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

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

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

Stable isotope compositions of serpentinite seamounts in the Mariana forearc: Serpentinization processes, fluid sources and sulfur metasomatism

Science.gov (United States)

Alt, J.C.; Shanks, Wayne C.

2006-01-01

The Mariana and Izu-Bonin arcs in the western Pacific are characterized by serpentinite seamounts in the forearc that provide unique windows into the mantle wedge. We present stable isotope (O, H, S, and C) data for serpentinites from Conical seamount in the Mariana forearc and S isotope data for Torishima seamount in the Izu-Bonin forearc in order to understand the compositions of fluids and temperatures of serpentinization in the mantle wedge, and to investigate the transport of sulfur from the slab to the mantle wedge. Six serpentine mineral separates have a restricted range of ??18O (6.5-8.5???). Antigorite separates have ??D values of -29.5??? to -45.5??? that reflect serpentinization within the mantle wedge whereas chrysotile has low ??D values (-51.8??? to -84.0???) as the result of re-equilibration with fluids at low temperatures. Fractionation of oxygen isotopes between serpentine and magnetite indicate serpentinization temperatures of 300-375 ??C. Two late cross-fiber chrysotile veins have higher ??18O values of 8.9??? to 10.8??? and formed at lower temperatures (as low as ???100 ??C). Aqueous fluids in equilibrium with serpentine at 300-375 ??C had ??18O = 6.5-9??? and ??D = -4??? to -26???, consistent with sediment dehydration reactions at temperatures aragonite veins in metabasalt and siltstone clasts within the serpentinite flows have ??18O = 16.7-24.5???, consistent with the serpentinizing fluids at temperatures <250 ??C. ??13C values of 0.1-2.5??? suggest a source in subducting carbonate sediments. The ??34S values of sulfide in serpentinites on Conical Seamount (-6.7??? to 9.8???) result from metasomatism through variable reduction of aqueous sulfate (??34S = 14???) derived from slab sediments. Despite sulfur metasomatism, serpentinites have low sulfur contents (generally < 164 ppm) that reflect the highly depleted nature of the mantle wedge. The serpentinites are mostly enriched in 34S (median ??34Ssulfide = 4.5???), consistent with a 34S

Influence of the enzyme dissimilatory sulfite reductase on stable isotope fractionation during sulfate reduction

Science.gov (United States)

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

2008-03-01

The stable isotopes of sulfate are often used as a tool to assess bacterial sulfate reduction on the macro scale. However, the mechanisms of stable isotope fractionation of sulfur and oxygen at the enzymatic level are not yet fully understood. In batch experiments with water enriched in 18O we investigated the effect of different nitrite concentrations on sulfur isotope fractionation by Desulfovibrio desulfuricans. With increasing nitrite concentrations, we found sulfur isotope enrichment factors ranging from -11.2 ± 1.8‰ to -22.5 ± 3.2‰. Furthermore, the δ18O values in the remaining sulfate increased from approximately 50-120‰ when 18O-enriched water was supplied. Since 18O-exchange with ambient water does not take place in sulfate, but rather in intermediates of the sulfate reduction pathway (e.g. SO32-), we suggest that nitrite affects the steady-state concentration and the extent of reoxidation of the metabolic intermediate sulfite to sulfate during sulfate reduction. Given that nitrite is known to inhibit the production of the enzyme dissimilatory sulfite reductase, our results suggest that the activity of the dissimilatory sulfite reductase regulates the kinetic isotope fractionation of sulfur and oxygen during bacterial sulfate reduction. Our novel results also imply that isotope fractionation during bacterial sulfate reduction strongly depends on the cell internal enzymatic regulation rather than on the physico-chemical features of the individual enzymes.

A neogene seawater sulfur isotope age curve from calcareous pelagic microfossils

International Nuclear Information System (INIS)

Burdett, J.W.; Arthur, M.A.; Richardson, M.

1989-01-01

Until now, our knowledge of the sulfur isotopic composition of seawater through geologic time has depended on stable isotopic analysis of sulfate from evaporites. Owing to the sporadic occurrence of evaporites through time, the secular sulfur isotope age curve contains many gaps with little or no data. In order to fill in some of these gaps, particularly the Neogene, we have analyzed the sulfur isotopic composition of carbonate-associated sulfate in carbonate tests of planktonic foraminifera. Other investigators have shown that sulfate may occur in biogenic calcites either lattice-bound, as micro-fluid inclusions, in adsorbed phases, or as protein polysaccharides. Whatever the origin, the sulfur isotopic composition of this sulfate appears to be representative of that of the water in which the organism lived, as shown by results on recent calcareous foraminifera and macrofossils. Using this approach for study of Miocene to Recent pelagic marine sediments supplemented by new data for Miocene marine evaporites from the Gulf of Suez, we have found that the δ 34 S of seawater has decreased about 2.5per mille over the past 25 m.y. and that most of the decrease has occurred over the past 5 m.y., paralleling a decrease in the δ 13 C of dissolved oceanic bicarbonate from the same interval. Sedimentary redox models based on isotope records suggest that organic carbon and sulfide burial have both decreased over the past 5 m.y. Alternatively, an increase in weathering rates over the past 5 m.y. would not require a decrease in organic carbon or sulfide burial as long as the isotopic effect of the increased river input exceeds the isotopic effect of the burial of the reduced species. In either case, the net result would be a decrease in atmospheric p O2 . (orig.)

Fluid inclusion and sulfur stable isotope evidence for the origin of the Ahangran Pb-Ag deposit

Directory of Open Access Journals (Sweden)

Mohammad Maanijou

2015-10-01

Full Text Available Introduction The Ahangaran Pb-Ag deposit is located in the Hamedan province, west Iran, 25 km southeast of the city of Malayer . . The deposit lies in the strongly folded Sanandaj-Sirjan tectonic zone, in which the ore bodies occur as thin lenses and layers. The host rocks of the deposit are Early Cretaceous carbonates and sandstones that are unconformably underlain by Jurassic rocks. Ore minerals include galena, pyrite, chalcopyrite, pyrrhotite and supergene iron oxide minerals. Gangue minerals consist of barite, dolomite, chlorite, calcite and quartz. The mineralization occurs as open-space fillings, veins, veinlets, disseminations, and massive replacements. Alteration consists of silicification, sericitization, and dolomitization. In this study, we carried out studies of mineralogy, microthermometry of fluid inclusions and sulfur isotopes to determine the source of sulfur and the physico-chemical conditions of formation. Materials and methods Seventy samples of different host rocks, alteration, and mineralization were collected from surface outcrops and different tunnels. Twenty of the samples were prepared for mineralogical studies at Tarbiat Modarres University in Tehran and 25 for petrological studies at the University of Bu-Ali Sina. Fluid-inclusion studies were done on 5 samples of quartz and calcite at Pouya Zamin Azin Company in Tehran using a Linkam THM 600 model heating-freezing stage (with a range of -196 to 480ºC. The accuracy and precision of the homogenization measurements are about ±1°C. Salinity estimates were determined from the last melting temperatures of ice, utilizing the equations by Bodnar and Vityk (1994 and for CO2 fluids using equations by Chen (1972. Nine samples of sulfides and barite were crushed and separated by handpicking under binocular microscope and powdered with agate mortar and pestle. About one gram of each sample was sent to the Stable Isotope and ICP/MS Laboratory of Queen’s University, Canada for

Isotope effects of sulfur in chemical reactions

International Nuclear Information System (INIS)

Mikolajczuk, A.

1999-01-01

Sulfur is an important component of organic matter because it forms compounds with many elements. Due to high chemical activity of sulfur, it takes part in biological and geological processes in which isotope effects are occurring. It has been shown during last years research of isotope effects that we have take into account not only mass difference but also many other physical properties of nuclides e.g. even or odd number of neutrons in nuclei, shape and distribution of charge, turn of nuclear spin etc. The factor remains that new theoretical ideas have been formed on the base of data, being obtained in fractionation processes of heavy element isotope, particularly uranium. Now it is being well known that effects unconnected with vibration energy have also caused an effect on fractionation of considerably lighter elements like iron and magnesium. The important question is, if these effects would come to light during the separation of sulfur isotopes. Sulfur have three even isotopes M = (32, 34, 36) and one odd M 33). This problem is still open. (author)

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...

Sulfur and Oxygen Isotope Fractionation During Bacterial Sulfur Disproportionation Under Anaerobic Haloalkaline Conditions

NARCIS (Netherlands)

Poser, Alexander; Vogt, Carsten; Knöller, Kay; Sorokin, Dimitry Y.; Finster, Kai W.; Richnow, Hans H.

2016-01-01

Sulfur and oxygen isotope fractionation of elemental sulfur disproportionation at anaerobic haloalkaline conditions was evaluated for the first time. Isotope enrichment factors of the strains Desulfurivibrio alkaliphilus and Dethiobacter alkaliphilus growing at pH 9 or 10 were −0.9‰ to −1‰ for

Oxygen, hydrogen, sulfur, and carbon isotopes in the Pea Ridge magnetite-apatite deposit, southeast Missouri, and sulfur isotope comparisons to other iron deposits in the region

Science.gov (United States)

Johnson, Craig A.; Day, Warren C.; Rye, Robert O.

2016-01-01

Oxygen, hydrogen, sulfur, and carbon isotopes have been analyzed in the Pea Ridge magnetite-apatite deposit, the largest historic producer among the known iron deposits in the southeast Missouri portion of the 1.5 to 1.3 Ga eastern granite-rhyolite province. The data were collected to investigate the sources of ore fluids, conditions of ore formation, and provenance of sulfur, and to improve the general understanding of the copper, gold, and rare earth element potential of iron deposits regionally. The δ18O values of Pea Ridge magnetite are 1.9 to 4.0‰, consistent with a model in which some magnetite crystallized from a melt and other magnetite—perhaps the majority—precipitated from an aqueous fluid of magmatic origin. The δ18O values of quartz, apatite, actinolite, K-feldspar, sulfates, and calcite are significantly higher, enough so as to indicate growth or equilibration under cooler conditions than magnetite and/or in the presence of a fluid that was not entirely magmatic. A variety of observations, including stable isotope observations, implicate a second fluid that may ultimately have been meteoric in origin and may have been modified by isotopic exchange with rocks or by evaporation during storage in lakes.Sulfur isotope analyses of sulfides from Pea Ridge and seven other mineral deposits in the region reveal two distinct populations that average 3 and 13‰. Two sulfur sources are implied. One was probably igneous melts or rocks belonging to the mafic- to intermediate-composition volcanic suite that is present at or near most of the iron deposits; the other was either melts or volcanic rocks that had degassed very extensively, or else volcanic lakes that had trapped rising magmatic gases. The higher δ34S values correspond to deposits or prospects where copper is noteworthy—the Central Dome portion of the Boss deposit, the Bourbon deposit, and the Vilander prospective area. The correspondence suggests that (1) sulfur either limited the deposition

The influence of sulfur and hair growth on stable isotope diet estimates for grizzly bears.

Directory of Open Access Journals (Sweden)

Garth Mowat

Full Text Available Stable isotope ratios of grizzly bear (Ursus arctos guard hair collected from bears on the lower Stikine River, British Columbia (BC were analyzed to: 1 test whether measuring δ34S values improved the precision of the salmon (Oncorhynchus spp. diet fraction estimate relative to δ15N as is conventionally done, 2 investigate whether measuring δ34S values improves the separation of diet contributions of moose (Alces alces, marmot (Marmota caligata, and mountain goat (Oreamnos americanus and, 3 examine the relationship between collection date and length of hair and stable isotope values. Variation in isotope signatures among hair samples from the same bear and year were not trivial. The addition of δ34S values to mixing models used to estimate diet fractions generated small improvement in the precision of salmon and terrestrial prey diet fractions. Although the δ34S value for salmon is precise and appears general among species and areas, sulfur ratios were strongly correlated with nitrogen ratios and therefore added little new information to the mixing model regarding the consumption of salmon. Mean δ34S values for the three terrestrial herbivores of interest were similar and imprecise, so these data also added little new information to the mixing model. The addition of sulfur data did confirm that at least some bears in this system ate marmots during summer and fall. We show that there are bears with short hair that assimilate >20% salmon in their diet and bears with longer hair that eat no salmon living within a few kilometers of one another in a coastal ecosystem. Grizzly bears are thought to re-grow hair between June and October however our analysis of sectioned hair suggested at least some hairs begin growing in July or August, not June and, that hair of wild bears may grow faster than observed in captive bears. Our hair samples may have been from the year of sampling or the previous year because samples were collected in summer when

The influence of sulfur and hair growth on stable isotope diet estimates for grizzly bears.

Science.gov (United States)

Mowat, Garth; Curtis, P Jeff; Lafferty, Diana J R

2017-01-01

Stable isotope ratios of grizzly bear (Ursus arctos) guard hair collected from bears on the lower Stikine River, British Columbia (BC) were analyzed to: 1) test whether measuring δ34S values improved the precision of the salmon (Oncorhynchus spp.) diet fraction estimate relative to δ15N as is conventionally done, 2) investigate whether measuring δ34S values improves the separation of diet contributions of moose (Alces alces), marmot (Marmota caligata), and mountain goat (Oreamnos americanus) and, 3) examine the relationship between collection date and length of hair and stable isotope values. Variation in isotope signatures among hair samples from the same bear and year were not trivial. The addition of δ34S values to mixing models used to estimate diet fractions generated small improvement in the precision of salmon and terrestrial prey diet fractions. Although the δ34S value for salmon is precise and appears general among species and areas, sulfur ratios were strongly correlated with nitrogen ratios and therefore added little new information to the mixing model regarding the consumption of salmon. Mean δ34S values for the three terrestrial herbivores of interest were similar and imprecise, so these data also added little new information to the mixing model. The addition of sulfur data did confirm that at least some bears in this system ate marmots during summer and fall. We show that there are bears with short hair that assimilate >20% salmon in their diet and bears with longer hair that eat no salmon living within a few kilometers of one another in a coastal ecosystem. Grizzly bears are thought to re-grow hair between June and October however our analysis of sectioned hair suggested at least some hairs begin growing in July or August, not June and, that hair of wild bears may grow faster than observed in captive bears. Our hair samples may have been from the year of sampling or the previous year because samples were collected in summer when bears were

Stable isotope compositions of serpentinite seamounts in the Mariana forearc: Serpentinization processes, fluid sources and sulfur metasomatism

Science.gov (United States)

Alt, J.C.; Shanks, Wayne C.

2006-01-01

The Mariana and Izu-Bonin arcs in the western Pacific are characterized by serpentinite seamounts in the forearc that provide unique windows into the mantle wedge. We present stable isotope (O, H, S, and C) data for serpentinites from Conical seamount in the Mariana forearc and S isotope data for Torishima seamount in the Izu-Bonin forearc in order to understand the compositions of fluids and temperatures of serpentinization in the mantle wedge, and to investigate the transport of sulfur from the slab to the mantle wedge. Six serpentine mineral separates have a restricted range of ??18O (6.5-8.5???). Antigorite separates have ??D values of -29.5??? to -45.5??? that reflect serpentinization within the mantle wedge whereas chrysotile has low ??D values (-51.8??? to -84.0???) as the result of re-equilibration with fluids at low temperatures. Fractionation of oxygen isotopes between serpentine and magnetite indicate serpentinization temperatures of 300-375 ??C. Two late cross-fiber chrysotile veins have higher ??18O values of 8.9??? to 10.8??? and formed at lower temperatures (as low as ???100 ??C). Aqueous fluids in equilibrium with serpentine at 300-375 ??C had ??18O = 6.5-9??? and ??D = -4??? to -26???, consistent with sediment dehydration reactions at temperatures arc lavas. ?? 2006 Elsevier B.V. All rights reserved.

Stable isotopes back-track the origin of alabaster from the 'Ulrich Epitaph', Güstrow, Germany

Science.gov (United States)

Böttcher, Michael E.; Fuchs, Arnold; Gehre, Matthias; Krempler, Michael; Cooper, Anthony H.

2017-04-01

Natural calcium sulphate minerals (like gypsum, in the variety of 'alabaster') have been used for a long time for art and ornamental works despite its high solubility in aqueous solution due to its easy way of recovery and handling. To identify different European source provenances, geochemical and stable isotope forensic methods have been applied, thereby defining historical pathways of trade. A detailed geochemical characterization of both alabaster samples from the monument and potential sources is a pre-requisite for a backtracking material sources. Several tracers have been tested in the past identifiying the coupled sulfur and oxygen isotope composition of the sulfate molecule in the evaporite minerals to be highly characteristic. In the present study, we analyzed the stable sulfur and oxygen isotope composition of raw alabaster from the famous Ulrich Epithaph in Güstrow, Northeastern Germany, and compared the results with new measurements from one of the major European contributors of alabaster in the 16th century, the Cellaston quarry, Derbyshire (England) and literature data for further potential Spanish and Frensh source quarries (Kloppmann et a., 2014; Archaeometry, 56). We found that the stable sulfur and oxygen isotope signatures of alabaster from the Ulrich Epitaph indicate the origin from the Upper Triassic (Keuper) evaporites of the English Cellaston quarry and are not related to other potential alabaster sources. This further illustrates the alabaster trade way between England and Germany in the late 16th century.

Stable isotope variation as a tool to trace the authenticity of beef

International Nuclear Information System (INIS)

Boner, M.; Foerstel, H.

2004-01-01

Organic beef coming principally from Germany was analysed for the hydrogen, carbon, oxygen, nitrogen and sulfur stable isotopic composition to test the possibility of tracing back the geographical origin. Since there is a well-known pattern of D/H and 18 O/ 16 O in meteoric water and in ground water, there is an existing link to tissue water in the beef. By including the stable isotope ratios of the other elements of life further information is available: soils show different isotope ratios of 15 N/ 14 N and 34 S/ 32 S depending on the geological composition, cultivation and atmospheric sulfur deposition. As organic farming is mainly obliged to use only their produced fodder, that ratio is reflected in the beef as well. Different organic beef samples from various German farms have been collected and analysed over nearly two years. To check the differentiation of foreign beef, samples from Argentina and Chile were also included in the study. The analyses of meat samples indicate that it is possible to trace back the region (e.g. Argentina and Germany) by using isotopes of oxygen and hydrogen. A local geographical differentiation can be done by using the stable isotopes of nitrogen and sulfur, as was demonstrated for three farms in Colonia Bay. An optimal differentiation also depends on the quality of further information (e.g. the season, kind of cattle breeding or the declaration of the local geographical origin). Certainly authenticity of beef is not only linked with the geographical origin but can also reflect the differentiation of organic and conventional farming. The fodder of organic cattle farming consists mainly of C 3 plants and the use of C 4 plants is more usual in conventional cattle farming. A 13 C/ 12 C ratio above -20 permille appears as a limit for organic farming. Increased values have to be controlled based on their authenticity. (orig.)

Isotopic abundance analysis of carbon, nitrogen and sulfur with a combined elemental analyzer-mass spectrometer system

International Nuclear Information System (INIS)

Pichlmayer, F.; Blochberger, K.

1988-01-01

Stable isotope ratio measurements of carbon, nitrogen and sulfur are of growing interest as analytical tool in many fields of research, but applications were somewhat hindered in the past by the fact that cumbersome sample preparation was necessary. A method has therefore been developed, consisting in essential of coupling an elemental analyzer with an isotope mass spectrometer, enabling fast and reliable conversion of C-, N- and S-compounds in any solid or liquid sample into the measuring gases carbon dioxide, nitrogen and sulfur dioxide for on-line isotopic analysis. The experimental set-up and the main characteristics are described in short and examples of application in environmental research, food analysis and clinical diagnosis are given. (orig.)

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)

SO2 photoexcitation mechanism links mass-independent sulfur isotopic fractionation in cryospheric sulfate to climate impacting volcanism

DEFF Research Database (Denmark)

Hattori, Shohei; Schmidt, Johan Albrecht; Johnson, Matthew Stanley

2013-01-01

Natural climate variation, such as that caused by volcanoes, is the basis for identifying anthropogenic climate change. However, knowledge of the history of volcanic activity is inadequate, particularly concerning the explosivity of specific events. Some material is deposited in ice cores......, but the concentration of glacial sulfate does not distinguish between tropospheric and stratospheric eruptions. Stable sulfur isotope abundances contain additional information, and recent studies show a correlation between volcanic plumes that reach the stratosphere and mass-independent anomalies in sulfur isotopes...... plume chemistry, allowing the production and preservation of a mass-independent sulfur isotope anomaly in the sulfate product. The model accounts for the amplitude, phases, and time development of Δ(33)S/δ(34)S and Δ(36)S/Δ(33)S found in glacial samples. We are able to identify the process controlling...

Estimation of microbial respiration rates in groundwater by geochemical modeling constrained with stable isotopes

International Nuclear Information System (INIS)

Murphy, E.M.

1998-01-01

Changes in geochemistry and stable isotopes along a well-established groundwater flow path were used to estimate in situ microbial respiration rates in the Middendorf aquifer in the southeastern United States. Respiration rates were determined for individual terminal electron acceptors including O 2 , MnO 2 , Fe 3+ , and SO 4 2- . The extent of biotic reactions were constrained by the fractionation of stable isotopes of carbon and sulfur. Sulfur isotopes and the presence of sulfur-oxidizing microorganisms indicated that sulfate is produced through the oxidation of reduced sulfur species in the aquifer and not by the dissolution of gypsum, as previously reported. The respiration rates varied along the flow path as the groundwater transitioned between primarily oxic to anoxic conditions. Iron-reducing microorganisms were the largest contributors to the oxidation of organic matter along the portion of the groundwater flow path investigated in this study. The transition zone between oxic and anoxic groundwater contained a wide range of terminal electron acceptors and showed the greatest diversity and numbers of culturable microorganisms and the highest respiration rates. A comparison of respiration rates measured from core samples and pumped groundwater suggests that variability in respiration rates may often reflect the measurement scales, both in the sample volume and the time-frame over which the respiration measurement is averaged. Chemical heterogeneity may create a wide range of respiration rates when the scale of the observation is below the scale of the heterogeneity

Recycling of water, carbon, and sulfur during subduction of serpentinites: A stable isotope study of Cerro del Almirez, Spain

Science.gov (United States)

Alt, Jeffrey C.; Garrido, Carlos J.; Shanks, Wayne C.; Turchyn, Alexandra; Padrón-Navarta, José Alberto; López Sánchez-Vizcaíno, Vicente; Gómez Pugnaire, María Teresa; Marchesi, Claudio

2012-01-01

We use the concentrations and isotope compositions of water, carbon, and sulfur in serpentinites and their dehydration products to trace the cycling of volatiles during subduction. Antigorite serpentinites from the Cerro del Almirez complex, Spain, contain 9–12 wt.% H2O and 910 ± 730 ppm sulfur, and have bulk δ18O values of 8.6 ± 0.4‰, δD = − 54 ± 5‰, and δ34S = 5.0‰, consistent with serpentinization at temperatures of ~ 200 °C by seawater hydrothermal fluids in a seafloor setting. The serpentinites were dehydrated to chlorite–harzburgite (olivine + orthopyroxene + chlorite) at 700 °C and 1.6–1.9 GPa during subduction metamorphism, resulting in loss of water, and sulfur. The chlorite–harzburgites contain 5.7 ± 1.9 wt.% H2O, and have bulk δ18O = 8.0 ± 0.9‰, and δD = − 77 ± 11‰. The rocks contain 650 ± 620 ppm sulfur having δ34S = 1.2‰. Dehydration of serpentinite resulted in loss of 5 wt.% H2O having δ18O = 8–10‰ and δD = − 27 to − 65‰, and loss of 260 ppm sulfur as sulfate, having δ34S = 14.5‰. The contents and δ13C of total carbon in the two rock types overlap, with a broad trend of decreasing carbon contents and δ13C from ~ 1300 to 200 ppm and − 9.6 to − 20.2‰. This reflects mixing between reduced carbon in the rocks (210 ppm, δ13C ≈ − 26‰) and seawater-derived carbonate (δ13C ≈ − 1‰). Our results indicate: 1) Serpentinized oceanic peridotites carry significant amounts of isotopically fractionated water, carbon and sulfur into subduction zones; 2) Subduction of serpentinites to high P and T results in loss of water, and sulfur, which can induce melting and contribute to 18O, D, and 34S enrichments and oxidation of the sub-arc mantle wedge; and 3) Isotopically fractionated water, carbon, and sulfur in serpentinite dehydration products are recycled deeper into the mantle where they can contribute to isotope heterogeneities and may be significant for volatile budgets of the deep Earth.

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

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

Sulfur isotope ratios and the origins of the aerosols and cloud droplets in California stratus

International Nuclear Information System (INIS)

Ludwig, F.L.

1976-01-01

Marine aerosols often have sulfur-to-chloride ratios greater than that found in seawater. Sulfur isotope ratios ( 34 S/ 32 S) were measured in aerosol and cloud droplet samples collected in the San Francisco Bay Area in an attempt to understand the processes that produce the observed sulfur-to-chloride ratios. Seawater sulfur usually has very high sulfur isotope ratios: fossil fuel sulfur tends to have smaller isotope ratios and sulfur of bacteriogenic origin still smaller. Samples collected in unpolluted marine air over the hills south of San Francisco had sulfur ratios that were significantly lower than the values for samples collected in nearby areas that were subject to urban pollution. The highest sulfur isotope ratios were found in the offshore seawater. The results suggest bacteriogenic origins, of the marine air sulfur aerosol material. The low isotope ratios in the marine air cannot be explained as a mixture of seawater sulfur and pollutant sulfur, because both tend to have higher isotope ratios. (Auth.)

