Application Of Stable Isotopes Research Articles

Isotopic reconnaissance of urban water supply system dynamics

Abstract. Public water supply systems (PWSS) are critical infrastructure that is vulnerable to contamination and physical disruption. Exploring susceptibility of PWSS to such perturbations requires detailed knowledge of supply system structure and operation. The physical structure of the distribution system (i.e., pipeline connections) and basic information on sources are documented for most industrialized metropolises. Yet, most information on PWSS function comes from hydrodynamic models that are seldom validated using observational data. In developing regions, the issue may be exasperated as information regarding the physical structure of the PWSS may be incorrect, incomplete, undocumented, or difficult to obtain in many cities. Here, we present a novel application of stable isotopes in water (SIW) to quantify the contribution of different water sources, identify static and dynamic regions (e.g., regions supplied chiefly by one source vs. those experiencing active mixing between multiple sources), and reconstruct basic flow patterns in a large and complex PWSS. Our analysis, based on a Bayesian mixing model framework, uses basic information on the SIW and production volumes of sources but requires no information on pipeline connections in the system. Our work highlights the ability of stable isotopes in water to analyze PWSS and document aspects of supply system structure and operation that can otherwise be challenging to observe. This method could allow water managers to document spatiotemporal variation in flow patterns within PWSS, validate hydrodynamic model results, track pathways of contaminant propagation, optimize water supply operation, and help monitor and enforce water rights.

The discovery of chemically produced mass independent isotope effects: The physical chemistry basis and applications to the early solar system, planetary atmospheres, and the origin of life

The discovery of chemically produced mass independent isotope effects: The physical chemistry basis and applications to the early solar system, planetary atmospheres, and the origin of life

Application of non-traditional stable isotopes in source tracing of airborne particulate matter

Airborne particulate matter (PM) is a serious environmental pollution problem, which adversely affects the environment and human health. Source tracing of PM is an essential prerequisite for the air pollution control. Natural stable isotopes were used as novel tracers for PM in recent years. This review introduced the recent advances in the development of analytical methods of non-traditional stable isotopes (e.g., silicon, strontium, iron, zinc, copper, neodymium, lead, mercury, and iodine) and their source tracing applications of PM. The temporal and spatial distribution characteristics of the non-traditional stable isotopic compositions in PM and the stable isotopic signatures of major emission sources were also summarized. Finally, we also discussed current challenges and perspectives in the future development of this research area.

Barley Yield and Nitrogen Derived by Plants from Mineral and Organic Fertilizers with Application of 15N Stable Isotope.

Barley Yield and Nitrogen Derived by Plants from Mineral and Organic Fertilizers with Application of 15N Stable Isotope.

Nutrient cycling in a tropical montane rainforest under a supply-limited weathering regime traced by elemental mass balances and Mg stable isotopes

Forest ecosystem nutrition and rock weathering are intimately linked through the supply of mineral nutrients and recycling (re-utilisation of nutrients released from plant litter during mineralisation). Here, we report on novel applications of Mg stable isotopes in combination with mass balance calculations to quantify nutrient supply (from bedrock, atmospheric wet and dry deposition) and recycling in a tropical ecosystem, characterised by a supply-limited weathering regime in the Central Highlands of Sri Lanka. We measured Mg stable isotopes, radiogenic Sr isotope ratios, and element concentrations in the different compartments of the Earth's Critical Zone (bedrock, saprolite, soil, soil pore water, stream water and vegetation) as tracers for element mass fluxes and pathways. We find that in the clay-rich saprolite Mg isotopes are fractionated towards isotopically heavy Mg during secondary mineral formation. Soil pore water and stream water are the complementary isotopically light reservoirs. The Mg isotope composition of above-ground vegetation is on average identical to soil pore water. Based on these observations we suggest that a tight near-surface mineral nutrient loop between plants and soil sustains the tropical forest ecosystem. This loop is disconnected from the rock weathering nutrient source in the saprolite beneath soil. External atmospheric wet and dry inputs (mainly Mg and Ca) strongly contribute to the plant-available nutrient budget that the nutrient depleted regolith does not supply. These findings, based on Mg stable isotopes, agree with independently-obtained information on bio-element (P, K, Ca, Mg, Si) recycling. This nutrient supply setting contrasts with that reported for the Southern Sierra Nevada (USA), where a kinetically limited weathering regime prevails. Our study illustrates the application of new flux estimators based on elemental and metal stable isotope measurements across a range of climate and weathering regimes.

