frank; Taubert, Martin; Seifert, Jana; Bastida, Felipe; von Bergen, Martin; Richnow, Hans-Hermann; Vogt, Carsten

    2010-12-01

    We describe a stable isotope probing (SIP) technique that was developed to link microbe-specific metabolic function to phylogenetic information. Carbon ((13)C)- or nitrogen ((15)N)-labeled substrates (typically with >98% heavy label) were used in cultivation experiments and the heavy isotope incorporation into proteins (protein-SIP) on growth was determined. The amount of incorporation provides a measure for assimilation of a substrate, and the sequence information from peptide analysis obtained by mass spectrometry delivers phylogenetic information about the microorganisms responsible for the metabolism of the particular substrate. In this article, we provide guidelines for incubating microbial cultures with labeled substrates and a protocol for protein-SIP. The protocol guides readers through the proteomics pipeline, including protein extraction, gel-free and gel-based protein separation, the subsequent mass spectrometric analysis of peptides and the calculation of the incorporation of stable isotopes into peptides. Extraction of proteins and the mass fingerprint measurements of unlabeled and labeled fractions can be performed in 2-3 d.

  2. Geochemistry of the stable isotopes of silicon

    Energy Technology Data Exchange (ETDEWEB)

    Douthitt, C B [California Inst. of Tech., Pasadena (USA). Div. of Geological and Planetary Sciences

    1982-08-01

    One hundred thirty two new measurements of the relative abundances of the stable isotopes of silicon in terrestrial materials are presented. The total variation of delta/sup 30/Si found is 6.2 parts per thousand, centered on the mean of terrestrial mafic and ultramafic igneous rocks, delta/sup 30/Si = -0.4 parts per thousand. Igneous rocks show limited variation; coexisting minerals exhibit small, systematic silicon isotopic fractionations that are roughly 1/3 the magnitude of concomitant oxygen isotopic fractionations at 1150/sup 0/C. In both igneous minerals and rocks, delta/sup 30/Si shows a positive correlation with silicon content, as does delta/sup 18/O. Opal from both sponge spicules and sinters is light, with delta/sup 30/Si = -2.3 and -1.4 parts per thousand respectively. Large delta/sup 30/Si values of both positive and negative sign are reported for the first time from clay minerals, opaline phytoliths, and authigenic quartz. All highly fractionated samples were precipitated from solution at low temperatures; however, aqueous silicon is not measurably fractionated relative to quartz at equilibrium. A kinetic isotope fractionation of approximately 3.5 parts per thousand is postulated to occur during the low temperature precipitation of opal and, possibly, poorly ordered phyllosilicates, with the silicate phase being enriched in /sup 28/Si. This fractionation, coupled with a Rayleigh precipitation model, is capable of explaining most non-magmatic delta/sup 30/Si variations.

  3. Protein labelling with stable isotopes: strategies

    International Nuclear Information System (INIS)

    Lirsac, P.N.; Gilles, N.; Jamin, N.; Toma, F.; Gabrielsen, O.; Boulain, J.C.; Menez, A.

    1994-01-01

    A protein labelling technique with stable isotopes has been developed at the CEA: a labelled complete medium has been developed, performing as well as the Luria medium, but differing from it because it contains not only free aminated acids and peptides, but also sugars (96% of D-glucopyrannose) and labelled nucleosides. These precursors are produced from a labelled photosynthetic micro-organisms biomass, obtained with micro-algae having incorporated carbon 13, nitrogen 15 and deuterium during their culture. Labelling costs are reduced. 1 fig., 1 tab., 3 refs

  4. 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

  5. A counter-intuitive approach to calculating non-exchangeable 2H isotopic composition of hair: treating the molar exchange fraction fE as a process-related rather than compound-specific variable

    Science.gov (United States)

    Landwehr, J.M.; Meier-Augenstein, W.; Kemp, H.F.

    2011-01-01

    Hair is a keratinous tissue that incorporates hydrogen from material that an animal consumes but it is metabolically inert following synthesis. The stable hydrogen isotope composition of hair has been used in ecological studies to track migrations of mammals as well as for forensic and archaeological purposes to determine the provenance of human remains or the recent geographic life trajectory of living people. Measurement of the total hydrogen isotopic composition of a hair sample yields a composite value comprised of both metabolically informative, non-exchangeable hydrogen and exchangeable hydrogen, with the latter reflecting ambient or sample preparation conditions. Neither of these attributes is directly measurable, and the non-exchangeable hydrogen composition is obtained by estimation using a commonly applied mathematical expression incorporating sample measurements obtained from two distinct equilibration procedures. This commonly used approach treats the fraction of exchangeable hydrogen as a mixing ratio, with a minimal procedural fractionation factor assumed to be close or equal to 1. Instead, we propose to use full molar ratios to derive an expression for the non-exchangeable hydrogen composition explicitly as a function of both the procedural fractionation factor α and the molar hydrogen exchange fraction fE. We apply these derivations in a longitudinal study of a hair sample and demonstrate that the molar hydrogen exchange fraction fE should, like the procedural fractionation factor α, be treated as a process-dependent parameter, i.e. a reaction-specific constant. This is a counter-intuitive notion given that maximum theoretical values for the molar hydrogen exchange fraction fE can be calculated that are arguably protein-type specific and, as such, fE could be regarded as a compound-specific constant. We also make some additional suggestions for future approaches to determine the non-exchangeable hydrogen composition of hair and the use of

  6. Carbon sources in suspended particles and surface sediments from the Beaufort Sea revealed by molecular lipid biomarkers and compound-specific isotope analysis

    Directory of Open Access Journals (Sweden)

    I. Tolosa

    2013-03-01

    Full Text Available Molecular lipid biomarkers (hydrocarbons, alcohols, sterols and fatty acids and compound-specific isotope analysis of suspended particulate organic matter (SPM and surface sediments of the Mackenzie Shelf and slope (southeast Beaufort Sea, Arctic Ocean were studied in summer 2009. The concentrations of the molecular lipid markers, characteristic of known organic matter sources, were grouped and used as proxies to evaluate the relative importance of fresh algal, detrital algal, fossil, C3 terrestrial plants, bacterial and zooplankton material in the organic matter (OM of this area. Fossil and detrital algal contributions were the major fractions of the freshwater SPM from the Mackenzie River with ~34% each of the total molecular biomarkers. Fresh algal, C3 terrestrial, bacterial and zooplanktonic components represented much lower percentages, 17, 10, 4 and 80%, with a minor contribution of fossil and C3 terrestrial biomarkers. Characterization of the sediments revealed a major sink of refractory algal material mixed with some fresh algal material, fossil hydrocarbons and a small input of C3 terrestrial sources. In particular, the sediments from the shelf and at the mouth of the Amundsen Gulf presented the highest contribution of detrital algal material (60–75%, whereas those from the slope contained the highest proportion of fossil (40% and C3 terrestrial plant material (10%. Overall, considering that the detrital algal material is marine derived, autochthonous sources contributed more than allochthonous sources to the OM lipid pool. Using the ratio of an allochthonous biomarker (normalized to total organic carbon, TOC found in the sediments to those measured at the river mouth water, we estimated that the fraction of terrestrial material preserved in the sediments accounted for 30–40% of the total carbon in the inner shelf sediments, 17% in the outer shelf and Amundsen Gulf and up to 25% in the slope sediments. These estimates are low

  7. 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

  8. A theory of stable-isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Pickup, J.F.; McPherson, C.K.

    1977-01-01

    In order to perform quantitative analysis using stable isotope dilution with mass spectrometry, an equation is derived which describes the relationship between the relative proportions of natural and labelled material and measured isotope ratios

  9. Use of Compound-Specific Stable Isotope Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs

    Science.gov (United States)

    2013-11-01

    Chlorinated Hydrocarbons, Volatile Organics, TPH (HEM/SGT), CT- Extractable Petroleum Hydrocarbons (ETPH), MA-EPH, MA- VPH . Microbiology Parameters: Total...Toxaphene, CT-Extractable Petroleum Hydrocarbons (ETPH), MA-EPH, MA- VPH , Dicamba, 2,4-D, 2,4,5-T, 2,4,5-TP(Silvex), Dalapon, Volatile Organics (SW 8260...3510C, 3630C, 5030B, ME- DRO, ME-GRO, MA-EPH, MA- VPH .) Solid Waste/Soil (Inorganic Parameters: 9010B, 9012A, 9014A, 9030B, 9040B, 9045C, 6010B

  10. 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

  11. [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.

  12. 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 (<0.1-1% PAL) is based on geochemical and isotopic proxies, which track the mobilization of Fe and Mn on the continents. For example, large chromium isotope shifts occur at the Neoproterozoic Oxidation Event due to the initiation of Cr redox cycling, but this proxy is insensitive to fluctuations in the lower-pO2 conditions at other times during the Proterozoic. Tellurium, a metalloid with a lower threshold to oxidation, may be sensitive to pO2 shifts in a lower range. In the reduced forms, Te(-II) and Te(0), the element is insoluble and immobile. However, in the more oxidized phases, Te(IV) and Te(VI), Te can form soluble oxyanions (though it tends to adsorb to Fe-oxyhydroxides and clays) [2]. Te stable isotopes have been shown to fractionate during abiotic or 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

  13. Applications of stable isotope analysis in mammalian ecology.

    Science.gov (United States)

    Walter, W David; Kurle, Carolyn M; Hopkins, John B

    2014-01-01

    In this editorial, we provide a brief introduction and summarize the 10 research articles included in this Special Issue on Applications of stable isotope analysis in mammalian ecology. The first three articles report correction and discrimination factors that can be used to more accurately estimate the diets of extinct and extant mammals using stable isotope analysis. The remaining seven applied research articles use stable isotope analysis to address a variety of wildlife conservation and management questions from the oceans to the mountains.

  14. Stable isotope customer list and summary of shipments: FY 1975

    International Nuclear Information System (INIS)

    Davis, W.C.

    1975-10-01

    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: an alphabetical list of domestic and foreign customers, showing the stable isotopes purchased during the fiscal year; an alphabetical list of isotopes, cross-referenced to customer numbers and divided into domestic and foreign categories; an alphabetical list of states and countries, cross-referenced to customer numbers and indicating geographical concentrations of isotope users; and a tabulation of the shipments, quantities, and dollars for domestic, foreign, and project categories for each isotope, with the totals for loaned isotopes shown at the end of the table. (auth)

  15. 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.

  16. Compound-Specific Chlorine Isotope Analysis of Tetrachloromethane and Trichloromethane by Gas Chromatography-Isotope Ratio Mass Spectrometry vs Gas Chromatography-Quadrupole Mass Spectrometry: Method Development and Evaluation of Precision and Trueness.

    Science.gov (United States)

    Heckel, Benjamin; Rodríguez-Fernández, Diana; Torrentó, Clara; Meyer, Armin; Palau, Jordi; Domènech, Cristina; Rosell, Mònica; Soler, Albert; Hunkeler, Daniel; Elsner, Martin

    2017-03-21

    Compound-specific chlorine isotope analysis of tetrachloromethane (CCl 4 ) and trichloromethane (CHCl 3 ) was explored by both, gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and GC-quadrupole MS (GC-qMS), where GC-qMS was validated in an interlaboratory comparison between Munich and Neuchâtel with the same type of commercial GC-qMS instrument. GC-IRMS measurements analyzed CCl isotopologue ions, whereas GC-qMS analyzed the isotopologue ions CCl 3 , CCl 2 , CCl (of CCl 4 ) and CHCl 3 , CHCl 2 , CHCl (of CHCl 3 ), respectively. Lowest amount dependence (good linearity) was obtained (i) in H-containing fragment ions where interference of 35 Cl- to 37 Cl-containing ions was avoided; (ii) with tuning parameters favoring one predominant rather than multiple fragment ions in the mass spectra. Optimized GC-qMS parameters (dwell time 70 ms, 2 most abundant ions) resulted in standard deviations of 0.2‰ (CHCl 3 ) and 0.4‰ (CCl 4 ), which are only about twice as large as 0.1‰ and 0.2‰ for GC-IRMS. To compare also the trueness of both methods and laboratories, samples from CCl 4 and CHCl 3 degradation experiments were analyzed and calibrated against isotopically different reference standards for both CCl 4 and CHCl 3 (two of each). Excellent agreement confirms that true results can be obtained by both methods provided that a consistent set of isotopically characterized reference materials is used.

  17. Gas chromatographic isolation technique for compound-specific radiocarbon analysis

    International Nuclear Information System (INIS)

    Uchida, M.; Kumamoto, Y.; Shibata, Y.; Yoneda, M.; Morita, M.; Kawamura, K.

    2002-01-01

    Full text: We present here a gas chromatographic isolation technique for the compound-specific radiocarbon analysis of biomarkers from the marine sediments. The biomarkers of fatty acids, hydrocarbon and sterols were isolated with enough amount for radiocarbon analysis using a preparative capillary gas chromatograph (PCGC) system. The PCGC systems used here is composed of an HP 6890 GC with FID, a cooled injection system (CIS, Gerstel, Germany), a zero-dead-volume effluent splitter, and a cryogenic preparative collection device (PFC, Gerstel). For AMS analysis, we need to separate and recover sufficient quantity of target individual compounds (>50 μgC). Yields of target compounds from C 14 n-alkanes to C 40 to C 30 n-alkanes and approximately that of 80% for higher molecular weights compounds more than C 30 n-alkanes. Compound specific radiocarbon analysis of organic compounds, as well as compound-specific stable isotope analysis, provide valuable information on the origins and carbon cycling in marine system. Above PCGC conditions, we applied compound-specific radiocarbon analysis to the marine sediments from western north Pacific, which showed the possibility of a useful chronology tool for estimating the age of sediment using organic matter in paleoceanographic study, in the area where enough amounts of planktonic foraminifera for radiocarbon analysis by accelerator mass spectrometry (AMS) are difficult to obtain due to dissolution of calcium carbonate. (author)

  18. Unit of stable isotopic N15 analysis

    International Nuclear Information System (INIS)

    Cabrera de Bisbal, Evelin; Paredes U, Maria

    1997-01-01

    The continuous and growing demand of crops and cattle for the domestic inhabitants, forces the search of technical solutions in agriculture. One of the solutions able to be covered in a near future it is the escalation of agricultural production in lands already being cultivated, either by means of an intensification of cultivation and / or increasing the unitary yields. In the intensive cropping systems, the crops extract substantial quantities of nutriments that is recovered by means of the application of fertilizers. Due to the lack of resources and to the increase of commercial inputs prices, it has been necessary to pay attention to the analysis and improvement of low inputs cropping systems and to the effective use of resources. Everything has made to establish a concept of plant nutrition focused system, which integrate the sources of nutriments for plants and the production factors of crops in a productive cropping system, to improve the fertility of soils, the agricultural productivity and profitability. This system includes the biggest efficiency of chemical fertilizers as the maximum profit of alternative sources of nutriments, such as organic fertilizers, citrate-phosphate rocks and biological nitrogen fixation. By means of field experiments under different environmental conditions (soils and climate) it can be determined the best combination of fertilizers practice (dose, placement, opportunity and source) for selected cropping systems. The experimentation with fertilizer, marked with stable and radioactive isotopes, provides a direct and express method to obtain conclusive answers to the questions: where, when and how should be applied. The fertilizers marked with N 1 5 have been used to understand the application of marked fertilizer to the cultivations, and the determination of the proportion of crops nutritious element derived from fertilizer. The isotopic techniques offer a fast and reliable mean to obtain information about the distribution of

  19. Enriching stable isotopes: Alternative use for Urenco technology

    International Nuclear Information System (INIS)

    Rakhorst, H.; de Jong, P.G.T.; Dawson, P.D.

    1996-01-01

    The International Urenco Group utilizes a technologically advanced centrifuge process to enrich uranium in the fissionable isotope 235 U. The group operates plants in the United Kingdom, the Netherlands, and Germany and currently holds a 10% share of the multibillion dollar world enrichment market. In the early 1990s, Urenco embarked on a strategy of building on the company's uniquely advanced centrifuge process and laser isotope separation (LIS) experience to enrich nonradioactive isotopes colloquially known as stable isotopes. This paper summarizes the present status of Urenco's stable isotopes business

  20. 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

  1. 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

  2. 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

  3. Application of stable isotopes in ecological research : it's all elemental

    International Nuclear Information System (INIS)

    Rogers, K.M.

    2005-01-01

    Stable isotopes have been used traditionally in the physical sciences, primarily in geochemistry, sedimentology, and oceanography. Increasingly, however, stable isotopes are also being used in the biological sciences. Application of stable isotopes in ecological studies can provide new and innovative ways of examining a host of topics of fundamental importance to biologists. These topics include, among others, feeding ecology and food webs, nutrient flow and assimilation, habitat use, migration patterns, and distribution and discrimination of species subpopulations. Furthermore, ecological research with isotopes can be applied at many levels (i.e. tissue and organ, whole animal, population, community, and ecosystem). (author). 38 refs., 2 figs

  4. 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

  5. Biomedical applications of mass spectrometry. Clinical uses of stable isotopes

    International Nuclear Information System (INIS)

    Krahmer, U.I.; McCloskey, J.A.

    1978-01-01

    The review covers typical or important examples of stable isotope usage in clinical fields during the period since the last triennial mass spectrometry conference in 1973. Items are included which involve uses of stable isotopes in human or clinically oriented studies, including measurements carried out on materials of human origin. 163 references. (U.K.)

  6. 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.)

  7. 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

    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...

  8. Existing and emerging technologies for measuring stable isotope labelled retinol in biological samples: isotope dilution analysis of body retinol stores.

    Science.gov (United States)

    Preston, Tom

    2014-01-01

    This paper discusses some of the recent improvements in instrumentation used for stable isotope tracer measurements in the context of measuring retinol stores, in vivo. Tracer costs, together with concerns that larger tracer doses may perturb the parameter under study, demand that ever more sensitive mass spectrometric techniques are developed. GCMS is the most widely used technique. It has high sensitivity in terms of sample amount and uses high resolution GC, yet its ability to detect low isotope ratios is limited by background noise. LCMSMS may become more accessible for tracer studies. Its ability to measure low level stable isotope tracers may prove superior to GCMS, but it is isotope ratio MS (IRMS) that has been designed specifically for low level stable isotope analysis through accurate analysis of tracer:tracee ratios (the tracee being the unlabelled species). Compound-specific isotope analysis, where GC is interfaced to IRMS, is gaining popularity. Here, individual 13C-labelled compounds are separated by GC, combusted to CO2 and transferred on-line for ratiometric analysis by IRMS at the ppm level. However, commercially-available 13C-labelled retinol tracers are 2 - 4 times more expensive than deuterated tracers. For 2H-labelled compounds, GC-pyrolysis-IRMS has now become more generally available as an operating mode on the same IRMS instrument. Here, individual compounds are separated by GC and pyrolysed to H2 at high temperature for analysis by IRMS. It is predicted that GC-pyrolysis-IRMS will facilitate low level tracer procedures to measure body retinol stores, as has been accomplished in the case of fatty acids and amino acids. Sample size requirements for GC-P-IRMS may exceed those of GCMS, but this paper discusses sample preparation procedures and predicts improvements, particularly in the efficiency of sample introduction.

  9. 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

  10. 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

  11. An estimation of Central Iberian Peninsula atmospheric δ13C and water δD in the Upper Cretaceous using pyrolysis compound specific isotopic analysis (Py-CSIA) of a fossil conifer.

    Science.gov (United States)

    González-Pérez, José A.; Jiménez-Morillo, Nicasio T.; De la Rosa, José M.; Almendros, Gonzalo; González-Vila, Francisco J.

    2015-04-01

    Frenelopsis is a frequently found genus of the Cretaceous floras adapted to dry, saline and in general to environmental conditions marked by severe water stress [1]. Stable isotope analysis of fossil organic materials can be used to infer palaeoenvironmental variables helpful to reconstruct plant paleohabitats [2]. In this study stable isotope analysis of organic fossil remains (FR) and humic fractions (FA, HA and humin) of Frenelopsis oligiostomata are studied in bulk (C, H, O, N IRMS) and in specific compounds released by pyrolysis (C, H, Py-CSIA). Well preserved F. oligiostomata fossils were handpicked from a limestone included in compacted marls from Upper Cretaceous (Senonian c. 72 Mya) in Guadalix de la Sierra (Madrid, Spain) [3]. The fossils were decarbonated with 6M HCl. Humic substances were extracted from finely ground fossil remains (FR) by successive treatments with 0.1M Na4P2O7 + NaOH [4]. The extract was acidified resulting into insoluble HA and soluble FA fractions. The HA and FA were purified as in [5] and [6] respectively. Bulk stable isotopic analysis (δ13C, δD, δ18O, δ15N IRMS) was done in an elemental micro-analyser coupled to a continuous flow Delta V Advantage isotope ratio mass spectrometer (IRMS). Pyrolysis compound specific isotopic analysis Py-CSIA (δ13C, δD): was done by coupling a double-shot pyrolyzer to a chromatograph connected to an IRMS. Structural features of specific peaks were inferred by comparing/matching mass spectra from conventional Py-GC/MS (data not shown) with Py-GC/IRMS chromatograms obtained using the same chromatographic conditions. Bulk C isotopic signature found for FR (-20.5±0.02 ‰) was in accordance with previous studies [2, 7-9]. This heavy isotopic δ13C signature indicates a depleted stomatal conductance and paleoenvironmental growth conditions of water and salt stress. This is in line with the morphological and depositional characteristics [3] confirming that F. oligostomata was adapted to highly xeric

  12. Using stable isotope analysis to discriminate gasoline on the basis of its origin.

    Science.gov (United States)

    Heo, Su-Young; Shin, Woo-Jin; Lee, Sin-Woo; Bong, Yeon-Sik; Lee, Kwang-Sik

    2012-03-15

    Leakage of gasoline and diesel from underground tanks has led to a severe environmental problem in many countries. Tracing the production origin of gasoline and diesel is required to enable the development of dispute resolution and appropriate remediation strategies for the oil-contaminated sites. We investigated the bulk and compound-specific isotopic compositions of gasoline produced by four oil companies in South Korea: S-Oil, SK, GS and Hyundai. The relative abundance of several compounds in gasoline was determined by the peak height of the major ion (m/z 44). The δ(13)C(Bulk) and δD(Bulk) values of gasoline produced by S-Oil were significantly different from those of SK, GS and Hyundai. In particular, the compound-specific isotopic value (δ(13)C(CSIA)) of methyl tert-butyl ether (MTBE) in S-Oil gasoline was significantly lower than that of gasoline produced by other oil companies. The abundance of several compounds in gasoline, such as n-pentane, MTBE, n-hexane, toluene, ethylbenzene and o-xylene, differed widely among gasoline from different oil companies. This study shows that gasoline can be forensically discriminated according to the oil company responsible for its manufacture using stable isotope analysis combined with multivariate statistical analysis. Copyright © 2012 John Wiley & Sons, Ltd.

  13. 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

    2010-06-23

    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, Ubeda, 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.

  14. The use of stable isotopes in medicinal chemistry

    International Nuclear Information System (INIS)

    Halliday, D.; Thompson, G.N.

    1988-01-01

    Stable isotopes have been employed increasingly as tracers over the last decade both to provide the clinician with the opportunity to broaden, in a quantitative manner, discrete areas of diagnosis and research, and the clinical chemist with definitive methodology for specific analyte analysis. These non-radioactive 'heavy' isotopes contain one or more extra neutrons in the nucleus compared with their more abundant 'lighter' analogues. Impetus in the application of stable isotopes for in vivo studies has come from an increased awareness of the possible harmful effects in the use of radionuclides, and a realisation of several positive advantages conferred by the use of stable isotopes in their own right - certain elements of clinical importance (especially nitrogen) lack a useable radio-nuclide equivalent; use of a 'cocktail' of stable isotopes permits a range of studies to be performed in the same patient simultaneously and, within specific constraints, serial studies can be performed in the same patients. (author)

  15. 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

  16. Applications of stable isotopes in agriculture

    International Nuclear Information System (INIS)

    Koren'kov, D.A.; Faust, Kh.

    1977-01-01

    The stable isotope 15 N has become widely used in agricultural studies. With it one can determine the true uptake of fertilizer and soil nitrogen by different crops as a function of their particular biological characteristics. Under field conditions, the extent of fertilizer nitrogen uptake by plants does not as a rule exceed 50%, being less for winter cereals and significantly more for perennial grasses. Applied fertilizer nitrogen, by intensifying the mobilization processes, increases the mobility of soil nitrogen. As a result, the accessibility of soil nitrogen to plants increases, and there is a greater chance of its being lost through washing-out. A considerable fraction of fertilizer nitrogen (on average 20-30%) becomes fixed in the soil in compounds which are not easily hydrolized and hence not readily available to plants. Nitrogen fixed in fulvic acids and non-specific compounds is the most mobile and can be used by plants. Fertilizer nitrogen in the soil undergoes various changes, as a result of which some is lost in the form of gaseous compounds. A certain amount of fertilizer nitrogen may become lost through washing-out. On the basis of 15 N investigations, it is possible to find ways of increasing the effectiveness of nitrogenous fertilizers and reducing nitrogen losses - for example, fertilizer application closer to the beginning of the period of active utilization of nutrients by plants, selection of more efficient fertilizer forms and the use of nitrification inhibitors. The wider employment of 15 N in agricultural studies should become possible through the use of cheaper compounds depleted or slightly enriched in 15 N. (author)

  17. Penguin Proxies: Deciphering Millennial-Scale Antarctic Ecosystem Change using Amino Acid Stable Isotope Analysis.

    Science.gov (United States)

    Michelson, C.; McMahon, K.; Emslie, S. D.; Patterson, W. P.; McCarthy, M. D.; Polito, M. J.

    2017-12-01

    The Southern Ocean ecosystem is undergoing rapid environmental change due to ongoing and historic anthropogenic impacts such as climate change and marine mammal harvesting. These disturbances may have cascading effects through the Antarctic food webs, resulting in profound shifts in the sources and cycling of organic matter supporting higher-trophic organisms, such as penguins. For example, bulk stable isotope analyses of modern and ancient preserved penguin tissues suggest variations in penguin feeding ecology throughout the Holocene with dramatic isotopic shifts in the last 200 years. However, it is not clear whether these isotopic shifts resulted from changes at the base of the food web, dietary shifts in penguins, or some combination of both factors. Newly developed compound-specific stable nitrogen isotope analysis of individual amino acids (CSIA-AA) may provide a powerful new tool to tease apart these confounding variables. Stable nitrogen isotope values of trophic amino acids (e.g., glutamic acid) increase substantially with each trophic transfer in the food web, while source amino acid (e.g., phenylalanine) stable nitrogen isotope values remain relatively unchanged and reflect ecosystem baselines. As such, we can use this CSIA-AA approach to decipher between baseline and dietary shifts in penguins over time from modern and ancient eggshells of Pygoscelis penguins in the Antarctic Peninsula and the Ross Sea regions of Antarctica. In order to accurately apply this CSIA-AA approach, we first characterized the trophic fractionation factors of individual amino acids between diet and penguin consumers in a long-term controlled penguin feeding experiment. We then applied these values to modern and ancient eggshells from the Antarctic Peninsula and Ross Sea to evaluate shifts in penguin trophic dynamics as a function of climate and anthropogenic interaction throughout much of the Holocene. This work develops a cutting edge new molecular geochemistry approach

  18. 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

  19. 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.