Mixed total screening for sulfur isotope

International Nuclear Information System (INIS)

Cui Bin; Zhao Lei; Zhan Zhaoyang; He Zhijun

2003-01-01

The research on modern economic geology indicates that most ore deposits formed with characters of multi-origin, multi-stage and multi-genesis. Quantificational research of Sulfur isotope origin is a difficult problem that puzzles Geochemists all along. So the formation process of an ore deposit can be taken as the mix or the superposition of multi totals, which can be described by the mathematics model of mixed total screening. In the study of mid-down Yangtze River and Dongpo ore field in Hunan province, the authors successfully applied the mathematics model of mixed total screening, quantificationally resolved the problem of Sulfur isotope origin and mineralizing matter origin, and found out the mineralizing mechanism. This is very valuable. (authors)

Sulfur isotopic analysis of carbonyl sulfide and its application for biogeochemical cycles

Science.gov (United States)

Hattori, Shohei; Kamezaki, Kazuki; Ogawa, Takahiro; Toyoda, Sakae; Katayama, Yoko; Yoshida, Naohiro

2016-04-01

Carbonyl sulfide (OCS or COS) is the most abundant gas containing sulfur in the atmosphere, with an average mixing ratio of 500 p.p.t.v. in the troposphere. OCS is suggested as a sulfur source of the stratospheric sulfate aerosols (SSA) which plays an important role in Earth's radiation budget and ozone depletion. Therefore, OCS budget should be validated for prediction of climate change, but the global OCS budget is imbalance. Recently we developed a promising new analytical method for measuring the stable sulfur isotopic compositions of OCS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ (Hattori et al., 2015). The first measurement of the δ34S value for atmospheric OCS coupled with isotopic fractionation for OCS sink reactions in the stratosphere (Hattori et al., 2011; Schmidt et al., 2012; Hattori et al., 2012) explains the reported δ34S value for background stratospheric sulfate, suggesting that OCS is a potentially important source for background (nonepisodic or nonvolcanic) stratospheric sulfate aerosols. This new method measuring δ34S values of OCS can be used to investigate OCS sources and sinks in the troposphere to better understand its cycle. It is known that some microorganisms in soil can degrade OCS, but the mechanism and the contribution to the OCS in the air are still uncertain. In order to determine sulfur isotopic enrichment factor of OCS during degradation via microorganisms, incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia and Cupriavidus, isolated from natural soil environments (Kato et al., 2008). As a result, sulfur isotope ratios of OCS were increased during degradation of OCS, indicating that reaction for OC32S is faster than that for OC33S and OC34S. OCS degradation via microorganisms is not mass-independent fractionation (MIF) process, suggesting that this

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

Stable isotope sales: Mound Laboratory customer and shipment summaries, FY 1976 and FY 1976A

International Nuclear Information System (INIS)

Ruwe, A.H. Jr.

1977-01-01

A listing is given of Mound Laboratory's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, chlorine, and sulfur for fiscal years 1976 and 1976A (the period July 1, 1975 through September 30, 1976). 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

Large sulfur isotope fractionations in Martian sediments at Gale crater

Science.gov (United States)

Franz, H. B.; McAdam, A. C.; Ming, D. W.; Freissinet, C.; Mahaffy, P. R.; Eldridge, D. L.; Fischer, W. W.; Grotzinger, J. P.; House, C. H.; Hurowitz, J. A.; McLennan, S. M.; Schwenzer, S. P.; Vaniman, D. T.; Archer, P. D., Jr.; Atreya, S. K.; Conrad, P. G.; Dottin, J. W., III; Eigenbrode, J. L.; Farley, K. A.; Glavin, D. P.; Johnson, S. S.; Knudson, C. A.; Morris, R. V.; Navarro-González, R.; Pavlov, A. A.; Plummer, R.; Rampe, E. B.; Stern, J. C.; Steele, A.; Summons, R. E.; Sutter, B.

2017-09-01

Variability in the sulfur isotopic composition in sediments can reflect atmospheric, geologic and biological processes. Evidence for ancient fluvio-lacustrine environments at Gale crater on Mars and a lack of efficient crustal recycling mechanisms on the planet suggests a surface environment that was once warm enough to allow the presence of liquid water, at least for discrete periods of time, and implies a greenhouse effect that may have been influenced by sulfur-bearing volcanic gases. Here we report in situ analyses of the sulfur isotopic compositions of SO2 volatilized from ten sediment samples acquired by NASA’s Curiosity rover along a 13 km traverse of Gale crater. We find large variations in sulfur isotopic composition that exceed those measured for Martian meteorites and show both depletion and enrichment in 34S. Measured values of δ34S range from -47 +/- 14‰ to 28 +/- 7‰, similar to the range typical of terrestrial environments. Although limited geochronological constraints on the stratigraphy traversed by Curiosity are available, we propose that the observed sulfur isotopic signatures at Gale crater can be explained by equilibrium fractionation between sulfate and sulfide in an impact-driven hydrothermal system and atmospheric processing of sulfur-bearing gases during transient warm periods.

The investigation on physico-chemical conditions of sulfides and sulfates based on petrographic and sulfur - oxygen stable isotope studies from the Darreh-Zar porphyry copper deposit, Kerman

Directory of Open Access Journals (Sweden)

Anis Parsapoor

2014-04-01

Full Text Available The Darreh-Zar porphyry copper deposit, located in the Urumieh – Dokhtar magmatic belt, lies about 10 km southeast of Sar-Cheshmeh porphyry copper deposit. The ore body with hydrothermally altered zones including potassic, chlorite-sericite, sericite, argillic and propylitic all related to the Darreh-Zar porphyry stock intruded the Eocene volcanic rocks. Pyrite, chalcopyrite, molybdenite, with different textures as disseminated and veinlet, are the major sulfide minerals and chalcocite and covellite are considered as the secondary minerals. Sulfur isotopic composition of the sulfates and sulfides studied fall on the magmatic values. Two different origins may be suggested for the gypsums studied: 1- hydration of anhydrite and 2- oxidation of pyrite during supergene enrichment. The stable isotopic data calculated on couple minerals (pyrite-anhydrite point to the formation temperature of about 485-515οC for the fluids involved in mineralization. The fluid responsible for mineralization suggests magmatic sources for all sulfide phases and reduced aqueous sulfur species. Isotopic zoning, based on the δ34S pyrite values, divided the area into the east and the west parts with negative and positive correlation against the depth, respectively. Also, a negative correlation is observed between the Cu and the δ34S in the eastern portion of the area.

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

Stable isotope sales: Mound Laboratory customer and shipment summaries, FY 1976 and FY 1976A

Energy Technology Data Exchange (ETDEWEB)

Ruwe, A.H. Jr. (comp.)

1977-06-06

A listing is given of Mound Laboratory's sales of stable isotopes of noble gases, carbon, oxygen, nitrogen, chlorine, and sulfur for fiscal years 1976 and 1976A (the period July 1, 1975 through September 30, 1976). 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.

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.

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.

Sulfur and Hydrogen Isotope Anomalies in Meteorite Sulfonic Acids

Science.gov (United States)

Cooper, George W.; Thiemens, Mark H.; Jackson, Teresa L.; Chang, Sherwood

1997-01-01

Intramolecular carbon, hydrogen, and sulfur isotope ratios were measured on a homologous series of organic sulfonic acids discovered in the Murchison meteorite. Mass-independent sulfur isotope fractionations were observed along with high deuterium/hydrogen ratios. The deuterium enrichments indicate formation of the hydrocarbon portion of these compounds in a low-temperature environment that is consistent with that of interstellar clouds. Sulfur-33 enrichments observed in methanesulfonic acid could have resulted from gas-phase ultraviolet irradiation of a precursor, carbon disulfide. The source of the sulfonic acid precursors may have been the reactive interstellar molecule carbon monosulfide.

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

Stable carbon, nitrogen and sulfur isotopes in non-carbonate fractions of cold-seep carbonates

Science.gov (United States)

Feng, Dong; Peng, Yongbo; Peckmann, Jörn; Roberts, Harry; Chen, Duofu

2017-04-01

Sulfate-driven anaerobic oxidation of methane (AOM) supports chemosynthesis-based communities and limits the release of methane from marine sediments. This process promotes the formation of carbonates close to the seafloor along continental margins. The geochemical characteristics of the carbonate minerals of these rocks are increasingly understood, questions remain about the geochemical characteristics of the non-carbonate fractions. Here, we report stable carbon, nitrogen and sulfur isotope patterns in non-carbonate fractions of seep carbonates. The authigenic carbonates were collected from three modern seep provinces (Black Sea, Gulf of Mexico, and South China Sea) and three ancient seep deposits (Marmorito, northern Italy, Miocene; SR4 deposit of the Lincoln Creek Formation and Whiskey Creek, western Washington, USA, Eocene to Oligocene). The δ13C values of non-carbonate fractions range from ˜-25‰ to -80‰ VPDB. These values indicate that fossil methane mixed with varying amounts of pelagic organic matter is the dominant source of carbon in these fractions. The relatively small offset between the δ34S signatures of the non-carbonate fractions and the respective sulfide minerals suggests that locally produced hydrogen sulfide is the main source of sulfur in seep environments. The δ15N values of the non-carbonate fractions are generally lower than the corresponding values of deep-sea sediments, suggesting that organic nitrogen is mostly of a local origin. This study reveals the potential of using δ13C, δ15N, δ34S values to discern seep and non-seep deposits. In cases where δ13Ccarbonate values are only moderately low due to mixing processes and lipid biomarkers have been erased in the course of burial, it is difficult to trace back AOM owing to the lack of other records. This problem is even more pronounced when authigenic carbonate is not available in ancient seep environments. Acknowledgments: The authors thank BOEM and NOAA for their years' support

Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer–chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS)

Science.gov (United States)

Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B.; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A.; Schimmelmann, Arndt

2017-01-01

Rationale: Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H2) is responsible for non-quantitative H2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer–Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems.

Tetrathionate and Elemental Sulfur Shape the Isotope Composition of Sulfate in Acid Mine Drainage

Directory of Open Access Journals (Sweden)

Nurgul Balci

2017-08-01

Full Text Available Sulfur compounds in intermediate valence states, for example elemental sulfur, thiosulfate, and tetrathionate, are important players in the biogeochemical sulfur cycle. However, key understanding about the pathways of oxidation involving mixed-valance state sulfur species is still missing. Here we report the sulfur and oxygen isotope fractionation effects during the oxidation of tetrathionate (S4O62− and elemental sulfur (S° to sulfate in bacterial cultures in acidic conditions. Oxidation of tetrathionate by Acidithiobacillus thiooxidans produced thiosulfate, elemental sulfur and sulfate. Up to 34% of the tetrathionate consumed by the bacteria could not be accounted for in sulfate or other intermediate-valence state sulfur species over the experiments. The oxidation of tetrathionate yielded sulfate that was initially enriched in 34S (ε34SSO4−S4O6 by +7.9‰, followed by a decrease to +1.4‰ over the experiment duration, with an average ε34SSO4−S4O6 of +3.5 ± 0.2‰ after a month of incubation. We attribute this significant sulfur isotope fractionation to enzymatic disproportionation reactions occurring during tetrathionate decomposition, and to the incomplete transformation of tetrathionate into sulfate. The oxygen isotope composition of sulfate (δ18OSO4 from the tetrathionate oxidation experiments indicate that 62% of the oxygen in the formed sulfate was derived from water. The remaining 38% of the oxygen was either inherited from the supplied tetrathionate, or supplied from dissolved atmospheric oxygen (O2. During the oxidation of elemental sulfur, the product sulfate became depleted in 34S between −1.8 and 0‰ relative to the elemental sulfur with an average for ε34SSO4−S0 of −0.9 ± 0.2‰ and all the oxygen atoms in the sulfate derived from water with an average normal oxygen isotope fractionation (ε18OSO4−H2O of −4.4‰. The differences observed in δ18OSO4 and the sulfur isotope composition of sulfate (δ34SSO4

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.

Non-mass-dependent fractionation of sulfur and oxygen isotopes during UV photolysis of sulfur dioxide

Science.gov (United States)

Pen, Aranh

Since the discovery of anomalous sulfur isotope abundance in the geological record in sulfate and sulfide minerals (Farquhar et al., 2000), much effort has been put into understanding their origin to provide new insights into the environmental conditions on the early Earth (Farquhar et al., 2001; Pavlov and Kasting, 2002; Ono et al., 2003; Zahnle et al., 2006; Farquhar et al., 2007; Lyons, 2007; Lyons, 2008). This discovery gained immense interest because of its implications for both the lack of oxygen in the atmosphere during the Archean era 2.5-3.8 Gya (billion years ago), and for rise of oxygen, or the "Great Oxidation Event", that occurred 2.2-2.4 Gya (Holland, 2002). These signatures are believed to be produced in an anticorrelation to oxygen abundance in the early atmosphere, which will aid in quantifying the rate of oxygenation during the "Great Oxidation Event". According to Farquhar et al. (2000), the non-mass-dependent (NMD), or anomalous, fractionation signatures were produced by photochemical reactions of volcanic sulfur species in Earth's early atmosphere (> 2.3 Gya) due to the lack of an oxygen and ozone shield, resulting in an atmosphere transparent to solar ultraviolet (UV) radiation (Farquhar et al., 2001). Interpretation of the anomalous rock records, though, depends on the identification of (1) chemical reactions that can produce the NMD signature (Farquhar and Wing, 2003); and (2) conditions necessary for conversion of the gas-phase products into solid minerals (Pavlov and Kasting, 2002). The focus of my research addresses the first step, which is to determine whether the chemical reactions that occurred in Earth's early atmosphere, resulting in NMD fractionation of sulfur isotopes, were due to broadband UV photochemistry, and to test isotopic self-shielding as the possible underlying mechanism. In this project, our goals were to test isotopic self-shielding during UV photolysis as a possible underlying mechanism for anomalous sulfur isotopic

Sulfur isotope evidence for the contemporary formation of pyrite in a coastal acid sulfate soil

International Nuclear Information System (INIS)

Bush, R.T.; Sullivan, L.A.; Prince, K.; White, I.

2000-01-01

The sulfur isotopic composition of pyrite (FeS 2 ), greigite (Fe 3 S 4 ) and pore-water sulfate was determined for a typical coastal acid sulfate soil (ASS). Greigite occurs only in the partially oxidised upper-most pyrite sediments as blackish clusters within vertical fissures and other macro-pores. The concentration of pyrite was an order of magnitude greater than greigite in this layer, continuing through the underlying reduced estuarine sediments. δ 34 S of pyrite (0.45 per mil) associated with greigite accumulations were distinctly different to the bulk average for pyrite (-3.7 per mil), but similar to greigite (0.9 per mil). Greigite is meta-stable under reducing conditions, readily transforming to pyrite. The transformation of iron monosulfides (including greigite) to pyrite is a sulfur-isotope conservative process and therefore, these observations indicate that pyrite is forming from greigite at the oxic/anoxic boundary

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.

USE OF SLACK-WATER ENVIRONMENTS BY COHO SALMON JUVENILES IN A COASTAL OREGON STREAM AS INDICATED BY 34S STABLE ISOTOPE ANALYSIS

Science.gov (United States)

Stable isotopes of sulfur are rarely used in studies of elemental cycling, trophic position or use of marine-derived nutrients by salmonids. The main reason for this probably is the reluctance on the part of isotope labs to expose their instruments to SO2 (because of its corrosi...

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.)

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.

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

SO2 photoexcitation mechanism links mass-independent sulfur isotopic fractionation in cryospheric sulfate to climate impacting volcanism

Science.gov (United States)

Hattori, Shohei; Schmidt, Johan A.; Johnson, Matthew S.; Danielache, Sebastian O.; Yamada, Akinori; Ueno, Yuichiro; Yoshida, Naohiro

2013-01-01

Natural climate variation, such as that caused by volcanoes, is the basis for identifying anthropogenic climate change. However, knowledge of the history of volcanic activity is inadequate, particularly concerning the explosivity of specific events. Some material is deposited in ice cores, but the concentration of glacial sulfate does not distinguish between tropospheric and stratospheric eruptions. Stable sulfur isotope abundances contain additional information, and recent studies show a correlation between volcanic plumes that reach the stratosphere and mass-independent anomalies in sulfur isotopes in glacial sulfate. We describe a mechanism, photoexcitation of SO2, that links the two, yielding a useful metric of the explosivity of historic volcanic events. A plume model of S(IV) to S(VI) conversion was constructed including photochemistry, entrainment of background air, and sulfate deposition. Isotopologue-specific photoexcitation rates were calculated based on the UV absorption cross-sections of 32SO2, 33SO2, 34SO2, and 36SO2 from 250 to 320 nm. The model shows that UV photoexcitation is enhanced with altitude, whereas mass-dependent oxidation, such as SO2 + OH, is suppressed by in situ plume chemistry, allowing the production and preservation of a mass-independent sulfur isotope anomaly in the sulfate product. The model accounts for the amplitude, phases, and time development of Δ33S/δ34S and Δ36S/Δ33S found in glacial samples. We are able to identify the process controlling mass-independent sulfur isotope anomalies in the modern atmosphere. This mechanism is the basis of identifying the magnitude of historic volcanic events. PMID:23417298

Diversity of sulfur isotope fractionations by sulfate-reducing prokaryotes

DEFF Research Database (Denmark)

Detmers, Jan; Brüchert, Volker; Habicht, K S

2001-01-01

Batch culture experiments were performed with 32 different sulfate-reducing prokaryotes to explore the diversity in sulfur isotope fractionation during dissimilatory sulfate reduction by pure cultures. The selected strains reflect the phylogenetic and physiologic diversity of presently known...... sulfate reducers and cover a broad range of natural marine and freshwater habitats. Experimental conditions were designed to achieve optimum growth conditions with respect to electron donors, salinity, temperature, and pH. Under these optimized conditions, experimental fractionation factors ranged from 2.......0 to 42.0 per thousand. Salinity, incubation temperature, pH, and phylogeny had no systematic effect on the sulfur isotope fractionation. There was no correlation between isotope fractionation and sulfate reduction rate. The type of dissimilatory bisulfite reductase also had no effect on fractionation...

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

Identifying the change in atmospheric sulfur sources in China using isotopic ratios in mosses

Science.gov (United States)

Xiao, Hua-Yun; Tang, Cong-Guo; Xiao, Hong-Wei; Liu, Xue-Yan; Liu, Cong-Qiang

2009-08-01

A considerable number of studies on rainwater sulfur isotopic ratios (δ34Srain) have been conducted to trace sulfur sources at a large number of sites in the past. If longitudinal studies on the isotope composition of precipitation sulfate were conducted, it is possible to relate that to changes in sulfur emissions. But direct measurement needs considerable labor and time. So, in this study, sulfur isotopic ratios in rainwater and mosses were analyzed at Guiyang and Nanchang to evaluate the possibility of using mosses as a substitute for rainwater. We found that present moss sulfur isotopic ratios were comparable to those of present rainwater. Additionally, we investigated the changes of atmospheric sulfur sources and sulfur concentrations using an isotopic graphic analysis at five industrial cities, two forested areas, and two remote areas in China. Mosses in industrial cities show a wide range of δ34S values, with the highest occurring at Chongqing (+3.9‰) and the lowest at Guiyang (-3.1‰). But as compared to those in forested and remote areas, δ34S values of mosses in all the five industrial cities are lower. On the basis of isotopic comparisons between past rainwater (reported in the literature) and present mosses, in the plot of δ34Smoss versus δ34Srain, six zones indicating different atmospheric sulfur change are separated by the 1:1 line and δ34S values of potential sulfur sources. Our results indicate that atmospheric sulfur pollution in most of the industrial cities decreased, while at the two forested areas, no significant changes were observed, and a new anxiousness coming from new energy sources (e.g., oil) appeared in some cities. Studies on the change of ambient SO2 concentrations support these results.

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

Sulfur cycling in contaminated aquifers: What can we learn from oxygen isotopes in sulfate? (Invited)

Science.gov (United States)

Knoeller, K.; Vogt, C.; Hoth, N.

2009-12-01

Bacterial reduction of dissolved sulfate (BSR) is a key process determining the natural attenuation in many contaminated aquifers. For example, in groundwater bodies affected by acid mine drainage (AMD) BSR reduces the contaminant load by producing alkalinity and facilitating a sustainable fixation of sulfur in the sediment. In aquifers contaminated with petroleum hydrocarbons sulfate may act as a terminal electron acceptor for the anaerobic oxidation of the organic contaminants to carbon dioxide and water. Due to the isotope selectivity of sulfate reducing bacteria, BSR shows the most pronounced isotope fractionation within the sulfur cycle. While sulfur displays a straightforward kinetic enrichment in the residual sulfate described by the enrichment factor epsilon (ɛ), the mechanism of oxygen isotope fractionation is still being discussed controversially. Nevertheless, it is agreed on that oxygen isotope exchange between ambient water and residual sulfate occurs during BSR in natural environments. With respect to this potential isotope exchange, the fractionation parameter theta (θ) is introduced instead of the kinetic enrichment factor epsilon (ɛ). The dual isotope system considering both sulfate-sulfur and sulfate-oxygen isotope fractionation and the respective fractionation parameters ɛ and θ provides an excellent tool for the recognition and quantification of BSR. Beyond that, the dual isotope approach may help identify and estimate interfering sulfur transformations such as re-oxidation and disproportionation processes which is especially vital for the understanding of the overall natural attenuation potential of the investigated aquifers. We present two examples from different field studies showing the benefits of applying the combination of sulfur and oxygen isotopes in dissolved sulfate to reveal the details of the sulfur cycle. The first case study is concerned with the evaluation of the potential for BSR in an AMD-affected aquifer close to an

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

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

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

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

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

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

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

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.)

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

Evaluation of nutrient and energy sources of the deepest known serpentinite-hosted ecosystem using stable carbon, nitrogen, and sulfur isotopes.

Science.gov (United States)

Onishi, Yuji; Yamanaka, Toshiro; Okumura, Tomoyo; Kawagucci, Shinsuke; Watanabe, Hiromi Kayama; Ohara, Yasuhiko

2018-01-01

The Shinkai Seep Field (SSF) in the southern Mariana forearc discovered in 2010 is the deepest (~5,700 m in depth) known serpentinite-hosted ecosystem dominated by a vesicomyid clam, Calyptogena (Abyssogena) mariana. The pioneering study presumed that the animal communities are primary sustained by reducing fluid originated from the serpentinization of mantle peridotite. For understanding the nutrient and energy sources for the SSF community, this study conducted four expeditions to the SSF and collected additional animal samples such as polychaetes and crustaceans as well as sediments, fragments of chimneys developing on fissures of serpentinized peridotite, seeping fluid on the chimneys, and pore water within the chimneys. Geochemical analyses of seeping fluids on the chimneys and pore water of the chimneys revealed significantly high pH (~10) that suggest subseafloor serpentinization controlling fluid chemistry. Stable isotope systematics (carbon, nitrogen, and sulfur) among animals, inorganic molecules, and environmental organic matter suggest that the SSF animal community mostly relies on the chemosynthetic production while some organisms appear to partly benefit from photosynthetic production despite the great depth of SSF.

Isotopic insights into microbial sulfur cycling in oil reservoirs

Directory of Open Access Journals (Sweden)

Christopher G Hubbard

2014-09-01

Full Text Available Microbial sulfate reduction in oil reservoirs (biosouring is often associated with secondary oil production where seawater containing high sulfate concentrations (~28 mM is injected into a reservoir to maintain pressure and displace oil. The sulfide generated from biosouring can cause corrosion of infrastructure, health exposure risks, and higher production costs. Isotope monitoring is a promising approach for understanding microbial sulfur cycling in reservoirs, enabling early detection of biosouring, and understanding the impact of souring. Microbial sulfate reduction is known to result in large shifts in the sulfur and oxygen isotope compositions of the residual sulfate, which can be distinguished from other processes that may be occurring in oil reservoirs, such as precipitation of sulfate and sulfide minerals. Key to the success of this method is using the appropriate isotopic fractionation factors for the conditions and processes being monitored. For a set of batch incubation experiments using a mixed microbial culture with crude oil as the electron donor, we measured a sulfur fractionation factor for sulfate reduction of -30‰. We have incorporated this result into a simplified 1D reservoir reactive transport model to highlight how isotopes can help discriminate between biotic and abiotic processes affecting sulfate and sulfide concentrations. Modeling results suggest that monitoring sulfate isotopes can provide an early indication of souring for reservoirs with reactive iron minerals that can remove the produced sulfide, especially when sulfate reduction occurs in the mixing zone between formation waters containing elevated concentrations of volatile fatty acids and injection water containing elevated sulfate. In addition, we examine the role of reservoir thermal, geochemical, hydrological, operational and microbiological conditions in determining microbial souring dynamics and hence the anticipated isotopic signatures.

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)

Transport-Induced Spatial Patterns of Sulfur Isotopes (δ34S) as Biosignatures

Science.gov (United States)

Mansor, Muammar; Harouaka, Khadouja; Gonzales, Matthew S.; Macalady, Jennifer L.; Fantle, Matthew S.