Zinc Isotope Fractionation during Sorption onto Al Oxides: Atomic Level Understanding from EXAFS

Interactions between aqueous Zn and mineral surfaces can lead to notable Zn isotope fractionation that affects Zn source fingerprinting, which needs an atomic-level understanding. In this study, we demonstrate that Zn isotope fractionation (Δ66Znsorbed-aqueous) during Zn sorption onto γ-Al2O3 depends on both pH and Zn concentration and ultimately correlates to surface coverage (Γ). At pH values of 6.0-6.5 and/or Zn concentrations of 0.1-0.2 mM, where Γ < 0.8 μmol m-2, Δ66Znsorbed-solution is 0.47 ± 0.03‰, whereas Δ66Znsorbed-aqueous decreases to 0.02 ± 0.07‰ at pH values of 7.0-8.0 and Zn concentrations of 0.4-0.8 mM, with a high Γ ranging from 1.5 to 3.2 μmol m-2. Using extended X-ray absorption fine structure (EXAFS) spectroscopy, we elucidated that a Zn-Al layered double hydroxide (LDH) with a Zn-O bond length of 2.06 Å forms at high surface coverage (1.5 < Γ < 3.2 μmol m-2). In contrast, at low surface coverage (Γ < 0.8 μmol m-2), the sorbed Zn occurs as a tetrahedrally coordinated inner-sphere surface complex with an average Zn-O interatomic distance of 1.98 Å. Such contrasts lead to an atomic level understanding of the strong links between isotope fractionation, local bonding structures (i.e., coordination and bond distances), and solution chemistry, which is crucial for more effective applications of stable metal isotopes as environmental tracers.

Applying the principles of isotope analysis in plant and animal ecology to forensic science in the Americas.

The heart of forensic science is application of the scientific method and analytical approaches to answer questions central to solving a crime: Who, What, When, Where, and How. Forensic practitioners use fundamentals of chemistry and physics to examine evidence and infer its origin. In this regard, ecological researchers have had a significant impact on forensic science through the development and application of a specialized measurement technique-isotope analysis-for examining evidence. Here, we review the utility of isotope analysis in forensic settings from an ecological perspective, concentrating on work from the Americas completed within the last three decades. Our primary focus is on combining plant and animal physiological models with isotope analyses for source inference. Examples of the forensic application of isotopes-including stable isotopes, radiogenic isotopes, and radioisotopes-span from cotton used in counterfeit bills to anthrax shipped through the U.S. Postal Service and from beer adulterated with cheap adjuncts to human remains discovered in shallow graves. Recent methodological developments and the generation of isotope landscapes, or isoscapes, for data interpretation promise that isotope analysis will be a useful tool in ecological and forensic studies for decades to come.

The Climatological Impacts of Continental Surface Evaporation, Rainout, and Subcloud Processes on δD of Water Vapor and Precipitation in Europe

AbstractAll types of applications of stable water isotopes, for example, for the reconstruction of paleotemperatures or for climate model validation, rely on a proper understanding of the mechanisms determining the isotopic composition of water vapor and precipitation. In this study, we use the isotope‐enabled limited‐area model COSMOiso to characterize the impacts of continental evapotranspiration, rainout, and subcloud processes on δD of European water vapor and precipitation. To this end, we first confirm a reliable implementation of the most important isotope fractionation processes in COSMOiso by comparing 5 years of modeled δD values with multiplatform δD observations from Europe (remote sensing observations of the δD of water vapor around 2.6 km above ground level, in situ δD measurements in near‐surface water vapor, and δD precipitation data from the Global Network of Isotopes in Precipitation). Based on six 15 year sensitivity simulations, we then quantify the climatological impacts of the different fractionation processes on the δD values. We find δD of European water vapor and precipitation to be most strongly controlled by rainout. Superimposed to this are the effect of subcloud processes, which especially affects δD in precipitation under warm conditions, and the effect of continental evapotranspiration, which exerts an important control over the δD of near‐surface water vapor. In future studies, the validated COSMOiso model can be employed in a similar way for a comprehensive interpretation of European isotope records from climatologically different time periods.