  20. Compound-specific carbon isotopes from Earth’s largest flood basalt eruptions directly linked to the end-Triassic mass extinction

    Science.gov (United States)

    Whiteside, Jessica H.; Olsen, Paul E.; Eglinton, Timothy; Brookfield, Michael E.; Sambrotto, Raymond N.

    2010-01-01

    A leading hypothesis explaining Phanerozoic mass extinctions and associated carbon isotopic anomalies is the emission of greenhouse, other gases, and aerosols caused by eruptions of continental flood basalt provinces. However, the necessary serial relationship between these eruptions, isotopic excursions, and extinctions has never been tested in geological sections preserving all three records. The end-Triassic extinction (ETE) at 201.4 Ma is among the largest of these extinctions and is tied to a large negative carbon isotope excursion, reflecting perturbations of the carbon cycle including a transient increase in CO2. The cause of the ETE has been inferred to be the eruption of the giant Central Atlantic magmatic province (CAMP). Here, we show that carbon isotopes of leaf wax derived lipids (n-alkanes), wood, and total organic carbon from two orbitally paced lacustrine sections interbedded with the CAMP in eastern North America show similar excursions to those seen in the mostly marine St. Audrie’s Bay section in England. Based on these results, the ETE began synchronously in marine and terrestrial environments slightly before the oldest basalts in eastern North America but simultaneous with the eruption of the oldest flows in Morocco, a CO2 super greenhouse, and marine biocalcification crisis. Because the temporal relationship between CAMP eruptions, mass extinction, and the carbon isotopic excursions are shown in the same place, this is the strongest case for a volcanic cause of a mass extinction to date. PMID:20308590

  1. 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

  2. Stable isotope customer list and summary of shipments:

    International Nuclear Information System (INIS)

    Tracy, J.G.

    1988-03-01

    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: alphabetical lists of domestic and foreign customers;alphabetical lists of isotopes and services;alphabetical lists of states and countries;tabulation of the shipments, quantities, and dollars for each isotope and dollars for services divided into domestic, foreign, and DOE project categories. During FY 1987 sales of stable isotope products and services were made to 272 differnt customers, of whom 159 were domestic and 113 were foreign, representing 18 different foreign countries. The total revenue was $3,785,609 of which 12.3% was from sales to DOE project customers, 60.4% was from sales to other domestic customers, and 27.3% was from sales to foreign customers. this represented sales of 189 different stable isotopes plus associated services and was a 16.5% increase over FY 1986

  3. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin.

    Science.gov (United States)

    Shen, Xiaoli; Xu, Zemin; Zhang, Xichang; Yang, Fangxing

    2015-11-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from -29.0‰ to -26.5‰ in soil spiked with 2mg/kg lambda-cyhalothrin, and to -27.5‰ with 10mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as -2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Stable Isotope Fractionation Caused by Glycyl Radical Enzymes during Bacterial Degradation of Aromatic Compounds

    Science.gov (United States)

    Morasch, Barbara; Richnow, Hans H.; Vieth, Andrea; Schink, Bernhard; Meckenstock, Rainer U.

    2004-01-01

    Stable isotope fractionation was studied during the degradation of m-xylene, o-xylene, m-cresol, and p-cresol with two pure cultures of sulfate-reducing bacteria. Degradation of all four compounds is initiated by a fumarate addition reaction by a glycyl radical enzyme, analogous to the well-studied benzylsuccinate synthase reaction in toluene degradation. The extent of stable carbon isotope fractionation caused by these radical-type reactions was between enrichment factors (ɛ) of −1.5 and −3.9‰, which is in the same order of magnitude as data provided before for anaerobic toluene degradation. Based on our results, an analysis of isotope fractionation should be applicable for the evaluation of in situ bioremediation of all contaminants degraded by glycyl radical enzyme mechanisms that are smaller than 14 carbon atoms. In order to compare carbon isotope fractionations upon the degradation of various substrates whose numbers of carbon atoms differ, intrinsic ɛ (ɛintrinsic) were calculated. A comparison of ɛintrinsic at the single carbon atoms of the molecule where the benzylsuccinate synthase reaction took place with compound-specific ɛ elucidated that both varied on average to the same extent. Despite variations during the degradation of different substrates, the range of ɛ found for glycyl radical reactions was reasonably narrow to propose that rough estimates of biodegradation in situ might be given by using an average ɛ if no fractionation factor is available for single compounds. PMID:15128554

  5. Compound-specific nitrogen and carbon isotope analysis of nitroaromatic compounds in aqueous samples using solid-phase microextraction coupled to GC/IRMS.

    Science.gov (United States)

    Berg, Michael; Bolotin, Jakov; Hofstetter, Thomas B

    2007-03-15

    Solid-phase microextraction (SPME) coupled to gas chromatography/isotope ratio mass spectrometry was used to determine the delta15N and delta13C signatures of selected nitroaromatic contaminants such as the explosive 2,4,6-trinitrotoluene (TNT) for derivation of isotopic enrichment factors of contaminant transformation. Parameters for efficient extraction of nitroaromatic compounds (NACs) and substituted anilines from water samples were evaluated by SPME-GC/MS. delta13C signatures determined by SPME-GC/IRMS and elemental analyzer IRMS (EA-IRMS) were in good agreement, generally within +/-0.7 per thousand, except for 2,4-dinitrotoluene (2,4-DNT) and TNT, which showed slight deviations (IRMS were between 73 and 780 microg L-1 and correlated with the extraction efficiencies of the compounds determined by SPME-GC/MS. Nitrogen isotope measurements by SPME-GC/IRMS were of similar precision (standard deviations IRMS within +/-1.3 per thousand (+2.5 per thousand for TNT), but no systematic trend was found for the deviations. LODs of delta15N measurements ranged from 1.6 to 9.6 mg L-1 for nitrotoluenes, chlorinated NACs and DNTs (22 mg L-1 for TNT). The SPME-GC/IRMS method is well suited for the determination of isotopic enrichment factors of various NAC transformation processes and provides so far unexplored possibilities to elucidate behavior and degradation mechanisms of nitroaromatic contaminants in soils and groundwaters.

  6. Stable isotope labeling strategy based on coding theory

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takuma; Koshiba, Seizo; Yokoyama, Jun; Kigawa, Takanori, E-mail: kigawa@riken.jp [RIKEN Quantitative Biology Center (QBiC), Laboratory for Biomolecular Structure and Dynamics (Japan)

    2015-10-15

    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.

  7. 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

  8. 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)

  9. Stable Isotope Systematics of Martian Perchlorate

    Science.gov (United States)

    Martin, P.; Farley, K. A.; Archer, D., Jr.; Atreya, S. K.; Conrad, P. G.; Eigenbrode, J. L.; Fairen, A.; Franz, H. B.; Freissinet, C.; Glavin, D. P.; Mahaffy, P. R.; Malespin, C.; Ming, D. W.; Navarro-Gonzalez, R.; Sutter, B.

    2015-12-01

    Chlorine isotopic compositions in HCl released during evolved gas analysis (EGA) runs have been detected by the Sample Analysis at Mars (SAM) instrument on the Curiosity rover ranging from approximately -9‰ to -50‰ δ37Cl, with two spatially and isotopically separated groups of samples averaging -15‰ and -45‰. These extremely low values are the first such detection of any known natural material; common terrestrial values very rarely exceed ±5‰, and the most extreme isotopic signature yet detected elsewhere in the solar system are values of around +24‰ on the Moon. The only other known location in the solar system with large negative chlorine isotopes is the Atacama Desert, where perchlorate with -14‰ δ37Cl has been detected. The Atacama perchlorate has unusual Δ17O signatures associated with it, indicating a formation mechanism involving O3, which suggests an atmospheric origin of the perchlorate and associated large isotopic anomalies. Identification of non-zero positive Δ17O signatures in the O2 released during EGA runs would allow definitive evidence for a similar process having occurred on Mars. Perchlorate is thought to be the most likely source of HCl in EGA runs due to the simultaneous onset of O2 release. If perchlorate is indeed the HCl source, atmospheric chemistry could be responsible for the observed isotopic anomalies, with variable extents of perchlorate production producing the isotopic variability. However, chloride salts have also been observed to release HCl upon heating; if the timing of O2 release is merely coincidental, observed HCl could be coming from chlorides. At thermodynamic equilibrium, the fractionation factor of perchlorate reduction is 0.93, meaning that differing amounts of post-deposition reduction of isotopically normal perchlorate to chloride could account for the highly variable Cl isotopes. Additionally, post-deposition reduction could account for the difference between the two Cl isotopic groups if perchlorate

  10. Melting point of high-purity germanium stable isotopes

    Science.gov (United States)

    Gavva, V. A.; Bulanov, A. D.; Kut'in, A. M.; Plekhovich, A. D.; Churbanov, M. F.

    2018-05-01

    The melting point (Tm) of germanium stable isotopes 72Ge, 73Ge, 74Ge, 76Ge was determined by differential scanning calorimetry. With the increase in atomic mass of isotope the decrease in Tm is observed. The decrease was equal to 0.15 °C per the unit of atomic mass which qualitatively agrees with the value calculated by Lindemann formula accounting for the effect of "isotopic compression" of elementary cell.

  11. 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)

  12. Biogeochemistry of the stable hydrogen isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Estep, M F; Hoering, T C [Carnegie Institution of Washington, DC (USA)

    1980-08-01

    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.

  13. 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.

  14. 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)

  15. 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).

  16. 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.

  17. 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

  18. 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

  19. 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).

  20. 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.

  1. Factors controlling stable isotope composition of European precipitation

    International Nuclear Information System (INIS)

    Rozanski, K.; Sonntag, C.; Muennich, K.O.

    1982-01-01

    The seasonal and spatial variations of stable isotope ratios in present day European precipitation are simulated with a simple multibox model of the mean west-east horizontal transport of the atmospheric water vapour across the European continent. Isotope fractionation during the formation of precipitation leads to an increasing depletion of heavy isotopes in the residual air moisture as it moves towards the centre of the continent. This isotopic depletion is partly compensated, particularly in summer, by evapotranspiration, which is assumed to transfer soil water into the atmosphere without isotope fractionation. The model estimates are based on horizontal water vapour flux data, varying seasonally between 88 and 130 kg m -1 s -1 for the Atlantic coast region, and on the monthly precipitation, evapotranspiration and surface air temperature data available for various locations in Europe. Both continental and seasonal temperature effects observed in the stable isotope composition of European precipitation are fairly well reproduced by the model. The calculations show that the isotopic composition of local precipitation is primarily controlled by regional scale processes, i.e. by the water vapour transport patterns into the continent, and by the average precipitation-evapotranspiration history of the air masses precipitating at a given place. Local parameters such as the surface and/or cloud base temperature or the amount of precipitation modify the isotope ratios only slightly. Implications of the model predictions for the interpretation of stable isotope ratios in earlier periods as they are preserved in ice cores and in groundwater are also discussed. (Auth.)

  2. Stable-carbon isotope variability in tree foliage and wood

    International Nuclear Information System (INIS)

    Leavitt, S.W.; Long, A.

    1986-01-01

    This study documents variation of stable-carbon isotope ratios ( 13 C/ 12 C) in trees of genera Juniperus and Pinus under field conditions. Results are from cellulose analysis on leaves, twigs, and wood from a number of localities in the southwestern US. Substantial variability, typically 1-3%, exists among leaves, within wood (radially, vertically, circumferentially), and between individuals at a site. These results may help guide sampling in tracer-type studies with stable-carbon isotope ratios and aid in the interpretation of isotopic results from such studies

  3. 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...

  4. 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...

  5. 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.

  6. 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)

  7. 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.

  8. 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...

  9. 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)

  10. 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

  11. Compound-specific C- and H-isotope compositions of enclosed organic matter in carbonate rocks: Implications for source identification of sedimentary organic matter and paleoenvironmental reconstruction

    International Nuclear Information System (INIS)

    Xiong Yongqiang; Wang Yanmei; Wang Yongquan; Xu Shiping

    2007-01-01

    The Bohai Bay Basin is one of the most important oil-producing provinces in China. Molecular organic geochemical characteristics of Lower Paleozoic source rocks in this area have been investigated by analyzing chemical and isotopic compositions of solvent extracts and acid-released organic matter from the Lower Paleozoic carbonate rocks in the Jiyang Sub-basin of the Bohai Bay Basin. The results indicate that enclosed organic matter in carbonate rocks has not been recognizably altered by post-depositional processes. Two end-member compositions are suggested for early organic matter trapped in the Lower Paleozoic carbonate rocks: (1) a source dominated by aquatic organisms and deposited in a relatively deep marine environment and (2) a relatively high saline, evaporative marine depositional environment. In contrast, chemical and isotopic compositions of solvent extracts from these Lower Paleozoic carbonate rocks are relatively complicated, not only inheriting original characteristics of their precursors, but also overprinted by various post-depositional alterations, such as thermal maturation, biodegradation and mixing. Therefore, the integration of both organic matter characteristics can provide more useful information on the origin of organic matter present in carbonate rocks and the environments of their deposition

  12. Compound-specific C- and H-isotope compositions of enclosed organic matter in carbonate rocks: Implications for source identification of sedimentary organic matter and paleoenvironmental reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Xiong Yongqiang [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)], E-mail: xiongyq@gig.ac.cn; Wang Yanmei; Wang Yongquan; Xu Shiping [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2007-11-15

    The Bohai Bay Basin is one of the most important oil-producing provinces in China. Molecular organic geochemical characteristics of Lower Paleozoic source rocks in this area have been investigated by analyzing chemical and isotopic compositions of solvent extracts and acid-released organic matter from the Lower Paleozoic carbonate rocks in the Jiyang Sub-basin of the Bohai Bay Basin. The results indicate that enclosed organic matter in carbonate rocks has not been recognizably altered by post-depositional processes. Two end-member compositions are suggested for early organic matter trapped in the Lower Paleozoic carbonate rocks: (1) a source dominated by aquatic organisms and deposited in a relatively deep marine environment and (2) a relatively high saline, evaporative marine depositional environment. In contrast, chemical and isotopic compositions of solvent extracts from these Lower Paleozoic carbonate rocks are relatively complicated, not only inheriting original characteristics of their precursors, but also overprinted by various post-depositional alterations, such as thermal maturation, biodegradation and mixing. Therefore, the integration of both organic matter characteristics can provide more useful information on the origin of organic matter present in carbonate rocks and the environments of their deposition.

  13. Principles and limitations of stable isotopes in differentiating organic and conventional foodstuffs: 2. Animal products.

    Science.gov (United States)

    Inácio, Caio T; Chalk, Phillip M

    2017-01-02

    In this review, we examine the variation in stable isotope signatures of the lighter elements (δ 2 H, δ 13 C, δ 15 N, δ 18 O, and δ 34 S) of tissues and excreta of domesticated animals, the factors affecting the isotopic composition of animal tissues, and whether stable isotopes may be used to differentiate organic and conventional modes of animal husbandry. The main factors affecting the δ 13 C signatures of livestock are the C3/C4 composition of the diet, the relative digestibility of the diet components, metabolic turnover, tissue and compound specificity, growth rate, and animal age. δ 15 N signatures of sheep and cattle products have been related mainly to diet signatures, which are quite variable among farms and between years. Although few data exist, a minor influence in δ 15 N signatures of animal products was attributed to N losses at the farm level, whereas stocking rate showed divergent findings. Correlations between mode of production and δ 2 H and δ 18 O have not been established, and only in one case of an animal product was δ 34 S a satisfactory marker for mode of production. While many data exist on diet-tissue isotopic discrimination values among domesticated animals, there is a paucity of data that allow a direct and statistically verifiable comparison of the differences in the isotopic signatures of organically and conventionally grown animal products. The few comparisons are confined to beef, milk, and egg yolk, with no data for swine or lamb products. δ 13 C appears to be the most promising isotopic marker to differentiate organic and conventional production systems when maize (C4) is present in the conventional animal diet. However, δ 13 C may be unsuitable under tropical conditions, where C4 grasses are abundant, and where grass-based husbandry is predominant in both conventional and organic systems. Presently, there is no universal analytical method that can be applied to differentiate organic and conventional animal products.

  14. 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

  15. 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

  16. 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.

  17. 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

  18. The use of sterol distributions combined with compound specific isotope analyses as a tool to identify the origin of fecal contamination in rivers.

    Science.gov (United States)

    Biache, Coralie; Philp, R Paul

    2013-03-01

    The sterol distributions of 9 sediment samples from the Illinois River Basin (OK and AR, USA) were examined in order to identify the source of fecal contamination. The samples were extracted with organic solvent using sonication and the fractions containing the sterols were isolated and analyzed by gas chromatography-mass spectrometry. The sterol distributions of the Illinois River samples were dominated by phytosterols. They were compared to those of different animal feces and manures using a principal component analysis and correspondence appeared between the sediments and one group of chicken feces samples. Gas chromatography-isotope ratio mass spectrometry analyses were also performed to determine the δ(13)C values for the phytosterols and to get an indication of their origin based on the C(3)/C(4) plant signatures. The δ(13)C values obtained ranged from -30.6 ‰ to -17.4 ‰ (VPDB) corresponding to a mixed signature between C(3) and C(4) plants, indicating a C(4) plant contribution to the C(3) plant natural background. These observations indicate that a proportion of the phytosterols originated from chicken feces. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Stable isotope enrichment by thermal diffusion

    International Nuclear Information System (INIS)

    Vasaru, Gheorghe

    2003-01-01

    Thermal diffusion (TD) in both gaseous and liquid phase has been the subject of extensive experimental and theoretical investigations, especially after the invention by K. Clusius and G. Dickel of the thermal diffusion column, sixty years ago. This paper gives a brief overview of the most important applications and developments of this transport phenomenon for enrichment of 13 C and of some noble gases isotopes in our institute. The results of calculations of the transport coefficients H and K for a concentric tube type TD column, operated with methane as process gas, are presented. Static separation factor at equilibrium vs gas pressure has been calculated for various molecular models. The experimental separation factors for different gas pressure were found to be consistent with those calculated for the inverse power repulsion model and the Lennard-Jones model. The most important characteristics of a seven-stage cascade consisting of 19 TD columns of concentric tube type are given. This system has been constructed and successfully operated at a temperature of 673 K and produces an enrichment of methane of natural isotopic 13 C abundance, up to the concentration of 25% 13 CH 4 . Enrichment of the noble gases isotopes implies: - a . Enrichment of 20 Ne and 22 Ne in a eight-stage cascade consisting of 8 TD columns; - b. enrichment of 46 Ar in a seven-stage cascade consisting of TD columns and finally; - c. enrichment of 78 Kr and 86 Kr in a fifteen-stage cascade, consisting of 35 TD columns. For all these installations we have adopted TD columns of hot wire type (4 m in length), operated at a temperature of 1073 K. (author)

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

    DEFF Research Database (Denmark)

    Stausberg, Niklas

    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......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...... in magmas, Fe. Fe isotope compositions of magmatic rocks exhibit systematic differences, where the heaviest compositions are found in rhyolites and granites. Understanding of these systematics is complicated by a lack of constraints on Fe isotope fractionation among minerals and liquids under magmatic...

  1. 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.

  2. 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.

  3. 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

  4. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Xiaoli [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Environmental Engineering, Quzhou University, Quzhou 324000 (China); Xu, Zemin [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Zhang, Xichang [Laboratory for Teaching in Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Fangxing, E-mail: fxyang@zju.edu.cn [MOE Key Laboratory of Environmental Remediation and Ecosystem Health, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 (China); Department of Effect-Directed Analysis, Helmholtz Centre for Environmental Research — UFZ, Leipzig 04318 (Germany)

    2015-11-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2 mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10 mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from − 29.0‰ to − 26.5‰ in soil spiked with 2 mg/kg lambda-cyhalothrin, and to − 27.5‰ with 10 mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as − 2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. - Highlights: • Abiotic and biotic degradation of lambda-cyhalothrin were observed in soil. • Biodegradation of lambda-cyhalothrin was evaluated by CSIA. • Biodegradation of lambda-cyhalothrin leads to carbon isotope fractionation. • An enrichment factor ε of lambda-cyhalothrin was determined as − 2.53‰.

  5. Stable carbon isotope fractionation during the biodegradation of lambda-cyhalothrin

    International Nuclear Information System (INIS)

    Shen, Xiaoli; Xu, Zemin; Zhang, Xichang; Yang, Fangxing

    2015-01-01

    In this study, the microbial degradation of lambda-cyhalothrin in soil was investigated using compound-specific stable isotope analysis. The results revealed that lambda-cyhalothrin was biodegraded in soil under laboratory conditions. The half-lives of lambda-cyhalothrin were determined to be 49 and 161 days in non-sterile and sterile soils spiked with 2 mg/kg lambda-cyhalothrin and 84 and 154 days in non-sterile and sterile soils spiked with 10 mg/kg lambda-cyhalothrin, respectively. The biodegradation of lambda-cyhalothrin resulted in carbon isotope fractionation, which shifted from − 29.0‰ to − 26.5‰ in soil spiked with 2 mg/kg lambda-cyhalothrin, and to − 27.5‰ with 10 mg/kg lambda-cyhalothrin. A relationship was established between the stable carbon isotope fraction and the residual concentrations of lambda-cyhalothrin by the Rayleigh equation in which the carbon isotope enrichment factor ε of the microbial degradation of lambda-cyhalothrin in the soil was calculated as − 2.53‰. This study provides an approach to quantitatively evaluate the biodegradation of lambda-cyhalothrin in soil in field studies. - Highlights: • Abiotic and biotic degradation of lambda-cyhalothrin were observed in soil. • Biodegradation of lambda-cyhalothrin was evaluated by CSIA. • Biodegradation of lambda-cyhalothrin leads to carbon isotope fractionation. • An enrichment factor ε of lambda-cyhalothrin was determined as − 2.53‰

  6. 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)

  7. 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.

  8. Stable isotopic composition of East African lake waters

    International Nuclear Information System (INIS)

    Odada, E.O.

    2001-01-01

    The investigation of stable isotopic composition of East African lake waters was conducted by scientists from the Department of Geology, University of Nairobi, as part of the International Decade for the East African Lakes (IDEAL) project and in close collaboration with the scientists from Large Lakes Observatory of the University of Minnesota and the Isotope Hydrology Laboratory of the IAEA in Vienna. The Research Contract was part of the IAEA Co-ordinated Research Programme on Isotope Techniques in Lake Dynamics Investigations, and was sponsored by the Agency. Water and grab sediment samples were obtained from East African Lakes during the month of January and February 1994 and July/August 1995. Water samples were analysed for oxygen and deuterium isotopic composition at the IAEA Laboratories in Vienna, Austria. In this final paper we report the results of the study of oxygen and deuterium isotopic composition from the East African lake waters. (author)

  9. 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

  10. Stable isotope geochemistry of deep sea cherts

    Energy Technology Data Exchange (ETDEWEB)

    Kolodny, Y; Epstein, S [California Inst. of Tech., Pasadena (USA). Div. of Geological Sciences

    1976-10-01

    Seventy four samples of DSDP (Deep Sea Drilling Project) recovered cherts of Jurassic to Miocene age from varying locations, and 27 samples of on-land exposed cherts were analyzed for the isotopic composition of their oxygen and hydrogen. These studies were accompanied by mineralogical analyses and some isotopic analyses of the coexisting carbonates. delta/sup 18/0 of chert ranges between 27 and 39 parts per thousand relative to SMOW, delta/sup 18/0 of porcellanite - between 30 and 42 parts per thousand. The consistent enrichment of opal-CT in porcellanites in /sup 18/0 with respect to coexisting microcrystalline quartz in chert is probably a reflection of a different temperature (depth) of diagenesis of the two phases. delta/sup 18/0 of deep sea cherts generally decrease with increasing age, indicating an overall cooling of the ocean bottom during the last 150 m.y. A comparison of this trend with that recorded by benthonic foraminifera (Douglas et al., Initial Reports of the Deep Sea Drilling Project; 32:509(1975)) indicates the possibility of delta/sup 18/0 in deep sea cherts not being frozen in until several tens of millions of years after deposition. Cherts of any Age show a spread of delta/sup 18/0 values, increasing diagenesis being reflected in a lowering of delta/sup 18/0. Drusy quartz has the lowest delta/sup 18/0 values. On land exposed cherts are consistently depleted in /sup 18/0 in comparison to their deep sea time equivalent cherts. Water extracted from deep sea cherts ranges between 0.5 and 1.4 wt%. deltaD of this water ranges between -78 and -95 parts per thousand and is not a function of delta/sup 18/0 of the cherts (or the temperature of their formation).

  11. [Progress in stable isotope labeled quantitative proteomics methods].

    Science.gov (United States)

    Zhou, Yuan; Shan, Yichu; Zhang, Lihua; Zhang, Yukui

    2013-06-01

    Quantitative proteomics is an important research field in post-genomics era. There are two strategies for proteome quantification: label-free methods and stable isotope labeling methods which have become the most important strategy for quantitative proteomics at present. In the past few years, a number of quantitative methods have been developed, which support the fast development in biology research. In this work, we discuss the progress in the stable isotope labeling methods for quantitative proteomics including relative and absolute quantitative proteomics, and then give our opinions on the outlook of proteome quantification methods.

  12. Stable isotope dimethyl labelling for quantitative proteomics and beyond

    Science.gov (United States)

    Hsu, Jue-Liang; Chen, Shu-Hui

    2016-01-01

    Stable-isotope reductive dimethylation, a cost-effective, simple, robust, reliable and easy-to- multiplex labelling method, is widely applied to quantitative proteomics using liquid chromatography-mass spectrometry. This review focuses on biological applications of stable-isotope dimethyl labelling for a large-scale comparative analysis of protein expression and post-translational modifications based on its unique properties of the labelling chemistry. Some other applications of the labelling method for sample preparation and mass spectrometry-based protein identification and characterization are also summarized. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644970

  13. Stable isotope applications of AMS in geology

    International Nuclear Information System (INIS)

    Rucklidge, J.C.

    1981-01-01

    The subject of geochemistry has become increasingly concerned with the distribution of trace elements in and between mineral phases. Part per million detection is routine, but part per billion measurements are, for certain elements, beyond the range of such sensitive analytical methods as neutron activation analysis (NAA). Tandem AMS has the ability to extend this limit several orders of magnitude for those elements which readily form negative ions. There is no doubt that such information can be most valuable for elements which are partitioned strongly between different mineral phases. While bulk analyses may indicate trace levels of certain elements to be present in a rock, it has always been difficult to state with certainty whether the trace element occurs at a uniformly low level throughout the various phases, or whether it is concentrated at a high level in small grains of an extremely rare phase scattered through the rock. The milli- or micro-probe analytical capability, which can be part of AMS, enables such problems concerning ultra-low level element concentrations to be tackled. With the same approach isotopic ratios of both major and minor elements in microgram amounts of material may be undertaken

  14. 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.

  15. Heavy element stable isotope ratios. Analytical approaches and applications

    International Nuclear Information System (INIS)

    Tanimizu, Masaharu; Sohrin, Yoshiki; Hirata, Takafumi

    2013-01-01

    Continuous developments in inorganic mass spectrometry techniques, including a combination of an inductively coupled plasma ion source and a magnetic sector-based mass spectrometer equipped with a multiple-collector array, have revolutionized the precision of isotope ratio measurements, and applications of inorganic mass spectrometry for biochemistry, geochemistry, and marine chemistry are beginning to appear on the horizon. Series of pioneering studies have revealed that natural stable isotope fractionations of many elements heavier than S (e.g., Fe, Cu, Zn, Sr, Ce, Nd, Mo, Cd, W, Tl, and U) are common on Earth, and it had been widely recognized that most physicochemical reactions or biochemical processes induce mass-dependent isotope fractionation. The variations in isotope ratios of the heavy elements can provide new insights into past and present biochemical and geochemical processes. To achieve this, the analytical community is actively solving problems such as spectral interference, mass discrimination drift, chemical separation and purification, and reduction of the contamination of analytes. This article describes data calibration and standardization protocols to allow interlaboratory comparisons or to maintain traceability of data, and basic principles of isotope fractionation in nature, together with high-selectivity and high-yield chemical separation and purification techniques for stable isotope studies.