2018-01-01

Cave minerals deposited in the presence of microbes may host geochemical biosignatures that can be utilized to detect subsurface life on Earth, Mars, or other habitable worlds. The sulfur isotopic composition of gypsum (CaSO4·2H2O) formed in the presence of sulfur-oxidizing microbes in the Frasassi cave system, Italy, was evaluated as a biosignature. Sulfur isotopic compositions (δ34SV-CDT) of gypsum sampled from cave rooms with sulfidic air varied from -11 to -24‰, with minor deposits of elemental sulfur having δ34S values between -17 and -19‰. Over centimeter-length scales, the δ34S values of gypsum varied by up to 8.5‰. Complementary laboratory experiments showed negligible fractionation during the oxidation of elemental sulfur to sulfate by Acidithiobacillus thiooxidans isolated from the caves. Additionally, gypsum precipitated in the presence and absence of microbes at acidic pH characteristic of the sulfidic cave walls has δ34S values that are on average 1‰ higher than sulfate. We therefore interpret the 8.5‰ variation in cave gypsum δ34S (toward more negative values) to reflect the isotopic effect of microbial sulfide oxidation directly to sulfate or via elemental sulfur intermediate. This range is similar to that expected by abiotic sulfide oxidation with oxygen, thus complicating the use of sulfur isotopes as a biosignature at centimeter-length scales. However, at the cave room (meter-length) scale, reactive transport modeling suggests that the overall ˜13‰ variability in gypsum δ34S reflects isotopic distillation of circulating H2S gas due to microbial sulfide oxidation occurring along the cave wall-atmosphere interface. Systematic variations of gypsum δ34S along gas flow paths can thus be interpreted as biogenic given that slow, abiotic oxidation cannot produce the same spatial patterns over similar length scales. The expression and preservation potential of this biosignature is dependent on gas flow parameters and diagenetic

Geochemical and stable isotopic constraints on the generation and passive treatment of acidic, Fe-SO{sub 4} rich waters

Energy Technology Data Exchange (ETDEWEB)

Matthies, Romy, E-mail: rmatthies@uwaterloo.ca [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Aplin, Andrew C., E-mail: andrew.aplin@ncl.ac.uk [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom); Boyce, Adrian J., E-mail: a.boyce@suerc.gla.ac.uk [Scottish Universities Environment Research Centre, East Kilbride, G75 0QF (United Kingdom); Jarvis, Adam P., E-mail: a.p.jarvis@ncl.ac.uk [School of Civil Engineering and Geosciences, Newcastle University, Newcastle upon Tyne, NE1 7RU (United Kingdom)

2012-03-15

Reducing and Alkalinity Producing Systems (RAPS) remediate net-acidic metalliferous mine drainage by creating anoxic conditions in which bacterial sulfate reduction (BSR) raises alkalinity and drives the precipitation of iron and other chalcophilic elements as sulfides. We report chemical and stable isotopic data from a study monitoring the biogeochemical processes involved in the generation of mine waters and their remediation by two RAPS. Sulfur isotopes show that sulfate in all mine waters has a common source (pyrite oxidation), whilst oxygen isotopes show that oxidation of pyritic sulfur is mediated by Fe(III){sub aq}. The isotopic composition of dissolved sulfide, combined with the sulfur and oxygen isotopic composition of sulfate in RAPS effluents, proves BSR and details its dual isotope systematics. The occurrence and isotopic composition of solid phase iron sulfides indicate the removal of reduced sulfur within the RAPS, with significant amounts of elemental sulfur indicating reoxidation steps. However, only 0 to 9% of solid phase iron occurs as Fe sulfides, with approximately 70% of the removed iron occurs as Fe(III) (hydr)oxides. Some of the (hydr)oxide is supplied to the wetland as solids and is simply filtered by the wetland substrate, playing no role in alkalinity generation or proton removal. However, the majority of iron is supplied as dissolved Fe(II), indicating that acid generating oxidation and hydrolysis reactions dominate iron removal. The overall contribution of BSR to the sulfur geochemistry in the RAPS is limited and sulfate retention is dominated by sulfate precipitation, comparable to aerobic treatment systems, and show that the proton acidity resulting from iron oxidation and hydrolysis must be subsequently neutralised by calcite dissolution and/or BSR deeper in the RAPS sediments. BSR is not as important as previously thought for metal removal in RAPS. The results have practical consequences for the design, treatment performance and long

Stable isotope and trace element studies of black bear hair, Big Bend ecosystem, Texas and Mexico

Science.gov (United States)

Shanks, W.C. Pat; Hellgren, Eric C.; Stricker, Craig A.; Gemery-Hill, Pamela A.; Onorato, David P.

2008-01-01

Hair from black bears (Ursus americanus), collected from four areas in the Big Bend ecosystem, has been analyzed for stable isotopes of carbon, nitrogen, and sulfur to determine major food sources and for trace metals to infer possible effects of environmental contaminants. Results indicate that black bears are largely vegetarian, feeding on desert plants, nuts, and berries. Mercury concentrations in bear hair are below safe level standards (

Sulfur isotope fractionation during oxidation of sulfur dioxide: gas-phase oxidation by OH radicals and aqueous oxidation by H2O2, O3 and iron catalysis

Directory of Open Access Journals (Sweden)

J. N. Crowley

2012-01-01

Full Text Available The oxidation of SO2 to sulfate is a key reaction in determining the role of sulfate in the environment through its effect on aerosol size distribution and composition. Sulfur isotope analysis has been used to investigate sources and chemical processes of sulfur dioxide and sulfate in the atmosphere, however interpretation of measured sulfur isotope ratios is challenging due to a lack of reliable information on the isotopic fractionation involved in major transformation pathways. This paper presents laboratory measurements of the fractionation factors for the major atmospheric oxidation reactions for SO2: Gas-phase oxidation by OH radicals, and aqueous oxidation by H2O2, O3 and a radical chain reaction initiated by iron. The measured fractionation factor for 34S/32S during the gas-phase reaction is αOH = (1.0089±0.0007−((4±5×10−5 T(°C. The measured fractionation factor for 34S/32S during aqueous oxidation by H2O2 or O3 is αaq = (1.0167±0.0019−((8.7±3.5 ×10−5T(°C. The observed fractionation during oxidation by H2O2 and O3 appeared to be controlled primarily by protonation and acid-base equilibria of S(IV in solution, which is the reason that there is no significant difference between the fractionation produced by the two oxidants within the experimental error. The isotopic fractionation factor from a radical chain reaction in solution catalysed by iron is αFe = (0.9894±0.0043 at 19 °C for 34S/32S. Fractionation was mass-dependent with regards to 33S/32S for all the reactions investigated. The radical chain reaction mechanism was the only measured reaction that had a faster rate for the light isotopes. The results presented in this study will be particularly useful to determine the importance of the transition metal-catalysed oxidation pathway compared to other oxidation pathways, but other main oxidation pathways can not be distinguished based on stable sulfur isotope measurements alone.

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

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

Optimization of on-line hydrogen stable isotope ratio measurements of halogen- and sulfur-bearing organic compounds using elemental analyzer-chromium/high-temperature conversion isotope ratio mass spectrometry (EA-Cr/HTC-IRMS).

Science.gov (United States)

Gehre, Matthias; Renpenning, Julian; Geilmann, Heike; Qi, Haiping; Coplen, Tyler B; Kümmel, Steffen; Ivdra, Natalija; Brand, Willi A; Schimmelmann, Arndt

2017-03-30

Accurate hydrogen isotopic analysis of halogen- and sulfur-bearing organics has not been possible with traditional high-temperature conversion (HTC) because the formation of hydrogen-bearing reaction products other than molecular hydrogen (H 2 ) is responsible for non-quantitative H 2 yields and possible hydrogen isotopic fractionation. Our previously introduced, new chromium-based EA-Cr/HTC-IRMS (Elemental Analyzer-Chromium/High-Temperature Conversion Isotope Ratio Mass Spectrometry) technique focused primarily on nitrogen-bearing compounds. Several technical and analytical issues concerning halogen- and sulfur-bearing samples, however, remained unresolved and required further refinement of the reactor systems. The EA-Cr/HTC reactor was substantially modified for the conversion of halogen- and sulfur-bearing samples. The performance of the novel conversion setup for solid and liquid samples was monitored and optimized using a simultaneously operating dual-detection system of IRMS and ion trap MS. The method with several variants in the reactor, including the addition of manganese metal chips, was evaluated in three laboratories using EA-Cr/HTC-IRMS (on-line method) and compared with traditional uranium-reduction-based conversion combined with manual dual-inlet IRMS analysis (off-line method) in one laboratory. The modified EA-Cr/HTC reactor setup showed an overall H 2 -recovery of more than 96% for all halogen- and sulfur-bearing organic compounds. All results were successfully normalized via two-point calibration with VSMOW-SLAP reference waters. Precise and accurate hydrogen isotopic analysis was achieved for a variety of organics containing F-, Cl-, Br-, I-, and S-bearing heteroelements. The robust nature of the on-line EA-Cr/HTC technique was demonstrated by a series of 196 consecutive measurements with a single reactor filling. The optimized EA-Cr/HTC reactor design can be implemented in existing analytical equipment using commercially available material and

Sulfur contents and sulfur-isotope compositions of thiotrophic symbioses in bivalve molluscs and vestimentiferan worms

Science.gov (United States)

Vetter, R.D.; Fry, B.

1998-01-01

Total sulfur (S(TOT)), elemental sulfur (S??) and sulfur-isotope compositions (??34S) of marine animals were analyzed to determine whether these chemical characteristics could help distinguish animals with a sulfur-based, thiotrophic nutrition from animals whose nutrition is based on methanotrophy or on more normal consumption of phytoplankton-derived organic matter. The presence of S??was almost entirely confined to the symbiont-containing tissues of thiotrophs, but was sometimes undetectable in thiotrophic species where sulfide availability was probably low. When S??contents were subtracted, the remaining tissue-sulfur concentrations were similar for all nutritional groups. ??34S values were typically lower for thiotrophs than for other groups, although there was overlap in methanotroph and thiotroph values at some sites. Field evidence supported the existence of small to moderate (1 to 10???)34S fractionations in the uptake of sulfides and metabolism of thiosulfate. In general, a total sulfur content of >3% dry weight, the presence of elemental sulfur, and ??34S values less than + 5??? can be used to infer a thiotrophic mode of nutrition.

A study on hydrogen, oxygen, carbon, sulfur and lead isotopes in the rich uranium deposit No.201

International Nuclear Information System (INIS)

Li Yuexiang; Li Tiangang; Tong Hongshou; Feng Mingyue; Xu Zhan

1995-01-01

The uranium deposit No.201 located in Indonesian granite is one of the richest uranium deposits of granite type in China. An attempt is made to investigate the sources of ore-forming solutions and ore-forming materials, and to presume the environment of ore formation in the light of the study on composition of stable isotopes such as hydrogen, oxygen, carbon, sulfur and lead. The research results indicate that the ore-forming fluids in the deposit is mainly composed of meteoric water, the ore-forming materials principally came from pre-Yanshanian granite Massif and possibly, partly from the lower crust, and metallogenesis was undertaken under relatively stable physicochemical conditions

A study on hydrogen, oxygen, carbon, sulfur and lead isotopes in the rich uranium deposit No.201

Energy Technology Data Exchange (ETDEWEB)

Yuexiang, Li; Tiangang, Li; Hongshou, Tong; Mingyue, Feng; Zhan, Xu [Beijing Research Inst. of Uranium Geology (China)

1995-09-01

The uranium deposit No.201 located in Indonesian granite is one of the richest uranium deposits of granite type in China. An attempt is made to investigate the sources of ore-forming solutions and ore-forming materials, and to presume the environment of ore formation in the light of the study on composition of stable isotopes such as hydrogen, oxygen, carbon, sulfur and lead. The research results indicate that the ore-forming fluids in the deposit is mainly composed of meteoric water, the ore-forming materials principally came from pre-Yanshanian granite Massif and possibly, partly from the lower crust, and metallogenesis was undertaken under relatively stable physicochemical conditions.

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.

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

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.

34S/32S fractionation in sulfur cycles catalyzed by anaerobic bacteria

Science.gov (United States)

Fry, B.; Gest, H.; Hayes, J. M.

1988-01-01

Stable isotopic distributions in the sulfur cycle were studied with pure and mixed cultures of the anaerobic bacteria, Chlorobium vibrioforme and Desulfovibrio vulgaris. D. vulgaris and C. vibrioforme can catalyze three reactions constituting a complete anaerobic sulfur cycle: reduction of sulfate to sulfide (D. vulgaris), oxidation of sulfide to elemental sulfur (C. vibrioforme), and oxidation of sulfur to sulfate (C. vibrioforme). In all experiments, the first and last reactions favored concentration of the light 32S isotope in products (isotopic fractionation factor epsilon = -7.2 and -1.7%, respectively), whereas oxidation of sulfide favored concentration of the heavy 34S isotope in products (epsilon = +1.7%). Experimental results and model calculations suggest that elemental sulfur enriched in 34S versus sulfide may be a biogeochemical marker for the presence of sulfide-oxidizing bacteria in modern and ancient environments.

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.

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)

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

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

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

Sulfur Isotope Composition of Some Polymetallic Deposits in the Republic of Macedonia

International Nuclear Information System (INIS)

Serafimovski, Todor; Tasev, Goran

2005-01-01

The attempt to obtain an exact information about the origin of sulfur and other metals present in polymetallic deposits at the territory of the Republic of Macedonia have resulted in a detailed sulfur isotope composition study, which have enclosed the following deposits: Toranica, Sasa, Zletovo, Buchim and Alshar deposit. Results obtained for the formerly mentioned deposits have shown that sulfur isotope composition β 34 S is in the range -7.52 to +2.18 per mils in Toranica, -1.22 -- +6.94 per mils in Sasa, -3.12 -- +3.40 per mils in Zletovo (without ore associated barites), +0.00 to +2.53 per mils in Buchim (the narrowest range of all studied deposits) and -6.84 to +0.351 per mils β 34 S in Alshar. Therefore, the most probably origin of primary sulfur in studied deposits from Earth's crust or eventually Upper Mantle. Such sources of sulfur and other mineralizing metals confirmed the theories about the endo gene origin of mineralization fluids, which have formed studied deposits. (Author)

Decoding mass-independent fractionation of sulfur isotopes in modern atmosphere using cosmogenic 35S: A five-isotope approach and possible implications for Archean sulfur isotope records

Science.gov (United States)

Lin, M.; Thiemens, M. H.; Shen, Y.; Zhang, X.; Huang, X.; Chen, K.; Zhang, Z.; Tao, J.

2017-12-01

The signature of sulfur isotopic mass-independent fractionation (S-MIF) observed in Archean sediments have been interpreted as a proxy of the origins and evolution of atmospheric oxygen and early life on Earth [1]. Photochemistry of SOx in the short (negative Δ36S. After eliminating combustion impacts, the obtained Δ36S/Δ33S slope of -4.0 in the modern atmosphere is close to the Δ36S/Δ33S slope (-3.6) in some records from Paleoarchean [4], an era probably with active volcanism [5]. The significant role of volcanic OCS in the Archean atmosphere has been called for in terms of its ability to provide a continual SO2 high altitude source for photolysis [2]. The strong but previously underappreciated stratospheric signature of S-MIF in tropospheric sulfates suggests that a more careful investigation of wavelength-dependent sulfur isotopic fractionation at different altitudes are required. The combustion-induced negative Δ36S may be linked to recombination reactions of elemental sulfur [6], and relevant experiments are being conducted to test the isotope effect. Although combustion is unlikely in Archean, recombination reactions may occur in other previously unappreciated processes such as volcanism and may contribute in part to the heavily depleted 36S in some Paleoarchean records [5,7]. The roles of both photochemical and non-photochemical reactions in the variability of Archean S-MIF records require further analysis in the future. Refs: [1] Farquhar et al., Science 2000; [2] Shaheen et al., PNAS 2014; [3] Lin et al., PNAS 2016; [4] Wacey et al., Precambrian Res 2015; [5] Muller et al., PNAS 2016; [6] Babikov, PNAS 2017; [7] Shen et al., EPSL, 2009.

Quantification and isotopic analysis of intracellular sulfur metabolites in the dissimilatory sulfate reduction pathway

Science.gov (United States)

Sim, Min Sub; Paris, Guillaume; Adkins, Jess F.; Orphan, Victoria J.; Sessions, Alex L.

2017-06-01

Microbial sulfate reduction exhibits a normal isotope effect, leaving unreacted sulfate enriched in 34S and producing sulfide that is depleted in 34S. However, the magnitude of sulfur isotope fractionation is quite variable. The resulting changes in sulfur isotope abundance have been used to trace microbial sulfate reduction in modern and ancient ecosystems, but the intracellular mechanism(s) underlying the wide range of fractionations remains unclear. Here we report the concentrations and isotopic ratios of sulfur metabolites in the dissimilatory sulfate reduction pathway of Desulfovibrio alaskensis. Intracellular sulfate and APS levels change depending on the growth phase, peaking at the end of exponential phase, while sulfite accumulates in the cell during stationary phase. During exponential growth, intracellular sulfate and APS are strongly enriched in 34S. The fractionation between internal and external sulfate is up to 49‰, while at the same time that between external sulfate and sulfide is just a few permil. We interpret this pattern to indicate that enzymatic fractionations remain large but the net fractionation between sulfate and sulfide is muted by the closed-system limitation of intracellular sulfate. This 'reservoir effect' diminishes upon cessation of exponential phase growth, allowing the expression of larger net sulfur isotope fractionations. Thus, the relative rates of sulfate exchange across the membrane versus intracellular sulfate reduction should govern the overall (net) fractionation that is expressed. A strong reservoir effect due to vigorous sulfate reduction might be responsible for the well-established inverse correlation between sulfur isotope fractionation and the cell-specific rate of sulfate reduction, while at the same time intraspecies differences in sulfate uptake and/or exchange rates could account for the significant scatter in this relationship. Our approach, together with ongoing investigations of the kinetic isotope

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

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

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.

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)

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.

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)

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.

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

Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products.

Science.gov (United States)

Boulyga, Sergei F; Heilmann, Jens; Heumann, Klaus G

2005-08-01

Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different 34S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured 34S/32S isotope ratio of the isotope-diluted sample remained constant-a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 microg g(-1) ('sulfur-free' premium gasoline) to 10.4 mg g(-1) (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 microg g(-1) and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level.

Sulfur isotopic fractionation of carbonyl sulfide during degradation by soil bacteria and enzyme

Science.gov (United States)

Kamezaki, Kazuki; Hattori, Shohei; Ogawa, Takahiro; Toyoda, Sakae; Kato, Hiromi; Katayama, Yoko; Yoshida, Naohiro

2017-04-01

Carbonyl sulfide (COS) is an atmospheric trace gas that possess great potential for tracer of carbon cycle (Campbell et al., 2008). COS is taken up by vegetation during photosynthesis like absorption of carbon dioxide but COS can not emit by respiration of vegetation, suggesting possible tracer for gross primary production. However, some studies show the COS-derived GPP is larger than the estimates by using carbon dioxide flux because COS flux by photolysis and soil flux are not distinguished (e.g. Asaf et al., 2013). Isotope analysis is a useful tool to trace sources and transformations of trace gases. Recently our group developed a promising new analytical method for measuring the stable sulfur isotopic compositions of COS using nanomole level samples: the direct isotopic analytical technique of on-line gas chromatography-isotope ratio mass spectrometry (GC-IRMS) using fragmentation ions S+ enabling us to easily analyze sulfur isotopes in COS (Hattori et al., 2015). Soil is thought to be important as both a source and a sink of COS in the troposphere. In particular, soil has been reported as a large environmental sink for atmospheric COS. Bacteria isolated from various soils actively degrade COS, with various enzymes such as carbonic anhydrase and COSase (Ogawa et al., 2013) involved in COS degradation. However, the mechanism and the magnitude of bacterial contribution in terms of a sink for atmospheric COS is still uncertain. Therefore, it is important to quantitatively evaluate this contribution using COS sulfur isotope analysis. We present isotopic fractionation constants for COS by laboratory incubation experiments during degradation by soil bacteria and COSase. Incubation experiments were conducted using strains belonging to the genera Mycobacterium, Williamsia, Cupriavidus, and Thiobacillus, isolated from natural soil or activated sludge and enzyme purified from a bacteria. As a result, the isotopic compositions of OCS were increased during degradation of

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)

Stable isotope studies. Progress report, August 1, 1974--July 31, 1975

International Nuclear Information System (INIS)

Flynn, G.W.; Hsu, D.S.Y.; Preses, J.M.; Spindel, W.; Weston, R.E.

1975-01-01

Progress is reported in the following studies: selective two-step laser-induced photodissociation, unimolecular processes induced by multiple-photon absorption, and vibrational energy transfer processes involving isotopic species of sulfur dioxide. These laser-induced chemical reactions can possibly be applied to isotope separation

Sulfur Isotope Exchange between S-35 Labeled Inorganic Sulfur-Compounds in Anoxic Marine-Sediments

DEFF Research Database (Denmark)

FOSSING, H.; THODEANDERSEN, S.; JØRGENSEN, BB

1992-01-01

Isotope exchange reactions between S-35-labeled sulfur compounds were studied in anoxic estuarine sediment slurries at 21-degrees-C and pH 7.4-7.7. Two experiments labeled with radioactive elemental sulfur (S-35-degrees) and one labeled with radioactive sulfate ((SO42-)-S-35) were performed as time......% of the total S-35 was recovered in the SIGMA-HS- pool in less than 1.5 h. With no detectable SIGMA-HS- (less than 1-mu-M) in the slurry, 58% of the total S-35 was observed in the pyrite pool within 1.5 h. The FeS pool received up to 31% of all S-35 added. The rapid S-35 incorporation from S-35-degrees...... into SIGMA-HS- and FeS pools was explained by isotope exchange reactions. In contrast, there was evidence that the radioactivity observed in the 'pyrite pool' was caused by adhesion of the added S-35-degrees to the FeS2 grains. In all S-35-degrees-labeled experiments we also observed oxidation...

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

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)

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).

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).

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

[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.

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

Sulfur isotope homogeneity of oceanic DMSP and DMS.

Science.gov (United States)

Amrani, Alon; Said-Ahmad, Ward; Shaked, Yeala; Kiene, Ronald P

2013-11-12

Oceanic emissions of volatile dimethyl sulfide (DMS) represent the largest natural source of biogenic sulfur to the global atmosphere, where it mediates aerosol dynamics. To constrain the contribution of oceanic DMS to aerosols we established the sulfur isotope ratios ((34)S/(32)S ratio, δ(34)S) of DMS and its precursor, dimethylsulfoniopropionate (DMSP), in a range of marine environments. In view of the low oceanic concentrations of DMS/P, we applied a unique method for the analysis of δ(34)S at the picomole level in individual compounds. Surface water DMSP collected from six different ocean provinces revealed a remarkable consistency in δ(34)S values ranging between +18.9 and +20.3‰. Sulfur isotope composition of DMS analyzed in freshly collected seawater was similar to δ(34)S of DMSP, showing that the in situ fractionation between these species is small (DMS to the atmosphere results in a relatively small fractionation (-0.5 ± 0.2‰) compared with the seawater DMS pool. Because δ(34)S values of oceanic DMS closely reflect that of DMSP, we conclude that the homogenous δ(34)S of DMSP at the ocean surface represents the δ(34)S of DMS emitted to the atmosphere, within +1‰. The δ(34)S of oceanic DMS flux to the atmosphere is thus relatively constant and distinct from anthropogenic sources of atmospheric sulfate, thereby enabling estimation of the DMS contribution to aerosols.

A sulfur isotopic study of alabandites from some manganese ore deposits in Japan

International Nuclear Information System (INIS)

Sasaki, Akira; Hirowatari, Fumitoshi; Fukuoka, Masato.

1985-01-01

Alabandites from Pretertiary bedded- and Tertiary vein-type manganese deposits in Japan have been examined for their sulfur isotopic composition. delta 34 S(CDT) value ranges widely from -31 to +11 per mil in 12 specimens taken from 10 bedded type deposits. While the mineral is no more than a minor constituent in most of the deposits, the isotopic features clearly indicate that these alabandites are of bacteriogenic sedimentary origin, thus raising an important constraint for the genesis of this group of deposits. A cluster of delta 34 S around -30 per mil implies an open-system, steady-state reduction (Schwarcz and Burnie, 1973) from a source SO 4 2- with the isotopic level of ca. +20 per mil. The inferred source is likely to have been in the Triassic sea. Current conjectures upon the age of host sedimentary rocks of the deposits concerned are in favor of this view. Alabandites from the Tertiary (Miocene) vein type deposits show only a minor variation in delta 34 S, +4 to +5 per mil. The data are very similar to the average isotopic composition of sulfides of the Miocene, ''Green Tuff'' mineralization represented by the kuroko type deposits. The remarkable consistency in sulfur isotopic composition of the Green Tuff mineralization over an extensive area may require a huge, common reservoir of sulfur in some form, which still remains an enigma. (author)

The Application of Stable Isotopes for Assessing the Hydrological, Sulfur, and Iron Balances of Acidic Mining Lake ML 111 (Lusatia, Germany) as a Basis for Biotechnological Remediation

International Nuclear Information System (INIS)

Knoeller, K.; Strauch, G.