Current state and future challenges in stable isotope applications of the tropical hydrologic cycle (Invited Commentary)

Current state and future challenges in stable isotope applications of the tropical hydrologic cycle (<i>Invited Commentary</i>)

Environmental monitoring of a landfill area through the application of carbon stable isotopes, chemical parameters and multivariate analysis

Leachate produced during an organic matter decomposition process has a complex composition and can cause contamination of surface and groundwaters adjacent to a landfill area. The monitoring of these areas is extremely important for the characterization of the leachate produced and to avoid or mitigate environmental damages. Thus, the present study has the objective of monitoring the area of a Brazilian landfill using conventional parameters (dissolved metals and anions in water) and alternative, stable carbon isotopes parameters (δ13C of dissolved organic and inorganic carbons in water) in addition to multivariate analysis techniques. The use of conventional and alternative parameters together with multivariate analysis showed that cells of the residues are at different phases of stabilization of the organic matter and probably already at C3 of the methanogenic phase of decomposition. In addition, the data showed that organic matter stabilization ponds present in the landfill are efficient and improve the quality of the leachate. Enrichment of the heavy 13C isotope in both surface and groundwater suggested contamination in two sampling sites.

Calling all archaeologists: guidelines for terminology, methodology, data handling, and reporting when undertaking and reviewing stable isotope applications in archaeology.

Stable isotope analysis has been utilized in archaeology since the 1970s, yet standardized protocols for terminology, sampling, pretreatment evaluation, calibration, quality assurance and control, data presentation, and graphical or statistical treatment still remain lacking in archaeological applications. Here, we present recommendations and requirements for each of these in the archaeological context of: bulk stable carbon and nitrogen isotope analysis of organics; bulk stable carbon and oxygen isotope analysis of carbonates; single compound stable carbon and nitrogen isotope analysis on amino acids in collagen and keratin; and single compound stable carbon and hydrogen isotope analysis on fatty acids. The protocols are based on recommendations from the Commission on Isotopic Abundances and Atomic Weights of the International Union of Pure and Applied Chemistry (IUPAC) as well as an expanding geochemical and archaeological science experimental literature. We hope that this will provide a useful future reference for authors and reviewers engaging with the growing number of stable isotope applications and datasets in archaeology.

Characterizations of stable carbon and nitrogen isotopic ratios in wheat fractions and their feasibility for geographical traceability: A preliminary study

The study aims to investigate the characterization of stable isotopic ratios in wheat milling fractions (bran, wheat shorts, and flour) and extracts (defatted flour, gluten, lipid, starch, and crude fiber) and correlations among different matrices for each isotope, which could provide some references for the development and application of stable isotopes for geographical traceability of wheat and its milling products. Wheat samples with three genotypes were collected from three regions in China. δ13C and δ15N values in wholemeal, milling fractions and extracts were determined. Results showed that δ13C varied significantly among milling fractions and extracts, while no significant difference was found among δ15N values of different milling fractions or extracts. Each isotope shows significantly positive correlations among wheat fractions (p < 0.01). The variations of δ13C and δ15N were most contributed by fraction and region, respectively. Therefore, δ15N is suitable for geographical traceability of wheat and its milling products.

Examination of stable carbon and oxygen isotopic variability in the cellulose and wholewood of Castanea sativa Mill., Fagus sylvatica L., Pinus sylvestris L. and Quercus robur L.

This paper presents results from a comparison of wholewood and cellulose carbon and oxygen isotope ratios for four UK tree species. These species occur within the historic buildings archive as both primary and supplementary construction materials and have been used to reconstruct the climate of the past. New advances in the application of stable isotopes have widened the scope of the isotope approach, but require the time-consuming purification of cellulose. Comparison of the oxygen and carbon isotope signals preserved in the wood and cellulose components confirms and builds upon previous research in this field and provides additional insight into the covariance of these two sample types between species, and the potential to employ wood isotope analysis for both pre-screening trees for palaeoclimatology and chronology research.

Application of stable nitrogen isotopes in human colorectal cancer research

Application of stable nitrogen isotopes in human colorectal cancer research

Mitochondrial Bioenergetics by 13C-NMR Isotopomer Analysis.

Metabolic reprogramming has been associated to a plethora of diseases, and there has been increased demand for methodologies able to determine the metabolic alterations that characterize the pathological states and help developing metabolically centered therapies. In this chapter, methodologies for monitoring TCA cycle turnover and its interaction with pyruvate cycling and anaplerotic reactions will be presented. These methodologies are based in the application of stable 13C isotope "tracers"/substrates and 13C-NMR isotopomer analysis of metabolic intermediates. These methodologies can be applied at several organizational levels, ranging from isolated organelles and organs to whole organisms/humans. For the sake of simplicity, only very simple and well-defined models will be presented, including isolated heart mitochondria and isolated perfused hearts and livers.