  16. 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

  17. Applications of DNA-Stable Isotope Probing in Bioremediation Studies

    Science.gov (United States)

    Chen, Yin; Vohra, Jyotsna; Murrell, J. Colin

    DNA-stable isotope probing, a method to identify active microorganisms without the prerequisite of cultivation, has been widely applied in the study of microorganisms involved in the degradation of environmental pollutants. Recent advances and technique considerations in applying DNA-SIP in bioremediation are highlighted. A detailed protocol of a DNA-SIP experiment is provided.

  18. Stable carbon isotope biogeochemistry of lakes along a trophic gradient

    NARCIS (Netherlands)

    de Kluijver, A.; Schoon, P.L.; Downing, J.A.; Schouten, S.; Middelburg, J.J.

    2014-01-01

    The stable carbon (C) isotope variability of dissolved inorganic and organic C (DIC and DOC), particulate organic carbon (POC), glucose and polar-lipid derived fatty acids (PLFAs) was studied in a survey of 22 North American oligotrophic to eutrophic lakes. The d13C of different PLFAs were used as

  19. 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 ...

  20. 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

  1. 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)

  2. 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...

  3. 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

  4. Fractionation of Stable Isotopes in Atmospheric Aerosol Reactions

    DEFF Research Database (Denmark)

    Meusinger, Carl

    -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...... 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...... 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....

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

    Energy Technology Data Exchange (ETDEWEB)

    Unkefer, C.J.; Martinez, R.A.; Silks, L.A. III [Los Alamos National Laboratory, NM (United States); Lodwig, S.N. [Centralia College, WA (United States)

    1994-12-01

    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 {alpha}-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.

  6. 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

  7. Bulk and compound-specific isotope analysis of long-chain n-alkanes from a 85,000 year sediment core from Lake Peten Petén Itzá, Guatemala

    Science.gov (United States)

    Mays, J.; Brenner, M.; Curtis, J. H.; Curtis, K.; Hodell, D. A.; Correa-Metrio, A.; Escobar, J.; Dutton, A. L.; Zimmerman, A. R.; Guilderson, T. P.

    2013-12-01

    Sediment core PI-6 from Lake Petén Itzá, Guatemala possesses an 85-ka record of climate from lowland Central America. Variations in sediment lithology suggest large, abrupt changes in precipitation during the last glacial and deglacial periods, and into the early Holocene. Study of cores from nearby Lake Quexil demonstrated the utility of using the carbon isotopic composition of leaf wax n-alkanes to infer changes in terrestrial vegetation (Huang et al. 2001). Forty-nine samples were taken from composite Petén Itzá core PI-6 to measure carbon isotopes of bulk organic carbon and long-chain n alkanes. Changes in δ13C values indicate shifts in the relative proportion of C3 to C4 biomass. The record shows largest δ13C variations are associated with Heinrich Events. Carbon isotope values in sediments deposited during the Last Glacial Maximum (LGM) indicate moderate precipitation and little rainfall fluctuation. The deglacial was a period of pronounced climate variability, e.g. the Bölling-Allerod and Younger Dryas. Arid times of the deglacial were inferred from samples with the greatest δ13C values in organic matter, reflecting the largest proportion of C4 plants. Such inferences are supported by stable isotope measurements on ostracod shells and analysis of pollen from the same sample depths in core PI-6. Carbon stable isotope measures on bulk organic carbon and n alkane compounds show similar trends throughout the record and the C:N ratio of Petén Itzá sediments indicates a predominantly allochthonous source for bulk organic matter. Hence, isotope measures on bulk organic carbon (δ13CTOC) in sediments from this lake are sufficient to infer climate-driven shifts in vegetation, making n-alkane extraction and isotope analysis superfluous.

  8. Stable isotope geochemistry of the Tongonan geothermal system, Leyte, Philippines

    International Nuclear Information System (INIS)

    Hulston, J.R.; Stewart, M.K.

    1982-01-01

    Stable isotope and geochemical data on samples from natural features, shallow wells and deep wells collected over a number of years from the Tongonan area of Leyte have been evaluated. The variations in the isotopic compositions of the thermal waters are used to describe natural processes occurring within the system. The effect of the ''excess enthalpy'' of the deep wells on the isotope data is formulated. Water from the deep Tongonan wells shows an oxygen-18 shift of 5 per mille, which is larger than at Wairakei and Broadlands, probably in part because of the high temperatures at Tongonan. Recent measurements indicate that the deuterium shift is very much smaller than previously thought. Isotopic measurements of methane in the gases suggests differing flows from the Eastern and Central Philippine faults

  9. Inferring foliar water uptake using stable isotopes of water.

    Science.gov (United States)

    Goldsmith, Gregory R; Lehmann, Marco M; Cernusak, Lucas A; Arend, Matthias; Siegwolf, Rolf T W

    2017-08-01

    A growing number of studies have described the direct absorption of water into leaves, a phenomenon known as foliar water uptake. The resultant increase in the amount of water in the leaf can be important for plant function. Exposing leaves to isotopically enriched or depleted water sources has become a common method for establishing whether or not a plant is capable of carrying out foliar water uptake. However, a careful inspection of our understanding of the fluxes of water isotopes between leaves and the atmosphere under high humidity conditions shows that there can clearly be isotopic exchange between the two pools even in the absence of a change in the mass of water in the leaf. We provide experimental evidence that while leaf water isotope ratios may change following exposure to a fog event using water with a depleted oxygen isotope ratio, leaf mass only changes when leaves are experiencing a water deficit that creates a driving gradient for the uptake of water by the leaf. Studies that rely on stable isotopes of water as a means of studying plant water use, particularly with respect to foliar water uptake, must consider the effects of these isotopic exchange processes.

  10. 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

  11. 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

  12. 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.

  13. Application of stable isotopes to hydrogeology in coal mine

    International Nuclear Information System (INIS)

    Duan Qi; Duan Yucheng

    1988-01-01

    Stable isotopes including Oxygen-18 and Deuterium have been applied to investigation of hydrogeology in main coal mines. By determination of stable isotopic composition of hydrogen and oxygen together with water analysis, the following studies have been developed: Identification of the hydrogeochemical characteristics of the groundwater from varied aquifers; Analysis of the hydraulic relationship between varied aquifers; Interpretation of the probable recharge source of mine water. The research results mentioned above reveal that: 1. The groundwater from main aquifers at coal mines in north China is of meteoric origin, which is recharged from hilly area surrounding the coal mine. Its isotopic composition differs slightly from that of the local precipitation. 2. There is a mutual hydraulic relationship between the Ordovician and Quarternary aquifers, so the difference of isotopic composition is very small. 3. By way of the variation of isotopic composition of groundwater from coal-bearing strata, we can infer the hydraulic relationship extent between overlaid alluvial layer and underlaid Ordovician limestone. (author). 9 refs, 6 figs, 8 tabs

  14. Tracking ENSO with tropical trees: Progress in stable isotope dendroclimatology

    Science.gov (United States)

    Evans, M. N.; Poussart, P. F.; Saleska, S. R.; Schrag, D. P.

    2002-12-01

    The terrestrial tropics remain an important gap in the growing proxy network used to characterize past ENSO behavior. Here we describe a strategy for development of proxy estimates of paleo-ENSO, via proxy rainfall estimates derived from stable isotope (δ18O) measurements made on tropical trees. The approach applies a new model of oxygen isotopic composition of alpha-cellulose (Roden et al., 2000), a rapid method for cellulose extraction from raw wood (Brendel et al., 2000), and continuous flow isotope ratio mass spectrometry (Brand, 1996) to develop proxy chronological, rainfall and growth rate estimates from tropical trees, even those lacking annual rings. The promise and pitfalls of the approach are illustrated in pilot datasets from the US, Costa Rica, Brazil, and Peru, which show isotopic cycles of 4-6 per mil, and interannual anomalies of up to 8 per mil. Together with the mature ENSO proxies (corals, extratropical tree-rings, varved sediments, and ice cores), replicated and well-dated stable isotope chronologies from tropical trees may eventually improve our understanding of ENSO history over the past several hundred years.

  15. Stable Isotope Identification of Nitrogen Sources for United ...

    Science.gov (United States)

    We used natural abundance stable isotope data to evaluate nitrogen sources to U.S. west coast estuaries. We collected δ15N of macroalgae data 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 addition, the δ15N of macroalgae suggested that the ocean and nitrogen-fixing trees in the watersheds were the dominant nitrogen sources. There was also a strong gradient in δ15N of macroalgae with heavier sites located near the estuary mouth. 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. Nutrients are the leading cause of water quality impairments in the United States, and as a result too

  16. 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

  17. 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.

  18. 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

  19. Analytical pyrolysis and stable isotope analyses reveal past environmental changes in coralloid speleothems from Easter Island (Chile).

    Science.gov (United States)

    Miller, Ana Z; De la Rosa, José M; Jiménez-Morillo, Nicasio T; Pereira, Manuel F C; González-Pérez, José A; Calaforra, José M; Saiz-Jimenez, Cesareo

    2016-08-26

    This study comprises an innovative approach based on the combination of chromatography (analytical pyrolysis and pyrolysis compound-specific isotope analysis (Py-CSIA)), light stable isotopes, microscopy and mineralogy analyses to characterize the internal layering of coralloid speleothems from the Ana Heva lava tube in Easter Island (Chile). This multidisciplinary proxy showed that the speleothems consist of banded siliceous materials of low crystallinity with different mineralogical compositions and a significant contribution of organic carbon. Opal-A constitutes the outermost grey layer of the coralloids, whereas calcite and amorphous Mg hydrate silicate are the major components of the inner whitish and honey-brown layers, respectively. The differences found in the mineralogical, elemental, molecular and isotopic composition of these distinct coloured layers are related to environmental changes during speleothem development. Stable isotopes and analytical pyrolysis suggested alterations in the water regime, pointing to wetter conditions during the formation of the Ca-rich layer and a possible increase in the amount of water dripping into the cave. The trend observed for δ(15)N values suggested an increase in the average temperature over time, which is consistent with the so-called climate warming during the Holocene. The pyrolysis compound-specific isotope analysis of each speleothem layer showed a similar trend with the bulk δ(13)C values pointing to the appropriateness of direct Py-CSIA in paleoenvironmental studies. The δ(13)C values for n-alkanes reinforced the occurrence of a drastic environmental change, indicating that the outermost Opal layer was developed under drier and more arid environmental conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. 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.

  1. Applications of stable isotope tracers to air pollution problems

    International Nuclear Information System (INIS)

    Kelly, W.R.

    1985-01-01

    One of the fundamental environmental problems facing the United States is how to effect acid rain abatement in the northeast United States and southeastern Canada in a cost effective manner. There are several key scientific questions that must be addressed in order to design an effective strategy. These questions include the following: (1) where do pollutants from a specified source area go., (2) what chemical transformations occur during transport., and (3) where and how are these pollutants deposited. One approach to address these questions is the use of enriched stable isotopes as intentional tracers of aerosol and sulfur emissions. Isotopic tracers can determine the location and pathways of pollutants in the environment and trace pollutants back to their original source. For an element with n isotopes, it is possible to intentionally tag n-2 sources. (For example, Nd, which has seven isotopes, could be used to tag 5 different aerosol sources). To trace sulfur compounds, the two minor isotopes of sulfur, 33 S and 36 S, could be used. Methods developed at NBS using high precision mass spectrometry permits the detection of the small changes in isotopic composition brought about by the intentional tagging at a source. This may make possible the identification of a source at a particular sampling site

  2. 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.

  3. Source characterization using compound composition and stable carbon isotope ratio of PAHs in sediments from lakes, harbor, and shipping waterway

    International Nuclear Information System (INIS)

    Kim, Moonkoo; Kennicutt, Mahlon C.; Qian, Yaorong

    2008-01-01

    Molecular compositions and compound specific stable carbon isotope ratios of polycyclic aromatic hydrocarbons (PAH) isolated from sediments were used to characterize possible sources of contamination at an urban lake, a harbor, a shipping waterway, and a relatively undisturbed remote lake in the northwest United States. Total PAH concentrations in urban lake sediments ranged from 66.0 to 16,500 μg g -1 dry wt. with an average of 2600 μg g -1 , which is ∼ 50, 100, and 400 times higher on average than PAH in harbor (48 μg g -1 on average), shipping waterway (26 μg g -1 ), and remote lake (7 μg g -1 ) sediments, respectively. The PAH distribution patterns, methyl phenanthrene/phenanthrene ratios, and a pyrogenic index at the sites suggest a pyrogenic origin for PAHs. Source characterization using principal component analysis and various molecular indices including C2-dibenzothiophenes/C2-phenanthrenes, C3-dibenzothiophenes/C3-phenanthrenes, and C2-chrysenes/C2-phenanthrenes ratios, was able to differentiate PAH deposited in sediments from the four sites. The uniqueness of the source of the sediment PAHs from urban lake was also illustrated by compound specific stable carbon isotope analysis. It was concluded that urban lake sediments are accumulating PAH from sources that are unique from contamination detected at nearby sites in the same watershed

  4. 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.

  5. 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

  6. Soil organic matter (SOM) dynamics determined by stable isotope techniques

    International Nuclear Information System (INIS)

    Gerzabek, M. H.

    1998-09-01

    Being aware of limitations and possible bias the 13 C natural abundance technique using the different 13 C enrichments in plants with differing photosynthetic pathways in a powerful tool to quantify turnover processes, both in long-term field studies and short-term laboratory experiments. Special care is needed in choosing reference plots and the proper number of replicate samples. The combination of 13 C and 14 C measurements has a high potential for a further improvement of isotope techniques in SOM studies. Natural abundance of 15 N is less powerful with respect to quantification of SOM processes than the isotope dilution technique. However its usefulness could be distinctly improved by introducing other stable isotopes into the studies.(author)

  7. 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...... method for discerning MeHg exposure sources. We characterized Hg isotope fractionation between humans and their diets using hair samples from Faroese whalers exposed to MeHg predominantly from pilot whales. We observed an increase of 1.75‰ in δ(202)Hg values between pilot whale muscle tissue and Faroese...... whalers' hair but no mass-independent fractionation. We found a similar offset in δ(202)Hg between consumed seafood and hair samples from Gulf of Mexico recreational anglers who are exposed to lower levels of MeHg from a variety of seafood sources. An isotope mixing model was used to estimate individual...

  8. DNA stable-isotope probing (DNA-SIP).

    Science.gov (United States)

    Dunford, Eric A; Neufeld, Josh D

    2010-08-02

    DNA stable-isotope probing (DNA-SIP) is a powerful technique for identifying active microorganisms that assimilate particular carbon substrates and nutrients into cellular biomass. As such, this cultivation-independent technique has been an important methodology for assigning metabolic function to the diverse communities inhabiting a wide range of terrestrial and aquatic environments. Following the incubation of an environmental sample with stable-isotope labelled compounds, extracted nucleic acid is subjected to density gradient ultracentrifugation and subsequent gradient fractionation to separate nucleic acids of differing densities. Purification of DNA from cesium chloride retrieves labelled and unlabelled DNA for subsequent molecular characterization (e.g. fingerprinting, microarrays, clone libraries, metagenomics). This JoVE video protocol provides visual step-by-step explanations of the protocol for density gradient ultracentrifugation, gradient fractionation and recovery of labelled DNA. The protocol also includes sample SIP data and highlights important tips and cautions that must be considered to ensure a successful DNA-SIP analysis.

  9. Stable strontium isotopic ratios from archaeological organic remains from the Thorsberg peat bog

    DEFF Research Database (Denmark)

    Nosch, Marie-Louise Bech; von Carnap-Bornheim, Claus; Grupe, Gisela

    2007-01-01

    Pilot study analysing stable strontium isotopic ratios from Iron Age textile and leather finds from the Thorsberg peat bog.......Pilot study analysing stable strontium isotopic ratios from Iron Age textile and leather finds from the Thorsberg peat bog....

  10. Diets of introduced predators using stable isotopes and stomach contents

    Science.gov (United States)

    Meckstroth, A.M.; Miles, A.K.; Chandra, S.

    2007-01-01

    In a study of predation on ground-nesting birds at South San Francisco Bay (South Bay), California, USA, we analyzed stomach contents and stable isotopes of carbon and nitrogen to identify commonly consumed prey. We obtained the stomach contents from 206 nonnative red foxes (Vulpes vulpes regalis) collected in the South Bay area and Monterey County during 1995-2001 and from 68 feral cats (Felis silvestris) from the South Bay area during 2001-2002. We determined prey identity, biomass, and frequency, described seasonal diet trends, and derived an Index of Relative Importance. Avian species were the most frequent prey we found in the stomachs of red foxes from South Bay (61%), whereas small rodents were most frequent for red foxes from Monterey County (62%). Small rodents were the most frequent prey we found in feral cats (63%). Carbon and nitrogen isotopic signatures for foxes supported stomach content findings. However, isotope results indicated that cats received a majority of their energy from a source other than rodents and outside the natural system, which differed from the stomach content analysis. We demonstrated the utility of both stable isotope and stomach content analyses to establish a more complete understanding of predators' diets. This information aids natural resource managers in planning and evaluating future predator-removal programs and increases our understanding of the impacts of nonnative foxes and cats on native species.

  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. Development of Laser Application Technology for Stable Isotope Production

    International Nuclear Information System (INIS)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee

    2007-04-01

    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

  13. 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

  14. 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.

  15. Stable isotopes applied as water tracers for infiltration experiment

    International Nuclear Information System (INIS)

    Liu Xiaoyan; Chen Jiansheng; Sun Xiaoxu; Su Zhiguo

    2011-01-01

    The δD and δ 18 O vertical profiles of soil water were measured prior to and after a rainfall event. Mechanisms of soil water movement were deciphered by comparing the soil water isotope profiles with the isotopic composition of precipitation. The results show that evaporation at the upper depth led to enrichment of the heavy isotopes. Compared to the loess profile, the shallow soil water of sand profile is relatively enriched in D and 18 O due to macro-pore and low water-holding capacity. The precipitation is infiltrated into soil in piston mode, accompanied with significant mixing of older soil water. The preferential fluid flow in loess was observed at depths of 0-20 cm, caused by cracks in the depths. The hydrogen and oxygen isotopic compositions in outflow are close to the precipitation, which shows a mixing of the precipitation and old soil water, and indicates that the isotopic composition of outflow water is mainly controlled by that of the precipitation. The δD and δ 18 O in outflow decreased with time until stable δ values of outflow are close to those of the precipitation. (authors)

  16. 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

  17. 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.

  18. 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.

  19. Geographic variation of stable isotopes in African elephant ivory

    Science.gov (United States)

    Ziegler, S.; Merker, S.; Jacob, D.

    2012-04-01

    In 1989, the international community listed the African elephant in Appendix I of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) thus prohibiting commercial ivory trade. Recent surveillance data show that the illegal trade in ivory has been growing worldwide. Long-term preservation of many of the African elephant populations can be supported with a control mechanism that helps with the implementation of remedial conservation action. Therefore, setting up a reference database that predicts the origin of ivory specimens can assist in determining smuggling routes and the provenance of illegal ivory. Our research builds on earlier work to seek an appropriate method for determining the area of origin for individual tusks. Several researchers have shown that the provenance of elephant ivory can be traced by its isotopic composition, but this is the first attempt to produce an integrated isotopic reference database of elephant ivory provenance. We applied a combination of various routine geochemical analyses to measure the stable isotope ratios of hydrogen, carbon, nitrogen, oxygen, and sulphur. Up to now, we analysed 606 ivory samples of known geographical origin from African range states, museums and private collections, comprising 22 African elephant range states. The isotopic measurements were superimposed with data layers from vegetation, geology and climate. A regression function for the isotope composition of the water isotopes in precipitation and collagen in ivory was developed to overcome the problem of imprecise origin of some of the sampled material. Multivariate statistics, such as nearest neighborhood and discriminate analysis were applied to eventually allow a statistical determination of the provenance for ivory of unknown origin. Our results suggest that the combination of isotopic parameters have the potential to provide predictable and complementary markers for estimating the origin of seized elephant ivory.

  20. 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)

  1. 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.

  2. 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...

  3. Climatic signals in multiple highly resolved stable isotope records from Greenland

    DEFF Research Database (Denmark)

    Vinther, Bo Møllesøe; Dahl-Jensen, Dorthe; Johnsen, Sigfus Johann

    2010-01-01

    are found to correspond better with winter stable isotope data than with summer or annual average stable isotope data it is suggested that a strong local Greenland temperature signal can be extracted from the winter stable isotope data even on centennial to millennial time scales. Udgivelsesdato: Feb....

  4. 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,

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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)

  11. Platinum stable isotopes in ferromanganese crust and nodules

    Science.gov (United States)

    Corcoran, Loretta; Seward, Terry; Handler, Monica R.

    2015-04-01

    Hydrogenetic ferromanganese (Fe-Mn) crust and nodules are slow-growing chemical sediments that form by direct precipitation from seawater, resulting in a record of changing seawater chemistry. These sediments are the primary sink for platinum in the modern oxic marine environment, hosting well-documented enrichments over other platinum-group elements (PGEs): the Pt anomaly [1]. Platinum is a non-bio-essential, highly siderophile, transition metal with six stable isotopes (190Pt, 192Pt, 194Pt, 195Pt, 196Pt, and 198Pt) with several oxidation states (Pt0, Pt2+ and Pt4+). Platinum is generally considered to exist in the hydrosphere as Pt2+ although its behaviour in the marine environment is poorly constrained, and Pt4+may also be present. Variations in ocean redox state, together with changes in source fluxes to the oceans, may therefore lead to small variations (Leaching experiments conducted on platinum rich terrestrial materials underwent platinum stable isotopic measurement as an analogue for the Pt isotopic fractionation associated with continental weathering. [1] Hodge, V.F. et al. (1985) Earth and Planetary Science Letters, 72, 158-162. [2] Creech, J. et al. (2013) Journal of Analytical Atomic Spectrometry, 28. 853-865.

  12. 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

  13. Stable isotopes and elasmobranchs: tissue types, methods, applications and assumptions.

    Science.gov (United States)

    Hussey, N E; MacNeil, M A; Olin, J A; McMeans, B C; Kinney, M J; Chapman, D D; Fisk, A T

    2012-04-01

    Stable-isotope analysis (SIA) can act as a powerful ecological tracer with which to examine diet, trophic position and movement, as well as more complex questions pertaining to community dynamics and feeding strategies or behaviour among aquatic organisms. With major advances in the understanding of the methodological approaches and assumptions of SIA through dedicated experimental work in the broader literature coupled with the inherent difficulty of studying typically large, highly mobile marine predators, SIA is increasingly being used to investigate the ecology of elasmobranchs (sharks, skates and rays). Here, the current state of SIA in elasmobranchs is reviewed, focusing on available tissues for analysis, methodological issues relating to the effects of lipid extraction and urea, the experimental dynamics of isotopic incorporation, diet-tissue discrimination factors, estimating trophic position, diet and mixing models and individual specialization and niche-width analyses. These areas are discussed in terms of assumptions made when applying SIA to the study of elasmobranch ecology and the requirement that investigators standardize analytical approaches. Recommendations are made for future SIA experimental work that would improve understanding of stable-isotope dynamics and advance their application in the study of sharks, skates and rays. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

  14. Novel Stable Isotope Methods for Assessing Changes in Seasonality of Precipitation from Sediments of Ombrotrophic Peatlands

    Science.gov (United States)

    Nichols, J. E.; Booth, R. K.; Jackson, S. T.; Pendall, E. G.; Walcott, M.; Bradley, R.; Pilcher, J.; Huang, Y.

    2007-12-01

    The seasonality of precipitation is a key but often elusive climate parameter in paleoclimate reconstructions. Sediments from ombrotrophic peatlands are excellent archives of past changes in precipitation/evaporation balance. Here we show that these peatland sediments can also be used to assess changes in the seasonality of precipitation. We have recently determined that distributions of Sphagnum and vascular plant biomarkers sensitively record changes in hydrologic balance (Nichols et al., 2006, Org. Geochem. 37, 1505-1513), but biomarker distributions alone do not offer detailed information for the changes in seasonal precipitation. In this study, we combine biomarker and compound-specific H and C isotope ratios to create a more comprehensive picture of the changing climate affecting these sensitive ombrotrophic systems. We present here two sets of downcore data from sites in Arctic Europe as well as Eastern North America. Basic paleohydrology is established using a ratio of Sphagnum to vascular plant biomarkers (C23 and C29 n-alkanes, respectively. We further describe paleohydrology using novel stable isotope proxies based on δD and δ13C measurements of Sphagnum and vascular plant biomarkers. Because Sphagnum has no vascular system and loses water directly by evaporation, Sphagnum biomarkers enriched in deuterium indicate an evaporative growing season (summer). Vascular plants use their root systems to take up water stored within the peatland, so deuterium-depleted vascular plant biomarkers should indicate increased winter recharge of the peatland. A methanotrophic symbiont living inside the Sphagnum's hyaline (water-holding) cells is more active when the Sphagnum is wet and therefore provides more 13C depleted (methane- derived) carbon dioxide for biomass production when the growing season is less evaporative. Hence, 13C depleted Sphagnum biomarkers indicate increased methanotrophy and therefore a wetter summer. We corroborate our stable isotope proxies by

  15. 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

  16. The geochemistry of the stable isotopes of silicon

    International Nuclear Information System (INIS)

    Douthitt, C.B.

    1982-01-01

    One hundred thirty two new measurements of the relative abundances of the stable isotopes of silicon in terrestrial materials are presented. The total variation of delta 30 Si found is 6.2 parts per thousand, centered on the mean of terrestrial mafic and ultramafic igneous rocks, delta 30 Si = -0.4 parts per thousand. Igneous rocks show limited variation; coexisting minerals exhibit small, systematic silicon isotopic fractionations that are roughly 1/3 the magnitude of concomitant oxygen isotopic fractionations at 1150 0 C. In both igneous minerals and rocks, delta 30 Si shows a positive correlation with silicon content, as does delta 18 O. Opal from both sponge spicules and sinters is light, with delta 30 Si = -2.3 and -1.4 parts per thousand respectively. Large delta 30 Si values of both positive and negative sign are reported for the first time from clay minerals, opaline phytoliths, and authigenic quartz. All highly fractionated samples were precipitated from solution at low temperatures; however, aqueous silicon is not measurably fractionated relative to quartz at equilibrium. A kinetic isotope fractionation of approximately 3.5 parts per thousand is postulated to occur during the low temperature precipitation of opal and, possibly, poorly ordered phyllosilicates, with the silicate phase being enriched in 28 Si. This fractionation, coupled with a Rayleigh precipitation model, is capable of explaining most non-magmatic delta 30 Si variations. (author)

  17. A stable isotope-based approach to tropical dendroclimatology

    Science.gov (United States)

    Evans, Michael N.; Schrag, Daniel P.