2002-01-01

Stable isotope (δ 18 O-H 2 O, δ 2 H-H 2 O δ 34 S-SO 4 2- ) and hydrochemical data (SO 4 2- , Fe-concentrations) have been used to estimate the annual groundwater inflow and outflow of mining lake ML 111 and to calculate the total amount of dissolved sulfate and iron that is carried into the lake by groundwater. The hydrological balance suggests an annual groundwater inflow of 23 700 m 3 and an annual groundwater outflow of 15 700 m 3 . The calculation of the sulfur and iron balances yielded an annual sulfate input of 37 800 kg and an annual iron input of 7000 kg with the groundwater inflow. Furthermore it was shown that significant fluxes of these elements go into the lake sediments which results in continuous release of acidity in the lake water

Isotope dilution ICP-MS with laser-assisted sample introduction for direct determination of sulfur in petroleum products

Energy Technology Data Exchange (ETDEWEB)

Boulyga, Sergei F.; Heilmann, Jens; Heumann, Klaus G. [Johannes Gutenberg-University Mainz (Germany). Institute of Inorganic Chemistry and Analytical Chemistry

2005-08-01

Inductively coupled plasma isotope dilution mass spectrometry (ICP-IDMS) with direct laser-assisted introduction of isotope-diluted samples into the plasma, using a laser ablation system with high ablation rates, was developed for accurate sulfur determinations in different petroleum products such as 'sulfur-free' premium gasoline, diesel fuel, and heating oil. Two certified gas oil reference materials were analyzed for method validation. Two different {sup 34}S-enriched spike compounds, namely, elementary sulfur dissolved in xylene and dibenzothiophene in hexane, were synthesized and tested for their usefulness in this isotope dilution technique. The isotope-diluted sample was adsorbed on a filter-paper-like material, which was fixed in a special holder for irradiation by the laser beam. Under these conditions no time-dependent spike/analyte fractionation was only observed for the dibenzothiophene spike during the laser ablation process, which means that the measured {sup 34}S/{sup 32}S isotope ratio of the isotope-diluted sample remained constant - a necessary precondition for accurate results with the isotope dilution technique. A comparison of LA-ICP-IDMS results with the certified values of the gas oil reference materials and with results obtained from ICP-IDMS analyses with wet sample digestion demonstrated the accuracy of the new LA-ICP-IDMS method in the concentration range of 9.2 {mu}g g{sup -1} ('sulfur-free' premium gasoline) to 10.4 mg g{sup -1} (gas oil reference material BCR 107). The detection limit for sulfur by LA-ICP-IDMS is 0.04 {mu}g g{sup -1} and the analysis time is only about 10 min, which therefore also qualifies this method for accurate determinations of low sulfur contents in petroleum products on a routine level. (orig.)

Development of Stable Isotope Analysis Technology for Epidemiological Study of Migratory Birds in Connection with Avian Influenza

International Nuclear Information System (INIS)

Kim, Jongyun; Park, Jongho; Han, Sunho; Song, Kyuseok; Ko, Yongkwon; Bae, Inae; Cho, Mihyun; Jung, Gahee; Yeom, Ina

2012-03-01

In order to clarify correlations between the spread of avian influenza and migratory routes of birds, various conventional methods including a ring method, gene analysis, geolocator and a satellite tracking method are being used together. We first report on the estimation of origin of migratory bird in the Korea based on the statistical method of stable isotope ratio analysis of feathers. It is expected that migratory birds in Junam reservoir were from the two different regions according to the stable isotope ration analysis. However, it is not easy to conclude the breeding ground of northern pintails based on the current data because the degree of precision or accuracy can be influenced by many factors. For this reason, this statistical analysis accuracy can be influenced by many factors. For this reason, this statistical analysis can have a scientific significance if the reliability of the whole measurement system is improved. Furthermore, databases are not enough to prepare base map of regional isotope ratios because database of stable isotope ratio in oxygen and hydrogen of rainwater in Korea should be constructed. Though the research has focused on the hydrogen and oxygen until now, investigation of other elements, such as carbon, sulfur, nitrogen and others that can describe metabolic process or regional characteristics, is also worthwhile subject. And it is believed that this research will improve a resolution of detection for the migratory pathway and habitat of birds

Development of Stable Isotope Analysis Technology for Epidemiological Study of Migratory Birds in Connection with Avian Influenza

Energy Technology Data Exchange (ETDEWEB)

Kim, Jongyun; Park, Jongho; Han, Sunho; Song, Kyuseok; Ko, Yongkwon; Bae, Inae; Cho, Mihyun; Jung, Gahee; Yeom, Ina

2012-03-15

In order to clarify correlations between the spread of avian influenza and migratory routes of birds, various conventional methods including a ring method, gene analysis, geolocator and a satellite tracking method are being used together. We first report on the estimation of origin of migratory bird in the Korea based on the statistical method of stable isotope ratio analysis of feathers. It is expected that migratory birds in Junam reservoir were from the two different regions according to the stable isotope ration analysis. However, it is not easy to conclude the breeding ground of northern pintails based on the current data because the degree of precision or accuracy can be influenced by many factors. For this reason, this statistical analysis accuracy can be influenced by many factors. For this reason, this statistical analysis can have a scientific significance if the reliability of the whole measurement system is improved. Furthermore, databases are not enough to prepare base map of regional isotope ratios because database of stable isotope ratio in oxygen and hydrogen of rainwater in Korea should be constructed. Though the research has focused on the hydrogen and oxygen until now, investigation of other elements, such as carbon, sulfur, nitrogen and others that can describe metabolic process or regional characteristics, is also worthwhile subject. And it is believed that this research will improve a resolution of detection for the migratory pathway and habitat of birds.

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.

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.

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

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

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.

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....

Determination of sulfur in steels by isotope dilution mass spectrometry after dissolution with sealed tube

International Nuclear Information System (INIS)

Watanabe, Kazuo

1981-01-01

The scaled tube dissolution technique was studied for the complete conversion of sulfur in steels to sulfate. Isotope dilution mass spectrometry was used for the determination of sulfur in the sulfate. Sample (0.5 g) was dissolved in nitric acid (7 ml) and hydrochloric acid (3 ml) in a scaled borosilicate glass tube on being heated above 180 0 C overnight. Nitrate ions were removed by repeated evaporation with hydrochloric acid. The residue was dissolved in hydrochloric acid. Sulfate was reduced with a mixture of hydrochloric, hydroiodic and hypophosphorous acids; hydrogen sulfide evolved was absorbed in cadmium acetate solution, then converted to silver sulfide, which was burned to sulfur dioxide in pure oxygen at low pressure, for isotopic analysis. Analytical blank in whole procedure was 0.8 μg of sulfur. This technique was applied to the determination of sulfur in NBS low alloy steels. The principal cause of low values obtained by the open beaker dissolution technique was evaporation losses of sulfur as sulfur dioxide during the dissolution. (author)

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.

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

Mineralogy, Geochemistry and Stable Isotope Investigation of Gürkuyu Sb Mineralization (Gediz-Kütahya-NW Turkey

Directory of Open Access Journals (Sweden)

Yeşim ÖZEN

2016-11-01

Full Text Available Abstract. The Gürkuyu Sb mineralization is located in the western part of Anatolian tectonic belt, in southern part of İzmir-Ankara zone and in northern part of Menderes Massif. The mineralization located at west of the Koca hill in east of Gürkuyu village of Gediz (Kütahya-Turkey has been characterized through the detailed examinations involving sulfur and oxygen isotope. Serpentinites of Dağardı melange and crystallized limestones of Budağan limestone were hydrothermally altered by hydrothermal solutions, come from fissures and fractures due to tectonic movement during the thrust of melange and occurred silicified zone. Gürkuyu Sb mineralization suggest that occurred in this silicified zone. In Gürkuyu mineralization, primary ore minerals are antimonite and pyrite, secondary ore minerals are senarmontite, valentinite, orpiment and realgar. Quartz and calcite are the most common gangue minerals. In Gürkuyu Sb mineralization, δ34S values of stibnite are ranged from 1.0 ‰ to 1.3 ‰. δ18O values of quartz are ranged is 15.8 ‰ in Gürkuyu mineralization. Sulfur and oxygen isotope values are similar to the values for magmatic rocks and to the values for fluids of magmatic origin.Keywords: Stable isotope, Gürkuyu, Sb mineralization, Gediz, Kütahya, NW Turkey.

Sulfur isotope variability of oceanic DMSP generation and its contributions to marine biogenic sulfur emissions.

Science.gov (United States)

Oduro, Harry; Van Alstyne, Kathryn L; Farquhar, James

2012-06-05

Oceanic dimethylsulfoniopropionate (DMSP) is the precursor to dimethylsulfide (DMS), which plays a role in climate regulation through transformation to methanesulfonic acid (MSA) and non-seasalt sulfate (NSS-SO(4)(2-)) aerosols. Here, we report measurements of the abundance and sulfur isotope compositions of DMSP from one phytoplankton species (Prorocentrum minimum) and five intertidal macroalgal species (Ulva lactuca, Ulva linza, Ulvaria obscura, Ulva prolifera, and Polysiphonia hendryi) in marine waters. We show that the sulfur isotope compositions (δ(34)S) of DMSP are depleted in (34)S relative to the source seawater sulfate by ∼1-3‰ and are correlated with the observed intracellular content of methionine, suggesting a link to metabolic pathways of methionine production. We suggest that this variability of δ(34)S is transferred to atmospheric geochemical products of DMSP degradation (DMS, MSA, and NSS-SO(4)(2-)), carrying implications for the interpretation of variability in δ(34)S of MSA and NSS-SO(4)(2-) that links them to changes in growth conditions and populations of DMSP producers rather than to the contributions of DMS and non-DMS sources.

Sulfur isotope study of the Velardeña skarn (Zn-Pb), Durango, Mexico

Science.gov (United States)

Jimenez, A.

2012-04-01

Sulfur isotope study of the Velardeña skarn (Zn-Pb), Durango, Mexico Abigail Jimenez-Franco1*, Pura Alfonso Abella2, Carles Canet3, Eduardo González-Partida4 1 Posgrado en Ciencias de la Tierra, Universidad Nacional Autónoma de México, Ciudad Universitaria, Delegación Coyoacán, 04510 México D.F., Mexico 2 Departament d'Enginyeria Minera i Recursos Naturals, Universitat Politècnica de Catalunya, Av de Les Bases de Manresa 61-73, 08242 Manresa. 3Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, Delegación Coyoacán, 04510 México D.F., Mexico 4Centro de Geociencias, Universidad Nacional Autónoma de México, Campus Juriquilla, Boulevard Juriquilla 3001, 76230 Santiago de Querétaro, Qro., Mexico The Velardeña mining district is located in north-eastern part of the state of Durango, in northern of Mexico. The ore deposit is a lead-zinc, garnet-rich skarn developed at the contact between granite porphyry dikes (Eocene) and well-laminated limestones with interbedded chert (Albian-Cenomanian). A study of sulfur isotopes has been carried out in various sulfide minerals of the ores of Velardeña, in order to: (a) constrain the possible sources of sulfur and, therefore, better understand the sulfide mineralizing processes, and (b) to estimate the temperature of the ore-forming stage of the skarn. Sulfur isotope analyses were performed in 21 pure fractions of sulfide minerals of the ore mineralization (pyrite, chalcopyrite, sphalerite and galena). The mineral separation was performed using a series of sieves, and the purity of the samples was verified under a binocular microscope. Isotopic analyses were done on a Finnigan MAT Delta C flow elemental analyzer coupled to a TC-EA, according with the method of Giesemann et al. (1974). The δ34S values of the analyzed sulfides range mostly between -0.6 and +2.6 ‰ (relative to the CDT standard). These values are indicative of a magmatic source of sulfur. A single analysis falls

Improved analytical techniques of sulfur isotopic composition in nanomole quantities by MC-ICP-MS.

Science.gov (United States)

Yu, Tsai-Luen; Wang, Bo-Shian; Shen, Chuan-Chou; Wang, Pei-Ling; Yang, Tsanyao Frank; Burr, George S; Chen, Yue-Gau

2017-10-02

We propose an improved method for precise sulfur isotopic measurements by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) in conjunction with a membrane desolvation nebulization system. The problems of sulfur loss through the membrane desolvation apparatus are carefully quantified and resolved. The method overcomes low intrinsic sulfur transmission through the instrument, which was initially 1% when operating at a desolvation temperature of 160 °C. Sulfur loss through the membrane desolvation apparatus was resolved by doping with sodium. A Na/S ratio of 2 mol mol -1 produced sulfur transmissions with 98% recovery. Samples of 3 nmol (100 ng) sulfur achieved an external precision of ±0.18‰ (2 SD) for δ 34 S and ±0.10‰ (2 SD) for Δ 33 S (uppercase delta expresses the extent of mass-independent isotopic fractionation). Measurements made on certified reference materials and in-house standards demonstrate analytical accuracy and reproducibility. We applied the method to examine microbial-induced sulfur transformation in marine sediment pore waters from the sulfate-methane transition zone. The technique is quite versatile, and can be applied to a range of materials, including natural waters and minerals. Copyright © 2017 Elsevier B.V. All rights reserved.

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.)

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

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.)

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.

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.

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

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

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,

Macroinvertebrate diet in intertidal seagrass and sandflat communities : a study using C, N, and S stable isotopes

International Nuclear Information System (INIS)

Leduc, D.; Probert, P.K.; Frew, R.D.; Hurd, C.L.

2006-01-01

Most seagrass community food-web studies using stable isotopes have been carried out in subtidal habitats during one sampling event. We used C, N, and S stable isotopes to characterise the diet of the dominant macroinvertebrates found in intertidal Zostera capricorni and sandflat communities of southern New Zealand in late summer and winter. The range of δ 13 C and δ 34 S values for Z. capricorni was wide (>5 permille), which highlights the importance of accounting for spatial and temporal variability in primary producer isotopic signatures. The range of δ 15 N values for Z. capricorni was comparatively small ( 13 C and δ 15 N signatures suggested that Z. capricorni was a potentially important contributor (24-99%) to the diet of most consumers sampled at the seagrass site, whereas microphytobenthos dominated the diet of the same consumers at the sandflat site. The main exception was the bivalve Austrovenus stutchburyi, which had a diet consisting mostly (up to 85%) of Ulva and Polysiphonia spp. at both sites. S isotopes proved to be of limited use owing to the difficulty of sampling microphytobenthos and to potential non-dietary sources of 34 S-depleted sulfur to consumers. Mixing models also suggested that Z. capricorni contributed more to the diet of deposit feeders in August (late winter) than in March (late summer). (author). 75 refs., 3 figs., 3 tabs

Gas chromatographic studies of the relative retention of the sulfur isotopes in carbonyl sulfide, carbon disulfide, and sulfur dioxide

International Nuclear Information System (INIS)

Fetzer, J.C.; Rogers, L.B.

1980-01-01

A precision gas chromatograph, coupled to a quadrupole mass spectrometer and an on-line computer, was used to study the fractionation on Porasil A of the 32 S/ 34 S isotopic pair in a variety of sulfur-containing molecules. Carbonyl sulfide (COS) yielded an average α value of 1.00074 +- 0.00017 (standard deviation) for the temperature range 25 0 C to 75 0 C. The carbon disulfide (CS 2 ) value was 1.00069 +- 0.00023 for the range 53 0 C to 103 0 C, and that for sulfur dioxide (SO 2 ) was 1.00090 +- 0.00018 for the range 62 0 C to 112 0 C. Differential thermodynamic data have been reported. A Porapak Q column showed no fractionation of this isotopic pair in these three molecules

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

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

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

Science.gov (United States)

Valenzuela, Luciano O; Chesson, Lesley A; Bowen, Gabriel J; Cerling, Thure E; Ehleringer, James R

2012-01-01

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

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

Directory of Open Access Journals (Sweden)

Luciano O Valenzuela

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

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

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)

A guide for the laboratory information management system (LIMS) for light stable isotopes--Versions 7 and 8

Science.gov (United States)

Coplen, Tyler B.

2000-01-01

data based on the time of day of analysis. Whereas Finnigan ISODAT software is confined to using only a single peak for calculating delta values, LIMS now enables one to use the mean of two or more reference injections during a continuous flow analysis to calculate delta values. This is useful with Finnigan?s GasBench II online sample preparation system. Concentrations of carbon, nitrogen, and sulfur can be calculated based one or more isotopic reference materials analyzed with a group of samples. Both sample data and isotopic analysis data can now be exported to Excel files. A calculator for determining the amount of sample needed for isotopic analysis based on a previous amount of sample and continuous flow area is now an integral part of LIMS for Light Stable Isotopes. LIMS for Light Stable Isotopes can now assign an error code to Finnigan elemental analyzer analyses in which one of the electrometers has saturated due to analysis of too much sample material, giving rise to incorrect isotopic abundances. Information on downloading this report and downloading code and databases is provided at the Internet addresses: http://water.usgs.gov/software/geochemical.html or http://www.geogr.uni-jena.de/software/geochemical.html in the Eastern Hemisphere.

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...

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

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

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

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

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)

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...

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...

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

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

Preparation of Authigenic Pyrite from Methane-bearing Sediments for In Situ Sulfur Isotope Analysis Using SIMS.

Science.gov (United States)

Lin, Zhiyong; Sun, Xiaoming; Peckmann, Jörn; Lu, Yang; Strauss, Harald; Xu, Li; Lu, Hongfeng; Teichert, Barbara M A

2017-08-31

Different sulfur isotope compositions of authigenic pyrite typically result from the sulfate-driven anaerobic oxidation of methane (SO4-AOM) and organiclastic sulfate reduction (OSR) in marine sediments. However, unravelling the complex pyritization sequence is a challenge because of the coexistence of different sequentially formed pyrite phases. This manuscript describes a sample preparation procedure that enables the use of secondary ion mass spectroscopy (SIMS) to obtain in situ δ 34 S values of various pyrite generations. This allows researchers to constrain how SO4-AOM affects pyritization in methane-bearing sediments. SIMS analysis revealed an extreme range in δ 34 S values, spanning from -41.6 to +114.8‰, which is much wider than the range of δ 34 S values obtained by the traditional bulk sulfur isotope analysis of the same samples. Pyrite in the shallow sediment mainly consists of 34 S-depleted framboids, suggesting early diagenetic formation by OSR. Deeper in the sediment, more pyrite occurs as overgrowths and euhedral crystals, which display much higher SIMS δ 34 S values than the framboids. Such 34 S-enriched pyrite is related to enhanced SO4-AOM at the sulfate-methane transition zone, postdating OSR. High-resolution in situ SIMS sulfur isotope analyses allow for the reconstruction of the pyritization processes, which cannot be resolved by bulk sulfur isotope analysis.

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...

Coupled sulfur isotopic and chemical mass transfer modeling: Approach and application to dynamic hydrothermal processes

International Nuclear Information System (INIS)

Janecky, D.R.

1988-01-01

A computational modeling code (EQPSreverse arrowS) has been developed to examine sulfur isotopic distribution pathways coupled with calculations of chemical mass transfer pathways. A post processor approach to EQ6 calculations was chosen so that a variety of isotopic pathways could be examined for each reaction pathway. Two types of major bounding conditions were implemented: (1) equilibrium isotopic exchange between sulfate and sulfide species or exchange only accompanying chemical reduction and oxidation events, and (2) existence or lack of isotopic exchange between solution species and precipitated minerals, parallel to the open and closed chemical system formulations of chemical mass transfer modeling codes. All of the chemical data necessary to explicitly calculate isotopic distribution pathways is generated by most mass transfer modeling codes and can be input to the EQPS code. Routines are built in to directly handle EQ6 tabular files. Chemical reaction models of seafloor hydrothermal vent processes and accompanying sulfur isotopic distribution pathways illustrate the capabilities of coupling EQPSreverse arrowS with EQ6 calculations, including the extent of differences that can exist due to the isotopic bounding condition assumptions described above. 11 refs., 2 figs

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...

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

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.

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.

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.

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

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.

Guidelines for the use of isotopes of sulfur in soil-plant studies

International Nuclear Information System (INIS)

2003-01-01

Sulfur (S) is an essential element in plant, human and animal nutrition. This publication provides an overview of the sulfur cycle and how isotopic tracers can be used to obtain unique and precise information on the fluxes and movement of S between and within different compartments of the soil-plant system. It provides information on the theory and measurement of 35S and 34S, safety procedures using 35S, preparation of labelled S fertilizers and plant residues, estimation of the quantity of isotope required for different temporal and spatial scales, preparation digestion /extraction) and analysis of soil and plant samples and guidelines on comparative advantages with non-nuclear techniques and applications, including case studies and references. It is a timely publication in that greater attention is now being focused on S deficiencies in agriculture, which are becoming more common due to reduced atmospheric accretions from industrial sources and to the reduced use of fertilizer materials that contain sulfur as a secondary nutrient. The sub-programme in Soil and Water Management and Crop Nutrition is committed to the dissemination of information to Member States on the practical applications of nuclear techniques through the IAEA Training Course Series. The present publication is preceded by IAEA-TCS-14 (2001), Use of Isotope and Radiation Methods in Soil and Water Management and Crop Nutrition, and IAEA-TCS-16 (2002), Neutron and Gamma Probes: Their Use in Agronomy

Guidelines for the use of isotopes of sulfur in soil-plant studies

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-08-01

Sulfur (S) is an essential element in plant, human and animal nutrition. This publication provides an overview of the sulfur cycle and how isotopic tracers can be used to obtain unique and precise information on the fluxes and movement of S between and within different compartments of the soil-plant system. It provides information on the theory and measurement of 35S and 34S, safety procedures using 35S, preparation of labelled S fertilizers and plant residues, estimation of the quantity of isotope required for different temporal and spatial scales, preparation digestion /extraction and analysis of soil and plant samples and guidelines on comparative advantages with non-nuclear techniques and applications, including case studies and references. It is a timely publication in that greater attention is now being focused on S deficiencies in agriculture, which are becoming more common due to reduced atmospheric accretions from industrial sources and to the reduced use of fertilizer materials that contain sulfur as a secondary nutrient. The sub-programme in Soil and Water Management and Crop Nutrition is committed to the dissemination of information to Member States on the practical applications of nuclear techniques through the IAEA Training Course Series. The present publication is preceded by IAEA-TCS-14 (2001), Use of Isotope and Radiation Methods in Soil and Water Management and Crop Nutrition, and IAEA-TCS-16 (2002), Neutron and Gamma Probes: Their Use in Agronomy.

Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

Energy Technology Data Exchange (ETDEWEB)

Mango, Helen, E-mail: helen.mango@castleton.edu [Department of Natural Sciences, Castleton State College, 233 South Street, Castleton, VT 05735 (United States); Ryan, Peter, E-mail: pryan@middlebury.edu [Department of Geology, Middlebury College, 276 Bicentennial Way, Middlebury, VT 05753 (United States)

2015-02-01

Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ{sup 34}S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in {sup 34}S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ{sup 34}S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ{sup 34}S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ{sup 34}S = – 5.2 to 63‰ with higher {sup 34}S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ{sup 34}S.

Source of arsenic-bearing pyrite in southwestern Vermont, USA: Sulfur isotope evidence

International Nuclear Information System (INIS)

Mango, Helen; Ryan, Peter

2015-01-01

Arsenic-bearing pyrite is the source of arsenic in groundwater produced in late Cambrian and Ordovician gray and black slates and phyllites in the Taconic region of southwestern Vermont, USA. The aim of this study is to analyze the sulfur isotopic composition of this pyrite and determine if a relationship exists between pyrite δ 34 S and arsenic content. Pyrite occurs in both sedimentary/diagenetic (bedding-parallel layers and framboids) and low-grade metamorphic (porphyroblast) forms, and contains up to > 2000 ppm As. The sulfur isotopic composition of arsenic-bearing pyrite ranges from − 5.2‰ to 63‰. In the marine environment, the sulfur in sedimentary pyrite becomes increasingly enriched in 34 S as the geochemical environment becomes increasingly anoxic. There is a positive correlation between δ 34 S and arsenic content in the Taconic pyrite, suggesting that uptake of arsenic by pyrite increased as the environment became more reducing. This increased anoxia may have been due to a rise in sea level and/or tectonic activity during the late Cambrian and Ordovician. Low-grade metamorphism appears to have little effect on sulfur isotope composition, but does correlate with lower arsenic content in pyrite. New groundwater wells drilled in this region should therefore avoid gray and black slates and phyllites that contain sedimentary/diagenetic pyrite with heavy δ 34 S values. - Highlights: • Pyrite is the source of arsenic in groundwater in the Taconic region of Vermont, USA. • As-bearing pyrite δ 34 S = – 5.2 to 63‰ with higher 34 S as environment becomes more anoxic. • High sea level, tectonic activity create anoxia, with incorporation of As into pyrite. • New wells should avoid slate/phyllite containing sedimentary pyrite with heavy δ 34 S

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

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...

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...

An Experimental Study of Low-Temperature Sulfurization of Carbohydrates Using Various Sulfides Reveals Insights into Structural Characteristics and Sulfur Isotope Compositions of Macromolecular Organic Matter in the Environment

Science.gov (United States)

OBeirne, M. D.; Werne, J. P.; Van Dongen, B.; Gilhooly, W., III

2017-12-01

Sulfurization of carbohydrates has been suggested as an important mechanism for the preservation of organic matter in anoxic/euxinic depositional environments. In this study, glucose was sulfurized under laboratory conditions at room temperature (24°C) using three commercially available sulfides - ammonium sulfide ([NH4]2S), sodium sulfide (Na2S), and sodium hydrosulfide (NaHS), each mixed with elemental sulfur to produce polysulfide solutions. The reaction products were analyzed using Fourier transform infrared spectroscopy (FTIR), which revealed structural differences among the products formed via the three sulfide reactants. Additionally, analysis of the bulk sulfur isotope compositions of reactants and products was used to determine the fractionation(s) associated with abiotic sulfur incorporation into organic matter. Samples from both modern (Mahoney Lake, British Colombia, Canada) and ancient (Jurassic aged Blackstone Band from the Kimmeridge Clay Formation, Dorset, United Kingdom) euxinic systems were also analyzed for comparison to laboratory samples. Results from this study provide experimental evidence for the structural and sulfur isotopic relationships of sulfurized organic matter in the geosphere.

[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.

Nitrogen, Sulfur, and Oxygen Isotope Ratios of Animal- and Plant-Based Organic Fertilizers Used in South Korea.