Mixing models and stable isotopes as tools for research on feeding aquatic organisms

ABSTRACT: Implementation of mixture models in isotopic analysis has been increasing due to the need to analyze sources and understand their variations in relation to consumers, which requires an accurate determination of their discriminant rate and fractioning. In this context, we presented the main concepts related to the application of stable isotopes and mixing models, with the aim to analyze the benefits and problems of these tools in surveys on nutrition of aquatic organisms. The predominant methods identified included application of the models IsoSource, MixSIR, SIBER and SIAR, with the use of C and N isotopes in research with aquatic organisms. Studies in both freshwater and marine environments were evaluated to determine the relative contribution of the main food items and understand trophic relationships between organisms. It can be concluded that the application of mixing models, with the stable isotope technique, is a promising tool for research on feeding aquatic organisms and understanding issues related to trophic ecology of these organisms.

Novel application of Compound Specific Stable Isotope (CSSI) techniques to investigate on-site sediment origins across arable fields

In recent years, Compound Specific Stable Isotope (CSSI) techniques have enabled promising new tracers to track land-use-specific sediment sources. However, empirical data exploring the technique, particularly under controlled conditions, is still scarce. Hence, the main goal of this study is to explore the suitability of CSSI to identify sediment sources under different land use in the small agricultural site of Mistelbach (8.7ha) located in Austria. In a previous study, the authors quantified, with a 137Cs-based reconnaissance approach, a sedimentation magnitude of 4mmyear−1 in the deposition zone at the outlet of that study site. To obtain detailed information on the sediment provenance, CSSI techniques based on the measurement of δ13C signatures of natural fatty acids (FAs), were used. A cost effective sampling approach involving composite sampling, identified potential sediment source materials from the four main agricultural fields. Two long-chain FAs (i.e. C22:0=behenic acid; C24:0=lignoceric acid) as well as bulk δ13C allowed the best statistical discrimination for apportioning the origin of the sediments. Four mixing models (i.e. IsoSource, SIAR, MixSIAR and SIMMR) applied to the data generated similar results. IsoSource performed as well as the other Bayesian models tested.The main grazed waterway of the basin, identified as one of the four sources of the sediment, was evaluated to have contributed 55.1±5% (IsoSource), 53.9±2.7% (SIAR), 53.9±2.7% (MixSIAR) and 54.0±2.7% (SIMMR) to the sediment. The estimated contributions of the sources to the sediment are consistent with the land use information and the distance of the sources to the outlet. More than 80% of the sediment deposited at the basin exit originates from the two sources which had maize cultivation, one of the more erosive crops, in particular at the beginning of the growing season. This study emphasizes that CSSI and 137Cs techniques are complementary for establishing land sediment redistribution. Their combined use could provide key decision support knowledge for optimised decision-making of land managers to ensure the sustainability of agro-ecosystem management.

Coupling Stable Isotope Analysis with Gas Push‐Pull Tests to Derive In Situ Values for the Fractionation Factor αox Associated with the Microbial Oxidation of Methane in Soils

Core Ideas: Methane CH4 isotopologue fraction was measured in situ for the first time. αox varied strongly with oxidation rate. αox varied between landfills and between individual points on the same landfill. αox varied with spatial and temporal variability of soil properties. Our findings limit application of stable isotopes for CH4 oxidation quantification. A prerequisite for the application of stable isotope fractionation for the quantification of the methane (CH4) oxidation efficiency of landfill covers is that the fractionation factor αox is known or can be estimated with adequate accuracy. So far, αox has only been determined in laboratory experiments. In this study, αox was determined under in situ conditions in the field by coupling two independent methods, gas push‐pull tests and stable isotope analysis, to assess biological fractionation of CH4 isotopologues in landfill cover soils. On six landfills with nine points of investigation, 22 measurements were performed, covering a wide range of environmental conditions, such as soil temperature and moisture and observed oxidation rates. Values for αox varied between near 1, indicating little fractionation, and 1.151. Correlation of αox with the CH4 oxidation rate found by gas push‐pull tests revealed a clear asymptotic relationship, with low rates being associated with high values for αox and high rates resulting in little fractionation. Values for αox varied between the different landfills and between the individual points of investigation on the same landfill. The latter is assumed to reflect the spatial variability of methanotrophic activity due to spatial variability in soil moisture and hence air‐filled porosity as well as the spatial variability of gas fluxes. Significant variation of αox was observed for the same sampling point, presumably reflecting the temporal variability of factors influencing methanotrophic activity. These effects could include seasonally changing environmental conditions (e.g., soil temperature and moisture) but also the temporal variability of gas fluxes through the landfill soil cover, changing exposure of methanotrophs to CH4 and oxygen and hence their activity. The quantification of the CH4 oxidation efficiency using fractionation of stable isotopes is very sensitive to αox. Assuming a value constant in time and space and transferring this value from laboratory experiments to field settings entails significant uncertainty regarding the quantification of CH4 oxidation.