    2004-08-01

    We describe a strategy for development of chronological control in tropical trees lacking demonstrably annual ring formation, using high resolution δ 18O measurements in tropical wood. The approach applies existing models of the oxygen isotopic composition of alpha-cellulose (Roden et al., 2000), a rapid method for cellulose extraction from raw wood (Brendel et al., 2000), and continuous flow isotope ratio mass spectrometry (Brenna et al., 1998) to develop proxy chronological, rainfall and growth rate estimates from tropical trees lacking visible annual ring structure. Consistent with model predictions, pilot datasets from the temperate US and Costa Rica having independent chronological control suggest that observed cyclic isotopic signatures of several permil (SMOW) represent the annual cycle of local rainfall and relative humidity. Additional data from a plantation tree of known age from ENSO-sensitive northwestern coastal Peru suggests that the 1997-8 ENSO warm phase event was recorded as an 8‰ anomaly in the δ 18O of α-cellulose. The results demonstrate reproducibility of the stable isotopic chronometer over decades, two different climatic zones, and three tropical tree genera, and point to future applications in paleoclimatology.

  18. Stable isotope separation; Separations physicochimiques d'isotopes stables realisations et etudes de petites productions

    Energy Technology Data Exchange (ETDEWEB)

    Botter, F; Molinari, Ph; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    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 {alpha} 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{sub 2} from a 50 p. 100 D{sub 2}, 50 p. 100 100 H{sub 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 {sup 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

  19. Stable isotopes determination in some Romanian fruit juices.

    Science.gov (United States)

    Magdas, Dana Alina; Puscas, Romulus

    2011-09-01

    The characterisation of 45 Romanian single-strength fruit juices (apples, pears, plums and grapes) collected from different Transylvanian areas by means of stable isotope approach are presented and discussed in this study. We measured (2)H/(1)H, (18)O/(16)O ratios from water juice and (13)C/(12)C from pulp and compared these results with those already reported in the literature for single-strength juices, in order to see how the geographical and climatic conditions of Transylvania and the meteorological peculiarities of the year 2010 influence the isotopic composition of the investigated fruit juices. The δ(13)C mean values that we found for apple pulp picked up from different Transylvanian areas show slight differences, probably due to the environmental conditions of the plants. No significant correlation either between the variety of apple or the geographical origin and δ(13)C value was established.

  20. 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

  1. Biomarkers and their stable isotopes in Cenozoic sediments above the Chicxulub impact crater

    Science.gov (United States)

    Grice, K.; Schaefer, B.; Coolen, M.; Greenwood, P. F.; Scarlett, A. G.; Freeman, K.; Lyons, S. L.

    2017-12-01

    The most widely accepted hypothesis for the cause of the End-Cretaceous mass extinction (K/Pg event) 66 Ma ago is the impact of an extra-terrestrial body, which produced the 200 km wide Chicxulub impact structure. This event led to an extinction of 75% of all species on Earth. The massive extinction in the terrestrial realm is partly attributed to the intense heat pulse, the widespread wild fires caused by the impact and the ensuing darkness, as dust and sulfate aerosols blocked out the sun leading to photosynthesis shut off and productivity collapse in both the terrestrial and marine realms. The marine realm may additionally have experienced ocean acidification resulting in mass extinction of plankton (foraminifera and coccolithophorids) and marine reptiles. Samples from the Cenozoic marine sediments including the Paleocene-Eocene Thermal Maximum (PETM) have been extracted for hydrocarbons and analysed to investigate the molecular and isotopic organic record of biotic and environmental change after the K/Pg boundary event. Specific biomarker-precursor relationship has been established by the direct correlation of sedimentary biomarkers with the biochemicals (e.g. lipids) of extant biological systems. The structural characterisation of biomarkers as well as their stable isotopic compositions (C, H and N) are used to evaluate the source(s) of organic matter (OM) and to reconstruct paleoenvironmental depositional conditions. Throughout the Cenozoic sediments (including the PETM) the biomarker distribution suggests a variation in the source of organic matter from terrestrial to marine. Furthermore, the presence of sulfurised biomarkers indicates euxinic environmental conditions at the time of deposition. Biomarker distributions indicative of green sulfur bacteria reveal persistent photic zone euxinic conditions at several intervals in the Cenozoic. Further compound specific isotope analyses will provide insights into the long-term biogeochemical cycling of C, H and S

  2. 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

  3. Stable carbon isotope analysis (δ13C values) of polybrominated diphenyl ethers and their UV-transformation products

    International Nuclear Information System (INIS)

    Rosenfelder, Natalie; Bendig, Paul; Vetter, Walter

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) are frequently detected in food and environmental samples. We used compound specific isotope analysis to determine the δ 13 C values of individual PBDEs in two technical mixtures. Within the same technical product (DE-71 or DE-79), BDE congeners were the more depleted in 13 C the higher brominated they were. In contrast, the products of light-induced hydrodebromination of BDE 47 and technical DE-79 were more enriched in 13 C because of more stable bonds between 13 C and bromine. As a result, the δ 13 C values of the irradiated solution progressed diametrically compared to those of the technical synthesis. The ratio of the δ 13 C values of BDE 47 to BDE 99 and of BDE 99 to BDE 153 are thus suggested as indicators to distinguish native technical products from transformation products. Ratios 1) is typical of transformation products. - Highlights: → δ 13 C values of PBDEs were determined by means of compound specific isotope analysis. → PBDEs in technical mixtures were the more depleted in 13 C the higher they were brominated. → Solutions of individual PBDEs and technical PBDE mixtures were irradiated by UV light. → δ 13 C values of irradiated PBDEs and technical PBDEs progressed diametrically. → Ratios of the δ 13 C values were used to distinguish native from transformed PBDEs. - Diametrically progressing δ 13 C values in technical mixtures and UV-transformation products of DE-79 may be useful for source appointment of PBDEs in environmental samples

  4. A reliable compound-specific nitrogen isotope analysis of amino acids by GC-C-IRMS following derivatisation into N-pivaloyl-iso-propyl (NPIP)esters for high-resolution food webs estimation.

    Science.gov (United States)

    Zhang, Zhongyi; Tian, Jing; Xiao, Hongwei; Zheng, Nengjian; Gao, Xiaofei; Zhu, Renguo; Xiao, Huayun

    2016-10-15

    The signatures of natural stable nitrogen isotopic composition (δ(15)N) of individual amino acid (AA) have been confirmed to be a potentially effective tool for elucidating nitrogen cycling and trophic position of various organisms in food webs. In the present study, a two-stage derivatisation approach of esterification followed by acylation was evaluated. The biological samples underwent acid hydrolysis and the released individual AA was derivatived into corresponding N-pivaloyl-isopropyl (NPIP) esters for nitrogen isotopic analysis in gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). Usually, 13 individual AA derivatives were separated with fine baseline resolution based on a nonpolar gas chromatography column (DB-5ms). The minimum sample amount required under the presented conditions is larger than 20ngN on column in order to accurately determine the δ(15)N values. The δ(15)N values determined by GC-C-IRMS with a precision of better than 1‰, were within 1‰ after empirical correction compared to the corresponding measured by element analysis (EA)-IRMS. Bland-Altman plot showed highly consistency of the δ(15)N values determined by the two measurement techniques. Cation-exchange chromatography was applied to remove interfering fraction from the extracts of plant and animal samples and without nitrogen isotope fractionation during the treatment procedure. Moreover, this approach was carried out to estimate the trophic level of various natural organisms in a natural lake environment. Results highly proved that the trophic level estimated via the presented AA method well reflected the actual food web structure in natural environments. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. 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

  6. 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.)

  7. Stable lead isotopes as a tracer in coastal waters

    International Nuclear Information System (INIS)

    Stukas, V.J.; Wong, C.S.

    1981-01-01

    The natural abundances of the stable isotopes of lead are used to identify natural and industrial sources of lead in the coastal waters of British Columbia, Canada. The 206 Pb/ 207 Pb ratios, used to characterize the lead source, had values of approx. 1.24 for coastal oceanic water, approx. 1.22 for fjord waters receiving lead from mine tailings, and approx. 1.163 for waters near urban centers. The lead concentration data are in agreement with presently accepted seawater values

  8. 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.

  9. Stable nitrogen isotopes in coastal macroalgae: geographic and anthropogenic variability

    OpenAIRE

    González-Viana, I. (Inés); Bode, A. (Antonio)

    2013-01-01

    Proyectos ANILE (CTM2009-08396 and CTM2010-08804-E) del Plan Nacional de I+D+i y RADIALES del Instituto Español de Oceanografía (IEO). I.G.V. recibió un contrato FPI del Ministerio de Economía y Competividad Growing human population add to the natural nitrogen loads to coastal waters. As the excess nitrogen is readily incorporated in new biomass anthropogenic and natural nitrogen sources may be traced by the measurement of stable nitrogen isotopes (δ15N). In this study δ15N was dete...

  10. Applications of stable isotope analysis to atmospheric trace gas budgets

    Directory of Open Access Journals (Sweden)

    Brenninkmeijer C. A.M.

    2009-02-01

    Full Text Available Stable isotope analysis has become established as a useful method for tracing the budgets of atmospheric trace gases and even atmospheric oxygen. Several new developments are briefly discussed in a systematic way to give a practical guide to the scope of recent work. Emphasis is on applications and not on instrumental developments. Processes and reactions are less considered than applications to resolve trace gas budgets. Several new developments are promising and applications hitherto not considered to be possible may allow new uses.

  11. 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

  12. 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.)

  13. 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.)

  14. Tracing carbon flow in an arctic marine food web using fatty acid-stable isotope analysis.

    Science.gov (United States)

    Budge, S M; Wooller, M J; Springer, A M; Iverson, S J; McRoy, C P; Divoky, G J

    2008-08-01

    Global warming and the loss of sea ice threaten to alter patterns of productivity in arctic marine ecosystems because of a likely decline in primary productivity by sea ice algae. Estimates of the contribution of ice algae to total primary production range widely, from just 3 to >50%, and the importance of ice algae to higher trophic levels remains unknown. To help answer this question, we investigated a novel approach to food web studies by combining the two established methods of stable isotope analysis and fatty acid (FA) analysis--we determined the C isotopic composition of individual diatom FA and traced these biomarkers in consumers. Samples were collected near Barrow, Alaska and included ice algae, pelagic phytoplankton, zooplankton, fish, seabirds, pinnipeds and cetaceans. Ice algae and pelagic phytoplankton had distinctive overall FA signatures and clear differences in delta(13)C for two specific diatom FA biomarkers: 16:4n-1 (-24.0+/-2.4 and -30.7+/-0.8 per thousand, respectively) and 20:5n-3 (-18.3+/-2.0 and -26.9+/-0.7 per thousand, respectively). Nearly all delta(13)C values of these two FA in consumers fell between the two stable isotopic end members. A mass balance equation indicated that FA material derived from ice algae, compared to pelagic diatoms, averaged 71% (44-107%) in consumers based on delta(13)C values of 16:4n-1, but only 24% (0-61%) based on 20:5n-3. Our estimates derived from 16:4n-1, which is produced only by diatoms, probably best represented the contribution of ice algae relative to pelagic diatoms. However, many types of algae produce 20:5n-3, so the lower value derived from it likely represented a more realistic estimate of the proportion of ice algae material relative to all other types of phytoplankton. These preliminary results demonstrate the potential value of compound-specific isotope analysis of marine lipids to trace C flow through marine food webs and provide a foundation for future work.

  15. Protein Stable Isotope Fingerprinting (P-SIF): Multidimensional Protein Chromatography Coupled to Stable Isotope-Ratio Mass Spectrometry

    Science.gov (United States)

    Pearson, A.; Bovee, R. J.; Mohr, W.; Tang, T.

    2012-12-01

    As metagenomics increases our insight into microbial community diversity and metabolic potential, new approaches are required to determine the biogeochemical expression of this potential within ecosystems. Because stable isotopic analysis of the major bioactive elements (C, N) has been used historically to map flows of substrates and energy among macroscopic food webs, similar principles may apply to microbes. To address this challenge, we have developed a new analytical approach called Protein Stable Isotope Fingerprinting (P-SIF). P-SIF generates natural stable isotopic fingerprints of microbial individual or community proteomes. The main advantage of P-SIF is the potential to bridge the gap between diversity and function, thereby providing a window into the "black box" of environmental microbiology and helping to decipher the roles of uncultivated species. Our method implements a three-way, orthogonal scheme to separate mixtures of whole proteins into subfractions dominated by single or closely-related proteins. Protein extracts first are isoelectrically focused in a gel-free technique that yields 12 fractions separated over a gradient of pH 3-10. Each fraction then is separated by size-exclusion chromatography into 20 pools, ranging from >100kD to ~10kD. Finally, each of these pools is subjected to HPLC and collected in 40 time-slices based on protein hydrophobicity. Theoretical calculation reveals that the true chromatographic resolution of the total scheme is 5000, somewhat less than the 9600 resulting fractions. High-yielding fractions are subjected to δ13C analysis by spooling-wire microcombustion irMS (SWiM-irMS) optimized for samples containing 1-5 nmol carbon. Here we will present the method, results for a variety of pure cultures, and preliminary data for a sample of mixed environmental proteins. The data show the promise of this method for unraveling the metabolic complexity hidden within microbial communities.

  16. Stable isotope signatures reflect dietary diversity in European forest moths.

    Science.gov (United States)

    Adams, Marc-Oliver; Seifert, Carlo Lutz; Lehner, Lisamarie; Truxa, Christine; Wanek, Wolfgang; Fiedler, Konrad

    2016-01-01

    Information on larval diet of many holometabolous insects remains incomplete. Carbon (C) and nitrogen (N) stable isotope analysis in adult wing tissue can provide an efficient tool to infer such trophic relationships. The present study examines whether moth feeding guild affiliations taken from literature are reflected in isotopic signatures. Non-metric multidimensional scaling and permutational analysis of variance indicate that centroids of dietary groups differ significantly. In particular, species whose larvae feed on mosses or aquatic plants deviated from those that consumed vascular land plants. Moth δ(15)N signatures spanned a broader range, and were less dependent on species identity than δ(13)C values. Comparison between moth samples and ostensible food sources revealed heterogeneity in the lichenivorous guild, indicating only Lithosia quadra as an obligate lichen feeder. Among root-feeding Agrotis segetum, some specimens appear to have developed on crop plants in forest-adjacent farm land. Reed-feeding stem-borers may partially rely on intermediary trophic levels such as fungal or bacterial growth. Diagnostic partitioning of moth dietary guilds based on isotopic signatures alone could not be achieved, but hypotheses on trophic relationships based on often vague literature records could be assessed with high resolution. Hence, the approach is well suited for basic categorization of moths where diet is unknown or notoriously difficult to observe (i.e. Microlepidoptera, lichen-feeders).

  17. Evaluation of Kilauea Eruptions By Using Stable Isotope Analysis

    Science.gov (United States)

    Rahimi, K. E.; Bursik, M. I.

    2016-12-01

    Kilauea, on the island of Hawaii, is a large volcanic edifice with numerous named vents scattered across its surface. Halema`uma`u crater sits with Kilauea caldera, above the magma reservoir, which is the main source of lava feeding most vents on Kilauea volcano. Halema`uma`u crater produces basaltic explosive activity ranging from weak emission to sub-Plinian. Changes in the eruption style are thought to be due to the interplay between external water and magma (phreatomagmatic/ phreatic), or to segregation of gas from magma (magmatic) at shallow depths. Since there are three different eruption mechanisms (phreatomagmatic, phreatic, and magmatic), each eruption has its own isotope ratios. The aim of this study is to evaluate the eruption mechanism by using stable isotope analysis. Studying isotope ratios of D/H and δ18O within fluid inclusion and volcanic glass will provide an evidence of what driven the eruption. The results would be determined the source of water that drove an eruption by correlating the values with water sources (groundwater, rainwater, and magmatic water) since each water source has a diagnostic value of D/H and δ18O. These results will provide the roles of volatiles in eruptions. The broader application of this research is that these methods could help volcanologists forecasting and predicting the current volcanic activity by mentoring change in volatiles concentration within deposits.

  18. 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.

  19. Use of stable isotope techniques in soil organic matter studies

    International Nuclear Information System (INIS)

    Gerzabek, M.H.

    1998-01-01

    Plants differ distinctly in their C-isotopic composition. The largest differences occur between plant species with different photosynthetic pathways. C 3 - and C 4 -plants are differentiated by approximately 1.4% on the δ-scale (approx. -2.7% 13 C versus -1.3% 13 C). Modern elemental analyser - mass spectrometer combinations reach accuracies of at least 0.01% δ 13 C. Therefore, the difference between C 3 and C 4 plants is sufficient to be used for tracer studies. Several investigations of soil organic mater (SOM) turnover under field conditions were undertaken using the fact that the vegetation cover changed between C 3 and C 4 plants. The discrimination between SOM originating from indigenous vegetation (forest, C 3 ) and sugar cane (C 4 ) after 50 years of cropping introducing two SOM compartments of different stability was described. Another example is the change from prairie vegetation (C 4 ) to different C 3 -crops and the evaluation of the carbon origin at or near equilibrium. More recent studies use 15 N-labelled C 4 -plant residues or 13 C-labelled C 3 -plants to elucidate the fate of carbon and nitrogen in soils developed under C 3 -vegetation. Both in situ experiments and laboratory incubations were used to evaluate carbon and nitrogen fluxes from crop residues. Physical fractionation of bulk soil into particle sizes proved to be of advantage to follow short and long-term dynamics of crop residues within SOM. Changes in the natural abundance of 13 C and 15 N within soil profiles can elucidate leaching or mineralization of humic substances. Changes in the natural abundance of stable isotopes are also possible due to the application of organic manures, quantification, however is not easy because of the small isotopic differences between soil and manure carbon and nitrogen. 15 N labelling of soil nitrogen has been widely used in the last two decades to quantify biological nitrogen fixation. Considerable progress has been made due to the isotope dilution

  20. Mercury emissions and stable isotopic compositions at Vulcano Island (Italy)

    Science.gov (United States)

    Zambardi, T.; Sonke, J. E.; Toutain, J. P.; Sortino, F.; Shinohara, H.

    2009-01-01

    Sampling and analyses methods for determining the stable isotopic compositions of Hg in an active volcanic system were tested and optimized at the volcanic complex of Vulcano (Aeolian Islands, Italy). Condensed gaseous fumarole Hg (fum)T, plume gaseous elemental Hg (g)0 and plume particulate Hg (p)II were obtained at fumaroles F0, F5, F11, and FA. The average total Hg emissions, based on Hg T/SO 2 in condensed fumarolic gases and plumes, range from 2.5 to 10.1 kg y - 1 , in agreement with published values [Ferrara, R., Mazzolai, B., Lanzillotta, E., Nucaro, E., Pirrone, N., 2000. Volcanoes as emission sources of atmospheric mercury in the Mediterranean Basin. Sci. Total Environ. 259(1-3), 115-121; Aiuppa, A., Bagnato, E., Witt, M.L.I., Mather, T.A., Parello, F., Pyle, D.M., Martin, R.S., 2007. Real-time simultaneous detection of volcanic Hg and SO 2 at La Fossa Crater, Vulcano (Aeolian Islands, Sicily). Geophys. Res. Lett. 34(L21307).]. Plume Hg (p)II increases with distance from the fumarole vent, at the expense of Hg (g)0 and indicates significant in-plume oxidation and condensation of fumarole Hg (fum)T. Relative to the NIST SRM 3133 Hg standard, the stable isotopic compositions of Hg are δ 202Hg (fum)T = - 0.74‰ ± 0.18 (2SD, n = 4) for condensed gaseous fumarole Hg (fum)T, δ 202Hg (g)0 = - 1.74‰ ± 0.36 (2SD, n = 1) for plume gaseous elemental Hg (g)0 at the F0 fumarole, and δ 202Hg (p)II = - 0.11‰ ± 0.18 (2SD, n = 4) for plume particulate Hg (p)II. The enrichment of Hg (p)II in the heavy isotopes and Hg (g)0 in the light isotopes relative to the total condensed fumarolic Hg (fum)T gas complements the speciation data and demonstrates a gas-particle fractionation occurring after the gas expulsion in ambient T° atmosphere. A first order Rayleigh equilibrium condensation isotope fractionation model yields a fractionation factor α cond-gas of 1.00135 ± 0.00058.

  1. Culture of microalgae Spirulina platensis with isotope stable Carbon-13

    International Nuclear Information System (INIS)

    Cronemberger, Luiz C.A.; Costa, Vladimir E.

    2017-01-01

    Gastric emptying time abnormalities cause complications that affect the quality of life in humans and scintigraphy is the gold standard for this diagnosis. However its application has restrictions due to the use of the radiopharmaceutical 99m Tc. An alternative to this method is the stable carbon isotope respiratory test. This is a non-radioactive, noninvasive technique with no contraindications. Its application varies according to the substrate used. For evaluation of gastric emptying time one of the substrates that can be used in the respiratory test is Spirulina platensis labeled at 97% carbon atoms with the stable isotope carbon-13 ( 13 C). In Brazil, there is no production of this substrate and its high cost (US$475.00/g, excluding import taxes) makes it difficult to apply the test. Thus, the objective of the work is to cultivate labeled S. platensis at 97% of 13 C for use in the respiratory test for gastric emptying and to establish optimization parameters for the best cost-benefit of this culture. In the cultivation process the microalgae will be kept in a closed sterilized glass volumetric flask, with deionized water and a pure 13 C source. The light (photoperiod 12h light / dark), pH (∼ 9.5) and temperature (30 deg C) will be controlled and after 35-40 days of growth, the cyanobacteria will be lyophilized and ground for the acquisition of a powder that will be analyzed by IRMS and compared to S. platensis, which will be our reference standard

  2. Advances in stable isotope assisted labeling strategies with information science.

    Science.gov (United States)

    Kigawa, Takanori

    2017-08-15

    Stable-isotope (SI) labeling of proteins is an essential technique to investigate their structures, interactions or dynamics by nuclear magnetic resonance (NMR) spectroscopy. The assignment of the main-chain signals, which is the fundamental first step in these analyses, is usually achieved by a sequential assignment method based on triple resonance experiments. Independently of the triple resonance experiment-based sequential assignment, amino acid-selective SI labeling is beneficial for discriminating the amino acid type of each signal; therefore, it is especially useful for the signal assignment of difficult targets. Various combinatorial selective labeling schemes have been developed as more sophisticated labeling strategies. In these strategies, amino acids are represented by combinations of SI labeled samples, rather than simply assigning one amino acid to one SI labeled sample as in the case of conventional amino acid-selective labeling. These strategies have proven to be useful for NMR analyses of difficult proteins, such as those in large complex systems, in living cells, attached or integrated into membranes, or with poor solubility. In this review, recent advances in stable isotope assisted labeling strategies will be discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Enantioselective stable isotope analysis (ESIA) — A new concept to evaluate the environmental fate of chiral organic contaminants

    International Nuclear Information System (INIS)

    Badea, Silviu-Laurentiu; Danet, Andrei-Florin

    2015-01-01

    Since 2011, the enantiospecific stable carbon isotope analysis (ESIA) has emerged as an innovative technique to assess the environmental fate of chiral emerging compounds by combining in one experimental technique both compound specific isotope analysis (CSIA) and enantioselective analysis. To date, the ESIA was applied for four classes of compounds: α-hexachlorocyclohexane (α-HCH), polar herbicides (phenoxy acids), synthetic polycyclic musk galaxolide (HHCB), and phenoxyalkanoic methyl herbicides. From an analytical point of view there are factors that are hindering the application of ESIA methods for the field samples: (i.e. amounts of target analyte, matrix effects, GC resolution) and overcoming these factors is challenging. While ESIA was shown as a mature technique for the first three abovementioned class of compounds, no isotope analysis of individual enantiomers could be performed for phenoxyalkanoic methyl herbicides. With respect to field studies, one study showed that ESIA might be a promising tool to distinguish between biotic and abiotic transformation pathways of chiral organic contaminants and even to differentiate between their aerobic and anaerobic biotransformation pathways. The development of ESIA methods for new chiral emerging contaminants in combination with development of multi-element isotope analysis will contribute to a better characterization of transformation pathways of chiral organic contaminants. - Highlights: • ESIA is an innovative technique to assess the environmental fate of chiral pollutants • Overcoming the analytical limitations of ESIA is challenging • Development of ESIA methods for new chiral emerging contaminants is needed

  4. Enantioselective stable isotope analysis (ESIA) — A new concept to evaluate the environmental fate of chiral organic contaminants

    Energy Technology Data Exchange (ETDEWEB)

    Badea, Silviu-Laurentiu, E-mail: badeasilviu@gmail.com [Department of Chemistry, Umeå University, SE-901 87 Umeå (Sweden); Danet, Andrei-Florin [Department of Analytical Chemistry, University of Bucharest, Faculty of Chemistry, 90-92 Panduri Str., Bucharest 050657 (Romania)

    2015-05-01

    Since 2011, the enantiospecific stable carbon isotope analysis (ESIA) has emerged as an innovative technique to assess the environmental fate of chiral emerging compounds by combining in one experimental technique both compound specific isotope analysis (CSIA) and enantioselective analysis. To date, the ESIA was applied for four classes of compounds: α-hexachlorocyclohexane (α-HCH), polar herbicides (phenoxy acids), synthetic polycyclic musk galaxolide (HHCB), and phenoxyalkanoic methyl herbicides. From an analytical point of view there are factors that are hindering the application of ESIA methods for the field samples: (i.e. amounts of target analyte, matrix effects, GC resolution) and overcoming these factors is challenging. While ESIA was shown as a mature technique for the first three abovementioned class of compounds, no isotope analysis of individual enantiomers could be performed for phenoxyalkanoic methyl herbicides. With respect to field studies, one study showed that ESIA might be a promising tool to distinguish between biotic and abiotic transformation pathways of chiral organic contaminants and even to differentiate between their aerobic and anaerobic biotransformation pathways. The development of ESIA methods for new chiral emerging contaminants in combination with development of multi-element isotope analysis will contribute to a better characterization of transformation pathways of chiral organic contaminants. - Highlights: • ESIA is an innovative technique to assess the environmental fate of chiral pollutants • Overcoming the analytical limitations of ESIA is challenging • Development of ESIA methods for new chiral emerging contaminants is needed.

  5. 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

    In July 2010, a woman was jailed for nine years in the UK after the prosecution successfully argued that attempting to import a cutting agent was proof of involvement in a conspiracy to supply Cocaine. That landmark ruling provided law enforcement agencies with much greater scope to tackle those involved in this aspect of the drug trade, specifically targeting those importing the likes of benzocaine or lidocaine. Huge quantities of these compounds are imported into the UK and between May and August 2010, four shipments of Benzocaine amounting to more then 4 tons had been seized as part of Operation Kitley, a joint initiative between the UK Border Agency and the Serious Organised Crime Agency (SOCA). By diluting cocaine, traffickers can make it go a lot further for very little cost, leading to huge profits. In recent years, dealers have moved away from inert substances, like sugar and baby milk powder, in favour of active pharmaceutical ingredients (APIs), including anaesthetics like Benzocaine and Lidocaine. Both these mimic the numbing effect of cocaine, and resemble it closely in colour, texture and some chemical behaviours, making it easier to conceal the fact that the drug has been diluted. API cutting agents have helped traffickers to maintain steady supplies in the face of successful interdiction and even expand the market in the UK, particularly to young people aged from their mid teens to early twenties. From importation to street-level, the purity of the drug can be reduced up to a factor of 80 and street level cocaine can have a cocaine content as low as 1%. In view of the increasing use of Benzocaine as cutting agent for Cocaine, a study was carried out to investigate if 2H, 13C, 15N and 18O stable isotope signatures could be used in conjunction with multivariate chemometric data analysis to determine potential linkage between benzocaine exhibits seized from different locations or individuals to assist with investigation and prosecution of drug

  6. Comparison of gas chromatography/isotope ratio mass spectrometry and liquid chromatography/isotope ratio mass spectrometry for carbon stable-isotope analysis of carbohydrates.