Science.gov (United States)

Shin, Woo-Jin; Ryu, Jong-Sik; Mayer, Bernhard; Lee, Kwang-Sik; Kim, Insu

2017-05-01

Organic fertilizers are increasingly used in agriculture in Asia and elsewhere. Tracer techniques are desirable to distinguish the fate of nutrients added to agroecosystems with organic fertilizers from those contained in synthetic fertilizers. Therefore, we determined the nitrogen, sulfur, and oxygen isotope ratios of nitrogen- and sulfur-bearing compounds in animal- and plant-based organic fertilizers (ABOF and PBOF, respectively) used in South Korea to evaluate whether they are isotopically distinct. The δN values of total and organic nitrogen for ABOF ranged from +7 to +19‰ and were higher than those of PBOF (generally fertilizer compounds in the plant-soil-water system, whereas PBOFs have similar δN values to synthetic fertilizers. However, δO values for nitrate (δO) from organic fertilizer samples (fertilizers. The δS values of total sulfur, organic sulfur compounds (e.g., carbon-bonded sulfur and hydriodic acid-reducible sulfur), and sulfate for ABOFs yielded wide and overlapping ranges of +0.3 to +6.3, +0.9 to +7.2, and -2.6 to +14.2‰, whereas those for PBOFs varied from -3.4 to +7.7, +1.4 to +9.4, and -4.1 to +12.5‰, respectively, making it challenging to distinguish the fate of sulfur compounds from ABOF and PBOF in the environment using sulfur isotopes. We conclude that the δN values of ABOFs and the O values of organic fertilizers are distinct from those of synthetic fertilizers and are a promising tool for tracing the fate of nutrients added by organic fertilizers to agroecosystems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

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)

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.)

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.

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.

RARE ISOTOPIC SPECIES OF SULFUR MONOXIDE: THE ROTATIONAL SPECTRUM IN THE THz REGION

Energy Technology Data Exchange (ETDEWEB)

Lattanzi, Valerio; Cazzoli, Gabriele; Puzzarini, Cristina, E-mail: lattanzi@mpe.mpg.de [Dipartimento di Chimica “Giacomo Ciamician,” Università di Bologna, Via Selmi 2, I-40126 Bologna (Italy)

2015-11-01

Many sulfur-bearing species have been detected in different astronomical environments and have allowed us to derive important information about the chemical and physical composition of interstellar regions. In particular, these species have also been shown to trace and probe hot-core environment time evolution. Among the most prominent sulfur-bearing molecules is SO, the sulfur monoxide radical, one of the more ubiquitous and abundant, which is also observed in its isotopic substituted species such as {sup 34}SO and S{sup 18}O. Due to the importance of this simple diatomic system, and in order to face the challenge of modern radioastronomical facilities, an extension to the THz range of the rare isotopologues of sulfur monoxide has been performed. High-resolution rotational molecular spectroscopy has been employed to extend the available data set of four isotopic species, SO, {sup 34}SO, S{sup 17}O, and S{sup 18}O, up to the 1.5 THz region. The frequency coverage and spectral resolution of our measurements allowed a better constraint of the molecular constants of the four species considered, specifically focusing on the two oxygen-substituted isotopologues. Our measurements were also employed in an isotopically invariant fit including all of the available pure rotational and ro-vibrational transitions for all of the SO isotopologues, thus enabling accurate predictions of the rotational transitions at higher frequencies. We also provide comparisons with recent works performed on the same system, demonstrating the quality of our experiment and the improvement of the data sets for all of the species considered. Transition frequencies for this system can now be used with confidence by the astronomical community well into the THz spectral region.

Quadruple sulfur isotope constraints on the origin and cycling of volatile organic sulfur compounds in a stratified sulfidic lake

Science.gov (United States)

Oduro, Harry; Kamyshny, Alexey; Zerkle, Aubrey L.; Li, Yue; Farquhar, James

2013-11-01

We have quantified the major forms of volatile organic sulfur compounds (VOSCs) distributed in the water column of stratified freshwater Fayetteville Green Lake (FGL), to evaluate the biogeochemical pathways involved in their production. The lake's anoxic deep waters contain high concentrations of sulfate (12-16 mmol L-1) and sulfide (0.12 μmol L-1 to 1.5 mmol L-1) with relatively low VOSC concentrations, ranging from 0.1 nmol L-1 to 2.8 μmol L-1. Sulfur isotope measurements of combined volatile organic sulfur compounds demonstrate that VOSC species are formed primarily from reduced sulfur (H2S/HS-) and zero-valent sulfur (ZVS), with little input from sulfate. Thedata support a role of a combination of biological and abiotic processes in formation of carbon-sulfur bonds between reactive sulfur species and methyl groups of lignin components. These processes are responsible for very fast turnover of VOSC species, maintaining their low levels in FGL. No dimethylsulfoniopropionate (DMSP) was detected by Electrospray Ionization Mass Spectrometry (ESI-MS) in the lake water column or in planktonic extracts. These observations indicate a pathway distinct from oceanic and coastal marine environments, where dimethylsulfide (DMS) and other VOSC species are principally produced via the breakdown of DMSP by plankton species.

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

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...

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.

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.

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.

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.)

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

Diets of nesting laughing gulls (Larus atricilla) at the Virginia Coast Reserve: observations from stable isotope analysis

Science.gov (United States)

Knoff, A.J.; Macko, S.A.; Erwin, R.M.

2001-01-01

Food web studies often ignore details of temporal, spatial, and intrapopulation dietary variation in top-level consumers. In this study, intrapopulation dietary variation of a dominant carnivore, the Laughing Gull (Larus atricilla), was examined using carbon, nitrogen, and sulfur isotope analysis of gull tissues as well as their prey (fish, invertebrates, and insects) from the Virginia Coast Reserve estuarine system. As earlier traditional diet studies found evidence of individual dietary specialization within gull populations, this study used stable isotope analysis to assess specialization in a coastal Laughing Gull population. Specifically, blood, muscle, and feather isotope values indicated significant intrapopulation dietary specialization. Some gulls relied more heavily on estuarine prey (mean blood δ13C = -17.5, δ15N = 12.6, and δ34S = 9.3), whereas others appeared to consume more foods of marine origin (mean blood δ13C = -19.4, δ15N = 14.8, and δ34S = 10.4). It is important to account for such dietary variability when assessing trophic linkages in dynamic estuarine systems.

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

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

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 ...

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....

Sulfur isotopic ratios of molybdenites from the Hida Mountains, Japan

International Nuclear Information System (INIS)

Ishihara, Shunso; Harayama, Satoru; Sasaki, Akira.

1990-01-01

Molybdenites occurring in Paleogene granitoids of the Northern Japan Alps of the Hida Mountains were analyzed for δ 34 S CDT at seven localities. The sulfur isotopic ratios vary from 3.0 to 6.4 per mille, which are within the range of ore molybdenites from the magnetite-series granitic terrane of the Sanin district, indicating that the Hida Mountains and Sanin district belong to the same metallogenic province. Porphyry-type molybdenite from the Kamioka lead-zinc mine has the δ 34 S value of 1.4 per mille. Sulfur of the molybdenite is not derived from the Jurassic Funatsu granitoids but brought up by the latest Cretaceous ilmenite-series magma, prior to the main Paleogene magnetite-series magmatism. (author)

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

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.

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.

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

Science.gov (United States)

Vystavna, Yuliya; Diadin, Dmytro; Huneau, Frédéric

2018-05-01

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

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.)

Isotopic composition of reduced and oxidized sulfur in the Canary Islands: implications for the mantle S cycle

Science.gov (United States)

Beaudry, P.; Longpre, M. A.; Wing, B. A.; Bui, T. H.; Stix, J.

2017-12-01

The Earth's mantle contains distinct sulfur reservoirs, which can be probed by sulfur isotope analyses of volcanic rocks and gases. We analyzed the isotopic composition of reduced and oxidized sulfur in a diverse range of volcanically derived materials spanning historical volcanism in the Canary Islands. Our sample set consists of subaerial volcanic tephras from three different islands, mantle and sedimentary xenoliths, as well as lava balloon samples from the 2011-2012 submarine El Hierro eruption and associated crystal separates. This large sample set allows us to differentiate between the various processes responsible for sulfur isotope heterogeneity in the Canary archipelago. Our results define an array in triple S isotope space between the compositions of the MORB and seawater sulfate reservoirs. Specifically, the sulfide values are remarkably homogeneous around d34S = -1 ‰ and D33S = -0.01 ‰, while sulfate values peak at d34S = +4 ‰ and D33S = +0.01 ‰. Lava balloons from the El Hierro eruption have highly enriched sulfate d34S values up to +19.3 ‰, reflecting direct interaction between seawater sulfate and the erupting magma. Several sulfate data points from the island of Lanzarote also trend towards more positive d34S up to +13.8 ‰, suggesting interaction with seawater sulfate-enriched lithologies or infiltration of seawater within the magmatic system. On the other hand, the modal values and relative abundances of S2- and S6+ in crystal separates suggest that the Canary Island mantle source has a d34S around +3 ‰, similar to the S-isotopic composition of a peridotite xenolith from Lanzarote. We infer that the S2- and S6+ modes reflect isotopic equilibrium between those species in the magmatic source, which requires 80 % of the sulfide to become oxidized after melting, consistent with measured S speciation. This 34S enrichment of the source could be due to the recycling of hydrothermally-altered oceanic crust, which has been previously suggested

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.

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

Sulfur isotope fractionation during heterogeneous oxidation of SO2 on mineral dust

Directory of Open Access Journals (Sweden)

P. Hoppe

2012-06-01

Full Text Available Mineral dust is a major fraction of global atmospheric aerosol, and the oxidation of SO2 on mineral dust has implications for cloud formation, climate and the sulfur cycle. Stable sulfur isotopes can be used to understand the different oxidation processes occurring on mineral dust. This study presents measurements of the 34S/32S fractionation factor α34 for oxidation of SO2 on mineral dust surfaces and in the aqueous phase in mineral dust leachate. Sahara dust, which accounts for ~60% of global dust emissions and loading, was used for the experiments. The fractionation factor for aqueous oxidation in dust leachate is αleachate = 0.9917±0.0046, which is in agreement with previous measurements of aqueous SO2 oxidation by iron solutions. This fractionation factor is representative of a radical chain reaction oxidation pathway initiated by transition metal ions. Oxidation on the dust surface at subsaturated relative humidity (RH had an overall fractionation factor of αhet = 1.0096±0.0036 and was found to be almost an order of magnitude faster when the dust was simultaneously exposed to ozone, light and RH of ~40%. However, the presence of ozone, light and humidity did not influence isotope fractionation during oxidation on dust surfaces at subsaturated relative humidity. All the investigated reactions showed mass-dependent fractionation of 33S relative to 34S. A positive matrix factorization model was used to investigate surface oxidation on the different components of dust. Ilmenite, rutile and iron oxide were found to be the most reactive components, accounting for 85% of sulfate production with a fractionation factor of α34 = 1.012±0.010. This overlaps within the analytical uncertainty with the fractionation of other major atmospheric oxidation pathways such as the oxidation of SO2 by H2O2 and O3 in the aqueous phase and OH in the gas phase. Clay minerals accounted for roughly 12% of the sulfate production, and oxidation on clay minerals

Neoproterozoic sulfur-isotope variation in Australia

International Nuclear Information System (INIS)

Gorjan, P.; Walter, M.R.

2000-01-01

A number of stages are apparent in sulfur-isotope geochemistry throughout the Neoproterozoic. Prior to the Sturtian glaciation (840-700 Ma) δ 34 S sulfate varied little (19 to 17.5 per mil), and δ 34 S sulfide ranged from -20 to +23 per mil. In the Bitter Springs Formation δ 34 S sulfide is greater in the non-marine portion compared to the marine portion. This can be explained by a paucity of sulfate in the non-marine waters, and is consistent with mineralogical evidence (Southgate, 1991). In the Sturtian glacial sediments δ 34 S sulfide starts below 0 per mil and rises to >30 per mil at the top of the glacial sediments. After the Sturtian glaciation δ 34 S sulfide averages ∼30 per mil (and 34 per mil for δ 34 S organic ) for the extent of silt deposition. This increase in δ 34 S sulfide also appears in China, Canada and Namibia (Gorjan et al., 2000). δ 34 S sulfate also rises but is lower than the average δ 34 S sulfate (5 sulfate nodules in the Tapley Hill Formation average 26 per mil). However, the sulfate nodules may not be preserving the original seawater δ 34 S sulfate 34 S enrichment in sulfides usually occurs in freshwater or euxinic settings, but all evidence points to a sulfate-rich and non-euxinic environment in the Sturtian post-glacial deposits (linear %C vs. %S plots; high FeS 2 :FeS ratios; low degree of pyritisation; Gorjan et al. 2000, Gorjan, 1998). Such a situation points to sulfides being formed from extremely 34 S enriched sulfate (perhaps up to 45 per mil). This global rise in δ 34 S of both sulfur fractions in the Sturtian postglacial has led us to speculate that 34 S enriched sulfate was formed beneath a stagnant, ice-covered ocean, an environment postulated by Hoffman (1998), during the Sturtian glaciation and was brought to shallower waters in an ocean-upwelling event. Sulfide depleted in 34 S may have been deposited on abyssal plains. δ 34 S sulfide and δ 34 S sulfate falls sharply at the conclusion of siltstone deposition

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)

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.

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.

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

Advances in primate stable isotope ecology-Achievements and future prospects.

Science.gov (United States)

Crowley, Brooke E; Reitsema, Laurie J; Oelze, Vicky M; Sponheimer, Matt

2016-10-01

Stable isotope biogeochemistry has been used to investigate foraging ecology in non-human primates for nearly 30 years. Whereas early studies focused on diet, more recently, isotopic analysis has been used to address a diversity of ecological questions ranging from niche partitioning to nutritional status to variability in life history traits. With this increasing array of applications, stable isotope analysis stands to make major contributions to our understanding of primate behavior and biology. Most notably, isotopic data provide novel insights into primate feeding behaviors that may not otherwise be detectable. This special issue brings together some of the recent advances in this relatively new field. In this introduction to the special issue, we review the state of isotopic applications in primatology and its origins and describe some developing methodological issues, including techniques for analyzing different tissue types, statistical approaches, and isotopic baselines. We then discuss the future directions we envision for the field of primate isotope ecology. Am. J. Primatol. 78:995-1003, 2016. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

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.

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

Measuring Sulfur Isotope Ratios from Solid Samples with the Sample Analysis at Mars Instrument and the Effects of Dead Time Corrections

Science.gov (United States)

Franz, H. B.; Mahaffy, P. R.; Kasprzak, W.; Lyness, E.; Raaen, E.

2011-01-01

The Sample Analysis at Mars (SAM) instrument suite comprises the largest science payload on the Mars Science Laboratory (MSL) "Curiosity" rover. SAM will perform chemical and isotopic analysis of volatile compounds from atmospheric and solid samples to address questions pertaining to habitability and geochemical processes on Mars. Sulfur is a key element of interest in this regard, as sulfur compounds have been detected on the Martian surface by both in situ and remote sensing techniques. Their chemical and isotopic composition can belp constrain environmental conditions and mechanisms at the time of formation. A previous study examined the capability of the SAM quadrupole mass spectrometer (QMS) to determine sulfur isotope ratios of SO2 gas from a statistical perspective. Here we discuss the development of a method for determining sulfur isotope ratios with the QMS by sampling SO2 generated from heating of solid sulfate samples in SAM's pyrolysis oven. This analysis, which was performed with the SAM breadboard system, also required development of a novel treatment of the QMS dead time to accommodate the characteristics of an aging detector.

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

Systematic sulfur stable isotope and fluid inclusion studies on veinlet groups in the Sarcheshmeh porphyry copper deposit: based on new data

Directory of Open Access Journals (Sweden)

Mohammad Maanijou

2012-10-01

Full Text Available Mineralization occurred by intrusion of granodioritic stock of middle Miocene in volcano–sedimenrary rocks in Sarcheshmeh of early Tertiary age. This research is based on samples of new drilled boreholes and benches of 2500m elevation. Based on mineralogy and crosscutting relationships, at least four groups of veinlets pertaining to four stages of mineralization were recognized. Sulfur isotope studies in the Sarcheshmeh porphyry copper deposit were conducted on pyrite, chalcopyrite, molybdenite and anhydrites of four groups of veinlets. The δ34S values in the sulfides and sulfates range from -2.2 to 1.27‰ and from 10.2 to 14.5 ‰, respectively. The average δ34S value in the sulfides is 1‰ and that for the sulfates is about 13‰. Considering these results, it can be concluded that the sulfides made up of a fluid that its sulfur has a magmatic origin. Also, fluid inclusions of different veinlet groups were studied, showing high temperature, high salinity and the occurrence of boiling in the mineralizing fluids. Moreover, these studies indicate presence of three types of fluids including magmatic, meteoritic and mixture of these two fluids in alteration and mineralizion processes.

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

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.

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

Variable sulfur isotope composition of sulfides provide evidence for multiple sources of contamination in the Rustenburg Layered Suite, Bushveld Complex

Science.gov (United States)

Magalhães, Nivea; Penniston-Dorland, Sarah; Farquhar, James; Mathez, Edmond A.

2018-06-01

The Rustenburg Layered Suite (RLS) of the Bushveld Complex (BC) is famous for its platinum group element (PGE) ore, which is hosted in sulfides. The source of sulfur necessary to generate this type of mineralization is inferred to be the host rock of the intrusion. The RLS has a sulfur isotopic signature that indicates the presence of Archean surface-derived material (Δ33 S ≠ 0) in the magma. This signature, with an average value of Δ33 S = 0.112 ± 0.024 ‰, deviates from the expected Δ33 S value of the mantle of 0 ± 0.008 ‰. Previous work suggested that this signature is uniform throughout the RLS, which contrasts with radiogenic isotopes which vary throughout the igneous stratigraphy of the RLS. In this study, samples from key intervals within the igneous stratigraphy were analyzed, showing that Δ33 S values vary in the same stratigraphic levels as Sr and Nd isotopes. However, the variation is not consistent; in some levels there is a positive correlation and in others a negative correlation. This observation suggests that in some cases distinct magma pulses contained assimilated sulfur from different sources. Textural analysis shows no evidence for late addition of sulfur. These results also suggest that it is unlikely that large-scale assimilation and/or efficient mixing of host rock material in a single magma chamber occurred during emplacement. The data do not uniquely identify the source of sulfur in the different layers of the RLS, but the variation in sulfur isotope composition and its relationship to radiogenic isotope data calls for a reevaluation of the models for the formation and evolution of the RLS, which has the potential to impact the knowledge of how PGE deposits form.

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)

Beyond diet reconstruction: stable isotope applications to human physiology, health, and nutrition.

Science.gov (United States)

Reitsema, Laurie J

2013-01-01

Analysis of stable carbon and nitrogen isotopes from soft or mineralized tissues is a direct and widely-used technique for modeling diets. In addition to its continued role in paleodiet analysis, stable isotope analysis is now contributing to studies of physiology, disease, and nutrition in archaeological and living human populations. In humans and other animals, dietary uptake and distribution of carbon and nitrogen among mineralized and soft tissue is carried out with varying efficiency due to factors of internal biology. Human pathophysiologies may lead to pathology-influenced isotopic fractionation that can be exploited to understand not just skeletal health and diet, but physiological health and nutrition. This study reviews examples from human biology, non-human animal ecology, biomedicine, and bioarchaeology demonstrating how stable isotope analyses are usefully applied to the study of physiological adaptation and adaptability. Suggestions are made for future directions in applying stable isotope analysis to the study of nutritional stress, disease, and growth and development in living and past human populations. Copyright © 2013 Wiley Periodicals, Inc.

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.

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.

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...

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.

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

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.)

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.

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

Early inner solar system origin for anomalous sulfur isotopes in differentiated protoplanets.

Science.gov (United States)

Antonelli, Michael A; Kim, Sang-Tae; Peters, Marc; Labidi, Jabrane; Cartigny, Pierre; Walker, Richard J; Lyons, James R; Hoek, Joost; Farquhar, James

2014-12-16

Achondrite meteorites have anomalous enrichments in (33)S, relative to chondrites, which have been attributed to photochemistry in the solar nebula. However, the putative photochemical reactions remain elusive, and predicted accompanying (33)S depletions have not previously been found, which could indicate an erroneous assumption regarding the origins of the (33)S anomalies, or of the bulk solar system S-isotope composition. Here, we report well-resolved anomalous (33)S depletions in IIIF iron meteorites (solar system (solar system S-isotope composition was chondritic (consistent with IAB iron meteorites, Earth, Moon, and Mars). The range of mass-independent sulfur isotope compositions may reflect spatial or temporal changes influenced by photochemical processes. A tentative correlation between S isotopes and Hf-W core segregation ages suggests that the two systems may be influenced by common factors, such as nebular location and volatile content.

The molecular physics of photolytic fractionation of sulfur and oxygen isotopes in planetary atmospheres (Invited)

Science.gov (United States)

Johnson, M. S.; Schmidt, J. A.; Hattori, S.; Danielache, S.; Meusinger, C.; Schinke, R.; Ueno, Y.; Nanbu, S.; Kjaergaard, H. G.; Yoshida, N.

2013-12-01

Atmospheric photochemistry is able to produce large mass independent anomalies in atmospheric trace gases that can be found in geological and cryospheric records. This talk will present theoretical and experimental investigations of the molecular mechanisms producing photolytic fractionation of isotopes with special attention to sulfur and oxygen. The zero point vibrational energy (ZPE) shift and reflection principle theories are starting points for estimating isotopic fractionation, but these models ignore effects arising from isotope-dependent changes in couplings between surfaces, excited state dynamics, line densities and hot band populations. The isotope-dependent absorption spectra of the isotopologues of HCl, N2O, OCS, CO2 and SO2 have been examined in a series of papers and these results are compared with experiment and ZPE/reflection principle models. Isotopic fractionation in planetary atmospheres has many interesting applications. The UV absorption of CO2 is the basis of photochemistry in the CO2-rich atmospheres of the ancient Earth, and of Mars and Venus. For the first time we present accurate temperature and isotope dependent CO2 absorption cross sections with important implications for photolysis rates of SO2 and H2O, and the production of a mass independent anomaly in the Ox reservoir. Experimental and theoretical results for OCS have implications for the modern stratospheric sulfur budget. The absorption bands of SO2 are complex with rich structure producing isotopic fractionation in photolysis and photoexcitation.

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.

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

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.)

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.

Quantification of Sulfur by the Wet Oxidation for the Determination of 35S

International Nuclear Information System (INIS)

Lee, Heung N.; Kang, Sang Hoon; Ahn, Hong Joo; Han, Sun Ho; Jee, Kwang Yong

2006-01-01

Natural sulfur contains four stable isotopes. The main isotopes are 32 S (95.02%) and 34 S (4.21%). Beside the stable isotopes, there exist also a radioactive one 35 S (T 1/2 = 87.4 d, Emax = 167 keV, pure β - emitter). Sulfur- 35 is one of the cosmogenic radionuclides generated by cosmic rays through spallation of argon atoms. 35 S for the labeled compound such as 35 S-thiourea is produced from the pile irradiation of the neutron ( 35 Cl(n,p) 35 S). Most 35 S produced by cosmic rays is rapidly converted to sulfur dioxide (SO 2 ) and sulfate (SO 4 2- ), and attached on the ambient aerosols. The quantities of 35 S do not present a significant external exposure hazard since the low-energy emissions barely penetrate the outer dead layer of skin. For uptakes of inorganic sulfur, 15% is assumed to be retained with a 20 day biological half-life and 5% retained with a 2,000 day biological half-life. The remaining 80% is assumed to be rapidly excreted. Because of its relatively weak emission, 35 S is primarily an internal radiation hazard. TLDs are not effective and Geiger-Muller detectors can measure to low efficiency (∼10%) for detecting 35 S. Therefore, it is important to use careful handling and frequent monitoring, either with survey meters with thin- windows probes or by taking wipe samples and counting in a liquid scintillation counter (LSC)

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.

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)

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.

Lipid Biomarkers and Stable Isotope Signatures of Microbial Mats in Hot Springs of Kamchatka, Russia

Science.gov (United States)

Romanek, C. S.; Mills, G. L.; Jones, M. E.; Paddock, L.; Li, Y.; Zhang, C. L.; Wiegel, J.

2004-12-01

Various hot springs of the Uzon Caldera, Kamchatka, were analyzed for their chemical and stable isotope composition to better understand the relationship(s) between thermophilic microorganisms and the environments in which they live. The springs had water temperatures ranging from 40-90\\deg C and pH ranging from 5.6-5.9. Gases that emanated from the springs were composed predominantly of CO2 (20 to 90%), with lesser amounts of CH4, (Archaea. Results of PLFA showed 16:0 as the most abundant fatty acid (33-44%), which is universal in all living organisms. Other significant biomarkers included 18:1ω (19 to 24%), 18:2ω (5 to 13%), 16:1ω (3 to 12%), and 18:0 (2 to 7%). These biomarkers are characteristic of cyanobacteria, green-sulfur bacteria, and green non-sulfur bacteria, respectively, which are common autotrophic organisms in terrestrial hot springs. On the other hand, biomarkers of heterotrophic bacteria, such as iso- and anteiso-15:0 were low (2-8%), indicating that the bacterial carbon cycle was dominated by autotrophic organisms. Analogous archaeal constituents were present in significant abundance in the ether lipids fraction.

Use of the natural abundance of stable isotopes in animal physiology

International Nuclear Information System (INIS)

Koyama, Takeo

1987-01-01

Recent studies on the natural abundance (δ-value) of stable isotopes in animals are reviewed. The δ 13 C value of livestock varies among different portions of the body and depending on living conditions, etc. Typically, however, it is about 1 percent larger than that of the feed used. The value of δ 15 N of the blood, milk and droppings is reported to be larger than that of the feed while that of urine is smaller with the decrease showing changes through the day. Natural δ 13 C and δ 15 N of animals are known to vary among the various organs and tissues. Investigations on cattle and two types musseks have shown that δ 13 C and δ 15 N have no significant relations with their age. The isotopic ratio of stable isotopes in animals is largely dependent on that of the feed used. Study results are cited on the changes in isotopic ratio of carbon and nitrogen along the digestion process of ruminants. Discussion is made on the causes for the changes in isotopic ratio during the metabolic process. Measurement of natural abundance of stable isotopes can be used as a tool for determining the eating habits of ungulate animals raised on grazing lands. (Nogami, K.)