Tissue-specific turnover and diet-tissue discrimination factors of carbon and nitrogen isotopes of a common forage fish held at two temperatures.

The application of stable isotopes to foraging ecology is dependent on understanding life-history and environmental factors unrelated to diet that may influence isotopic composition. Diet-tissue discrimination factors (DTDFs) and turnover rates will increase the accuracy of isotope-based studies. Furthermore, little consideration has been given to the effects of temperature or life-history stage on isotopic ratios despite the prevalence of variation in temperature and growth rates throughout life. We measured δ13 C and δ15 N values with an elemental analyzer coupled to a continuous flow isotope ratio mass spectrometer. These values were used to estimate turnover and DTDFs for Emerald Shiners (Notropis atherinoides), a common North American freshwater forage fish. Fish were assigned to a temperature treatment, either 10°C (Low) or 20°C (High), and provided one of three diets (commercial pellet, Artemia salina, or Hemimysis anomala). At regular intervals fish were sampled and the isotopic compositions of whole body and liver tissues were determined. Tissue turnover rates for fish fed Artemia were faster for liver than for whole body, but were also influenced by temperature. Turnover occurred faster at higher temperatures for body and liver δ15 N values, but not for δ13 C values. The pellet and Hemimysis treatments were in isotopic equilibrium from the start of the experiment and estimated DTDFs based on these treatments were lower than assumed for Δ15 N (+0.6 to 2.7‰) and variable, but within expected ranges for Δ13 C (-1.9 to +1.5‰). The results for Emerald Shiners differed from commonly made assumptions for applying stable isotopes to ecological questions, possibly related to a bias in the use of juveniles in studies of turnover and DTDFs and assumptions regarding thermal-independence of isotopic relationships. The species-specific DTDF and tissue turnover estimates provided here will inform interpretations of stable isotope data for smaller fish species and improve food-web studies.

Application of stable isotopes (δ13C and δ15N) in studies on heavy metals bioaccumulation in Daya Bay food web

The Daya Bay is a typical subtropical bay in Southern China, and chronically stressed by heavy metal pollution. The bioaccumulation of heavy metals in Daya Bay ecosystem is still unclear. In this study, heavy metals (Cr, Co, Ni, Cu, Zn, Ag, Cd, Pb) and stable isotopes (δ13C and δ15N) were analyzed in seawater, sediment, and organisms (planktons, benthos and nektons) sampled from Daya Bay in June and December of 2015, in order to illuminate the influences of heavy metals to Daya Bay ecosystem and the basic information of environmental monitoring and risk assessment. Results showed that the major source of matter in the organisms in Daya Bay was originated from the ocean, while the freshwater input was limited. The food chain of Daya Bay was short and the highest trophic level was 3.48. The nekton predators (e.g. fish) in Daya Bay were omnivorous, and preferred benthic feeding habit in the winter. The levels of heavy metals in environment and organisms generally did not exceed the criteria according to the National Agriculture Products and the National Water Quality of China, except Zn and Pb in seawater and Cd in two crustaceans (Oratosquilla oratoria and Oratosquilla interrupta). Cr, Co, Ni, Zn, Cd and Pb were found to be biominimized along the Daya Bay food web. Cu was biominimized in the summer, but this trend was not significant in the winter. There was no significant correlation between Ag concentration and trophic level in both seasons, in contrast, there was a potential biomagnification of Ag in crustacean. Overall, the levels of heavy metals in Daya Bay ecosystems were relatively low, and further attention should be paid to Zn, Ag, Cd and Pb.