    Science.gov (United States)

    Moerdijk-Poortvliet, Tanja C W; Schierbeek, Henk; Houtekamer, Marco; van Engeland, Tom; Derrien, Delphine; Stal, Lucas J; Boschker, Henricus T S

    2015-07-15

    We compared gas chromatography/isotope ratio mass spectrometry (GC/IRMS) and liquid chromatography/isotope ratio mass spectrometry (LC/IRMS) for the measurement of δ(13)C values in carbohydrates. Contrary to GC/IRMS, no derivatisation is needed for LC/IRMS analysis of carbohydrates. Hence, although LC/IRMS is expected to be more accurate and precise, no direct comparison has been reported. GC/IRMS with the aldonitrile penta-acetate (ANPA) derivatisation method was compared with LC/IRMS without derivatisation. A large number of glucose standards and a variety of natural samples were analysed for five neutral carbohydrates at natural abundance as well as at (13)C-enriched levels. Gas chromatography/chemical ionisation mass spectrometry (GC/CIMS) was applied to check for incomplete derivatisation of the carbohydrate, which would impair the accuracy of the GC/IRMS method. The LC/IRMS technique provided excellent precision (±0.08‰ and ±3.1‰ at natural abundance and enrichment levels, respectively) for the glucose standards and this technique proved to be superior to GC/IRMS (±0.62‰ and ±19.8‰ at natural abundance and enrichment levels, respectively). For GC/IRMS measurements the derivatisation correction and the conversion of carbohydrates into CO2 had a considerable effect on the measured δ(13)C values. However, we did not find any significant differences in the accuracy of the two techniques over the full range of natural δ(13)C abundances and (13)C-labelled glucose. The difference in the performance of GC/IRMS and LC/IRMS diminished when the δ(13)C values were measured in natural samples, because the chromatographic performance and background correction became critical factors, particularly for LC/IRMS. The derivatisation of carbohydrates for the GC/IRMS method was complete. Although both LC/IRMS and GC/IRMS are reliable techniques for compound-specific stable carbon isotope analysis of carbohydrates (provided that derivatisation is complete and the

  7. Stable isotope tracking of endangered sea turtles: validation with satellite telemetry and δ15N analysis of amino acids.

    Directory of Open Access Journals (Sweden)

    Jeffrey A Seminoff

    Full Text Available Effective conservation strategies for highly migratory species must incorporate information about long-distance movements and locations of high-use foraging areas. However, the inherent challenges of directly monitoring these factors call for creative research approaches and innovative application of existing tools. Highly migratory marine species, such as marine turtles, regularly travel hundreds or thousands of kilometers between breeding and feeding areas, but identification of migratory routes and habitat use patterns remains elusive. Here we use satellite telemetry in combination with compound-specific isotope analysis of amino acids to confirm that insights from bulk tissue stable isotope analysis can reveal divergent migratory strategies and within-population segregation of foraging groups of critically endangered leatherback sea turtles (Dermochelys coriacea across the Pacific Ocean. Among the 78 turtles studied, we found a distinct dichotomy in δ(15N values of bulk skin, with distinct "low δ(15N" and "high δ(15N" groups. δ(15N analysis of amino acids confirmed that this disparity resulted from isotopic differences at the base of the food chain and not from differences in trophic position between the two groups. Satellite tracking of 13 individuals indicated that their bulk skin δ(15N value was linked to the particular foraging region of each turtle. These findings confirm that prevailing marine isoscapes of foraging areas can be reflected in the isotopic compositions of marine turtle body tissues sampled at nesting beaches. We use a Bayesian mixture model to show that between 82 and 100% of the 78 skin-sampled turtles could be assigned with confidence to either the eastern Pacific or western Pacific, with 33 to 66% of all turtles foraging in the eastern Pacific. Our forensic approach validates the use of stable isotopes to depict leatherback turtle movements over broad spatial ranges and is timely for establishing wise conservation

  8. Stable isotope tracking of endangered sea turtles: validation with satellite telemetry and δ15N analysis of amino acids.

    Science.gov (United States)

    Seminoff, Jeffrey A; Benson, Scott R; Arthur, Karen E; Eguchi, Tomoharu; Dutton, Peter H; Tapilatu, Ricardo F; Popp, Brian N

    2012-01-01

    Effective conservation strategies for highly migratory species must incorporate information about long-distance movements and locations of high-use foraging areas. However, the inherent challenges of directly monitoring these factors call for creative research approaches and innovative application of existing tools. Highly migratory marine species, such as marine turtles, regularly travel hundreds or thousands of kilometers between breeding and feeding areas, but identification of migratory routes and habitat use patterns remains elusive. Here we use satellite telemetry in combination with compound-specific isotope analysis of amino acids to confirm that insights from bulk tissue stable isotope analysis can reveal divergent migratory strategies and within-population segregation of foraging groups of critically endangered leatherback sea turtles (Dermochelys coriacea) across the Pacific Ocean. Among the 78 turtles studied, we found a distinct dichotomy in δ(15)N values of bulk skin, with distinct "low δ(15)N" and "high δ(15)N" groups. δ(15)N analysis of amino acids confirmed that this disparity resulted from isotopic differences at the base of the food chain and not from differences in trophic position between the two groups. Satellite tracking of 13 individuals indicated that their bulk skin δ(15)N value was linked to the particular foraging region of each turtle. These findings confirm that prevailing marine isoscapes of foraging areas can be reflected in the isotopic compositions of marine turtle body tissues sampled at nesting beaches. We use a Bayesian mixture model to show that between 82 and 100% of the 78 skin-sampled turtles could be assigned with confidence to either the eastern Pacific or western Pacific, with 33 to 66% of all turtles foraging in the eastern Pacific. Our forensic approach validates the use of stable isotopes to depict leatherback turtle movements over broad spatial ranges and is timely for establishing wise conservation efforts in

  9. 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

  10. Coastal niches for terrestrial predators: a stable isotope study

    Energy Technology Data Exchange (ETDEWEB)

    Mellbrand, K.; Hamback, P.A., E-mail: peter.hamback@botan.su.se [Stockholm Univ., Dept. of Botany, Stockholm (Sweden)

    2010-12-15

    The purpose of this study was to identify the use of marine versus terrestrial food items by terrestrial arthropod predators on Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g., chironomids). Diets of coastal arthropods were examined using carbon and nitrogen stable isotope analysis in a two source mixing model. The results suggest that spiders are the terrestrial predators mainly utilizing nutrients and energy of marine origin on Baltic Sea shores, whereas insect predators such as beetles and heteropterans mainly utilize nutrients and energy derived from terrestrial sources, possibly owing to differences in hunting behaviour. That spiders are the predators which benefit the most from the marine inflow suggest that eventual effects of marine subsidies for the coastal ecosystem as a whole are likely mediated by spiders. (author)

  11. Coastal niches for terrestrial predators: a stable isotope study

    International Nuclear Information System (INIS)

    Mellbrand, K.; Hamback, P.A.

    2010-01-01

    The purpose of this study was to identify the use of marine versus terrestrial food items by terrestrial arthropod predators on Baltic Sea shores. The inflow of marine nutrients in the area consists mainly of marine algal detritus and emerging aquatic insects (e.g., chironomids). Diets of coastal arthropods were examined using carbon and nitrogen stable isotope analysis in a two source mixing model. The results suggest that spiders are the terrestrial predators mainly utilizing nutrients and energy of marine origin on Baltic Sea shores, whereas insect predators such as beetles and heteropterans mainly utilize nutrients and energy derived from terrestrial sources, possibly owing to differences in hunting behaviour. That spiders are the predators which benefit the most from the marine inflow suggest that eventual effects of marine subsidies for the coastal ecosystem as a whole are likely mediated by spiders. (author)

  12. Systematic investigation of electromagnetic properties of all stable hafnium isotopes

    International Nuclear Information System (INIS)

    Napiorkowski, T.J.; Choinski, J.; Czosnyka, T.; Iwanicki, J.; Kownacki, J.; Zemlo, L.; Srebrny, J.; Starosta, K.; Boer, J. de.; Gollwitzer, A.; Loewe, M.; Wuerkner, M.; Guenther, C.; Weber, T.; Hagemann, G.; Sletten, G.

    1996-01-01

    In a systematic investigation of the electromagnetic structure of hafnium stable isotopes enriched targets of 176, 177, 178, 179, 180 Hf were Coulomb exciting using: 67 MeV 19 F beam from NBITAL FN Tandem, 125 MeV 32 S beam from MP Tandem in Accelerator Laboratory LMU and TU Munich, 225 MeV 58 Ni beam from NBITAL FN Tandem plus 2 Liniac Boosters complex. Scattered particle-gamma as well as p-γ-γ coincidence were registered. A further simultaneous analysis of Coulomb excitation cross section as a function of scattering angle of 19 F, 32 S, 58 Ni projectiles should be sufficient to deduce reduced probabilities of E2 transitions in ground state band

  13. Stable Isotopes and Oral Tori in Greenlandic Norse and Inuit

    DEFF Research Database (Denmark)

    Baumann, M.; Lynnerup, N.; Scott, G. R.

    2017-01-01

    Palatine (PT) and mandibular torus (MT) have long been of interest to dental researchers and anthropologists, but their aetiology remains unresolved. Some combination of genetic and environmental factors influences their expression, but the relative role of each remains contentious. Previous...... research has shown that the Greenlandic Norse exhibit exceptionally high frequencies and pronounced expressions of PT and MT. In this regard, they are significantly different from genetically related medieval Scandinavian populations, so environmental factors have to be considered. An earlier study...... that estimated stable carbon and nitrogen isotope compositions for a Greenlandic Norse sample makes it possible to compare directly PT and MT expression with the relative degree of marine protein intake. For comparative purposes, parallel observations were made on a Greenlandic Inuit sample. Some researchers...

  14. Stable Isotopes of Precipitation During Tropical Sumatra Squalls in Singapore

    Science.gov (United States)

    He, Shaoneng; Goodkin, Nathalie F.; Kurita, Naoyuki; Wang, Xianfeng; Rubin, Charles Martin

    2018-04-01

    Sumatra Squalls, organized bands of thunderstorms, are the dominant mesoscale convective systems during the intermonsoon and southwest monsoon seasons in Singapore. To understand how they affect precipitation isotopes, we monitored the δ value of precipitation daily and continuously (every second and integrated over 30 s) during all squalls in 2015. We found that precipitation δ18O values mainly exhibit a "V"-shape pattern and less commonly a "W"-shape pattern. Variation in δ18O values during a single event is about 1 to 6‰ with the lowest values mostly observed in the stratiform zone, which agrees with previous observations and modeling simulations. Reevaporation can significantly affect δ values, especially in the last stage of the stratiform zone. Daily precipitation is characterized by periodic negative shifts in δ value, largely associated with the squalls rather than moisture source change. The shifts can be more than 10‰, larger than intraevent variation. Initial δ18O values of events are highly variable, and those with the lowest values also have the lowest initial values. Therefore, past convective activities in the upwind area can significantly affect the δ18O, and convection at the sampling site has limited contribution to isotopic variability. A significant correlation between precipitation δ18O value and regional outgoing longwave radiation and rainfall in the Asian monsoon region and western Pacific suggests that regional organized convection probably drives stable isotopic compositions of precipitation. A drop in the frequency of the squalls in 2015 is related to weak organized convection in the region caused by El Niño.

  15. 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.

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

    International Nuclear Information System (INIS)

    Viana, Inés G.; Bode, Antonio

    2013-01-01

    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 15 N). In this study δ 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 15 N was not related to either inorganic nitrogen concentrations or δ 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 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 15 N in macroalgae from rias and estuaries compared to those from open coastal areas and in areas with more than 15 × 10 3 inhabitants in the watershed. These results indicate that, in contrast with other studies, macroalgal δ 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 15 N was studied. ► The influence of populations and upwelling has not been made before on macroalgal δ 15 N. ► Natural variability has not been taken into account in most biomonitoring studies. ► Upwelling explains most of the variability in δ 15 N in macroalgae

  17. 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.

  18. Stable nitrogen isotopes in coastal macroalgae: geographic and anthropogenic variability.

    Science.gov (United States)

    Viana, Inés G; 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(15)N). In this study δ(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(15)N was not related to either inorganic nitrogen concentrations or δ(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(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(15)N in macroalgae from rias and estuaries compared to those from open coastal areas and in areas with more than 15×10(3) inhabitants in the watershed. These results indicate that, in contrast with other studies, macroalgal δ(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. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. 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

  20. 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)

  1. Stable Isotopic Variations in Precipitation in Southwest China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    This study analyzes the relationships of stable isotopes in precipitation with temperature, air pressure and humidity at different altitudes, and the potential influencing mechanisms of control factors on the stable isotopes in precipitation in Southwest China. There appear marked negative correlations of the δ18O in precipitation with precipitation amount, vapor pressure and atmospheric precipitable water (PW)at the Mengzi, Simao and Tengchong stations on the synoptic timescale; the marked negative correlations between the δ18O in precipitation and the diurnal mean temperature at 400 hPa, 500 hPa, 700 hPa and 850hPa are different from the temperature effect in middle-high-latitude inland areas. In addition, the notable positive correlation between the δ18O in precipitation and the dew-point deficit △Td at different altitudes is found at the three stations. Precipitation is not the only factor generating an amount effect. Probably,the amount effect is related to the variations of atmospheric circulation and vapor origins. On the annual timescale, the annual precipitation amount weighted-mean δ18O displays negative correlations not only with annual precipitation but also with annual mean temperature at 500 hPa. It can be deduced that, in the years with an abnormally strong summer monsoon, more warm and wet air from low-latitude oceans is transported northward along the vapor channel located in Southwest China and generates abnormally strong rainfall on the way. Meanwhile, the abnormally strong condensation process will release more condensed latent heat in the atmosphere, and this will lead to a rise of atmospheric temperature during rainfall but a decline of δ18O in the precipitation. On the other hand, in the years with an abnormally weak summer monsoon, the precipitation and the atmospheric temperature during rainfalls decrease abnormally but the δ18O in precipitation increases.

  2. 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

  3. 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.

  4. 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

  5. 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

  6. 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.)

  7. Tracing organic matter sources of estuarine tidal flat nematodes with stable carbon isotopes

    NARCIS (Netherlands)

    Moens, T.; Luyten, C.; Middelburg, J.J.; Herman, P.M.J.; Vincx, M.

    2002-01-01

    The present study explores the use of stable carbon isotopes to trace organic matter sources of intertidal nematodes in the Schelde estuary (SW Netherlands). Stable carbon isotope signatures of nematodes from a saltmarsh and 4 tidal flat stations were determined in spring and winter situations, and

  8. 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...

  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. Investigating differences in light stable isotopes between Thai jasmine rice and Sungyod rice

    Science.gov (United States)

    Kukusamude, C.; Kongsri, S.

    2017-10-01

    We report the differences in light stable isotopes between two kinds of Thai rice (Thai jasmine and Sungyod rice). Thai jasmine rice and Sungyod rice were cultivated in the northeast and the south of Thailand. Light isotopes including 13C, 15N and 18O of Thai jasmine rice and Sungyod rice samples were carried out using isotope ratio mass spectrometry (IRMS). Thai jasmine rice (Khao Dawk Mali 105) was cultivated from Thung Kula Rong Hai area, whereas Sungyod rice was cultivated from Phathalung province. Hypothesis testing of difference of each isotope between Thai jasmine rice and Sungyod rice was also studied. The study was the feasibility test whether the light stable isotopes can be the variables to identify Thai jasmine rice and Sungyod rice. The result shows that there was difference in the isotope patterns of Thai jasmine rice and Sungyod rice. Our results may provide the useful information in term of stable isotope profiles of Thai rice.

  11. 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

  12. 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)

  13. NMR-based stable isotope resolved metabolomics in systems biochemistry

    International Nuclear Information System (INIS)

    Fan, Teresa W-M.; Lane, Andrew N.

    2011-01-01

    An important goal of metabolomics is to characterize the changes in metabolic networks in cells or various tissues of an organism in response to external perturbations or pathologies. The profiling of metabolites and their steady state concentrations does not directly provide information regarding the architecture and fluxes through metabolic networks. This requires tracer approaches. NMR is especially powerful as it can be used not only to identify and quantify metabolites in an unfractionated mixture such as biofluids or crude cell/tissue extracts, but also determine the positional isotopomer distributions of metabolites derived from a precursor enriched in stable isotopes such as 13 C and 15 N via metabolic transformations. In this article we demonstrate the application of a variety of 2-D NMR editing experiments to define the positional isotopomers of compounds present in polar and non-polar extracts of human lung cancer cells grown in either [U– 13 C]-glucose or [U– 13 C, 15 N]-glutamine as source tracers. The information provided by such experiments enabled unambiguous reconstruction of metabolic pathways, which is the foundation for further metabolic flux modeling.

  14. Stable-isotope composition of the water of apple juice

    International Nuclear Information System (INIS)

    Bricout, Jacques; Merlivat, Liliane

    1973-01-01

    By deuterium and oxygen 18 analysis, it was shown that apples' water is enriched in heavier isotopes as compared to rain water. The isotopic composition of the water of reconstituted apple juice is closed to the isotopic content of the rain water used for dilution. Thus, deuterium and oxyden 18 analysis allows a good analytical distinction between natural apple juice and reconstituted juices [fr

  15. 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.

    1997-01-01

    The Oak Ridge national laboratory (ORNL) has been supplying enriched stable and radioactive isotopes to the research, medical, and industrial communities for over 50 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)fwill 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. (orig.)

  16. 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.

  17. 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

  18. 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)

  19. 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.

  20. Stable oxygen and hydrogen isotopes of brines - comparing isotope ratio mass spectrometry and isotope ratio infrared spectroscopy

    Science.gov (United States)

    Ahrens, Christian; Koeniger, Paul; van Geldern, Robert; Stadler, Susanne

    2013-04-01

    Today's standard analytical methods for high precision stable isotope analysis of fluids are gas-water equilibration and high temperature pyrolysis coupled to isotope ratio mass spectrometers (IRMS). In recent years, relatively new laser-based analytical instruments entered the market that are said to allow high isotope precision data on nearly every media. This optical technique is referred to as isotope ratio infrared spectroscopy (IRIS). The objective of this study is to evaluate the capability of this new instrument type for highly saline solutions and a comparison of the analytical results with traditional IRMS analysis. It has been shown for the equilibration method that the presence of salts influences the measured isotope values depending on the salt concentration (see Lécuyer et al, 2009; Martineau, 2012). This so-called 'isotope salt effect' depends on the salt type and salt concentration. These factors change the activity in the fluid and therefore shift the isotope ratios measured by the equilibration method. Consequently, correction factors have to be applied to these analytical data. Direct conversion techniques like pyrolysis or the new laser instruments allow the measurement of the water molecule from the sample directly and should therefore not suffer from the salt effect, i.e. no corrections of raw values are necessary. However, due to high salt concentrations this might cause technical problems with the analytical hardware and may require labor-intensive sample preparation (e.g. vacuum distillation). This study evaluates the salt isotope effect for the IRMS equilibration technique (Thermo Gasbench II coupled to Delta Plus XP) and the laser-based IRIS instruments with liquid injection (Picarro L2120-i). Synthetic salt solutions (NaCl, KCl, CaCl2, MgCl2, MgSO4, CaSO4) and natural brines collected from the Stassfurt Salt Anticline (Germany; Stadler et al., 2012) were analysed with both techniques. Salt concentrations ranged from seawater salinity

  1. Fractionation of hydrogen, oxygen and carbon isotopes in n-alkanes and cellulose of three Sphagnum species

    NARCIS (Netherlands)

    Brader, A.V.; Winden, J.F.; Bohncke, S.J.P.; Beets, C.J.; Reichart, G.-J.; De Leeuw, J.W.

    2010-01-01

    Compound-specific isotope measurements of organic compounds are increasingly important in palaeoclimate reconstruction. Searching for more accurate peat-based palaeoenvironmental proxies, compound-specific fractionation of stable C, H and O isotopes of organic compounds synthesized by Sphagnum were

  2. 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

  3. 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

  4. Stable isotope analysis of Dacryoconarid carbonate microfossils: a new tool for Devonian oxygen and carbon isotope stratigraphy.

    Science.gov (United States)

    Frappier, Amy Benoit; Lindemann, Richard H; Frappier, Brian R

    2015-04-30

    Dacryoconarids are extinct marine zooplankton known from abundant, globally distributed calcite microfossils in the Devonian, but their shell stable isotope composition has not been previously explored. Devonian stable isotope stratigraphy is currently limited to less common invertebrates or bulk rock analyses of uncertain provenance. As with Cenozoic planktonic foraminifera, isotopic analysis of dacryoconarid shells could facilitate higher-resolution, geographically widespread stable isotope records of paleoenvironmental change, including marine hypoxia events, climate changes, and biocrises. We explored the use of Dacryoconarid isotope stratigraphy as a viable method in interpreting paleoenvironments. We applied an established method for determining stable isotope ratios (δ(13) C, δ(18) O values) of small carbonate microfossils to very well-preserved dacryoconarid shells. We analyzed individual calcite shells representing five common genera using a Kiel carbonate device coupled to a MAT 253 isotope ratio mass spectrometer. Calcite shell δ(13) C and δ(18) O values were compared by taxonomic group, rock unit, and locality. Single dacryoconarid calcite shells are suitable for stable isotope analysis using a Kiel-IRMS setup. The dacryoconarid shell δ(13) C values (-4.7 to 2.3‰) and δ(18) O values (-10.3 to -4.8‰) were consistent across taxa, independent of shell size or part, but varied systematically through time. Lower fossil δ(18) O values were associated with warmer water temperature and more variable δ(13) C values were associated with major bioevents. Dacryoconarid δ(13) C and δ(18) O values differed from bulk rock carbonate values. Dacryoconarid individual microfossil δ(13) C and δ(18) O values are highly sensitive to paleoenvironmental changes, thus providing a promising avenue for stable isotope chemostratigraphy to better resolve regional to global paleoceanographic changes throughout the upper Silurian to the upper Devonian. Our results

  5. Spatial Distribution of Stable Isotopes of Precipitation in Kumamoto, Japan

    Energy Technology Data Exchange (ETDEWEB)

    Anoue, M. T.; Shimada, J. [Graduate School of Science and Technology, Kumamoto University (Japan); Ichiyanagi, K. [Graduate School of Science and Technology, Kumamoto University and Japan Agency for Marine-Earth Science and Technology (Japan)

    2013-07-15

    To understand the spatial distribution of stable isotopic compositions in precipitation, precipitation samples were collected every two weeks from november 2009 to december 2010 at 6 points in Kumamoto, Japan. The {delta}{sup 18}O and {delta}{sup 2}H of precipitation samples were measured by isotope ratio mass spectrometry (Delta-S) with CO{sub 2}/H2{sub O} equivalent method for {delta}{sup 18}O and the chromium reduction method for {delta}2H. The range of {delta}{sup 18}O and d-excess (= {delta}{sup 2}H - 8 {delta}{sup 18}O) in precipitation is from -13.4 per mille to -3.5 per mille and from 2.6 per mille to 35.6 per mille , respectively. Seasonal variability of {delta}{sup 18}O (d-excess) in precipitation was low (high) in winter and high (low) in summer. The seasonal wind of this study area was dominated by south-westerly in summer (from June to August) and north-westerly in winter (from December to February). These wind regimes indicate seasonal variabilities of the water vapour pathway from the origin. In this paper the trend of inland effect to the {delta}{sup 18}O for both south-westerly and north-westerly are also considered. As a result, significant correlation between distances from the coastal line at south-westerly or north-westerly and {delta}{sup 18}O in precipitation was recognized, particularly from 18 February to 7 March and from 29 September to 19 October in 2010 (statistically significant with 5% level). Furthermore, in order to evaluate the course of precipitation, the column total of water vapour flux was considered in the whole period by using JRA-25 and JCDAS. It is interesting that the inland effect corresponded to the column total of water vapour flux at south-westerly (north-westerly). Hence, it is conceivable that the spatial distribution of {delta}{sup 18}O in precipitation was controlled by a column total of water vapour flux in this area. (author)

  6. "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.

  7. Experimental investigation of concentration and stable isotopes signals during organic contaminants back diffusion

    DEFF Research Database (Denmark)

    Jin, Biao; Nika, Chrysanthi-Elisabeth; Rolle, Massimo

    2017-01-01

    -dichloroethene (cis-DCE) as model contaminant and we investigated its back diffusion from an impermeable source into a permeable saturated layer, in which advection-dominated flow conditions were established. We used concentration and stable chlorine isotope measurements to investigate the plumes originated by cis...... and stable isotope gradients in the flow-through setup. In particular, steep concentration and stable isotope gradients were observed at the outlet. Lateral isotope gradients corresponding to chlorine isotope fractionation up to 20‰ were induced by cis-DCE back diffusion and subsequent advection......-dominated transport in all flow-through experiments. A numerical modeling approach, tracking individually all chlorine isotopologues, based on the accurate parameterization of local dispersion, as well as on the values of aqueous diffusion coefficients and diffusion-induced isotope fractionation from a previous study...

  8. 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.

  9. 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...... = 7.308%) results in a redefined Pt atomic weight of 195.08395 ± 0.00068. Using our technique we have measured small, reproducible and statistically significant offsets in Pt stable isotope ratios between different Pt element standards and the IRMM-010 standard, which potentially indicates...