Use of isotopic sulfur to determine whitebark pine consumption by Yellowstone bears: a reassessment

Science.gov (United States)

Schwartz, Charles C.; Teisberg, Justin E.; Fortin, Jennifer K.; Haroldson, Mark A.; Servheen, Christopher; Robbins, Charles T.; van Manen, Frank T.

2014-01-01

Use of naturally occurring stable isotopes to estimate assimilated diet of bears is one of the single greatest breakthroughs in nutritional ecology during the past 20 years. Previous research in the Greater Yellowstone Ecosystem (GYE), USA, established a positive relationship between the stable isotope of sulfur (δ34S) and consumption of whitebark pine (Pinus albicaulis) seeds. That work combined a limited sample of hair, blood clots, and serum. Here we use a much larger sample to reassess those findings. We contrasted δ34S values in spring hair and serum with abundance of seeds of whitebark pine in samples collected from grizzly (Ursus arctos) and American black bears (U. americanus) in the GYE during 2000–2010. Although we found a positive relationship between δ34S values in spring hair and pine seed abundance for grizzly bears, the coefficients of determination were small (R2 ≤ 0.097); we failed to find a similar relationship with black bears. Values of δ34S in spring hair were larger in black bears and δ34S values in serum of grizzly bears were lowest in September and October, a time when we expect δ34S to peak if whitebark pine seeds were the sole source of high δ34S. The relationship between δ34S in bear tissue and the consumption of whitebark pine seeds, as originally reported, may not be as clean a method as proposed. Data we present here suggest other foods have high values of δ34S, and there is spatial heterogeneity affecting the δ34S values in whitebark pine, which must be addressed.

Applications of stable isotope analysis in foodstuffs surveillance and environmental research

International Nuclear Information System (INIS)

Pichlmayer, F.; Blochberger, F.

1991-12-01

The instrumental coupling of Elemental Analysis and Mass Spectrometry, constituting a convenient tool for isotope ratio measurements of the bioelements in solid or liquid samples is now well established. Advantages of this technique compared with the so far usual wet chemistry sample preparation are: speed of analysis, easy operation and minor sample consumption. The performance of the system is described and some applications are given. Detection of foodstuffs adulterations is mainly based on the natural carbon isotope differences between C 3 - and C 4 -plants. In the field of environmental research the existing small isotopic variations of carbon, nitrogen and sulfur in nature, which depend on substance origin and history, are used as intrinsic signature of the considered sample. Examples of source appointment or exclusion by help of this natural isotopic tracer method are dealt with. (authors)

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.

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)

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....

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...

Development of a non-destructive micro-analytical method for stable carbon isotope analysis of transmission electron microscope (TEM) samples

Energy Technology Data Exchange (ETDEWEB)

Hode, Tomas [Department of Geology, Portland State University, Portland, P.O. Box 751, OR 97201 (United States)], E-mail: hode@pdx.edu; Kristiansson, Per; Elfman, Mikael [Division of Nuclear Physics, Department of Physics, Lund Institute of Technology, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Hugo, Richard C.; Cady, Sherry L. [Department of Geology, Portland State University, Portland, P.O. Box 751, OR 97201 (United States)

2009-10-01

The biogenicity of ancient morphological microfossil-like objects can be established by linking morphological (e.g. cell remnants and extracellular polymeric matrix) and chemical (e.g. isotopes, biomarkers and biominerals) evidence indicative of microorganisms or microbial activity. We have developed a non-destructive micro-analytical ion beam system capable of measuring with high spatial resolution the stable carbon isotope ratios of thin samples used for transmission electron microscopy. The technique is based on elastic scattering of alpha particles with an energy of 2.751 MeV. At this energy the {sup 13}C cross section is enhanced relative to the pure Rutherford cross section for {sup 13}C, whereas the {sup 12}C cross section is reduced relative to its pure Rutherford cross section. Here we report the initial results of this experimental approach used to characterize ultramicrotomed sections of sulfur-embedded graphite and microbial cells.

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

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

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.

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.)

Isotope ratio analysis by a combination of element analyzer and mass spectrometer

International Nuclear Information System (INIS)

Pichlmayer, F.

1987-06-01

The use of stable isotope ratios of carbon, nitrogen and sulfur as analytical tool in many fields of research is of growing interest. A method has therefore been developed, consisting in essential of coupling an Elemental Analyzer with an Isotope Mass Spectrometer, which enables the gas preparation of carbon dioxide, nitrogen and sulfur dioxide from any solid or liquid sample in a fast and easy way. Results of carbon isotope measurements in food analysis are presented, whereat it is possible to check origin and treatment of sugar, oils, fats, mineral waters, spirituous liquors etc. and to detect adulterations as well. Also applications in the field of environmental research are given. (Author)

Using stable isotopes of nitrogen and carbon to study seabird ecology: applications in the Mediterranean seabird community

Directory of Open Access Journals (Sweden)

Manuela G. Forero

2003-07-01

Full Text Available The application of the stable isotope technique to ecological studies is becoming increasingly widespread. In the case of seabirds, stable isotopes of nitrogen and carbon have been mainly used as dietary tracers. This approach relieson the fact that food web isotopic signatures are reflected in the tissues of the consumer. In addition to the study of trophic ecology, stable isotopes have been used to track the movement of seabirds across isotopic gradients, as individuals moving between isotopically distinct foodwebs can carry with them information on the location of previous feeding areas. Studies applying the stable isotope methodology to the study of seabird ecology show a clear evolution from broad and descriptive approaches to detailed and individual-based analyses. The purpose of this article is to show the different fields of application of stable isotopes to the study of the seabird ecology. Finally, we illustrate the utility of this technique by considering the particularities of the Mediterranean seabird community, suggesting different ecological questions and conservation problems that could be addressed by using the stable isotope approach in this community.

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

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

Fractionation of sulfur isotopes in the chemical and biochemical oxidation of sulfide to sulfate

International Nuclear Information System (INIS)

Maass, I.; Wetzel, K.; Weise, G.; Heyer, J.

1983-01-01

The behaviour of sulfur isotopes in the chemical and biochemical oxidation of marcasite (FeS 2 ) to sulfate has been investigated in rest and shaker cultures at 30 0 C. The microbiological oxidation was carried out using a mixed culture of Thiobacillus. The results show a considerably faster formation of sulfate in the biochemical oxidation in comparison with the chemical oxidation. Isotope analyses of the formed sulfates indicate no or only very small isotope fractionations depending on experimental conditions. The highest enrichment of 32 S in the sulfate is 1.7 per mille. In accordance with the results of other authors it is concluded that in both chemical and biochemical weathering of sedimentary sulfides resulting in the formation of sulfates isotope effects are not of importance. (author)

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)

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...

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

Sulfur isotope study of a modern intertidal environment, and the interpretation of ancient sulfides

International Nuclear Information System (INIS)

Chambers, L.A.

1982-01-01

Extensive sulfur isotope distribution data for sulfides precipitated in an intertidal environment show no distinctive features when compared with isotope values for other marine, sedimentary sulfides. The fractionation ranges from α = 1.030 to α = 1.048. The pattern is characteristic for a system essentially open to sulfate, and isotope analyses of interstitial sulfates are corroborative. A population of sulfate-reducing bacteria of the order of 10 9 organisms per cc of interstitial water is indicated. Seasonal variation of the isotope distribution reflects a transient sulfide composition and a bacterial population in which the fractionation effect is indirectly controlled by temperature. The data presented for this modern shallow water environment are at variance with an earlier assessment of isotopic distributions in ancient sulfides which linked shallow water environments with limited fractionation (α =< 1.025) in a closed system. (author)

Sulfur isotope study of a modern intertidal environment, and the interpretation of ancient sulfides

Energy Technology Data Exchange (ETDEWEB)

Chambers, L.A. (Baas Becking Geobiological Lab., Canberra City (Australia))

1982-05-01

Extensive sulfur isotope distribution data for sulfides precipitated in an intertidal environment show no distinctive features when compared with isotope values for other marine, sedimentary sulfides. The fractionation ranges from ..cap alpha.. = 1.030 to ..cap alpha.. = 1.048. The pattern is characteristic for a system essentially open to sulfate, and isotope analyses of interstitial sulfates are corroborative. A population of sulfate-reducing bacteria of the order of 10/sup 9/ organisms per cc of interstitial water is indicated. Seasonal variation of the isotope distribution reflects a transient sulfide composition and a bacterial population in which the fractionation effect is indirectly controlled by temperature. The data presented for this modern shallow water environment are at variance with an earlier assessment of isotopic distributions in ancient sulfides which linked shallow water environments with limited fractionation (..cap alpha.. =< 1.025) in a closed system.

Sulfur and Oxygen Isotopic Composition of Sulfate in the Fresh Water, King Sejong Station, King George Island, Antarctica

Science.gov (United States)

Kim, M.; Lee, I.; Lee, J.; Park, B.; Mayer, B.; Kaufman, A. J.; Park, S.; Kim, G.; Lee, K.

2008-12-01

Isotopic compositions of sulfur (δ34S) and oxygen (δ18O) were measured for the sulfate of the fresh water near the King Sejong Station, King George Island, Antarctica. Sejong station is located in the Barton peninsular of the King George Island. The geology around King Sejong station mainly composed of basalt-andesite, quart monzodiorite, and granodiorite. Lapilli tuff, conglomerate, sandstone, and siltstone occur along the southern and eastern shore of the Barton peninsula. Lapilli tuff also occurs on the highland located on southeastern part of the Barton peninsula. The δ34S values of sulfate extracted from fresh water samples at King Sejong Station range from 13.7 to 16.3 per mil excluding 1 sample. These sulfur values are very narrow in their range compared with those from anthropogenic sources. These sulfur values are 5 to 7 per mil lower than those of typical present seawater. Considering the rocks occurring near the King Sejong station, these sulfur isotopic values do not seem to be related to any evaporites of certain age. In Antarctic region the natural source of sulfate dissolved in water could be originated from marine biogenic source (DMS), sea-salt, volcanic source, or other continental sources. Most of the δ34S values of sulfate at King Sejong station seems to indicate the dominance of marine biogenic origin for the source of sulfur. The δ18O values of sulfate extracted from fresh water samples at King Sejong Station range from 1.9 to 6.4 per mil excluding 1 sample. These oxygen isotope values are lower than those of the sulfate in the present seawater by 6 per mil. However, both sulfur and oxygen isotope values strongly represent the influence of the seawater sulfate. One sample have 2.6 and -1.1 per mil in its δ34S and δ18O values, respectively, that are quite different from the isotopic values of other samples. This sample was collected in the highland far from the King Sejong station. Therefore this sample might reflect the composition of

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

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.

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

Application of Stable Isotope-Assisted Metabolomics for Cell Metabolism Studies

Science.gov (United States)

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

2014-01-01

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

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.

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.

Toward a unifying model for the late Neoproterozoic sulfur cycle

Science.gov (United States)

Johnston, D. T.; Gill, B. C.; Ries, J. B.; OBrien, T.; Macdonald, F. A.

2011-12-01

The latest Proterozoic has always fascinated Earth historians. Between the long identified enigmas surrounding the sudden appearance of animals and the more recent infatuation with large-sale geochemical anomalies (i.e. the Shuram - Wonaka event), the closing 90 million years of the Proterozoic - the Ediacaran - houses a number of important and unanswered questions. Detailed redox geochemistry and stable isotope reconstructions of stratigraphic units covering this time interval have begun to unravel some of it's mysteries, however much remains to be explained. The sulfur cycle, with it's intimate links to both the marine carbon cycle (through remineralization reactions) and overall oxidant budgets (via seawater sulfate), sits poised to provide a sharp tool to track environmental change. Previous work has recognized this potential, and serves as a point of entrance for our current work. However what is lacking - and the goal of this study - is to place quantitative constraints the geochemical evolution of marine basins through this interval. Here we will present multiple sulfur isotope data from pyrite and sulfates through Ediacaran stratigraphy from the Yukon, Russia and Namibia. To maximize the utility of sulfur isotope studies, we have focused on Ediacaran stratigraphic sections from multiple continents that record both the Shuram anomaly and contain rich fossil records. These sections provide, when interpreted together, a fresh opportunity to revisit the geochemical setting that gave rise to animals. Importantly, the inclusion of multiple sulfur isotope data allows us to place further constraints on the mechanisms underpinning isotopic variability. For instance, when coupled with new experimental data, tighter constraints are provided on how fractionation scales with sulfate concentrations. This may allow for decoupling changes in biological fractionations from modifications to the global sulfur cycle (i.e. changes in seawater sulfate concentrations or the vigor

Sulfur isotopic and proteomic profiles of sulfate reducers grown under differential steady-states

Science.gov (United States)

Leavitt, W.; Venceslau, S.; Waldbauer, J.; Smith, D. A.; Boidi, F. J.; Bradley, A. S.

2016-12-01

Microbial sulfate reducers (MSR) drive the Earth's biogeochemical sulfur cycle. At the heart of this energy metabolism is a cascade of redox transformations coupling organic carbon and/or hydrogen oxidation to the dissimilatory reduction of sulfate to sulfide. The product sulfide is depleted in the heavier isotopes of sulfur, relative to the reactant sulfate, consistent with a normal kinetic isotope effect. However, the magnitude of the net fractionation during MSR can range over a range of 70 permil, consistent with a multi-step set of reactions. This range in MSR fractionation has been shown to mainly depend on: i) the cell-specific sulfate reduction rate (csSRR), and ii) the ambient sulfate concentration. However, the fractionation under identical conditions differs among strains (Bradley et al. 2016. Geobio), and so must also be mediated by strain-specific processes, such as the nature and quantity of individual proteins involved in sulfate reduction, electron transport, and growth. In recent work we have examined the influence of electron donor, electron acceptor, and co-limitation under controlled steady-state culture conditions in order better inform models of MSR isotope fractionation, and the physiological and isotopic response to differential environmental forcings (e.g. Leavitt et al. (2013) PNAS). Recent models of the fractionation response to MSR rate (c.f. Bradley 2016; Wing & Halevy, 2016) make specific predictions for the responses of the cellular metabolome and proteome. Here we compare the steady-state S-isotopic fractionation and proteome of `fast' versus `slow' grown D. vulgaris, using replicate chemostats under electron donor limitation. We observe clear and statistically robust changes in some key central MSR and C-metabolism enzymes, though a host of the critical energy-transfer enzymes show no statistically discernable change. We discuss these results in light of recent theoretical advances and their relevance to modern and ancient

Application of stable isotopes and isotope pattern deconvolution-ICPMS to speciation of endogenous and exogenous Fe and Se in rats

International Nuclear Information System (INIS)

Gonzalez Iglesias, H.; Fernandez-Sanchez, M.L.; Garcia Alonso, J.I.; Lopez Sastre, J.B.; Sanz-Medel, A.

2009-01-01

Full text: Enriched stable isotopes are crucial to study essential trace element metabolism (e.g. Se, Fe) in biological systems. Measuring isotope ratios by ICPMS and using appropriate mathematical calculations, based on isotope pattern deconvolution (IPD) may provide quantitative data about endogenous and exogenous essential or toxic elements and their metabolism. In this work, IPD was applied to explore the feasibility of using two Se (or Fe) enriched stable isotopes, one as metabolic tracer and the other as quantitation tracer, to discriminate between the endogenous and supplemented Se (or Fe) species in rat fluids by collision cell ICPMS coupled to HPLC separation. (author)

Stable isotope hydrology. Deuterium and oxygen-18 in the water cycle

International Nuclear Information System (INIS)

Gat, J.R.; Gonfiantini, R.

1981-01-01

This monograph is mainly intended for hydrologists, hydrogeologists and geochemists who want to become acquainted, rapidly but in some detail, with the theoretical background of stable isotope fractionation in natural physico-chemical processes involving fresh water, with the isotopic differences actually encountered in natural waters and with their use for practical hydrological purposes. Throughout the monograph, and in particular in the last chapter, a series of examples are discussed, giving the results obtained with stable isotope techniques in current hydrological and hydrogeological investigations or, more generally, in water resources exploration and assessment. One chapter is also dedicated to the techniques for measuring D/H and 18 O/ 16 O ratios in water

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

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

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.

Monitoring in situ biodegradation of hydrocarbons by using stable carbon isotopes

International Nuclear Information System (INIS)

Aggarwal, P.K.; Hinchee, R.E.

1991-01-01

Spilled or leaked nonhalogenated petroleum hydrocarbons in the soil can generally be metabolized by indigenous, aerobic bacteria. In situ biological degradation of hydrocarbons may be accelerated by supplying inorganic nutrients and/or oxygen. Approaches to monitoring and verifying enhanced in situ biodegradation have included measurements of changes over time in the (a) concentration of hydrocarbons, (b) temperature, (c) number of hydrocarbon-degrading microorganisms, (d) ratio of fast-degrading hydrocarbons (e.g., pristanes or phytanes), and (e) metabolic intermediates. Measurements of oxygen consumption over time and elevated carbon dioxide concentrations in soil gas also have been used as indicators of hydrocarbon degradation. An alternative approach that may help substantiate biodegradation is to measure stable carbon isotope ratios in soil gas CO 2 . Stable carbon isotope ratio analysis is inexpensive and commercially available at many laboratories. Carbon dioxide produced by hydrocarbon degradation may be distinguished from that produced by other processes based on the carbon isotopic compositions characteristic of the source material and/or fractionation accompanying microbial metabolism. Here the authors demonstrate the applicability of the stable isotope technique for monitoring enhanced. aerobic biodegradation of hydrocarbons using data from three locations in the United States

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

In situ sulfur isotopes (δ{sup 34}S and δ{sup 33}S) analyses in sulfides and elemental sulfur using high sensitivity cones combined with the addition of nitrogen by laser ablation MC-ICP-MS

Energy Technology Data Exchange (ETDEWEB)

Fu, Jiali [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); Hu, Zhaochu, E-mail: zchu@vip.sina.com [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); The Beijing SHRIMP Center, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 102206 (China); Zhang, Wen [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); Yang, Lu [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China); National Research Council Canada, 1200 Montreal Rd., Ottawa, Ontario K1A 0R6 (Canada); Liu, Yongsheng; Li, Ming; Zong, Keqing; Gao, Shan; Hu, Shenghong [State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074 (China)

2016-03-10

The sulfur isotope is an important geochemical tracer in diverse fields of geosciences. In this study, the effects of three different cone combinations with the addition of N{sub 2} on the performance of in situ S isotope analyses were investigated in detail. The signal intensities of S isotopes were improved by a factor of 2.3 and 3.6 using the X skimmer cone combined with the standard sample cone or the Jet sample cone, respectively, compared with the standard arrangement (H skimmer cone combined with the standard sample cone). This signal enhancement is important for the improvement of the precision and accuracy of in situ S isotope analysis at high spatial resolution. Different cone combinations have a significant effect on the mass bias and mass bias stability for S isotopes. Poor precisions of S isotope ratios were obtained using the Jet and X cones combination at their corresponding optimum makeup gas flow when using Ar plasma only. The addition of 4–8 ml min{sup −1} nitrogen to the central gas flow in laser ablation MC-ICP-MS was found to significantly enlarge the mass bias stability zone at their corresponding optimum makeup gas flow in these three different cone combinations. The polyatomic interferences of OO, SH, OOH were also significantly reduced, and the interference free plateaus of sulfur isotopes became broader and flatter in the nitrogen mode (N{sub 2} = 4 ml min{sup −1}). However, the signal intensity of S was not increased by the addition of nitrogen in this study. The laser fluence and ablation mode had significant effects on sulfur isotope fractionation during the analysis of sulfides and elemental sulfur by laser ablation MC-ICP-MS. The matrix effect among different sulfides and elemental sulfur was observed, but could be significantly reduced by line scan ablation in preference to single spot ablation under the optimized fluence. It is recommended that the d{sub 90} values of the particles in pressed powder pellets for accurate

USGS42 and USGS43: Human-hair stable hydrogen and oxygen isotopic reference materials and analytical methods for forensic science and implications for published measurement results

Science.gov (United States)

Coplen, T.B.; Qi, H.

2012-01-01

Because there are no internationally distributed stable hydrogen and oxygen isotopic reference materials of human hair, the U.S. Geological Survey (USGS) has prepared two such materials, USGS42 and USGS43. These reference materials span values commonly encountered in human hair stable isotope analysis and are isotopically homogeneous at sample sizes larger than 0.2 mg. USGS42 and USGS43 human-hair isotopic reference materials are intended for calibration of δ(2)H and δ(18)O measurements of unknown human hair by quantifying (1) drift with time, (2) mass-dependent isotopic fractionation, and (3) isotope-ratio-scale contraction. While they are intended for measurements of the stable isotopes of hydrogen and oxygen, they also are suitable for measurements of the stable isotopes of carbon, nitrogen, and sulfur in human and mammalian hair. Preliminary isotopic compositions of the non-exchangeable fractions of these materials are USGS42(Tibetan hair)δ(2)H(VSMOW-SLAP) = -78.5 ± 2.3‰ (n = 62) and δ(18)O(VSMOW-SLAP) = +8.56 ± 0.10‰ (n = 18) USGS42(Indian hair)δ(2)H(VSMOW-SLAP) = -50.3 ± 2.8‰ (n = 64) and δ(18)O(VSMOW-SLAP) = +14.11 ± 0.10‰ (n = 18). Using recommended analytical protocols presented herein for δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurements, the least squares fit regression of 11 human hair reference materials is δ(2)H(VSMOW-SLAP) = 6.085δ(2)O(VSMOW-SLAP) - 136.0‰ with an R-square value of 0.95. The δ(2)H difference between the calibrated results of human hair in this investigation and a commonly accepted human-hair relationship is a remarkable 34‰. It is critical that readers pay attention to the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) of isotopic reference materials in publications, and they need to adjust the δ(2)H(VSMOW-SLAP) and δ(18)O(VSMOW-SLAP) measurement results of human hair in previous publications, as needed, to ensure all results on are on the same scales.

Seawater sulfate reduction and sulfur isotope fractionation in basaltic systems: interaction of seawater with fayalite and magnetite at 200-3500C

International Nuclear Information System (INIS)

Shanks, W.C. III; Bischoff, J.L.; Rosenbauer, R.J.

1981-01-01

Sulfate reduction during seawater reaction with fayalite and with magnetite was rapid at 350 0 C, producing equilibrium assemblages of talc-pyrite-hematite-magnetite at low water/rock ratios and talc-pyrite-hematite-anhydrite at higher water/rock ratios. At 250 0 C, seawater reacting with fayalite produced detectable amounts of dissolved H 2 S. At 200 0 C, dissolved H 2 S was not detected, even after 219 days. Reaction stoichiometry indicates that sulfate reduction requires large amounts of H + , which, in subseafloor hydrothermal systems is provided by Mg metasomatism. Seawater contains sufficient Mg to supply all the H + necessary for quantitative reduction of seawater sulfate. Systematics of sulfur isotopes in the 250 and 350 0 C experiments indicate that isotopic equilibrium is reached and can be modeled as a Rayleigh distillation process. Isotopic composition of hydrothermally produced H 2 S in natural systems is strongly dependent upon the seawater/basalt ratio in the geothermal system, which controls the relative sulfide contributions from the two important sulfur sources, seawater sulfate and sulfide phases in basalt. Anhydrite precipitation during geothermal heating severely limits sulfate ingress into high temperature interaction zones. Quantitative sulfate reduction can thus be accomplished without producing strongly oxidized rocks and resultant sulfide sulfur isotope values represent a mixture of seawater and basaltic sulfur. (author)

[Research advances in identifying nitrate pollution sources of water environment by using nitrogen and oxygen stable isotopes].

Science.gov (United States)

Mao, Wei; Liang, Zhi-wei; Li, Wei; Zhu, Yao; Yanng, Mu-yi; Jia, Chao-jie

2013-04-01

Water body' s nitrate pollution has become a common and severe environmental problem. In order to ensure human health and water environment benign evolution, it is of great importance to effectively identify the nitrate pollution sources of water body. Because of the discrepant composition of nitrogen and oxygen stable isotopes in different sources of nitrate in water body, nitrogen and oxygen stable isotopes can be used to identify the nitrate pollution sources of water environment. This paper introduced the fractionation factors of nitrogen and oxygen stable isotopes in the main processes of nitrogen cycling and the composition of these stable isotopes in main nitrate sources, compared the advantages and disadvantages of five pre-treatment methods for analyzing the nitrogen and oxygen isotopes in nitrate, and summarized the research advances in this aspect into three stages, i. e. , using nitrogen stable isotope alone, using nitrogen and oxygen stable isotopes simultaneously, and combining with mathematical models. The future research directions regarding the nitrate pollution sources identification of water environment were also discussed.

The neodymium stable isotope composition of the silicate Earth and chondrites

Science.gov (United States)

McCoy-West, Alex J.; Millet, Marc-Alban; Burton, Kevin W.