  10. Shifts in rotifer life history in response to stable isotope enrichment: testing theories of isotope effects on organismal growth

    Science.gov (United States)

    2017-01-01

    In ecology, stable isotope labelling is commonly used for tracing material transfer in trophic interactions, nutrient budgets and biogeochemical processes. The main assumption in this approach is that the enrichment with a heavy isotope has no effect on the organism growth and metabolism. This assumption is, however, challenged by theoretical considerations and experimental studies on kinetic isotope effects in vivo. Here, I demonstrate profound changes in life histories of the rotifer Brachionus plicatilis fed 15N-enriched algae (0.4–5.0 at%); i.e. at the enrichment levels commonly used in ecological studies. These findings support theoretically predicted effects of heavy isotope enrichment on growth, metabolism and ageing in biological systems and underline the importance of accounting for such effects when using stable isotope labelling in experimental studies. PMID:28405367

  11. 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

  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. Recent developments and future directions for stable isotope applications in nutrition research. Report of a consultants meeting

    International Nuclear Information System (INIS)

    2001-01-01

    The International Atomic Energy Agency (IAEA) at its Headquarters in Vienna convened a consultants meeting to provide the Agency with an overview of the current status of isotopic techniques in nutritional science with respect to both methodology and applications. The main objectives were: To assess the practice of stable isotope methodologies in human nutrition research; To explore high quality stable isotope spikes for use in humans; To standardise the mathematical approaches to evaluate mass spectrometric data when using stable isotope labels within metabolic studies; To identify new strategies for improving sensitivity of nutrition monitoring techniques for use in projects in nutrition. This exercise was conducted to also identify strengths and weaknesses of methodologies currently used in IAEA funded research (CRPs and Technical Cooperation Projects) and to see how they can be improved for the general user, and to provide a basis for the assessment of outcomes delivered by collaborating laboratories in IAEA funded studies. The consultants reviewed the methods relating to the measurement of energy expenditure and noted that the analytical methodologies had changed substantially and that there was further refinement to data fitting and the calculation of uncertainties. They also felt that a repeat of a comparison of laboratory performances with a dilution series similar to the one carried out earlier should be performed for quality control. Other methods using labelled isotopes 13 C and 2 H were also discussed. The meeting noted that it was IAEA's intention to support the development of compound specific reference materials for 2 H, 13 C, 15 N and 18 O. Contrary to light isotope techniques where attempts have been made in the past towards standardization, in particular by IAEA and Stable Isotopes in Gastroenterology and Nutrition (SIGN) harmonization of techniques between laboratories is unsatisfactory for the minerals and trace elements. It was decided that

  14. Recent developments and future directions for stable isotope applications in nutrition research. Report of a consultants meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The International Atomic Energy Agency (IAEA) at its Headquarters in Vienna convened a consultants meeting to provide the Agency with an overview of the current status of isotopic techniques in nutritional science with respect to both methodology and applications. The main objectives were: To assess the practice of stable isotope methodologies in human nutrition research; To explore high quality stable isotope spikes for use in humans; To standardise the mathematical approaches to evaluate mass spectrometric data when using stable isotope labels within metabolic studies; To identify new strategies for improving sensitivity of nutrition monitoring techniques for use in projects in nutrition. This exercise was conducted to also identify strengths and weaknesses of methodologies currently used in IAEA funded research (CRPs and Technical Cooperation Projects) and to see how they can be improved for the general user, and to provide a basis for the assessment of outcomes delivered by collaborating laboratories in IAEA funded studies. The consultants reviewed the methods relating to the measurement of energy expenditure and noted that the analytical methodologies had changed substantially and that there was further refinement to data fitting and the calculation of uncertainties. They also felt that a repeat of a comparison of laboratory performances with a dilution series similar to the one carried out earlier should be performed for quality control. Other methods using labelled isotopes {sup 13}C and {sup 2}H were also discussed. The meeting noted that it was IAEA's intention to support the development of compound specific reference materials for {sup 2}H, {sup 13}C, {sup 15}N and {sup 18}O. Contrary to light isotope techniques where attempts have been made in the past towards standardization, in particular by IAEA and Stable Isotopes in Gastroenterology and Nutrition (SIGN) harmonization of techniques between laboratories is unsatisfactory for the minerals and trace

  15. The geochemistry of stable chlorine and bromine isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Eggenkamp, Hans [Onderzock and Beleving, Bussum (Netherlands)

    2014-11-01

    First book solely dedicated to the geochemistry of chlorine and bromine isotopes. Detailed description of analytical techniques, including their advantages and disadvantages. Indication of research fields where measurement of these isotopes is especially useful. This book provides detailed information on the history, analysis and applications of chlorine and bromine isotope geochemistry. Chlorine and bromine are geochemically unique as they prefer to exist as single charged negative ions. For this reason isotope fractionation reflects mostly processes that are not related to changes in the redox state and this fractionation is generally modest. The book will describe the processes that are most easily detected using these isotopes. Also isotope variations, and processes that cause them, measured in oxidised species such as perchlorates and in organic molecules will be described in this book.

  16. Stable isotope ratio measurements in hydrogen, nitrogen, and oxygen using Raman scattering

    International Nuclear Information System (INIS)

    Harney, R.C.; Bloom, S.D.; Milanovich, F.P.

    1975-01-01

    A method for measuring stable isotope ratios using laser Raman scattering was developed which may prove of significant utility and benefit in stable isotope tracer studies. Crude isotope ratio measurements obtained with a low-power laser indicate that with current technology it should be possible to construct an isotope ratio measurement system using laser Raman scattering that is capable of performing 0.1 percent accuracy isotope ratio measurements of 16 O/ 18 O in natural abundance oxygen gas or 14 N/ 15 N in natural abundance nitrogen gas in times less than two minutes per sample. Theory pertinent to the technique, designs of specific isotope ratio spectrometer systems, and data relating to isotope ratio measurements in hydrogen, nitrogen, and oxygen are presented. In addition, the current status of several studies utilizing this technique is discussed. (auth)

  17. Stable Isotopes in Precipitation over Indonesia Maritime Continent

    Energy Technology Data Exchange (ETDEWEB)

    Ichiyanagi, K. [Graduate School of Science and Technology, Kumamoto University, and Japan Agency for Marine-Earth Science and Technology (JAMSTEC) (Japan); Suwarman, R. [Graduate School of Science and Technology, Kumamoto University (Japan); Yamanaka, M. D. [Japan Agency for Marine-Earth Science and Technology (JAMSTEC) (Japan)

    2013-07-15

    Daily variability of stable isotopes in precipitation was observed at 6 stations in the Indonesian Maritime Continent from 2000 to 2006. The annual mean {delta}{sup 18}O at Bukit Kototabang (GAW), Jambi, and Makassar are heavier than those for others. The precipitation amount effect was observed only at Denpasar and Makassar. There are 2 groups resulting from the local Meteoric Water line; (1) slope is nearly 7.0 and high d-excess more than 10 at GAW, Denpasar, and Manado, (2) slope is around 7.4 and low d-excess less than 7.5 per mille at Jambi, Makassar, and Palau. Seasonal variability of {delta}{sup 18}O and d-excess were classified into three patterns. There are no seasonal variations in {delta}{sup 18}O and d-excess at GAW and Jambi, but clear seasonal variations at Denpasar (DPS) and Makassar (MKS). Due to the amount effect, {delta}{sup 18}O in precipitation is high when the precipitation amount is low from May to october. In contrast, the amount effect is not significant and d-excess is constant throughout the year in Manado and Palau. The {delta}{sup 18}O in precipitation at 2 stations located in sumatra Island corresponded with the Madden-Jullian Oscillation index, while those for the other 4 stations in more easterly locations did not. This finding indicates that water vapour evaporated from the Indian Ocean can reach the Island of sumatra, but can't reach more easterly locations. (author)

  18. Utilization of stable isotopes for characterizing an underground gas generator

    International Nuclear Information System (INIS)

    Pirard, J.P.; Antenucci, D.; Renard, X.; Letolle, R.

    1994-01-01

    The principles of isotopic exchange and isotope ratio result interpretation are first reviewed; then, in the framework of an underground coal gasification project in Belgium, experiments and modelling of the underground gas generator have been carried out: isotopic abundances of carbon, hydrogen and oxygen have been measured in the gasifying agent (O 2 , H 2 O) and in the effluent (CO 2 , CO, H 2 , H 2 O, CH 4 , O 2 , heavy oils and various organic and mineral substances). Gasification kinetics and temperatures have been evaluated and isotope application to thermometry is discussed. 1 fig., 9 refs

  19. 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

  20. 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

  1. Lifetime Stable isotopes profiles in whale earplug: assessment of foraging and migrations in the Northern Hemisphere

    Science.gov (United States)

    Mansouri, F.; Crain, D.; Winfield, Z.; Trumble, S.; Usenko, S.

    2017-12-01

    Whale earplugs, historically used for aging, were used to reconstruct lifetime stable isotope profiles for carbon (δ13C) and nitrogen (δ15N) for individual whales by delaminating lamina within the earplug. These stable isotope profile, which provide Continuous lifetime records of feeding, foraging ecology, and migration, were determined for 20 individuals from 4 baleen species including fin, minke, humpback, and blue whales spanning more than a century (1869 - 2014) using stable isotope analysis. Approximately 1 mg tissue from each lamina (n=1200) was analyzed for carbon and nitrogen stable isotope using continuous flow isotope ratio mass spectrometer (CF-IRMS). This research using whale earplugs have combined age estimates with stable isotope measurements to reconstruct lifetime foraging profiles with a 6-month resolution, providing an unprecedented opportunity to assess periods and trends in dietary fluctuations as well as migration between different foraging area which have distinct isotope values. Trends with these profiles suggest long-term changing in migration, while annual variability highlights seasonal fasting and feeding. Isotopic ratios were also used to identify subpopulations of Atlantic fin whales, which enabled us to assign unidentified humpback and minke whales to the Atlantic or Pacific Oceans. This historical archive of data provides us an unprecedented tool to assess long term marine ecosystem and subsequently marine organism transition to alternate foraging area and shed light on the whale's population status in the Northern hemisphere.

  2. 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.

  3. Utilization of stable isotopes for characterizing an underground gas generator; Utilisation des isotopes stables pour caracteriser un gazogene souterrain

    Energy Technology Data Exchange (ETDEWEB)

    Pirard, J P; Antenucci, D; Renard, X [Liege Univ. (Belgium); Letolle, R [Paris-6 Univ., 75 (France)

    1994-12-31

    The principles of isotopic exchange and isotope ratio result interpretation are first reviewed; then, in the framework of an underground coal gasification project in Belgium, experiments and modelling of the underground gas generator have been carried out: isotopic abundances of carbon, hydrogen and oxygen have been measured in the gasifying agent (O{sub 2}, H{sub 2}O) and in the effluent (CO{sub 2}, CO, H{sub 2}, H{sub 2}O, CH{sub 4}, O{sub 2}, heavy oils and various organic and mineral substances). Gasification kinetics and temperatures have been evaluated and isotope application to thermometry is discussed. 1 fig., 9 refs.

  4. Changes of stable isotopes carbon-13 and nitrogen-15 in different tissues of cattle

    International Nuclear Information System (INIS)

    Sun Fengmei; Yu Hongxia; Wu Wei; Yang Shuming

    2009-01-01

    Stable isotope analysis is a potential tool for tracing food origin. The stable carbon and nitrogen isotope composition in different tissues of two varieties of cattle under the same culture condition were investigated. δ 13 C and δ 15 N values of different defatted muscle and crude fat, cattle tail hair, blood, liver and feed were determined by isotope ratio mass spectrometry, and statistical analysis was carried out. The results showed that stable isotopes of carbon and nitrogen composition was not affected by cattle variety; the δ 13 C values between different defatted muscle, blood, liver and cattle hair were not significantly different, but δ 15 N value in the liver was much higher than other muscle and the δ 13 C values didn't show difference among all the crude fat samples. So these results indicated that isotope fractionation in the various tissue was discrepant. (authors)

  5. 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.)

  6. The combined use of micro-hydropyrolysis and compound-specific isotope analysis (CSIA) as a novel technique to identify coal-derived biodegraded PAH flux in the complex environment

    Energy Technology Data Exchange (ETDEWEB)

    Cheng-Gong Sun; Gbolagade Olalere; Wisdom Ivwurie; Mick Cooper; Colin Snape [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre

    2007-07-01

    A novel analytical methodology combining CSIA and micro-hydropyrolysis (CSIA/micro-HyPy) has been developed to aid unambiguous source apportionment of PAHs in the complex environment where PAH matrices have been heavily biodegraded and/or their isotopic signatures are overlapping for some sources. Asphaltenes retain useful information of biogeochemical significance, which can be accessed via hydropyrolysis. The PAHs released from hydropyrolysis of asphaltenes, the bound PAHs, from different primary sources (e.g. crude oils, low and high temperature coal tars) were characterized and compared to free aromatics in regard to their molecular and 13C-isotopic profiles. It was found that hydropyrolysis of asphaltenes can generate molecular and isotopic profiles highly representative of their primary sources. For both low and high temperature coal tar, the bound aromatics have broadly similar molecular distributions to their free aromatic counterparts and have {sup 13}C-isotopic values almost identical to those of UK bituminous coals(-23{per_thousand}), indicating that the asphaltenes are actually released as representative fragments of coal structures during carbonization. As expected, the bound aromatics are more 13C-enriched by 1-3 {per_thousand} (-21 to -23{per_thousand}) compared to free aromatics (-24 to -26{per_thousand}). No significant isotopic difference was observed between free and bound aromatics for a North Sea crude oil, all having similar {sup 13}C-isotopic values (-27.2-30.2 {per_thousand}) that are significantly lighter than those for coal-derived aromatics. Applications of this novel methodological CSIA/micro-HyPy technique to samples previously examined from an area around a former carbonization plant have been successfully demonstrated where unambiguous source apportionment could not be achieved previously for the PAHs due to likely environmental alternation. 3 refs., 2 figs., 2 tabs.

  7. Combined stable isotope trajectories for water-rock interaction

    International Nuclear Information System (INIS)

    Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

    1981-01-01

    The 'mixed' model of water-rock interaction (1980 Workshop) is explained in detail. Based on the magnitude of the oxygen isotope shifts of their recharge water, different geothermal systems can be placed in an evolutionary series, from incipient (large shift of water) to mature (small shift of water). Isotopes of different chemical elements may be combined, to yield a stringent test of whether or not a given change in rock composition may be ascribed to interaction with water (L-shaped trajectories). For the acidic eruptives of the Taupo Volcanic Zone, available strontium and oxygen isotope data practically rule out an origin by partial melting of greywacke basement

  8. The future of producing separated stable isotopes at Oak Ridge National Laboratory for accelerator applications

    International Nuclear Information System (INIS)

    Collins, E.D.

    1994-01-01

    Separated stable isotopes, produced in the calutrons at Oak Ridge National Laboratory, are essential target materials for production of numerous radioisotopes in accelerators and reactors. Recently, separated stable isotope production has been curtailed because government appropriations were discontinued and salts revenues decreased. The calutrons were placed in standby and the operating staff reduced to enable support by sales from existing inventories. Appeals were made to industry and government to preserve this national capability. Methods for providing volume-based price reductions were created to attract support from commercial isotope users. In 1994, the Department of Energy's Isotope Production and Distribution Program was restructured and a strategy produced to seek appropriated funding for the future production of rare, nonprofitable isotopes for research uses. This strategy, together with new demands for medical isotopes, will enable future operation of the calutrons. Moreover, production may be enhanced by complementing calutron capabilities with the Plasma Separation Process

  9. Improved constraints on in situ rates and on quantification of complete chloroethene degradation from stable carbon isotope mass balances in groundwater plumes

    Science.gov (United States)

    Höhener, Patrick; Elsner, Martin; Eisenmann, Heinrich; Atteia, Olivier

    2015-11-01

    Spills of chloroethenes (CEs) at industrial and urban sites can create groundwater plumes in which tetrachloro- and trichloroethene sequentially degrade to dichloroethenes, vinyl chloride (VC) and ethene, or ethane under reducing conditions. For detoxification, degradation must go beyond VC. Assessments based on ethene and ethane, however, are difficult because these products are volatile, may stem from alternative sources, can be further transformed and are not always monitored. To alternatively quantify degradation beyond VC, stable carbon isotope mass balances have been proposed where concentration-weighted CE isotope ratios are summed up and compared to the original source isotope ratio. Reported assessments, however, have provided not satisfactorily quantified results entailing greatly differing upper and lower estimates. This work proposes an integrative approach to better constrain the extent of total chloroethene degradation in groundwater samples. It is based on fitting of measured concentration and compound-specific stable carbon isotope data to an analytical reactive transport equation simulating steady-state plumes in two dimensions using an EXCEL spreadsheet. The fitting also yields estimates of degradation rates, of source width and of dispersivities. The approach is validated using two synthetic benchmark cases where the true extent of degradation is well known, and using data from two real field cases from literature.

  10. Metal Stable Isotope Tagging: Renaissance of Radioimmunoassay for Multiplex and Absolute Quantification of Biomolecules.

    Science.gov (United States)

    Liu, Rui; Zhang, Shixi; Wei, Chao; Xing, Zhi; Zhang, Sichun; Zhang, Xinrong

    2016-05-17

    The unambiguous quantification of biomolecules is of great significance in fundamental biological research as well as practical clinical diagnosis. Due to the lack of a detectable moiety, the direct and highly sensitive quantification of biomolecules is often a "mission impossible". Consequently, tagging strategies to introduce detectable moieties for labeling target biomolecules were invented, which had a long and significant impact on studies of biomolecules in the past decades. For instance, immunoassays have been developed with radioisotope tagging by Yalow and Berson in the late 1950s. The later languishment of this technology can be almost exclusively ascribed to the use of radioactive isotopes, which led to the development of nonradioactive tagging strategy-based assays such as enzyme-linked immunosorbent assay, fluorescent immunoassay, and chemiluminescent and electrochemiluminescent immunoassay. Despite great success, these strategies suffered from drawbacks such as limited spectral window capacity for multiplex detection and inability to provide absolute quantification of biomolecules. After recalling the sequences of tagging strategies, an apparent question is why not use stable isotopes from the start? A reasonable explanation is the lack of reliable means for accurate and precise quantification of stable isotopes at that time. The situation has changed greatly at present, since several atomic mass spectrometric measures for metal stable isotopes have been developed. Among the newly developed techniques, inductively coupled plasma mass spectrometry is an ideal technique to determine metal stable isotope-tagged biomolecules, for its high sensitivity, wide dynamic linear range, and more importantly multiplex and absolute quantification ability. Since the first published report by our group, metal stable isotope tagging has become a revolutionary technique and gained great success in biomolecule quantification. An exciting research highlight in this area

  11. Use of stable isotope analysis to determine of the timing of ontogenic habitat shifts

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SAIP funding for stable isotope research was provided in FY11 and FY13; the FY11 funding was for loggerhead turtles (described below) as opposed to green turtles in...

  12. 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...

  13. 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...

  14. Precipitation and stream water stable isotope data from the Marys River, Oregon in water year 2015.

    Data.gov (United States)

    U.S. Environmental Protection Agency — Water stable isotope data collected from a range of streams throughout the Marys River basin in water year 2015, and precipitation data collected within the basin at...

  15. BASIN TCP Stable Isotope Composition of CO2 in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set reports stable isotope ratio data of CO2 (13C/12C and 18O/16O) associated with photosynthetic and respiratory exchanges across the biosphere-atmosphere...

  16. BASIN TCP Stable Isotope Composition of CO2 in Terrestrial Ecosystems

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set reports stable isotope ratio data of CO2 (13C/12C and 18O/16O) associated with photosynthetic and respiratory exchanges across the...

  17. Stable isotopic analysis of Barnacle larvae and their faecal pellets to evaluate the ingested food

    Digital Repository Service at National Institute of Oceanography (India)

    Gaonkar, C.A.; Anil, A.C.

    Stable isotopes of carbon and nitrogen are useful in the evaluation of food web dynamics and have been used extensively in the feeding studies. Barnacles are dominant component of the intertidal and bio-fouling communities. Life cycle of barnacles...

  18. Alaska Northern Fur Seal Foraging Habitat Model Stable Isotope Data, 2006-2008

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data sets were used by Zeppelin et al. (2015) to model northern fur seal foraging habitats based on stable isotope values measured in plasma and red blood...

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

    Indian Academy of Sciences (India)

    Ajoy K Bhaumik

    2017-07-24

    Jul 24, 2017 ... of a species for isotopic analysis has forced us to select multiple species from down-core samples. Thus ... microhabitat, climatic variability, bottom and pore ...... Trends, rhythms, and aberrations in global climate 65 Ma.

  20. Stable isotope measurement techniques for atmospheric greenhouse gases

    International Nuclear Information System (INIS)

    2002-01-01

    The technical requirements to perform useful measurements of atmospheric greenhouse gas concentrations and of their isotope ratios are of direct relevance for all laboratories engaged in this field. A meaningful interpretation of isotopes in global models on sources and sinks of CO 2 and other greenhouse gases depends on strict laboratory protocols and data quality control measures ensuring comparable data in time and space. Only with this precondition met, the isotope techniques can serve as a potentially powerful method for reducing uncertainties in the global CO 2 budgets and for tracing pathways and interaction of terrestrial, oceanic, and atmospheric pools of carbon. This publication provides four contributions describing methods for the determination of the isotopic composition of trace gases in atmospheric air and in ice cores. These contributions have been indexed separately

  1. Stable isotope composition of cocoa beans of different geographical origin.

    Science.gov (United States)

    Perini, Matteo; Bontempo, Luana; Ziller, Luca; Barbero, Alice; Caligiani, Augusta; Camin, Federica

    2016-09-01

    The isotopic profile (δ(13) C, δ(15) N, δ(18) O, δ(2) H, δ(34) S) was used to characterise a wide selection of cocoa beans from different renowned production areas (Africa, Asia, Central and South America). The factors most influencing the isotopic signatures of cocoa beans were climate and altitude for δ(13) C and the isotopic composition of precipitation water for δ(18) O and δ(2) H, whereas δ(15) N and δ(34) S were primarily affected by geology and fertilisation practises. Multi-isotopic analysis was shown to be sufficiently effective in determining the geographical origin of cocoa beans, and combining it with Canonical Discriminant Analysis led to more than 80% of samples being correctly reclassified. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Food-web inferences of stable isotope spatial patterns in copepods and yellowfin tuna in the pelagic eastern Pacific Ocean

    Science.gov (United States)

    Olson, Robert J.; Popp, Brian N.; Graham, Brittany S.; López-Ibarra, Gladis A.; Galván-Magaña, Felipe; Lennert-Cody, Cleridy E.; Bocanegra-Castillo, Noemi; Wallsgrove, Natalie J.; Gier, Elizabeth; Alatorre-Ramírez, Vanessa; Ballance, Lisa T.; Fry, Brian

    2010-07-01

    Evaluating the impacts of climate and fishing on oceanic ecosystems requires an improved understanding of the trophodynamics of pelagic food webs. Our approach was to examine broad-scale spatial relationships among the stable N isotope values of copepods and yellowfin tuna ( Thunnus albacares), and to quantify yellowfin tuna trophic status in the food web based on stable-isotope and stomach-contents analyses. Using a generalized additive model fitted to abundance-weighted-average δ 15N values of several omnivorous copepod species, we examined isotopic spatial relationships among yellowfin tuna and copepods. We found a broad-scale, uniform gradient in δ 15N values of copepods increasing from south to north in a region encompassing the eastern Pacific warm pool and parts of several current systems. Over the same region, a similar trend was observed for the δ 15N values in the white muscle of yellowfin tuna caught by the purse-seine fishery, implying limited movement behavior. Assuming the omnivorous copepods represent a proxy for the δ 15N values at the base of the food web, the isotopic difference between these two taxa, “ ΔYFT-COP,” was interpreted as a trophic-position offset. Yellowfin tuna trophic-position estimates based on their bulk δ 15N values were not significantly different than independent estimates based on stomach contents, but are sensitive to errors in the trophic enrichment factor and the trophic position of copepods. An apparent inshore-offshore, east to west gradient in yellowfin tuna trophic position was corroborated using compound-specific isotope analysis of amino acids conducted on a subset of samples. The gradient was not explained by the distribution of yellowfin tuna of different sizes, by seasonal variability at the base of the food web, or by known ambit distances (i.e. movements). Yellowfin tuna stomach contents did not show a regular inshore-offshore gradient in trophic position during 2003-2005, but the trophic

  3. 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...

  4. Stable isotope sales; Mound Facility customer and shipment summaries, FY 1977

    International Nuclear Information System (INIS)

    Ruwe, A.H. Jr.

    1978-01-01

    A listing is given of Mound Facility's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, chlorine, and sulfur for Fiscal Year 1977. Purchasers are listed alphabeticaly and are divided into domestic and foreign groups. A cross-reference index by location is included for domestic customers. Cross-reference listings by isotope purchased are included for all customers

  5. 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...

  6. Stable isotope sales: Mound Laboratory customer and shipment summaries, FY-1975

    International Nuclear Information System (INIS)

    Eck, C.F.

    1976-01-01

    A listing is given of Mound Laboratory's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, and sulfur for Fiscal Year 1975. Purchasers are listed alphabetically and are divided into domestic and foreign groups. A cross reference index by location is included for domestic customers. Cross reference listings by isotope purchased are included for all customers

  7. Stable isotope sales: Mound Facility customer and shipment summaries, FY 1981

    International Nuclear Information System (INIS)

    Ruwe, A.H. Jr.

    1982-01-01

    A listing is given of Mound Facility's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, chlorine, and sulfur for Fiscal Year 1981. Purchasers are listed alphabetically and are divided into domestic and foreign groups. A cross-reference index by location is included for domestic customers. Cross-reference listings by isotope purchased are included for all customers

  8. Stable isotopes dissect aquatic food webs from the top to the bottom

    NARCIS (Netherlands)

    Middelburg, J.J.

    2014-01-01

    Stable isotopes have been used extensively to study food-web functioning, that is, the flow of energy and matter among organisms. Traditional food-web studies are based on the natural variability of isotopes and are limited to larger organisms that can be physically separated from their environment.

  9. Stable isotope composition of environmental water and food products as a tracer of origin

    International Nuclear Information System (INIS)

    Wierzchnicki, R.; Owczarczyk, A.; Soltyk, W.

    2004-01-01

    The paper is the review of Institute of Nuclear Chemistry and Technology (INCT) activity in application of stable isotope ratios (especially D/H and 18 O/ 16 O) for environmental studies and food origin control. INCT has at disposal since 1998, a high class instrument - Isotope Ratio Mass Spectrometer, Delta Plus, Finnigan MAT, Germany - suitable to perform such measurements. (author)

  10. Carbon and Hydrogen Stable Isotope Fractionation during Aerobic Bacterial Degradation of Aromatic Hydrocarbons†

    Science.gov (United States)

    Morasch, Barbara; Richnow, Hans H.; Schink, Bernhard; Vieth, Andrea; Meckenstock, Rainer U.

    2002-01-01

    13C/12C and D/H stable isotope fractionation during aerobic degradation was determined for Pseudomonas putida strain mt-2, Pseudomonas putida strain F1, Ralstonia pickettii strain PKO1, and Pseudomonas putida strain NCIB 9816 grown with toluene, xylenes, and naphthalene. Different types of initial reactions used by the respective bacterial strains could be linked with certain extents of stable isotope fractionation during substrate degradation. PMID:12324375

  11. Development on traceability based on changes of stable isotopes in animal tissues and organs

    International Nuclear Information System (INIS)

    Cai Xianfeng; Guo Boli; Wei Yimin; Sun Shumin; Wei Shuai

    2011-01-01

    Stable isotope analysis is a new method in food traceability, which can be used to trace animals' geographical origin and life history. This paper reviews the recent progress of researches on characteristics of stable isotopes and turnover time in different animal tissues and organs, as well as their influence caused by feed, drinking water, geographical origin, storing and processing. The aim of this paper is to provide theoretical reference for studies on the traceability of animal derived food and animals' life history. (authors)

  12. 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)

  13. Stable isotopes in mid-ocean ridge hydrothermal systems: Interactions between fluids, minerals, and organisms

    Science.gov (United States)

    Shanks, W. C., III; Böhlke, J. K.; Seal, R. R., II

    Studies of abundance variations of light stable isotopes in nature have had a tremendous impact on all aspects of geochemistry since the development, in 1947, of a gas source isotope ratio mass spectrometer capable of measuring small variations in stable isotope ratios [Nier, 1947] Stable isotope geochemistry is now a mature field, as witnessed by the proliferation of commercially available mass spectrometers installed at virtually every major academic, government, and private-sector research geochemistry laboratory. A recent search of a literature database revealed over 3,000 articles that utilized stable isotope geochemistry over the last 20 years. Nonetheless, many exciting new technical developments are leading to exciting new discoveries and applications. In particular, micro analytical techniques involving new generations of laser- and ion-microprobes are revolutionizing the types of analyses that can be done on spot sizes as small as a few tens of micrometers [Shanks and Criss, 1989]. New generations of conventional gas source and thermal ionization mass spectrometers, with high levels of automation and increased sensitivity and precision, are allowing analyses of large numbers of samples, like those needed for stable isotope stratigraphy in marine sediments, and are enabling the development and application of new isotopic systems.

  14. Stable isotope separation in calutrons: Forty years of production and distribution

    International Nuclear Information System (INIS)

    Bell, W.A.; Tracy, J.G.

    1987-11-01

    The stable isotope separation program, established in 1945, has operated continually to provide enriched stable isotopes and selected radioactive isotopes, including the actinides, for use in research, medicine, and industrial applications. This report summarizes the first forty years of effort in the production and distribution of stable isotopes. Evolution of the program along with the research and development, chemical processing, and production efforts are highlighted. A total of 3.86 million separator hours has been utilized to separate 235 isotopes of 56 elements. Relative effort expended toward processing each of these elements is shown. Collection rates (mg/separator h), which vary by a factor of 20,000 from the highest to the lowest ( 205 Tl to 46 Ca), and the attainable isotopic purity for each isotope are presented. Policies related to isotope pricing, isotope distribution, and support for the enrichment program are discussed. Changes in government funding, coupled with large variations in sales revenue, have resulted in 7-fold perturbations in production levels

  15. The use of stable isotopes as minerals tracers in human nutrition research

    International Nuclear Information System (INIS)

    Sajet, A. S.

    2007-01-01

    The idea of using stable isotopes as tracers in metabolic studies of vital systems started when it was noted that stable isotopes have the ability to unite with biomolecules.The article aims to review the methods used to measure quantities of tracer in doses given to donors orally or via intravenous injection, determinants of detection and their estimation as well as the use of mass spectrometer and other devices to measure different stable isotopes. In fact, the use of stable isotopes in nutrition research is an essential technique in order to understand many of the processes related to minerals absorption and the human body composition of water, fat and bones, transportation of food components within the body and estimation of the ages of red blood cells. It is possible to use the secretion of stable isotopes taken by injection to determine the paths of excretion or estimate self-retaining material by the intestine. The stable isotope technology helps to know the mechanics of minerals absorption and excretion in the body. It was possible to find out metabolic reactions of metals using mathematical models based on the measurement of tracers amount in biological fluids in order to know the absorbance situation of metals in the body.

  16. Contamination risk of stable isotope samples during milling.

    Science.gov (United States)

    Isaac-Renton, M; Schneider, L; Treydte, K

    2016-07-15

    Isotope analysis of wood is an important tool in dendrochronology and ecophysiology. Prior to mass spectrometry analysis, wood must be homogenized, and a convenient method involves a ball mill capable of milling samples directly in sample tubes. However, sample-tube plastic can contaminate wood during milling, which could lead to biological misinterpretations. We tested possible contamination of whole wood and cellulose samples during ball-mill homogenization for carbon and oxygen isotope measurements. We used a multi-factorial design with two/three steel milling balls, two sample amounts (10 mg, 40 mg), and two milling times (5 min, 10 min). We further analyzed abrasion by milling empty tubes, and measured the isotope ratios of pure contaminants. A strong risk exists for carbon isotope bias through plastic contamination: the δ(13) C value of polypropylene deviated from the control by -6.77‰. Small fibers from PTFE filter bags used during cellulose extraction also present a risk as the δ(13) C value of this plastic deviated by -5.02‰. Low sample amounts (10 mg) showed highest contamination due to increased abrasion during milling (-1.34‰), which is further concentrated by cellulose extraction (-3.38‰). Oxygen isotope measurements were unaffected. A ball mill can be used to homogenize samples within test tubes prior to oxygen isotope analysis, but not prior to carbon or radiocarbon isotope analysis. There is still a need for a fast, simple and contamination-free sample preparation procedure. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  17. Amino acid stable isotope applications to deep-sea corals: A molecular geochemistry approach to reconstructing past ocean conditions

    Science.gov (United States)

    McMahon, K.; McCarthy, M. D.; Guilderson, T. P.; Sherwood, O.; Williams, B.; Larsen, T.; Glynn, D. S.

    2017-12-01

    Future climate change is predicted to alter ocean productivity, food web dynamics, biogeochemical cycling, and the efficacy of the biological pump. Proteinaceous deep-sea corals act as "living sediment traps," providing long-term, high-resolution records of exported surface ocean production and a window into past changes in ocean condition as a historical context for potential future changes. Here, we present recent work developing the application of compound-specific stable isotope analysis of individual amino acids to proteinaceous deep-sea corals to reconstruct past changes in phytoplankton community composition and biogeochemical cycling. We present new calibrations for molecular isotope comparisons between metabolically active coral polyp tissue and bioarchival proteinaceous skeleton. We then applied these techniques to deep-sea corals from the North Pacific Subtropical Gyre (NPSG) to reconstruct centennial to millennial time scale changes in phytoplankton community composition and biogeochemical cycling as a function of regional climate change. This work suggests that the NPSG has undergone multiple major phytoplankton regime shifts over the last millennium between prokaryotic and eukaryotic phytoplankton communities and associated sources of nitrogen fueling production. The most recent regime, which started around the end of the Little Ice Age and the onset of the Industrial era, is unprecedented in the last 1000 years and resulted in a 30-50% increase in diazotrophic cyanobacteria contribution to export production and an associated 17-27% increase in N2-fixation in the NPSG over last century. By offering the first direct phylogenetic context for long-term shifts in isotopic records of exported particulate organic matter, our data represent a major step forward in understanding the evolution of marine plankton community dynamics, food web architecture, biogeochemical cycling, and the climate feedback loops through the biological pump.

  18. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.; Wang, Lixin; Parkes, Stephen; Strauss, Josiah; McCabe, Matthew; Evans, Jason P.; Griffiths, Alan D.

    2015-01-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  19. Stable water isotope and surface heat flux simulation using ISOLSM: Evaluation against in-situ measurements

    KAUST Repository

    Cai, Mick Y.

    2015-04-01

    The stable isotopes of water are useful tracers of water sources and hydrological processes. Stable water isotope-enabled land surface modeling is a relatively new approach for characterizing the hydrological cycle, providing spatial and temporal variability for a number of hydrological processes. At the land surface, the integration of stable water isotopes with other meteorological measurements can assist in constraining surface heat flux estimates and discriminate between evaporation (E) and transpiration (T). However, research in this area has traditionally been limited by a lack of continuous in-situ isotopic observations. Here, the National Centre for Atmospheric Research stable isotope-enabled Land Surface Model (ISOLSM) is used to simulate the water and energy fluxes and stable water isotope variations. The model was run for a period of one month with meteorological data collected from a coastal sub-tropical site near Sydney, Australia. The modeled energy fluxes (latent heat and sensible heat) agreed reasonably well with eddy covariance observations, indicating that ISOLSM has the capacity to reproduce observed flux behavior. Comparison of modeled isotopic compositions of evapotranspiration (ET) against in-situ Fourier Transform Infrared spectroscopy (FTIR) measured bulk water vapor isotopic data (10. m above the ground), however, showed differences in magnitude and temporal patterns. The disparity is due to a small contribution from local ET fluxes to atmospheric boundary layer water vapor (~1% based on calculations using ideal gas law) relative to that advected from the ocean for this particular site. Using ISOLSM simulation, the ET was partitioned into E and T with 70% being T. We also identified that soil water from different soil layers affected T and E differently based on the simulated soil isotopic patterns, which reflects the internal working of ISOLSM. These results highlighted the capacity of using the isotope-enabled models to discriminate

  20. 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.

  1. Effects of euthanasia method on stable-carbon and stable-nitrogen isotope analysis for an ectothermic vertebrate.

    Science.gov (United States)

    Atwood, Meredith A

    2013-04-30

    Stable isotope analysis is a critical tool for understanding ecological food webs; however, results can be sensitive to sample preparation methods. To limit the possibility of sample contamination, freezing is commonly used to euthanize invertebrates and preserve non-lethal samples from vertebrates. For destructive sampling of vertebrates, more humane euthanasia methods are preferred to freezing and it is essential to evaluate how these euthanasia methods affect stable isotope results. Stable isotope ratios and elemental composition of carbon and nitrogen were used to evaluate whether the euthanasia method compromised the integrity of the sample for analysis. Specifically, the stable isotope and C:N ratios were compared for larval wood frogs (Rana sylvatica  =  Lithobates sylvaticus), an ectothermic vertebrate, that had been euthanized by freezing with four different humane euthanasia methods: CO2, benzocaine, MS-222 (tricaine methanesulfonate), and 70% ethanol. The euthanasia method was not related to the δ(13)C or δ(15)N values and the comparisons revealed no differences between freezing and any of the other treatments. However, there were slight (non-significant) differences in the isotope ratios of benzocaine and CO2 when each was compared with freezing. The elemental composition was altered by the euthanasia method employed. The percentage nitrogen was higher in CO2 treatments than in freezing, and similar (non-significant) trends were seen for ethanol treatments relative to freezing. The resulting C:N ratios were higher for benzocaine treatments than for both CO2 and ethanol. Similar (non-significant) trends suggested that the C:N ratios were also higher for animals euthanized by freezing than for both CO2 and ethanol euthanasia methods. The euthanasia method had a larger effect on elemental composition than stable isotope ratios. The percentage nitrogen and the subsequent C:N ratios were most affected by the CO2 and ethanol euthanasia methods, whereas

  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 Isotopic Composition of Rainfall in Western Cameroon

    Energy Technology Data Exchange (ETDEWEB)

    Ketchemen-Tandia, B.; Ngo Boum, S.; Ebonji Seth, C. R.; Nkoue Ndong, G. R.; Wonkam, C. [Universite de Douala, Douala (Cameroon); Huneau, F. [Universite de Bordeaux, EA Georessources and Environnement, Talence (France); Celle-Jeanton, H. [Clermont Universite, Clermont-Ferrand (France)

    2013-07-15

    Monthly rainfall collected at the douala station (Western cameroon) from 2006 to 2008 was analysed for oxygen-18 and deuterium content. The dataset, which is now integrated into the GNIP database, was compared to the local groundwater record in order to define the input function of regional hydrosystems. The isotope data displays a wide range of values from -0.59 to -6.14 per mille for oxygen-18 and from -7.75 to -38.8 per mille for deuterium, closely following the GMWL (global Meteoric Water line), suggesting that rain formation processes occurred under isotopic equilibrium conditions between the condensate and the corresponding vapour. No significant evaporation tendency was found. The comparison with the previous studies in the area provides a realistic pattern of isotope concentrations in both surface and groundwater throughout Cameroon. (author)

  4. Stable isotope content of South African river water

    International Nuclear Information System (INIS)

    Talma, A.S.

    1987-01-01

    Variations of the isotopic ratios 18 O/ 16 O and D/H in natural waters reflect the variety of processes to which the water was subjected within the hydrological cycle. Time series of the 18 O content of the major South African rivers over a few years have been obtained in order to characterise the main features of these variations in both time and space. Regionally the average '1 8 O content of river water reflects that of the prevailing rains within the catchment. 18 O variations with time are mainly correlated with river flow rates. Impoundments upstream and management of river flows reduce this correlation. Isotope variations along the course of a river show the effects of inflow from smaller streams and evaporation in the river or its impoundments. These observations indicate the use of isotopic methods to study the evaporation and mixing of river water and its interaction with the surrounding environment

  5. First stable isotope analysis of Asiatic wild ass tail hair from the Mongolian Gobi.

    Science.gov (United States)

    Horacek, Micha; Sturm, Martina Burnik; Kaczensky, Petra

    Stable isotope analysis has become a powerful tool to study feeding ecology, water use or movement pattern in contemporary, historic and ancient species. Certain hair and teeth grow continuously, and when sampled longitudinally can provide temporally explicit information on dietary regime and movement pattern. In an initial trial, we analysed a tail sample of an Asiatic wild ass ( Equus hemionus ) from the Mongolian Gobi. We found seasonal variations in H, C and N isotope patterns, likely being the result of temporal variations in available feeds, water supply and possibly physiological status. Thus stable isotope analysis shows promise to study the comparative ecology of the three autochthonous equid species in the Mongolian Gobi.

  6. The synthesis of a tritium, carbon-14, and stable isotope-labeled cathepsin C inhibitors.

    Science.gov (United States)

    Allen, Paul; Bragg, Ryan A; Caffrey, Moya; Ericsson, Cecilia; Hickey, Michael J; Kingston, Lee P; Elmore, Charles S

    2017-02-01

    As part of a medicinal chemistry program aimed at developing a highly potent and selective cathepsin C inhibitor, tritium, carbon-14, and stable isotope-labeled materials were required. The synthesis of tritium-labeled methanesulfonate 5 was achieved via catalytic tritiolysis of a chloro precursor, albeit at a low radiochemical purity of 67%. Tritium-labeled AZD5248 was prepared via a 3-stage synthesis, utilizing amide-directed hydrogen isotope exchange. Carbon-14 and stable isotope-labeled AZD5248 were successfully prepared through modifications of the medicinal chemistry synthetic route, enabling the use of available labeled intermediates. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Assessment of Stable Isotope Distribution in Complex Systems

    Science.gov (United States)

    He, Y.; Cao, X.; Wang, J.; Bao, H.

    2017-12-01

    Biomolecules in living organisms have the potential to approach chemical steady state and even apparent isotope equilibrium because enzymatic reactions are intrinsically reversible. If an apparent local equilibrium can be identified, enzymatic reversibility and its controlling factors may be quantified, which helps to understand complex biochemical processes. Earlier research on isotope fractionation tends to focus on specific process and compare mostly two different chemical species. Using linear regression, "Thermodynamic order", which refers to correlated δ13C and 13β values, has been proposed to be present among many biomolecules by Galimov et al. However, the concept "thermodynamic order" they proposed and the approach they used has been questioned. Here, we propose that the deviation of a complex system from its equilibrium state can be rigorously described as a graph problem as is applied in discrete mathematics. The deviation of isotope distribution from equilibrium state and apparent local isotope equilibrium among a subset of biomolecules can be assessed using an apparent fractionation difference matrix (|Δα|). Applying the |Δα| matrix analysis to earlier published data of amino acids, we show the existence of apparent local equilibrium among different amino acids in potato and a kind of green alga. The existence of apparent local equilibrium is in turn consistent with the notion that enzymatic reactions can be reversible even in living systems. The result also implies that previous emphasis on external carbon source intake may be misplaced when studying isotope distribution in physiology. In addition to the identification of local equilibrium among biomolecules, the difference matrix approach has the potential to explore chemical or isotope equilibrium state in extraterrestrial bodies, to distinguish living from non-living systems, and to classify living species. This approach will benefit from large numbers of systematic data and advanced pattern

  8. Kinetic fractionation of stable nitrogen isotopes during amino acid transamination

    International Nuclear Information System (INIS)

    Macko, S.A.; Fogel Estep, M.L.; Engel, M.H.; Hare, P.E.

    1986-01-01

    This study evaluates a kinetic isotope effect involving 15 N, during the transamination reactions catalyzed by glutamic oxalacetic transaminase. During the transfer of amino nitrogen from glutamic acid to oxaloacetate to form aspartic acid, 14 NH 2 reacted 1.0083 times faster than 15 NH 2 . In the reverse reaction transferring NH 2 from aspartic acid to α-ketoglutarate, 14 NH 2 was incorporated 1.0017 times faster than 15 NH 2 . Knowledge of the magnitude and sign of these isotope effects will be useful in the interpretation of the distribution of 15 N in biological and geochemical systems. (author)

  9. Chromium stable isotope fractionation in modern biogeochemical cycling

    DEFF Research Database (Denmark)

    Paulukat, Cora Stefanie

    oxygen in the Earth’s atmosphere. Oxidative rock weathering on land induces oxidation of immobile Cr(III) to mobile Cr(VI). Isotopically relatively heavy Cr(VI) is released to runoff, and transported by rivers to the oceans, where it is incorporated into chemical sediments and carbonate shells...... laterite soils from India, formed on ultramafic rocks, indicates extensive leaching of isotopically heavy Cr(VI). Transferring this knowledge to ancient weathering profiles, negatively fractionated Cr is clear evidence for the presence of free oxygen in the atmosphere. The second part demonstrates...

  10. Compound specific radiocarbon content of lignin oxidation products from the Altamaha river and Coastal Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Culp, Randy, E-mail: rculp@uga.edu [Center for Applied Isotope Studies, University of Georgia, Athens, Georgia (United States)

    2013-01-15

    Compound-specific isotope analysis (CSIA) is a powerful tool in organic geochemistry by providing detailed information about an individual organic compound's history with regard to its source and process of formation. Most CSIA involves measurement of the stable isotope ratio of carbon ({sup 13}C/{sup 12}C) and hydrogen (D/H) following separation by gas or liquid chromatography. New applications are being developed using compound-specific radiocarbon ({sup 14}C) content for delineating age of materials, rates of decomposition and residence time in various environments. This paper details the isotopic work on specific lignin monomers derived from terrestrial plants transported and deposited within the Altamaha River, estuary and off-shore Georgia in the Atlantic Ocean. By using gas chromatographic separation and identification of selected lignin oxidation products (LOP), the harvesting of these compounds using preparative fraction collection, and measurement of their {sup 14}C content using accelerator mass spectrometry, details of the age and presence of specific biomarkers unique to a given terrestrial source are revealed. Radiocarbon ages determined from water-column particulate organic carbon and sediment LOPs indicate a range of ages from modern to well over 5,000 years for the former and latter respectively. Transport mechanisms and particle size associations on mineral grains may play a significant role in {sup 14}C distribution in estuary and near-shore coastal environments. This data indicates higher than modern {sup 14}C activities in large particle-size sediment fractions in contrast to older LOP {sup 14}C ages found associated with the same coarse grain sediments. Individual LOP ages substantiate older terrestrial materials persist in the off-shore environment even though in the presence of modern marine {sup 14}C sources.

  11. Compound specific radiocarbon content of lignin oxidation products from the Altamaha river and Coastal Georgia

    International Nuclear Information System (INIS)

    Culp, Randy

    2013-01-01

    Compound-specific isotope analysis (CSIA) is a powerful tool in organic geochemistry by providing detailed information about an individual organic compound’s history with regard to its source and process of formation. Most CSIA involves measurement of the stable isotope ratio of carbon ( 13 C/ 12 C) and hydrogen (D/H) following separation by gas or liquid chromatography. New applications are being developed using compound-specific radiocarbon ( 14 C) content for delineating age of materials, rates of decomposition and residence time in various environments. This paper details the isotopic work on specific lignin monomers derived from terrestrial plants transported and deposited within the Altamaha River, estuary and off-shore Georgia in the Atlantic Ocean. By using gas chromatographic separation and identification of selected lignin oxidation products (LOP), the harvesting of these compounds using preparative fraction collection, and measurement of their 14 C content using accelerator mass spectrometry, details of the age and presence of specific biomarkers unique to a given terrestrial source are revealed. Radiocarbon ages determined from water-column particulate organic carbon and sediment LOPs indicate a range of ages from modern to well over 5,000 years for the former and latter respectively. Transport mechanisms and particle size associations on mineral grains may play a significant role in 14 C distribution in estuary and near-shore coastal environments. This data indicates higher than modern 14 C activities in large particle-size sediment fractions in contrast to older LOP 14 C ages found associated with the same coarse grain sediments. Individual LOP ages substantiate older terrestrial materials persist in the off-shore environment even though in the presence of modern marine 14 C sources.

  12. 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

  13. 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.

  14. Stable carbon and nitrogen isotope ratios of sodium and potassium cyanide as a forensic signature.

    Science.gov (United States)

    Kreuzer, Helen W; Horita, Juske; Moran, James J; Tomkins, Bruce A; Janszen, Derek B; Carman, April

    2012-01-01

    Sodium and potassium cyanide are highly toxic, produced in large amounts by the chemical industry, and linked to numerous high-profile crimes. The U.S. Centers for Disease Control and Prevention has identified cyanide as one of the most probable agents to be used in a chemical terrorism event. We investigated whether stable C and N isotopic content of sodium and potassium cyanide could serve as a forensic signature for sample matching, using a collection of 65 cyanide samples. Upon analysis, a few of the cyanide samples displayed nonhomogeneous isotopic content associated with degradation to a carbonate salt and loss of hydrogen cyanide. Most samples had highly reproducible isotope content. Of the 65 cyanide samples, >95% could be properly matched based on C and N isotope ratios, with a false match rate <3%. These results suggest that stable C and N isotope ratios are a useful forensic signature for matching cyanide samples. © 2011 American Academy of Forensic Sciences.

  15. Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel.

    Directory of Open Access Journals (Sweden)

    Niels J de Winter

    Full Text Available The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared with trace element profiles measured using laboratory micro X-Ray Fluorescence scanning. Using known patterns of tooth eruption and the relationship between stable oxygen isotopes and local temperature seasonality, an age model is constructed that links records from six cheek upper right teeth from the second premolar to the third molar. When plotted on this age model, the trace element ratios from horse tooth enamel show a seasonal pattern with a small shift in phase compared to stable oxygen isotope ratios. While stable oxygen and carbon isotopes in tooth enamel are forced respectively by the state of the hydrological cycle and the animal's diet, we argue that the seasonal signal in trace elements reflects seasonal changes in dust intake and diet of the animal. The latter explanation is in agreement with seasonal changes observed in carbon isotopes of the same teeth. This external forcing of trace element composition in mammal tooth enamel implies that trace element ratios may be used as proxies for seasonal changes in paleo-environment and paleo-diet.

  16. Seasonal Cyclicity in Trace Elements and Stable Isotopes of Modern Horse Enamel.

    Science.gov (United States)

    de Winter, Niels J; Snoeck, Christophe; Claeys, Philippe

    2016-01-01

    The study of stable isotopes in fossil bioapatite has yielded useful results and has shown that bioapatites are able to faithfully record paleo-environmental and paleo-climatic parameters from archeological to geological timescales. In an effort to establish new proxies for the study of bioapatites, intra-tooth records of enamel carbonate stable isotope ratios from a modern horse are compared with trace element profiles measured using laboratory micro X-Ray Fluorescence scanning. Using known patterns of tooth eruption and the relationship between stable oxygen isotopes and local temperature seasonality, an age model is constructed that links records from six cheek upper right teeth from the second premolar to the third molar. When plotted on this age model, the trace element ratios from horse tooth enamel show a seasonal pattern with a small shift in phase compared to stable oxygen isotope ratios. While stable oxygen and carbon isotopes in tooth enamel are forced respectively by the state of the hydrological cycle and the animal's diet, we argue that the seasonal signal in trace elements reflects seasonal changes in dust intake and diet of the animal. The latter explanation is in agreement with seasonal changes observed in carbon isotopes of the same teeth. This external forcing of trace element composition in mammal tooth enamel implies that trace element ratios may be used as proxies for seasonal changes in paleo-environment and paleo-diet.

  17. Possibilities for the production of non-stable isotopes

    International Nuclear Information System (INIS)

    Benlliure, J.; Enqvist, T.; Junghans, A.R.; Ricciardi, V.; Schmidt, K.H.; Farget, F.

    1999-04-01

    The production of neutron-rich isotopes is discussed in terms of the two main reaction mechanisms leading to the formation of these nuclei, projectile fragmentation and fission. Production cross sections are calculated for cold-fragmentation and fission. The expected yields are estimated taking into account different technical approaches actually discussed for the production of radioactive beams. (orig.)

  18. The use of stable isotopes to trace oil sands constituents

    International Nuclear Information System (INIS)

    Farwell, A.J.; Nero, V.; Dixon, D.G.

    2002-01-01

    A study was conducted to determine the biological effects of oil sands mining operations on aquatic ecosystems. The study focused on the Athabasca oil sand deposit, the largest of 4 deposits in northern Alberta. In particular, the study examined the cycling of oil sand constituents in Benthic invertebrates collected from test pits at Syncrude Canada Ltd.. The invertebrates were similar in size, but different in the quantity of process-affected water or mature fine tailings containing residual bitumen. Dragonflies and damselflies in particular, showed trends of depletion for the carbon 13 isotope and enrichment in nitrogen 15 isotope in pits where levels of process affected water was high. The depletion of carbon 13 isotope suggests that oil sand constituents assimilate into the benthic food chain. The greatest carbon 13 depletion, which was approximately 27 per cent, was found to be in test pits with high turbidity. This implies that oil sands constituents degrade microbially instead of by photosynthetic production. All benthic invertebrate group demonstrated an incremental enrichment in nitrogen 15 isotope from the control pit to the pit with greatest levels of mature fine tailings

  19. Analysis of Stable Isotope Contents of Surface and Underground ...

    African Journals Online (AJOL)

    Sam Eshun

    (2H/1H) ratios relative to a standard called Standard Mean Ocean Water (SMOW) ..... Hence, higher forest cover has greater influence on heavy isotope ... Accra Plains is influenced by the Atlantic Ocean where the relative humidity is higher ...

  20. 61 stable isotope compositions of organic carbon and contents of ...

    African Journals Online (AJOL)

    Mgina

    isotope record from Lake Ndutu shows a general downcore decrease in δ. 13C values ... in bulk δ13C of the terrestrial biomass in the tropics may ... CO2, temperature, moisture conditions and ... A map showing location of sampling sites of Ngorongoro Crater, Lake Ndutu and .... the Lakes Makat and Masek records cannot.

  1. Spatiotemporal variation of stable isotopic composition in precipitation

    DEFF Research Database (Denmark)

    Müller, Sascha; Stumpp, Christine; Sørensen, Jens Havskov

    2017-01-01

    influences the isotopic composition at the study site. A simple model of evaporation on falling rain was applied with the aim to reproduce observational data and show the potential influence of changing humidity conditions on precipitation compositions. The rather simple model approach did not fully explain...

  2. Vacuum-arc plasma centrifuge applied to stable isotope separation

    International Nuclear Information System (INIS)

    Del Bosco, E.

    1989-09-01

    This work describes the results of a vacuum-arc plasma centrifuge experiment. A plasma centrifuge is an apparatus where a plasma column is produced due to the interaction of an electric current with an externally applied magnetic field, sup(→)J x sup(→)B. Among the applications of a rotating plasma, this work deals particularly with its utilization in an isotope enrichment device. The main characteristics of the plasma produced in this experiment are presented, with special attention to the plasma column rotation and the isotope enrichment. The analysis of the results is performed using a fluid model for a completely ionized rigid body rotating plasma column in steady state equilibrium. The main results are: a) rotation frequency of the plasma column in the range 2 x 10 sup(4) to 3 x 10 sup(5) rad/s; b) enrichment of 10 to 30% for the magnesium isotopes, and of 290 to 490% for the carbon 13 isotope; c) rigid body rotation of the plasma column only for radii smaller than the characteristic radius of the plasma column. re; d) linear dependence of the rotation frequency upon the magnetic field strength only for r < re; e) existence of an optimum value of the magnetic field for maximum enrichment; and f) dependence of the rotation frequency upon the inverse of the atomic mass. (author)

  3. Stable isotope characteristics of precipitation of Pamba River basin ...

    Indian Academy of Sciences (India)

    highly essential input function for isotope hydro- ... Wind speed in the Pamba River basin varies from 8.5 to. 13.6 km/hr (NWDA 2008). ... ets of low values in the hill stations of the Ghats ... reservoir for the hydroelectric power production in.

  4. Gas cleaning with hot char beds studied by stable isotopes

    DEFF Research Database (Denmark)

    Egsgaard, Helge; Ahrenfeldt, Jesper; Ambus, Per

    2014-01-01

    The chemistry taking place in a high temperature char bed used for binding aromatic tar compounds has been studied in detail. 13C labelled tar compounds were used to trace the incorporation into the char bed using isotope ratio mass spectrometry (IRMS) and GC-MS. Furthermore, compounds labelled...