2017-12-01

The non-chondritic neodymium (Nd) 142Nd/144Nd ratio of the silicate Earth potentially provides a key constraint on the accretion and early evolution of the Earth. Yet, it is debated whether this offset is due to the Earth being formed from material enriched in s-process Nd isotopes or results from an early differentiation process such as the segregation of a late sulfide matte during core formation, collisional erosion or a some combination of these processes. Neodymium stable isotopes are potentially sensitive to early sulfide segregation into Earth's core, a process that cannot be resolved using their radiogenic counterparts. This study presents the first comprehensive Nd stable isotope data for chondritic meteorites and terrestrial rocks. Stable Nd measurements were made using a double spike technique coupled with thermal ionisation mass spectrometry. All three of the major classes of chondritic meteorites, carbonaceous, enstatite and ordinary chondrites have broadly similar isotopic compositions allowing calculation of a chondritic mean of δ146/144Nd = -0.025 ± 0.025‰ (±2 s.d.; n = 39). Enstatite chondrites yield the most uniform stable isotope composition (Δ146/144Nd = 26 ppm), with considerably more variability observed within ordinary (Δ146/144Nd = 72 ppm) and carbonaceous meteorites (Δ146/144Nd = 143 ppm). Terrestrial weathering, nucleosynthetic variations and parent body thermal metamorphism appear to have little measurable effect on δ146/144Nd in chondrites. The small variations observed between ordinary chondrite groups most likely reflect inherited compositional differences between parent bodies, with the larger variations observed in carbonaceous chondrites being linked to varying modal proportions of calcium-aluminium rich inclusions. The terrestrial samples analysed here include rocks ranging from basaltic to rhyolitic in composition, MORB glasses and residual mantle lithologies. All of these terrestrial rocks possess a broadly similar Nd

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.

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

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

Use of stable isotopes to monitor the natural attenuation of dicyclopentadiene

International Nuclear Information System (INIS)

Stehemier, L.G.; Cooke, L.; Hornett, R.; Aravena, R.

2002-01-01

Stable isotope fractionation is a method used to prove that residual hydrocarbons from an oil spill are being naturally attenuated in soil and groundwater. Hydrogen isotopes and carbon isotopes are the two isotopes that have been used to provide this evidence. Evaporation, adsorption and biodegradation are among the processes that can cause fractionation of isotopes. However, the largest fractionations take place during biodegradation because of the unidirectional characteristics of metabolism and the thermodynamic selectivity of enzymatic processes in biological systems. This paper presents the results of a monitored natural attenuation program for hydrocarbons in soil and groundwater at a chemical plant in Alberta where dicyclopentadiene (DCPD) was biodegraded. DCPD is a co-product from the cracking of ethane to ethylene. Piezometers were used to monitor the stable isotope fractionation of DCPD over a three year period. Evidence that DCPD was biodegrading was the fact that the change in carbon 13 was enriched 4.1 per cent in one study area during the monitoring period. The results are among the first definitive proof that DCPD biodegrades in the field. Analysis by gas chromatography-carbon-isotope ratio mass spectrometry is an essential technique for monitoring recalcitrant, low water-soluble hydrocarbons. 16 refs., 4 tabs., 3 figs

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.

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.

Russian ElectroKhimPribor integrated plant - producer and supplier of enriched stable isotopes

International Nuclear Information System (INIS)

Tatarinov, A.N.; Polyakov, L.A.

1997-01-01

Russian ElectroKhimPribor Integrated Plant, as well as ORNL, is a leading production which manufactures and supplied to the world market such specific products as stable isotopes. More than 200 isotopes of 44 elements can be obtained at its electromagnetic separator. Changes being underway for a few last years in Russia affected production and distribution of stable isotopes. There arose a necessity in a new approach to handling work in this field so as to create favourable conditions for both producers and customers. As a result, positive changes in calutron operation at ElectroKhimPribor has been reached; quality management system covering all stages of production has been set up; large and attractive stock of isotopes has been created; prospective scientific isotope-based developments are taken into account when planning separation F campaigns; executing the contracts is guaranteed; business philosophy has been changed to meet maximum of customer needs. For more than forty years ElectroKhimPribor have had no claim from customers as to quality of products or implementing contracts. Supplying enriched stable isotopes virtually to all the world's leading customers, ElectroKhimPribor cooperates successfully with Canadian company Trace Science since 1996

Transmutation of stable isotopes and deactivation of radioactive waste in growing biological systems

International Nuclear Information System (INIS)

Vysotskii, Vladimir I.; Kornilova, Alla A.

2013-01-01

Highlights: ► The phenomena of isotope transmutation in growing microbiological cultures were investigated. ► Transmutation in microbiological associations is 20 times more effective than in pure cultures. ► Transmutation of radioactive nuclei to stable isotopes in such associations was investigated. ► The most accelerated rate of Cs 137 to stable Ba 138 isotope transmutation was 310 days. ► “Microbiological deactivation” may be used for deactivation of Chernobyl and Fukushima areas. - Abstract: The report presents the results of qualifying examinations of stable and radioactive isotopes transmutation processes in growing microbiological cultures. It is shown that transmutation of stable isotopes during the process of growth of microbiological cultures, at optimal conditions in microbiological associations, is 20 times more effective than the same transmutation process in the form of “one-line” (pure) microbiological cultures. In the work, the process of direct, controlled decontamination of highly active intermediate lifetime and long-lived reactor isotopes (reactor waste) through the process of growing microbiological associations has been studied. In the control experiment (flask with active water but without microbiological associations), the “usual” law of nuclear decay applies, and the life-time of Cs 137 isotope was about 30 years. The most rapidly increasing decay rate, which occurred with a lifetime τ * ≈ 310 days (involving an increase in rate, and decrease in lifetime by a factor of 35 times) was observed in the presence of Ca salt in closed flask with active water contained Cs 137 solution and optimal microbiological association

Oxygen and sulfur isotope systematics of sulfate produced during abiotic and bacterial oxidation of sphalerite and elemental sulfur

Science.gov (United States)

Balci, N.; Mayer, B.; Shanks, Wayne C.; Mandernack, K.W.

2012-01-01

Studies of metal sulfide oxidation in acid mine drainage (AMD) systems have primarily focused on pyrite oxidation, although acid soluble sulfides (e.g., ZnS) are predominantly responsible for the release of toxic metals. We conducted a series of biological and abiotic laboratory oxidation experiments with pure and Fe-bearing sphalerite (ZnS & Zn 0.88Fe 0.12S), respectively, in order to better understand the effects of sulfide mineralogy and associated biogeochemical controls of oxidation on the resultant ?? 34S and ?? 18O values of the sulfate produced. The minerals were incubated in the presence and absence of Acidithiobacillus ferrooxidans at an initial solution pH of 3 and with water of varying ?? 18O values to determine the relative contributions of H 2O-derived and O 2-derived oxygen in the newly formed sulfate. Experiments were conducted under aerobic and anaerobic conditions using O 2 and Fe(III) aq as the oxidants, respectively. Aerobic incubations with A. ferrooxidans, and S o as the sole energy source were also conducted. The ??34SSO4 values from both the biological and abiotic oxidation of ZnS and ZnS Fe by Fe(III) aq produced sulfur isotope fractionations (??34SSO4-ZnS) of up to -2.6???, suggesting the accumulation of sulfur intermediates during incomplete oxidation of the sulfide. No significant sulfur isotope fractionation was observed from any of the aerobic experiments. Negative sulfur isotope enrichment factors (??34SSO4-ZnS) in AMD systems could reflect anaerobic, rather than aerobic pathways of oxidation. During the biological and abiotic oxidation of ZnS and ZnS Fe by Fe(III) aq all of the sulfate oxygen was derived from water, with measured ?? 18OSO 4-H 2O values of 8.2??0.2??? and 7.5??0.1???, respectively. Also, during the aerobic oxidation of ZnS Fe and S o by A. ferrooxidans, all of the sulfate oxygen was derived from water with similar measured ?? 18OSO 4-H 2O values of 8.1??0.1??? and 8.3??0.3???, respectively. During biological oxidation

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)

Sulfur concentration and isotopic variation in apatites from granitic to granodioritic plutons of a Cretaceous Cordilleran Batholith

Science.gov (United States)

Economos, R. C.

2012-12-01

Apatite is a common igneous accessory mineral with a high saturation temperature which can therefore crystallize over a significant portion of magmatic compositional space. Sulfur presents an opportunity to identify zoning in apatites. Unlike other trace elements, sulfur is relatively immobile in the apatite crystal structure and can be present in typical concentrations up to 1500 - 2000 ppm (or 0.5 to 1 wt% SO3). Sulfur concentration zoning in igneous apatites from ore producing magmatic systems has been identified (Streck and Dilles, 1998), but the interpretation of the cause of this zoning remains an open question. δ34S isotopic ratios of whole apatites have been used to track isotopic evolution associated with changes in magma fO2 and eruptive degassing (Rye, 2005). The presented work combines sulfur concentration mapping in zoned apatite crystals with in-situ SIMS 34S and 32S isotope measurements. Apatites were extracted from granite to granodiorite samples from the Cadiz Valley Batholith in the central Mojave Desert. This batholith is related to the pulse of Cretaceous Cordilleran magmatism that generated large batholiths in the Sierra Nevada and the Penninsular Ranges. The Mojave segment of the Cretaceous arc is unique in their construction into a full thickness of continental crust which exerted a strong influence on magmatic compositions. Apatite grains were mounted parallel to C axes, ground until grains were approximately bisected, and analyzed by Electron Microprobe at UCLA, for CaO, P2O5, SO3 and SiO2. Grains were surveyed and those yielding anomalous SO3 contents were investigated by micron-scale concentration mapping. Typical SO3 concentrations of apatites from all samples were ~0.2 wt%, while 8 to 10% of apatite grains from two samples contained cores with concentrations ranging up to 0.5 wt%. The sulfur zoning in these samples is oscillatory, in some grains representing 5 to 6 repetitions of high and low concentrations. Based on these textures

Obtaining of culture of feengus-pathogene of pine root sponge-with double label (phosphorus-32 and sulfur-35)

Energy Technology Data Exchange (ETDEWEB)

Kobets, E V

1979-01-01

The culture of Fomitopsis annosa (Fr) Karst. is shown to be labelled with phosphorus and sulfur in the period of its development in the nutrient medium, which contains /sup 23/P and /sup 35/S radioactive isotopes. The labelled fungus culture retains the label in the process of its growing in the agar must medium, the correlation of sulfur-35 and phosphorus-32 activities being approximately stable.

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

Directory of Open Access Journals (Sweden)

Oliver Heiri

2012-10-01

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

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

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

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

Progresses in the stable isotope studies of microbial processes associated with wetland methane production

International Nuclear Information System (INIS)

Li Qing; Lin Guanghui

2013-01-01

Methane emissions from wetlands play a key role in regulating global atmospheric methane concentration, so better understanding of microbial processes for the methane emission in wetlands is critical for developing process models and reducing uncertainty in global methane emission inventory. In this review, we describe basic microbial processes for wetland methane production and then demonstrate how stable isotope fractionation and stable isotope probing can be used to investigate the mechanisms underlying different methanogenic pathways and to quantify microbial species involved in wetland methane production. When applying stable isotope technique to calculate contributions of different pathways to the total methane production in various wetlands, the technical challenge is how to determine isotopic fractionation factors for the acetate derived methane production and carbon dioxide derived methane production. Although the application of stable isotope probing techniques to study the actual functions of different microbial organisms to methane production process is significantly superior to the traditional molecular biology method, the combination of these two technologies will be crucial for direct linking of the microbial community and functional structure with the corresponding metabolic functions, and provide new ideas for future studies. (authors)

Recent developments in application of stable isotope analysis on agro-product authenticity and traceability.

Science.gov (United States)

Zhao, Yan; Zhang, Bin; Chen, Gang; Chen, Ailiang; Yang, Shuming; Ye, Zhihua

2014-02-15

With the globalisation of agro-product markets and convenient transportation of food across countries and continents, the potential for distribution of mis-labelled products increases accordingly, highlighting the need for measures to identify the origin of food. High quality food with identified geographic origin is a concern not only for consumers, but also for agriculture farmers, retailers and administrative authorities. Currently, stable isotope ratio analysis in combination with other chemical methods gradually becomes a promising approach for agro-product authenticity and traceability. In the last five years, a growing number of research papers have been published on tracing agro-products by stable isotope ratio analysis and techniques combining with other instruments. In these reports, the global variety of stable isotope compositions has been investigated, including light elements such as C, N, H, O and S, and heavy isotopes variation such as Sr and B. Several factors also have been considered, including the latitude, altitude, evaporation and climate conditions. In the present paper, an overview is provided on the authenticity and traceability of the agro-products from both animal and plant sources by stable isotope ratio analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Investigating Pathways of Nutrient and Energy Flows Through Aquatic Food Webs Using Stable Isotopes of Carbon and Nitrogen

Energy Technology Data Exchange (ETDEWEB)

Hadwen, W. L.; Bunn, S. E. [Australian Rivers Institute, Griffith School of Environment, Griffith University, Nathan Campus, Brisbane, Queensland (Australia)

2013-05-15

Carbon and nitrogen stable isotopes can provide valuable insights into pathways of nutrient and energy flows in aquatic ecosystems. Carbon stable isotopes are principally used to trace pathways of organic matter transfer through aquatic food webs, particularly with regard to identifying the dominant sources of nutrition for aquatic biota. Stable isotopes of carbon have been widely used to answer one of the most pressing questions in aquatic food web ecology - to what degree do in-stream (autochthonous) and riparian (allochthonous) sources of energy fuel riverine food webs? In conjunction with carbon stable isotopes, nitrogen stable isotopes have been used to determine the trophic position of consumers and to identify the number of trophic levels in aquatic food webs. More recently, stable nitrogen isotopes have been recommended as indicators of anthropogenic disturbances. Specifically, agricultural land uses and/or sewage effluent discharge have been shown to significantly increase {delta}{sup 15}N signatures in primary producers and higher order consumers in freshwater, estuarine and marine environments. Together, carbon and nitrogen stable isotopes can be used to examine natural food web functions as well as the degree to which human modifications to catchments and aquatic environments can influence aquatic ecosystem function. (author)

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.

Multiple sulfur isotopes monitor fluid evolution of an Archean orogenic gold deposit

Science.gov (United States)

LaFlamme, Crystal; Sugiono, Dennis; Thébaud, Nicolas; Caruso, Stefano; Fiorentini, Marco; Selvaraja, Vikraman; Jeon, Heejin; Voute, François; Martin, Laure

2018-02-01

The evolution of a gold-bearing hydrothermal fluid from its source to the locus of gold deposition is complex as it experiences rapid changes in thermochemical conditions during ascent through the crust. Although it is well established that orogenic gold deposits are generated during time periods of abundant crustal growth and/or reworking, the source of fluid and the thermochemical processes that control gold precipitation remain poorly understood. In situ analyses of multiple sulfur isotopes offer a new window into the relationship between source reservoirs of Au-bearing fluids and the thermochemical processes that occur along their pathway to the final site of mineralisation. Whereas δ34S is able to track changes in the evolution of the thermodynamic conditions of ore-forming fluids, Δ33S is virtually indelible and can uniquely fingerprint an Archean sedimentary reservoir that has undergone mass independent fractionation of sulfur (MIF-S). We combine these two tracers (δ34S and Δ33S) to characterise a gold-bearing laminated quartz breccia ore zone and its sulfide-bearing alteration halo in the (+6 Moz Au) structurally-controlled Archean Waroonga deposit located in the Eastern Goldfields Superterrane of the Yilgarn Craton, Western Australia. Over 250 analyses of gold-associated sulfides yield a δ34S shift from what is interpreted as an early pre-mineralisation phase, with chalcopyrite-pyrrhotite (δ34S = +0.7‰ to +2.9‰) and arsenopyrite cores (δ34S = ∼-0.5‰), to a syn-mineralisation stage, reflected in Au-bearing arsenopyrite rims (δ34S = -7.6‰ to +1.5‰). This shift coincides with an unchanging Δ33S value (Δ33S = +0.3‰), both temporally throughout the Au-hosting hydrothermal sulfide paragenesis and spatially across the Au ore zone. These results indicate that sulfur is at least partially recycled from MIF-S-bearing Archean sediments. Further, the invariant nature of the observed MIF-S signature demonstrates that sulfur is derived from a

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)

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.

Insights from quantitative metaproteomics and protein-stable isotope probing into microbial ecology.

Science.gov (United States)

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

2013-10-01

The recent development of metaproteomics has enabled the direct identification and quantification of expressed proteins from microbial communities in situ, without the need for microbial enrichment. This became possible by (1) significant increases in quality and quantity of metagenome data and by improvements of (2) accuracy and (3) sensitivity of modern mass spectrometers (MS). The identification of physiologically relevant enzymes can help to understand the role of specific species within a community or an ecological niche. Beside identification, relative and absolute quantitation is also crucial. We will review label-free and label-based methods of quantitation in MS-based proteome analysis and the contribution of quantitative proteome data to microbial ecology. Additionally, approaches of protein-based stable isotope probing (protein-SIP) for deciphering community structures are reviewed. Information on the species-specific metabolic activity can be obtained when substrates or nutrients are labeled with stable isotopes in a protein-SIP approach. The stable isotopes ((13)C, (15)N, (36)S) are incorporated into proteins and the rate of incorporation can be used for assessing the metabolic activity of the corresponding species. We will focus on the relevance of the metabolic and phylogenetic information retrieved with protein-SIP studies and for detecting and quantifying the carbon flux within microbial consortia. Furthermore, the combination of protein-SIP with established tools in microbial ecology such as other stable isotope probing techniques are discussed.

[Research progress on food sources and food web structure of wetlands based on stable isotopes].

Science.gov (United States)

Chen, Zhan Yan; Wu, Hai Tao; Wang, Yun Biao; Lyu, Xian Guo

2017-07-18

The trophic dynamics of wetland organisms is the basis of assessing wetland structure and function. Stable isotopes of carbon and nitrogen have been widely applied to identify trophic relationships in food source, food composition and food web transport in wetland ecosystem studies. This paper provided an overall review about the current methodology of isotope mixing model and trophic level in wetland ecosystems, and discussed the standards of trophic fractionation and baseline. Moreover, we characterized the typical food sources and isotopic compositions of wetland ecosystems, summarized the food sources in different trophic levels of herbivores, omnivores and carnivores based on stable isotopic analyses. We also discussed the limitations of stable isotopes in tra-cing food sources and in constructing food webs. Based on the current results, development trends and upcoming requirements, future studies should focus on sample treatment, conservation and trophic enrichment measurement in the wetland food web, as well as on combing a variety of methodologies including traditional stomach stuffing, molecular markers, and multiple isotopes.

Sulfur isotope fractionation between fluid and andesitic melt: An experimental study

Science.gov (United States)

Fiege, Adrian; Holtz, François; Shimizu, Nobumichi; Mandeville, Charles W.; Behrens, Harald; Knipping, Jaayke L.

2014-01-01

Glasses produced from decompression experiments conducted by Fiege et al. (2014a) were used to investigate the fractionation of sulfur isotopes between fluid and andesitic melt upon magma degassing. Starting materials were synthetic glasses with a composition close to a Krakatau dacitic andesite. The glasses contained 4.55–7.95 wt% H2O, ∼140 to 2700 ppm sulfur (S), and 0–1000 ppm chlorine (Cl). The experiments were carried out in internally heated pressure vessels (IHPV) at 1030 °C and oxygen fugacities (fO2) ranging from QFM+0.8 log units up to QFM+4.2 log units (QFM: quartz–fayalite–magnetite buffer). The decompression experiments were conducted by releasing pressure (P) continuously from ∼400 MPa to final P of 150, 100, 70 and 30 MPa. The decompression rate (r) ranged from 0.01 to 0.17 MPa/s. The samples were annealed for 0–72 h (annealing time, tA) at the final P and quenched rapidly from 1030 °C to room temperature (T).The decompression led to the formation of a S-bearing aqueous fluid phase due to the relatively large fluid–melt partitioning coefficients of S. Secondary ion mass spectrometry (SIMS) was used to determine the isotopic composition of the glasses before and after decompression. Mass balance calculations were applied to estimate the gas–melt S isotope fractionation factor αg-m.No detectable effect of r and tA on αg-m was observed. However, SIMS data revealed a remarkable increase of αg-m from ∼0.9985 ± 0.0007 at >QFM+3 to ∼1.0042 ± 0.0042 at ∼QFM+1. Noteworthy, the isotopic fractionation at reducing conditions was about an order of magnitude larger than predicted by previous works. Based on our experimental results and on previous findings for S speciation in fluid and silicate melt a new model predicting the effect of fO2 on αg-m (or Δ34Sg–m) in andesitic systems at 1030 °C is proposed. Our experimental results as well as our modeling are of high importance for the interpretation of S isotope

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.

Geospatial modeling of plant stable isotope ratios - the development of isoscapes

Science.gov (United States)

West, J. B.; Ehleringer, J. R.; Hurley, J. M.; Cerling, T. E.

2007-12-01

Large-scale spatial variation in stable isotope ratios can yield critical insights into the spatio-temporal dynamics of biogeochemical cycles, animal movements, and shifts in climate, as well as anthropogenic activities such as commerce, resource utilization, and forensic investigation. Interpreting these signals requires that we understand and model the variation. We report progress in our development of plant stable isotope ratio landscapes (isoscapes). Our approach utilizes a GIS, gridded datasets, a range of modeling approaches, and spatially distributed observations. We synthesize findings from four studies to illustrate the general utility of the approach, its ability to represent observed spatio-temporal variability in plant stable isotope ratios, and also outline some specific areas of uncertainty. We also address two basic, but critical questions central to our ability to model plant stable isotope ratios using this approach: 1. Do the continuous precipitation isotope ratio grids represent reasonable proxies for plant source water?, and 2. Do continuous climate grids (as is or modified) represent a reasonable proxy for the climate experienced by plants? Plant components modeled include leaf water, grape water (extracted from wine), bulk leaf material ( Cannabis sativa; marijuana), and seed oil ( Ricinus communis; castor bean). Our approaches to modeling the isotope ratios of these components varied from highly sophisticated process models to simple one-step fractionation models to regression approaches. The leaf water isosocapes were produced using steady-state models of enrichment and continuous grids of annual average precipitation isotope ratios and climate. These were compared to other modeling efforts, as well as a relatively sparse, but geographically distributed dataset from the literature. The latitudinal distributions and global averages compared favorably to other modeling efforts and the observational data compared well to model predictions

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.

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)

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.

Sulfur isotopes as a tracer for biogenic sulfate reduction in natural environments: A link between modern and ancient ecosystems. Geologica Ultraiectina (316)

NARCIS (Netherlands)

Stam, M.C.

2010-01-01

Sulfur isotopes have been widely used to trace the activity of sulfate reducing prokaryotes in modern and ancient geochemical settings and to estimate the role of this microbial metabolism in global sulfur cycling. Extensive pure culture data provide detailed insight into cellular mechanisms

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

Isotope determination of sulfur by mass spectrometry in soil samples

Directory of Open Access Journals (Sweden)

Alexssandra Luiza Rodrigues Molina Rossete

2012-12-01

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

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)

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

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

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)

Characterization of sulfur deposition over the period of industrialization in Japan using sulfur isotope ratio in Japanese cedar tree rings taken from stumps.

Science.gov (United States)

Ishida, Takuya; Tayasu, Ichiro; Takenaka, Chisato

2015-07-01

We characterized the sulfur deposition history over the period of industrialization in Japan based on the sulfur isotope ratio (δ(34)S) in tree rings of Japanese cedar (Cryptomeria japonica D. Don) stumps. We analyzed and compared δ(34)S values in the rings from two types of disk samples from 170-year-old stumps that had been cut 5 years earlier (older forest stand) and from 40-year-old living trees (younger forest stand) in order to confirm the validity of using stump disks for δ(34)S analysis. No differences in δ(34)S values by age were found between the sample types, indicating that stump disks can be used for δ(34)S analysis. The δ(34)S profile in tree rings was significantly correlated with anthropogenic SO2 emissions in Japan (r = -0.76, p tree rings serve as a record of anthropogenic sulfur emissions. In addition, the values did not change largely from pre-industrialization to the 1940s (+4.2 to +6.1‰). The values before the 1940s are expected to reflect the background sulfur conditions in Japan and, thus, disks containing rings formed before the 1940s contain information about the natural environmental sulfur, which is useful for biogeochemical studies.

A free-air system for long-term stable carbon isotope labeling of adult forest trees

Science.gov (United States)

Stable carbon (C) isotopes, in particular employed in labeling experiments, are an ideal tool to broaden our understanding of C dynamics in trees and forest ecosystems. Here, we present a free-air exposure system, named isoFACE, designed for long-term stable C isotope labeling in...

Analysis of stable isotope data to estimate vitamin A body stores

International Nuclear Information System (INIS)

2008-06-01

Vitamin A deficiency (VAD) is a serious public health problem in most developing countries. Because of the detrimental effects of vitamin A deficiency on human health, accurate assessment of vitamin A status is necessary to develop and evaluate intervention programmes. The IAEA is providing technical support to its Member States to use stable isotope dilution techniques to develop and evaluate programmes aimed at reducing vitamin A deficiency in populations. The stable isotope dilution technique, in contrast to other methods, have the potential to provide a quantitative estimate of vitamin A concentration across the continuum of status, from deficient to excess vitamin A body stores. In 2004 the IAEA, the United States Agency for International Development (USAID) and HarvestPlus initiated the Vitamin A Tracer Task Force, made up of international experts. HarvestPlus is a Global Challenge Program of the Consultative Group on International Agricultural Research (CGIAR). It is coordinated by the Centro Internacional de Agricultura Tropical (CIAT), a not-for-profit organization that conducts socially and environmentally progressive research aimed at reducing hunger and poverty and preserving natural resources in developing countries, located in Colombia, and the International Food Policy Research Institute (IFPRI), located in the United States of America and whose mission is to provide policy solutions aimed at reducing hunger and malnutrition in developing countries. The role of the Vitamin A Tracer Task Force was to prepare three complementary publications on the use of stable isotope dilution techniques to assess vitamin A body stores. The first publication entitled 'Appropriate Use of Vitamin A Tracer (Stable Isotope) Methodology' was published in 2004 by USAID/International Life Sciences Institute (ILSI) through the Micronutrient Global Leadership (MGL) project with co-sponsorship of IAEA and HarvestPlus. The second handbook is on 'Vitamin A Tracer Dilution

Enhanced understanding of ectoparasite: host trophic linkages on coral reefs through stable isotope analysis

Science.gov (United States)

Demopoulos, Amanda W. J.; Sikkel, Paul C.