  5. Stable carbon isotope response to oceanic anoxic events

    International Nuclear Information System (INIS)

    Hu Xiumian; Wang Chengshan; Li Xianghui

    2001-01-01

    Based on discussion of isotope compositions and fractionation of marine carbonate and organic carbon, the author studies the relationship between oceanic anoxic events and changes in the carbon isotope fractionation of both carbonate and organic matter. During the oceanic anoxic events, a great number of organisms were rapidly buried, which caused a kind of anoxic conditions by their decomposition consuming dissolved oxygen. Since 12 C-rich organism preserved, atmosphere-ocean system will enrich relatively of 13 C. As a result, simultaneous marine carbonate will record the positive excursion of carbon isotope. There is a distinctive δ 13 C excursion during oceanic anoxic events in the world throughout the geological time. In the Cenomanian-Turonian anoxic event. this positive excursion arrived at ∼0.2% of marine carbonate and at ∼0.4% of organic matter, respectively. Variations in the carbon isotopic compositions of marine carbonate and organic carbon record the changes in the fraction of organic carbon buried throughout the geological time and may provide clues to the changes in rates of weathering and burial of organic carbon. This will provide a possibility of interpreting not only the changes in the global carbon cycle throughout the geological time, but also that in atmospheric p CO 2

  6. 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

  7. Stable isotope fractionation during bacterial sulfate reduction is controlled by reoxidation of intermediates

    Science.gov (United States)

    Mangalo, Muna; Meckenstock, Rainer U.; Stichler, Willibald; Einsiedl, Florian

    2007-09-01

    Bacterial sulfate reduction is one of the most important respiration processes in anoxic habitats and is often assessed by analyzing the results of stable isotope fractionation. However, stable isotope fractionation is supposed to be influenced by the reduction rate and other parameters, such as temperature. We studied here the mechanistic basics of observed differences in stable isotope fractionation during bacterial sulfate reduction. Batch experiments with four sulfate-reducing strains ( Desulfovibrio desulfuricans, Desulfobacca acetoxidans, Desulfonatronovibrio hydrogenovorans, and strain TRM1) were performed. These microorganisms metabolize different carbon sources (lactate, acetate, formate, and toluene) and showed broad variations in their sulfur isotope enrichment factors. We performed a series of experiments on isotope exchange of 18O between residual sulfate and ambient water. Batch experiments were conducted with 18O-enriched (δ 18O water = +700‰) and depleted water (δ 18O water = -40‰), respectively, and the stable 18O isotope shift in the residual sulfate was followed. For Desulfovibrio desulfuricans and Desulfonatronovibrio hydrogenovorans, which are both characterized by low sulfur isotope fractionation ( ɛS > -13.2‰), δ 18O values in the remaining sulfate increased by only 50‰ during growth when 18O-enriched water was used for the growth medium. In contrast, with Desulfobacca acetoxidans and strain TRM1 ( ɛS factor ( ɛS exchange with water during sulfate reduction. However, this neither takes place in the sulfate itself nor during formation of APS (adenosine-5'-phosphosulfate), but rather in intermediates of the sulfate reduction pathway. These may in turn be partially reoxidized to form sulfate. This reoxidation leads to an incorporation of oxygen from water into the "recycled" sulfate changing the overall 18O isotopic composition of the remaining sulfate fraction. Our study shows that such incorporation of 18O is correlated with the

  8. 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.

  9. Stable isotope hydrology of a classical karst area, Trieste, Italy

    International Nuclear Information System (INIS)

    Flora, O.; Longinelli, A.

    1989-01-01

    Most of the karst springs that exist along the northeastern coast of the Adriatic Sea in the area of Trieste (Italy) have been studied for about 2 years. These studies were carried out to determine the oxygen isotopic composition of the water and, more recently, the major and minor dissolved ions and the water temperature. The isotopic composition of meteoric waters in different areas was also systematically studied during the same period to obtain basic information on environmental waters. The isotopic curves obtained from the springs generally showed a marked seasonal isotopic inversion. In fact, in most of the springs studied the results obtained from winter samples were the most positive. In contrast, summer samples were usually quite negative, the most negative being those obtained in the late summer months (August to October). The data obtained were considered to be the result of a variable mixing of waters from two different reservoirs. The less negative data probably resulted from 'local' meteoric waters falling on the western section of the karst area, at a mean elevation of about 400 metres above sea level. The most negative data were probably related to meteoric waters falling on the internal part of the karst area, at a mean elevation of about 800 to 900 metres. The isotopic values and the chemistry of the waters appeared to be in reasonable agreement. However, at least in the northern karst springs, it is likely that a third water system, basically fed by the Isonzo River which flows north of the karst highlands, might interfere with the previously mentioned reservoirs, so partially controlling the outflow of some of these springs. (author). 7 refs, 8 figs

  10. Water stable isotopes: application to the water cycle and climate variations study

    International Nuclear Information System (INIS)

    Risi, C.

    2009-12-01

    The stable isotopic composition of water (H 2 16 , HDO, H 2 18 , H 2 17 ) is a promising tracer of the present day water cycle and past climates. While the isotopic composition recorded in polar ice core have long been used to reconstruct past temperatures, however, what controls the isotopic composition of the tropical precipitation is more complex. The goal of this thesis is thus to better understand the processes that affect the isotopic composition of tropical precipitation and atmospheric water, more particularly in the tropics. Since most of the tropical precipitation arises from atmospheric convection, and most isotopic archives are on land, we focus more particularly on the impact of convective and land surface processes. In turn, what can be learned about convection and land surface processes using isotopic measurements? Can they help constrain their representation in models? At the inter-annual to climate change scale, what information about the tropical climate variability is recorded in isotopic signals observed in archives? First, we investigate the influence of convection on water stable isotopes. We use both (1) numerical modeling, with a hierarchy of models (single column model, two-dimensional model of squall lines, general circulation model) and (2) data analysis, using isotopic data from rain collected in the Sahel during the African Monsoon Multidisciplinary Analysis campaign, at the event and intra-event scales. These studies highlight the strong impact of convection on the precipitation composition, and stress the importance of rain evaporation and convective or meso-scale subsidence in controlling the rain isotopic composition. Convection also plays an important role on isotopic profiles in the upper troposphere-lower stratosphere. Second, we study what information about climatic variability is recorded by water stable isotopes in precipitation. We analyze simulations of present day and past climates with LMDZ, and evaluate to what extent

  11. Stable isotopes of authigenic minerals in variably-saturated fractured tuff

    Energy Technology Data Exchange (ETDEWEB)

    Weber, D.S.; Evans, D.D.

    1988-11-01

    Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water interaction. Oxygen isotope ratios of rock matrix opal samples exhibited an isotopic gradient believed to result from, leaching and reprecipitation of silica at depth. Methods and results can be used to further define primary flowpaths and the movement of water in variably-saturated fractured rock. 71 refs., 23 figs., 3 tabs.

  12. Stable isotopes of authigenic minerals in variably-saturated fractured tuff

    International Nuclear Information System (INIS)

    Weber, D.S.; Evans, D.D.

    1988-11-01

    Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ( 18 O/ 16 O) and carbon ( 13 C/ 12 C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water interaction. Oxygen isotope ratios of rock matrix opal samples exhibited an isotopic gradient believed to result from, leaching and reprecipitation of silica at depth. Methods and results can be used to further define primary flowpaths and the movement of water in variably-saturated fractured rock. 71 refs., 23 figs., 3 tabs

  13. Isotopic Analysis of Fingernails as a USGS Open House Demonstration of the Use of Stable Isotopes in Foodweb Studies

    Science.gov (United States)

    Silva, S. R.; Kendall, C.; Young, M. B.; Choy, D.

    2011-12-01

    The USGS Isotope Tracers Project uses stable isotopes and tritium to add a unique dimension of chemical information to a wide range of environmental investigations. The use and application of isotopes is usually an unfamiliar and even esoteric topic to the general public. Therefore during three USGS open house events, as a public outreach effort, we demonstrated the use of stable isotopes by analyzing nitrogen and carbon isotopes from very small fragments of fingernail from willing participants. We titled the exhibit "You Are What You Eat". The results from all participants were plotted on a graph indicating the general influence of different food groups on the composition of body tissues as represented by fingernails. All participants were assigned a number and no personal-identification information was collected. A subset of participants provided us with an estimate of the number of days a week various foods were eaten and if they were vegetarians, vegans or non-vegetarians. Volunteers from our research group were on hand to explain and discuss fundamental concepts such as how foods attain their isotopic composition, the difference between C3 and C4 plants, the effects of assimilation, trophic enrichment, and the various uses of stable isotopes in environmental studies. The results of the fingernail analyses showed the variation of the range of isotopic compositions among about 400 people at each event, the distinct influence of C4 plants (mainly corn and cane sugar) on our carbon isotopic composition, and the isotopic differences between vegetarians and non vegetarians among other details (http://wwwrcamnl.wr.usgs.gov/isoig/projects/fingernails/). A poll of visitors attending the open house event in 2006 indicated that "You Are What You Eat" was among the most popular exhibits. Following the first two open house events we were contacted by a group of researchers from Brazil who had completed a very similar study. Our collaboration resulted in a publication in

  14. Quantification of Labile Soil Mercury by Stable Isotope Dilution Techniques

    Science.gov (United States)

    Shetaya, Waleed; Huang, Jen-How; Osterwalder, Stefan; Alewell, Christine

    2016-04-01

    Mercury (Hg) is a toxic element that can cause severe health problems to humans. Mercury is emitted to the atmosphere from both natural and anthropogenic sources and can be transported over long distances before it is deposited to aquatic and terrestrial environments. Aside from accumulation in soil solid phases, Hg deposited in soils may migrate to surface- and ground-water or enter the food chain, depending on its lability. There are many operationally-defined extraction methods proposed to quantify soil labile metals. However, these methods are by definition prone to inaccuracies such as non-selectivity, underestimation or overestimation of the labile metal pool. The isotopic dilution technique (ID) is currently the most promising method for discrimination between labile and non-labile metal fractions in soil with a minimum disturbance to soil-solid phases. ID assesses the reactive metal pool in soil by defining the fraction of metal both in solid and solution phases that is isotopically-exchangeable known as the 'E-value'. The 'E-value' represents the metal fraction in a dynamic equilibrium with the solution phase and is potentially accessible to plants. This is carried out by addition of an enriched metal isotope to soil suspensions and quantifying the fraction of metal that is able to freely exchange with the added isotope by measuring the equilibrium isotopic ratio by ICP-MS. E-value (mg kg-1) is then calculated as follows: E-Value = (Msoil/ W) (CspikeVspike/ Mspike) (Iso1IAspike -Iso2IAspikeRss / Iso2IAsoil Rss - Iso1IAsoil) where M is the average atomic mass of the metal in the soil or the spike, W is the mass of soil (kg), Cspike is the concentration of the metal in the spike (mg L-1), Vspike is the volume of spike (L), IA is isotopic abundance, and Rss is the equilibrium ratio of isotopic abundances (Iso1:Iso2). Isotopic dilution has been successfully applied to determine E-values for several elements. However, to our knowledge, this method has not yet

  15. Systematics of the electric dipole response in stable tin isotopes

    Science.gov (United States)

    Bassauer, Sergej; von Neumann-Cosel, Peter; Tamii, Atsushi

    2018-05-01

    The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP), Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

  16. Systematics of the electric dipole response in stable tin isotopes

    Directory of Open Access Journals (Sweden)

    Bassauer Sergej

    2018-01-01

    Full Text Available The electric dipole is an important property of heavy nuclei. Precise information on the electric dipole response provides information on the electric dipole polarisability which in turn allows to extract important constraints on neutron-skin thickness in heavy nuclei and parameters of the symmetry energy. The tin isotope chain is particularly suited for a systematic study of the dependence of the electric dipole response on neutron excess as it provides a wide mass range of accessible isotopes with little change of the underlying structure. Recently an inelastic proton scattering experiment under forward angles including 0º on 112,116,124Sn was performed at the Research Centre for Nuclear Physics (RCNP, Japan with a focus on the low-energy dipole strength and the polarisability. First results are presented here. Using data from an earlier proton scattering experiment on 120Sn the gamma strength function and level density are determined for this nucleus.

  17. Stable isotope identification of Greek and Turkish marbles

    International Nuclear Information System (INIS)

    Coleman, M.; Walker, S.

    1979-01-01

    Carbon and oxygen isotope analyses have been used to test the provenance of the marble of some Attic sarcophagi in the British Museum collection. Of three believed to be of Pentelic marble, only one has been so confirmed. Analyses of fragmentary sarcophagi of similar workmanship has confirmed their Proconnesian origin. Data from fragments of Sidamara sarcophagi have supplemented observations of technique, finish and dimensions of carved figures and decoration to determine whether the fragments come from the same sarcophagus. (author)

  18. Proposal for implanting a magnetic stable isotope separator

    International Nuclear Information System (INIS)

    Lemos, O.F.

    1988-07-01

    The implantation of an electromagnetic isotope separator able to separate elements of mass from 20 to 250 a.m.u., with an enrichment factor from 10 to 200 times the initial concentration, depending on the elements, is proposed. The most suitable separator type for Brazilian CNEN, considering building installations and minimum conditions for the equipment facilities, the retinue chronogram, the infrastructure, and the personnel training for operation is defined. (M.C.K.) [pt

  19. Modeling of present and Eemian stable water isotopes in precipitation

    DEFF Research Database (Denmark)

    Sjolte, Jesper

    The subject of this thesis is the modeling of the isotopic temperature proxies d18O, dD and deuterium excess in precipitation. Two modeling studies were carried out, one using the regional climate model, and one using a global climate model. In the regional study the model was run for the period ...... the modeled isotopes do not agree with ice core data. The discrepancy between the model output and the ice core data is attributed to the boundary conditions, where changes in ice sheets and vegetation have not been accounted for.......The subject of this thesis is the modeling of the isotopic temperature proxies d18O, dD and deuterium excess in precipitation. Two modeling studies were carried out, one using the regional climate model, and one using a global climate model. In the regional study the model was run for the period...... 1959 to 2001 using meteorological data and a domain including Greenland and the surrounding North Atlantic. The model was found to reproduce the observed seasonal variability of temperature and precipitation well. In comparison with ice core data from Greenland and observations from coastal stations...

  20. A manual for a Laboratory Information Management System (LIMS) for light stable isotopes

    Science.gov (United States)

    Coplen, Tyler B.

    1998-01-01

    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 is presented herein. Major benefits of this system include (i) an increase in laboratory efficiency, (ii) reduction in the use of paper, (iii) reduction in workload due to the elimination or reduction of retyping of data by laboratory personnel, and (iv) decreased 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 stable isotope laboratories. Since the original publication of the manual for LIMS for Light Stable Isotopes, the isotopes 3 H, 3 He, and 14 C, and the chlorofluorocarbons (CFCs), CFC-11, CFC-12, and CFC-113, have been added to this program.

  1. 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

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

    International Nuclear Information System (INIS)

    Dorado Linan, Isabel; Gutierrez, Emilia; Helle, Gerhard; Heinrich, Ingo; Andreu-Hayles, Laia; Planells, Octavi; Leuenberger, Markus; Buerger, Carmen; Schleser, Gerhard

    2011-01-01

    δ 13 C and δ 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 δ 13 C and the δ 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 δ 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: → Pooled δ 13 C and δ 18 O chronologies are expected to be similar to the mean. → Empirical pooled chronologies δ 13 C and δ 18 O and the mean show a high synchronicity. → Pooled chronologies differ

  3. 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.

  4. Stable isotope reactive transport modeling in water-rock interactions during CO2 injection

    Science.gov (United States)

    Hidalgo, Juan J.; Lagneau, Vincent; Agrinier, Pierre

    2010-05-01

    Stable isotopes can be of great usefulness in the characterization and monitoring of CO2 sequestration sites. Stable isotopes can be used to track the migration of the CO2 plume and identify leakage sources. Moreover, they provide unique information about the chemical reactions that take place on the CO2-water-rock system. However, there is a lack of appropriate tools that help modelers to incorporate stable isotope information into the flow and transport models used in CO2 sequestration problems. In this work, we present a numerical tool for modeling the transport of stable isotopes in groundwater reactive systems. The code is an extension of the groundwater single-phase flow and reactive transport code HYTEC [2]. HYTEC's transport module was modified to include element isotopes as separate species. This way, it is able to track isotope composition of the system by computing the mixing between the background water and the injected solution accounting for the dependency of diffusion on the isotope mass. The chemical module and database have been expanded to included isotopic exchange with minerals and the isotope fractionation associated with chemical reactions and mineral dissolution or precipitation. The performance of the code is illustrated through a series of column synthetic models. The code is also used to model the aqueous phase CO2 injection test carried out at the Lamont-Doherty Earth Observatory site (Palisades, New York, USA) [1]. References [1] N. Assayag, J. Matter, M. Ader, D. Goldberg, and P. Agrinier. Water-rock interactions during a CO2 injection field-test: Implications on host rock dissolution and alteration effects. Chemical Geology, 265(1-2):227-235, July 2009. [2] Jan van der Lee, Laurent De Windt, Vincent Lagneau, and Patrick Goblet. Module-oriented modeling of reactive transport with HYTEC. Computers & Geosciences, 29(3):265-275, April 2003.

  5. Caution on the use of liquid nitrogen traps in stable hydrogen isotope-ratio mass spectrometry

    Science.gov (United States)

    Coplen, Tyler B.; Qi, Haiping

    2010-01-01

    An anomalous stable hydrogen isotopic fractionation of 4 ‰ in gaseous hydrogen has been correlated with the process of adding liquid nitrogen (LN2) to top off the dewar of a stainless-steel water trap on a gaseous hydrogen-water platinum equilibration system. Although the cause of this isotopic fractionation is unknown, its effect can be mitigated by (1) increasing the capacity of any dewars so that they do not need to be filled during a daily analytic run, (2) interspersing isotopic reference waters among unknowns, and (3) applying a linear drift correction and linear normalization to isotopic results with a program such as Laboratory Information Management System (LIMS) for Light Stable Isotopes. With adoption of the above guidelines, measurement uncertainty can be substantially improved. For example, the long-term (months to years) δ2H reproducibility (1& sigma; standard deviation) of nine local isotopic reference waters analyzed daily improved substantially from about 1‰ to 0.58 ‰. This isotopically fractionating mechanism might affect other isotope-ratio mass spectrometers in which LN2 is used as a moisture trap for gaseous hydrogen

  6. Industrial scale production of stable isotopes employing the technique of plasma separation

    International Nuclear Information System (INIS)

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

    2003-01-01

    Calutrons, centrifuges, diffusion and distillation processes are some of the devices and techniques that have been employed to produce substantial quantities of enriched stable isotopes. Nevertheless, the availability of enriched isotopes in sufficient quantities for industrial applications remains very restricted. Industries such as those involved with medicine, semiconductors, nuclear fuel, propulsion, and national defense have identified the potential need for various enriched isotopes in large quantities. Economically producing most enriched (non-gaseous) isotopes in sufficient quantities has so far eluded commercial producers. The plasma separation process is a commercial technique now available for producing large quantities of a wide range of enriched isotopes. Until recently, this technique has mainly been explored with small-scale ('proof-of-principle') devices that have been built and operated at research institutes. The new Theragenics TM facility at Oak Ridge, TN houses the only existing commercial scale PSP system. This device, which successfully operated in the 1980's, has recently been re-commissioned and is planned to be used to produce a variety of isotopes. Progress and the capabilities of this device and it's potential for impacting the world's supply of stable isotopes in the future is summarized. This technique now holds promise of being able to open the door to allowing new and exciting applications of these isotopes in the future. (author)

  7. Radioisotopes and stable isotopes and their applications in earth sciences, safety-in-mines, and environmental protection. 1

    International Nuclear Information System (INIS)

    1981-01-01

    The state of the art and objectives of isotope research in earth sciences, safety-in-mines, and environmental protection is reported. Volume 1 contains papers dedicated to origin and distribution of natural radioisotopes and stable isotopes

  8. Stable isotopes in a branching coral monitor seasonal temperature variation

    International Nuclear Information System (INIS)

    Dunbar, R.B.; Wellington, G.M.

    1981-01-01

    Results are reported of 18 O composition measurements of specimens of the branching reef coral Pocillopora damicornis, which have grown in the field, while seawater temperatures were continuously recorded. It is shown that seasonal temperature changes are accurately recorded by 18 O variations in branches of this reef coral and that isotopic profiles may be used to estimate growth rates of branching corals, which lack annual density banding. The method provides a technique for high resolution palaeoclimatic reconstruction of seasonal temperature ranges and accurate estimation of rates of reef carbonate production. (U.K.)

  9. 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.

  10. Recent research activities and future subjects on stable- and radio-isotopes of chlorine in environment

    International Nuclear Information System (INIS)

    Kushita, Kouhei

    2001-12-01

    This report reviews the recent studies on the stable- and radio-isotopes of chlorine from a viewpoint of environmental science, partly including historic references on this element. First, general properties, occurrence, and utilization of chlorine are described. Secondly, current status and research works on chlorine-compounds, which attract special attention in recent years as environmentally hazardous materials, are reported. Thirdly, research works on stable chlorine isotopes, 35 Cl and 37 Cl, are described with a focus laid on the newly-developed techniques; isotopic ratio mass spectrometry (IRMS) and thermal ionization mass spectrometry (TIMS). Fourthly, recent research works on chlorine radioisotopes, 36 Cl etc., are described, focusing on the development of accelerator mass spectrometry (AMS) and its application to geochemistry and others. Finally, taking account of the above-mentioned recent works on Cl isotopes, possible future research subjects are discussed. (author)

  11. Normalization Methods and Selection Strategies for Reference Materials in Stable Isotope Analyes. Review

    Energy Technology Data Exchange (ETDEWEB)

    Skrzypek, G. [West Australian Biogeochemistry Centre, John de Laeter Centre of Mass Spectrometry, School of Plant Biology, University of Western Australia, Crawley (Australia); Sadler, R. [School of Agricultural and Resource Economics, University of Western Australia, Crawley (Australia); Paul, D. [Department of Civil Engineering (Geosciences), Indian Institute of Technology Kanpur, Kanpur (India); Forizs, I. [Institute for Geochemical Research, Hungarian Academy of Sciences, Budapest (Hungary)

    2013-07-15

    Stable isotope ratio mass spectrometers are highly precise, but not accurate instruments. Therefore, results have to be normalized to one of the isotope scales (e.g., VSMOW, VPDB) based on well calibrated reference materials. The selection of reference materials, numbers of replicates, {delta}-values of these reference materials and normalization technique have been identified as crucial in determining the uncertainty associated with the final results. The most common normalization techniques and reference materials have been tested using both Monte Carlo simulations and laboratory experiments to investigate aspects of error propagation during the normalization of isotope data. The range of observed differences justifies the need to employ the same sets of standards worldwide for each element and each stable isotope analytical technique. (author)

  12. Recent research activities and future subjects on stable- and radio-isotopes of chlorine in environment

    Energy Technology Data Exchange (ETDEWEB)

    Kushita, Kouhei [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-12-01

    This report reviews the recent studies on the stable- and radio-isotopes of chlorine from a viewpoint of environmental science, partly including historic references on this element. First, general properties, occurrence, and utilization of chlorine are described. Secondly, current status and research works on chlorine-compounds, which attract special attention in recent years as environmentally hazardous materials, are reported. Thirdly, research works on stable chlorine isotopes, {sup 35}Cl and {sup 37}Cl, are described with a focus laid on the newly-developed techniques; isotopic ratio mass spectrometry (IRMS) and thermal ionization mass spectrometry (TIMS). Fourthly, recent research works on chlorine radioisotopes, {sup 36}Cl etc., are described, focusing on the development of accelerator mass spectrometry (AMS) and its application to geochemistry and others. Finally, taking account of the above-mentioned recent works on Cl isotopes, possible future research subjects are discussed. (author)

  13. Stable-carbon isotopic composition of maple sap and foliage

    International Nuclear Information System (INIS)

    Leavitt, S.W.; Long, A.

    1985-01-01

    The 13 C/ 12 C ratios of Acer grandidentatum sap sugar collected during the dormant period are compared to those of buds, leaves, and wood developed over the following growing season. As the primary carbon source for cellulose manufacture at initiation of annual growth in deciduous trees, sap sucrose would be expected to have an isotopic composition similar to first-formed cellulose. Although constancy in concentration and 13 C/ 12 C ratios of the maple sap sugar suggests any gains or losses (e.g. to maintenance metabolism) do not appreciably alter composition, the 13 C/ 12 C ratios of cellulose of the enlarging buds in the spring are quite distinct from those of the sap sugar, seemingly precluding a simple direct biochemical pathway of sap sucrose→glucose→cellulose in favor of a more complex pathway with greater likelihood of isotopic fractionation. The 13 C/ 12 C ratios of the leaves and in the growth ring were initially similar to the sap sugar but decreased steadily over the growing season. (author)

  14. Stable isotope quality assurance using the 'calibrated IRMS' strategy.

    Science.gov (United States)

    Meijer, Harro A J

    2009-06-01

    Procedures in our laboratory have always been directed towards complete understanding of all processes involved and corrections needed etc., instead of relying fully on laboratory reference materials. This rather principal strategy (or attitude) is probably not optimal in the economic sense, and is not necessarily more accurate either. Still, it has proven to be very rewarding in its capability to detect caveats that go undiscovered in the standard way of measurement, but that do influence the accuracy or reliability of the measurement procedure. An additional benefit of our laboratory procedures is that it makes us capable of assisting the International Atomic Energy Agency (IAEA) with primary questions like mutual scale assignments and comparison of isotope ratios of the same isotope in different matrices (like delta(18)O in water, carbonates and atmospheric CO(2)), establishment of the (17)O-(18)O relation, and the replenishment of the calibration standards. Finally, for manual preparation systems with a low sample throughput (and thus only few reference materials analysed) it may well be the only way to produce reliable results.

  15. New approaches for stable isotope ratio measurements. Proceedings of an advisory group meeting

    International Nuclear Information System (INIS)

    2001-10-01

    This report includes a summary of discussions at the meeting and contributions on isotope applications in a range of specific biogeochemical fields using the new analytical techniques. It is expected to serve as a useful reference for researchers and laboratory managers who plan to develop or apply state-of-the-art stable isotope techniques. Individual contributions contained in this book have been indexed separately

  16. New approaches for stable isotope ratio measurements. Proceedings of an advisory group meeting

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-10-01

    This report includes a summary of discussions at the meeting and contributions on isotope applications in a range of specific biogeochemical fields using the new analytical techniques. It is expected to serve as a useful reference for researchers and laboratory managers who plan to develop or apply state-of-the-art stable isotope techniques. Individual contributions contained in this book have been indexed separately.

  17. The use of stable isotopes for studies on the physiology of plants

    International Nuclear Information System (INIS)

    Moyse, Alexis.

    1982-01-01

    The use of the stable isotopes 15 N, 18 O, 13 C for studies on the physiology of plants especially of plants grown under natural environment conditions is reviewed. Analysis of isotopic discrimination give estimates of the various patterns of carbon and nitrogen nutrition and of the rate of water circulation. The method can also be used for paleoclimatology and for the detection of frauds in food products [fr

  18. Distinguishing feral and managed honeybees (Apis mellifera) using stable carbon isotopes

    OpenAIRE

    Anderson , Lucy; Dynes , Travis; Berry , Jennifer; Delaplane , Keith; McCormick , Lydia; Brosi , Berry

    2014-01-01

    International au