2015-01-01

Parasitism, although the most common type of ecological interaction, is usually ignored in food web models and studies of trophic connectivity. Stable isotope analysis is widely used in assessing the flow of energy in ecological communities and thus is a potentially valuable tool in understanding the cryptic trophic relationships mediated by parasites. In an effort to assess the utility of stable isotope analysis in understanding the role of parasites in complex coral-reef trophic systems, we performed stable isotope analysis on three common Caribbean reef fish hosts and two kinds of ectoparasitic isopods: temporarily parasitic gnathiids (Gnathia marleyi) and permanently parasitic cymothoids (Anilocra). To further track the transfer of fish-derived carbon (energy) from parasites to parasite consumers, gnathiids from host fish were also fed to captive Pederson shrimp (Ancylomenes pedersoni) for at least 1 month. Parasitic isopods had δ13C and δ15N values similar to their host, comparable with results from the small number of other host–parasite studies that have employed stable isotopes. Adult gnathiids were enriched in 15N and depleted in13C relative to juvenile gnathiids, providing insights into the potential isotopic fractionation associated with blood-meal assimilation and subsequent metamorphosis. Gnathiid-fed Pedersen shrimp also had δ13C values consistent with their food source and enriched in 15N as predicted due to trophic fractionation. These results further indicate that stable isotopes can be an effective tool in deciphering cryptic feeding relationships involving parasites and their consumers, and the role of parasites and cleaners in carbon transfer in coral-reef ecosystems specifically.

Enhanced understanding of ectoparasite–host trophic linkages on coral reefs through stable isotope analysis

Directory of Open Access Journals (Sweden)

Amanda W.J. Demopoulos

2015-04-01

Full Text Available Parasitism, although the most common type of ecological interaction, is usually ignored in food web models and studies of trophic connectivity. Stable isotope analysis is widely used in assessing the flow of energy in ecological communities and thus is a potentially valuable tool in understanding the cryptic trophic relationships mediated by parasites. In an effort to assess the utility of stable isotope analysis in understanding the role of parasites in complex coral-reef trophic systems, we performed stable isotope analysis on three common Caribbean reef fish hosts and two kinds of ectoparasitic isopods: temporarily parasitic gnathiids (Gnathia marleyi and permanently parasitic cymothoids (Anilocra. To further track the transfer of fish-derived carbon (energy from parasites to parasite consumers, gnathiids from host fish were also fed to captive Pederson shrimp (Ancylomenes pedersoni for at least 1 month. Parasitic isopods had δ13C and δ15N values similar to their host, comparable with results from the small number of other host–parasite studies that have employed stable isotopes. Adult gnathiids were enriched in 15N and depleted in 13C relative to juvenile gnathiids, providing insights into the potential isotopic fractionation associated with blood-meal assimilation and subsequent metamorphosis. Gnathiid-fed Pedersen shrimp also had δ13C values consistent with their food source and enriched in 15N as predicted due to trophic fractionation. These results further indicate that stable isotopes can be an effective tool in deciphering cryptic feeding relationships involving parasites and their consumers, and the role of parasites and cleaners in carbon transfer in coral-reef ecosystems specifically.

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...

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

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.

Water-rock-tailings interactions and sources of sulfur and metals in the subtropical mining region of Taxco, Guerrero (southern Mexico): A multi-isotopic approach

International Nuclear Information System (INIS)

Talavera Mendoza, Oscar; Ruiz, Joaquin; Díaz Villaseñor, Elvia; Ramírez Guzmán, Alejandro; Cortés, Alejandra; Salgado Souto, Sergio Adrián; Dótor Almazán, Azucena; Rivera Bustos, Reymundo

2016-01-01

Multi-isotope (H, O, S, Sr, Pb) systems coupled with conventional (major and trace element) hydrogeochemical analysis were applied to determine the origin of water, to model water-rock-tailings interactions and for source apportionment of sulfur and associated toxic metals in the mining region of Taxco, Guerrero in southern Mexico. Oxygen and H isotopes indicate that meteoric water in the zone is rainwater undergoing varying degrees of isotopic fractionation by atmospheric evaporation whereas Sr isotopes trace the interaction of pristine water from volcanics of the regional recharge zone and subsequently flowing through sandstone and shale to spring points. Leachates form from two distinctive sources (spring water and surface water) having differential interactions with bedrocks prior to entering the tailings. Compared to pristine water, leachates are enriched in sulfate, metals (e.g. Fe, Mn, Pb and Zn) and metalloids (e.g. As). The sulfur isotopic composition of ore-sulfides, leachates, secondary precipitates, regional surface water and hypogenic sulfates is described in terms of a two-component mixing model with shale of Mexcala and limestone of Morelos formations representing the light and heavy end-members, respectively, whereas Sr isotopic composition is bracketed combining three lithogenic (Mexcala/Morelos, Tilzapotla and Taxco Schist) sources. Finally, leachates have a mixture of lead from ore-sulfides and Taxco Schist Formation (Family I) or from ore-sulfides alone (Family II). The application of multiple environmental isotopic techniques is an outstanding tool for elucidating complex interactions of water with bedrocks and tailings and for determining the source of sulfur and toxic metal from mining and other metal polluted environments. - Highlights: • We applied multi-isotope techniques to model water-bedrocks-tailings interaction. • Spring water records fractionation by evaporation and interaction with local rocks. • The sulfur cycle is modeled in

Stable Isotope Technique to Assess Intake of Human Milk in Breastfed Infants

International Nuclear Information System (INIS)

2014-01-01

This publication was developed by an international group of experts as an integral part of the IAEA’s efforts to contribute to the transfer of technology and knowledge in nutrition. Its aim is to assist Member States in their efforts to combat malnutrition by facilitating the use of relevant nuclear techniques. The stable (non-radioactive) isotope technique has been developed to assess intake of human milk in breastfed infants. The practical application of the stable isotope technique, based on analysis of deuterium by Fourier transform infrared spectrometry (FTIR), is presented in this book

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‰.

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‰

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...

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.

Geological Sulfur Isotopes Indicate Elevated OCS in the Archean Atmosphere, Solving the Faint Young Sun Paradox

DEFF Research Database (Denmark)

Ueno, Yuichiro; Johnson, Matthew Stanley; Danielache, Sebastian Oscar

2009-01-01

Distributions of sulfur isotopes in geological samples would provide a record of atmospheric composition if the mechanism producing the isotope effects could be described quantitatively. We determined the UV absorption spectra of 32SO2, 33SO2, and 34SO2 and use them to interpret the geological re......-rich, reducing Archean atmosphere. The radiative forcing, due to this level of OCS, is able to resolve the faint young sun paradox. Further, the decline of atmospheric OCS may have caused the late Archean glaciation....

An Investigation into the Relationship Between Distillate Yield and Stable Isotope Fractionation

Science.gov (United States)

Sowers, T.; Wagner, A. J.

2016-12-01

Recent breakthroughs in laser spectrometry have allowed for faster, more efficient analyses of stable isotopic ratios in water samples. Commercially available instruments from Los Gatos Research and Picarro allow users to quickly analyze a wide range of samples, from seawater to groundwater, with accurate isotope ratios of D/H to within ± 0.2 ‰ and 18O/16O to within ± 0.03 ‰. While these instruments have increased the efficiency of stable isotope laboratories, they come with some major limitations, such as not being able to analyze hypersaline waters. The Los Gatos Research Liquid Water Isotope Analyzer (LWIA) can accurately and consistently measure the stable isotope ratios in waters with salinities ranging from 0 to 4 grams per liter (0 to 40 parts per thousand). In order to analyze water samples with salinities greater than 4 grams per liter, however, it was necessary to develop a consistent method through which to reduce salinity while causing as little fractionation as possible. Using a consistent distillation method, predictable fractionation of δ 18O and δ 2 H values was found to occur. This fractionation occurs according to a linear relationship with respect to the percent yield of the water in the sample. Using this method, samples with high salinity can be analyzed using laser spectrometry instruments, thereby enabling laboratories with Los Gatos or Picarro instruments to analyze those samples in house without having to dilute them using labor-intensive in-house standards or expensive premade standards.

Stable isotopic labeling-based quantitative targeted glycomics (i-QTaG).

Science.gov (United States)

Kim, Kyoung-Jin; Kim, Yoon-Woo; Kim, Yun-Gon; Park, Hae-Min; Jin, Jang Mi; Hwan Kim, Young; Yang, Yung-Hun; Kyu Lee, Jun; Chung, Junho; Lee, Sun-Gu; Saghatelian, Alan

2015-01-01

Mass spectrometry (MS) analysis combined with stable isotopic labeling is a promising method for the relative quantification of aberrant glycosylation in diseases and disorders. We developed a stable isotopic labeling-based quantitative targeted glycomics (i-QTaG) technique for the comparative and quantitative analysis of total N-glycans using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). We established the analytical procedure with the chemical derivatizations (i.e., sialic acid neutralization and stable isotopic labeling) of N-glycans using a model glycoprotein (bovine fetuin). Moreover, the i-QTaG using MALDI-TOF MS was evaluated with various molar ratios (1:1, 1:2, 1:5) of (13) C6 /(12) C6 -2-aminobenzoic acid-labeled glycans from normal human serum. Finally, this method was applied to direct comparison of the total N-glycan profiles between normal human sera (n = 8) and prostate cancer patient sera (n = 17). The intensities of the N-glycan peaks from i-QTaG method showed a good linearity (R(2) > 0.99) with the amount of the bovine fetuin glycoproteins. The ratios of relative intensity between the isotopically 2-AA labeled N-glycans were close to the theoretical molar ratios (1:1, 1:2, 1:5). We also demonstrated that the up-regulation of the Lewis antigen (~82%) in sera from prostate cancer patients. In this proof-of-concept study, we demonstrated that the i-QTaG method, which enables to achieve a reliable comparative quantitation of total N-glycans via MALDI-TOF MS analysis, has the potential to diagnose and monitor alterations in glycosylation associated with disease states or biotherapeutics. © 2015 American Institute of Chemical Engineers.

Physiochemical and environmental stable isotope profile of marine coastal water, Pakistan

International Nuclear Information System (INIS)

Mashiatullah, A.; Qureshi, R.M.; Javed, T.; Fazil, M.; Latif, Z.; Ahmad, N.

2005-01-01

Physiochemical and environmental stable isotope (delta /sup 13/C, delta /sup 18/O delta /sup 2/H, delta /sup 34/S) analysis of seawater samples collected from selected locations off Pakistan. Coast was performed to assess pollution scenario during 2002. Objective of the study was to establish a baseline data profile of Pakistan coastal waters. Coastal location includes: Indus Delta, Karachi Harbour, Southeast Coast Karachi, Northwest Coast Karachi, Sonmiani, Ormara. Pasni, Gwadar and Jiwani. In-situ physiochemical parameters such as: pH, electrical conductivity (E.C), salinity, turbidity and dissolved oxygen (DO) were performed with portable meters. Stable isotope of oxygen, hydrogen, carbon and sulfur was performed on GD -150 modified Mass Spectrometer. Values of delta /sup 18/O along the Sindh Coast (Indus Delta, Karachi Harbour High Tide, Karachi Harbour Low Tide, North West Coast South East Coast, Gadani), lie in range of -6.3 to -2.4 , -0.17 to -0.2, -0.13 to + 1.16, + 0.65 to + 1.25, + 0.88 to +0.93, and 1.14 %. SMOW respectively. The values of delta /sup 18/O along Baluchistan Coast (Sonmiani, Ormara, Pasni, Gwadar, and Jiwani) lie in the range of 0.74 to 1.08,0.77 to 0.82, 0.96 to + 1.07,0.38 to 1.23, and 0.45 to 0.83 % SMOW respectively. Values of delta /sup 13/ C of total dissolved inorganic carbon (TDIC) along Sindh Coast lie in the range of -2.7 to 0.55, -7.0 to -2.14, -11.48 to -2.98, -1.26 to 2.12, -2.91 to -0.56, and -1.31 to -0.28 % V- PDB. Values of delta /sup 13/ C of total dissolved inorganic carbon (TDIC) off Baluchistan Coast lie in the range of - 2.65 to -0.68, -8.5 to 0.07, -1.1 to 0.01, -1.3 to 0.47 and -5.2 to 0 % V-PDB respectively. Significantly depleted delta /sup 13/C (TDIC) values observed in water samples collected off Karachi coast, Indus Delta and Armor Coast indicate pollution inputs from industrial and domestic waste drains into shallow marine environment off these coasts. Carbon Isotope data shows that the Gwadar and Pasni are

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

Stable bromine isotopic composition of methyl bromide released from plant matter

Science.gov (United States)

Horst, Axel; Holmstrand, Henry; Andersson, Per; Thornton, Brett F.; Wishkerman, Asher; Keppler, Frank; Gustafsson, Örjan

2014-01-01

Methyl bromide (CH3Br) emitted from plants constitutes a natural source of bromine to the atmosphere, and is a component in the currently unbalanced global CH3Br budget. In the stratosphere, CH3Br contributes to ozone loss processes. Studies of stable isotope composition may reduce uncertainties in the atmospheric CH3Br budget, but require well-constrained isotope fingerprints of the source end members. Here we report the first measurements of stable bromine isotopes (δ81Br) in CH3Br from abiotic plant emissions. Incubations of both KBr-fortified pectin, a ubiquitous cell-stabilizing macromolecule, and of a natural halophyte (Salicornia fruticosa), yielded an enrichment factor (ε) of -2.00 ± 0.23‰ (1σ, n = 8) for pectin and -1.82 ± 0.02‰ (1σ, n = 4) for Salicornia (the relative amount of the heavier 81Br was decreased in CH3Br compared to the substrate salt). For short incubations, and up to 10% consumption of the salt substrate, this isotope effect was similar for temperatures from 30 up to 300 °C. For longer incubations of up to 90 h at 180 °C the δ81Br values increased from -2‰ to 0‰ for pectin and to -1‰ for Salicornia. These δ81Br source signatures of CH3Br formation from plant matter combine with similar data for carbon isotopes to facilitate multidimensional isotope diagnostics of the CH3Br budget.

Analysis of stable isotope assisted metabolomics data acquired by GC-MS

International Nuclear Information System (INIS)

Wei, Xiaoli; Shi, Biyun; Koo, Imhoi; Yin, Xinmin; Lorkiewicz, Pawel; Suhail, Hamid; Rattan, Ramandeep; Giri, Shailendra; McClain, Craig J.

2017-01-01

Stable isotope assisted metabolomics (SIAM) measures the abundance levels of metabolites in a particular pathway using stable isotope tracers (e.g., 13 C, 18 O and/or 15 N). We report a method termed signature ion approach for analysis of SIAM data acquired on a GC-MS system equipped with an electron ionization (EI) ion source. The signature ion is a fragment ion in EI mass spectrum of a derivatized metabolite that contains all atoms of the underivatized metabolite, except the hydrogen atoms lost during derivatization. In this approach, GC-MS data of metabolite standards were used to recognize the signature ion from the EI mass spectra acquired from stable isotope labeled samples, and a linear regression model was used to deconvolute the intensity of overlapping isotopologues. A mixture score function was also employed for cross-sample chromatographic peak list alignment to recognize the chromatographic peaks generated by the same metabolite in different samples, by simultaneously evaluating the similarity of retention time and EI mass spectrum of two chromatographic peaks. Analysis of a mixture of 16 13 C-labeled and 16 unlabeled amino acids showed that the signature ion approach accurately identified and quantified all isotopologues. Analysis of polar metabolite extracts from cells respectively fed with uniform 13 C-glucose and 13 C-glutamine further demonstrated that this method can also be used to analyze the complex data acquired from biological samples. - Highlights: • A signature ion approach is developed for analysis of stable isotope GC-MS data. • GC-MS data of compound standards are used for selection of the signature ion. • Linear regression model is used to deconvolute the overlapping isotopologue peaks. • The developed method was tested by known compounds and biological samples.

Effect of Different Carbon Substrates on Nitrate Stable Isotope Fractionation During Microbial Denitrification

DEFF Research Database (Denmark)

Wunderlich, Anja; Meckenstock, Rainer; Einsiedl, Florian

2012-01-01

-labeled water and 18O-labeled nitrite were added to the microcosm experiments to study the effect of putative backward reactions of nitrite to nitrate on the stable isotope fractionation. We found no evidence for a reverse reaction. Significant variations of the stable isotope enrichment factor ε were observed......In batch experiments, we studied the isotope fractionation in N and O of dissolved nitrate during dentrification. Denitrifying strains Thauera aromatica and “Aromatoleum aromaticum strain EbN1” were grown under strictly anaerobic conditions with acetate, benzoate, and toluene as carbon sources. 18O...... of nitrate transport across the cell wall compared to the kinetics of the intracellular nitrate reduction step of microbial denitrification....

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

Science.gov (United States)

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

2012-12-26

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

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

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.

Disentangling drought-induced variation in ecosystem and soil respiration using stable carbon isotopes.

Science.gov (United States)

Unger, Stephan; Máguas, Cristina; Pereira, João S; Aires, Luis M; David, Teresa S; Werner, Christiane

2010-08-01

Combining C flux measurements with information on their isotopic composition can yield a process-based understanding of ecosystem C dynamics. We studied the variations in both respiratory fluxes and their stable C isotopic compositions (delta(13)C) for all major components (trees, understory, roots and soil microorganisms) in a Mediterranean oak savannah during a period with increasing drought. We found large drought-induced and diurnal dynamics in isotopic compositions of soil, root and foliage respiration (delta(13)C(res)). Soil respiration was the largest contributor to ecosystem respiration (R (eco)), exhibiting a depleted isotopic signature and no marked variations with increasing drought, similar to ecosystem respired delta(13)CO(2), providing evidence for a stable C-source and minor influence of recent photosynthate from plants. Short-term and diurnal variations in delta(13)C(res) of foliage and roots (up to 8 and 4 per thousand, respectively) were in agreement with: (1) recent hypotheses on post-photosynthetic fractionation processes, (2) substrate changes with decreasing assimilation rates in combination with increased respiratory demand, and (3) decreased phosphoenolpyruvate carboxylase activity in drying roots, while altered photosynthetic discrimination was not responsible for the observed changes in delta(13)C(res). We applied a flux-based and an isotopic flux-based mass balance, yielding good agreement at the soil scale, while the isotopic mass balance at the ecosystem scale was not conserved. This was mainly caused by uncertainties in Keeling plot intercepts at the ecosystem scale due to small CO(2) gradients and large differences in delta(13)C(res) of the different component fluxes. Overall, stable isotopes provided valuable new insights into the drought-related variations of ecosystem C dynamics, encouraging future studies but also highlighting the need of improved methodology to disentangle short-term dynamics of isotopic composition of R (eco).

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 audience; The ability to distinguish feral and managed honeybees (Apis mellifera) has applications in studies of population genetics, parasite transmission, pollination, interspecific interactions, and bee breeding. We evaluated a diagnostic test based on theoretical differences in stable carbon isotope ratios generated by supplemental feeding. We evaluated (1) if carbon isotope ratios can distinguish feral and managed honeybees and (2) the temporal persistence of the signal aft...

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.

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.

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.

Measurement of organic carbon stable isotope composition of different soil types by EA-IRMS system

International Nuclear Information System (INIS)

Qi Biao; Ding Lingling; Cui Jiehua; Wang Yanhong

2009-01-01

Element analyzer-isotope ratio mass spectrometers (EA-IRMS) is a rapid and precise method for measuring stable carbon isotope. Pure CO 2 reference gas was calibrated via international standard-Urea, and the δ 13 C us PDB value of pure CO 2 is (-29.523 ± 0.0181)%. Stability and linearity of the EA-IRMS system, precision of δ 13 C measurement for samples were tested through experimental comparison. Moreover, determination method of organic carbon stable isotope in soil was based on the system. The EA-IRMS system had well linearity when ion intensity ranged from 1.0 to 7.0V, and it excelled the total linearity when the ion intensity was from 1.5 to 5.0V, and the accurate result of δ 13 C for sample analysis could be obtained with precision of 0.015%. If carbon content in sample is more than 5μg, the requirement for analyzing accurate result of δ 13 C could be achieved. The organic carbon stable isotope was measured in 18 different types soil samples, the average natural abundance of 13 C was 1.082%, and the organic carbon stable isotope composition was significantly different among different type soils. (authors)

Grasland Stable Isotope Flux Measurements: Three Isotopomers of Carbon Dioxide Measured by QCL Spectroscopy

Science.gov (United States)

Zeeman, M. J.; Tuzson, B.; Eugster, W.; Werner, R. A.; Buchmann, N.; Emmenegger, L.

2007-12-01

To improve our understanding of greenhouse gas dynamics of managed ecosystems such as grasslands, we not only need to investigate the effects of management (e.g., grass cuts) and weather events (e.g., rainy days) on carbon dioxide fluxes, but also need to increase the time resolution of our measurements. Thus, for the first time, we assessed respiration and assimilation fluxes with high time resolution (5Hz) stable isotope measurements at an intensively managed farmland in Switzerland (Chamau, 400m ASL). Two different methods were used to quantify fluxes of carbon dioxide and associated fluxes of stable carbon isotopes: (1) the flux gradient method, and (2) the eddy covariance method. During a week long intensive measurement campaign, we (1) measured mixing ratios of carbon dioxide isotopomers (12C16O2, 12C16O18O, 13C16O2) with a Quantum Cascade Laser (QCL, Aerodyne Inc.) spectroscope and (2) collected air samples for isotope analyses (13C/12C) and (18O/16O) of carbon dioxide by Isotope Ratio Mass Spectrometry (IRMS, Finnigan) every two hours, concurrently along a height profile (z = 0.05; 0.10; 0.31; 2.15m). In the following week, the QCL setup was used for closed-path eddy covariance flux measurement of the carbon dioxide isotopomers, with the air inlet located next to an open-path Infra Red Gas Analyzers (IRGA, LiCor 7500) used simultaneously for carbon dioxide measurements. During this second week, an area of grass inside the footprint was cut and harvested after several days. The first results of in-field continuous QCL measurements of carbon dioxide mixing ratios and their stable isotopic ratios show good agreement with IRGA measurements and isotope analysis of flask samples by IRMS. Thus, QCL spectroscopy is a very promising tool for stable isotope flux investigations.

Pollen-based reconstruction of Holocene climate variability in the Eifel region evaluated with stable isotopes

Science.gov (United States)

Kühl, Norbert; Moschen, Robert; Wagner, Stefanie

2010-05-01

Pollen as well as stable isotopes have great potential as climate proxy data. While variability in these proxy data is frequently assumed to reflect climate variability, other factors than climate, including human impact and statistical noise, can often not be excluded as primary cause for the observed variability. Multiproxy studies offer the opportunity to test different drivers by providing different lines of evidence for environmental change such as climate variability and human impact. In this multiproxy study we use pollen and peat humification to evaluate to which extent stable oxygen and carbon isotope series from the peat bog "Dürres Maar" reflect human impact rather than climate variability. For times before strong anthropogenic vegetation change, isotope series from Dürres Maar were used to validate quantitative reconstructions based on pollen. Our study site is the kettle hole peat bog "Dürres Maar" in the Eifel low mountain range, Germany (450m asl), which grew 12m during the last 10,000 years. Pollen was analysed with a sum of at least 1000 terrestrial pollen grains throughout the profile to minimize statistical effects on the reconstructions. A recently developed probabilistic indicator taxa method ("pdf-method") was used for the quantitative climate estimates (January and July temperature) based on pollen. For isotope analysis, attention was given to use monospecific Sphagnum leaves whenever possible, reducing the potential of a species effect and any potential artefact that can originate from selective degradation of different morphological parts of Sphagnum plants (Moschen et al., 2009). Pollen at "Dürres Maar" reflect the variable and partly strong human impact on vegetation during the last 4000 years. Stable isotope time series were apparently not influenced by human impact at this site. This highlights the potential of stable isotope investigations from peat for climatic interpretation, because stable isotope series from lacustrine

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.

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.

Carbon isotope fractionation by thermophilic phototrophic sulfur bacteria: evidence for autotrophic growth in natural populations

Science.gov (United States)

Madigan, M. T.; Takigiku, R.; Lee, R. G.; Gest, H.; Hayes, J. M.

1989-01-01

Purple phototrophic bacteria of the genus Chromatium can grow as either photoautotrophs or photoheterotrophs. To determine the growth mode of the thermophilic Chromatium species, Chromatium tepidum, under in situ conditions, we have examined the carbon isotope fractionation patterns in laboratory cultures of this organism and in mats of C. tepidum which develop in sulfide thermal springs in Yellowstone National Park. Isotopic analysis (13C/12C) of total carbon, carotenoid pigments, and bacteriochlorophyll from photoautotrophically grown cultures of C. tepidum yielded 13C fractionation factors near -20%. Cells of C. tepidum grown on excess acetate, wherein synthesis of the Calvin cycle enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase ribulose bisphosphate carboxylase) was greatly repressed, were isotopically heavier, fractionation factors of ca. -7% being observed. Fractionation factors determined by isotopic analyses of cells and pigment fractions of natural populations of C. tepidum growing in three different sulfide thermal springs in Yellowstone National Park were approximately -20%, indicating that this purple sulfur bacterium grows as a photoautotroph in nature.

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

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 ...

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

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)

Sources of carbon and sulfur nutrition for consumers in three meromictic lakes of New York State