Determination Of Stable Isotopes Research Articles

Surface and groundwater flow exchanges and lateral hydrological connectivity in environments of the Matusagaratí Wetland, Panama

The Matusagaratí wetland in the Panamanian Darien is one of the largest wetlands in Central America. These types of riverine wetlands, associated with large drainage basins, are complex hydrological environments where variations in water flows and exchanges condition the existence of different wetland habitats. The work aimed to establish the hydrological functioning of the Matusagaratí wetland in different sectors of the Balsas River, emphasizing the exchanges of surface and groundwater flows and the hydrological connectivity that exists between the different laterally linked wetland environments. For this purpose, a monitoring network for surface water and groundwater was established along transects intersecting various wetland environments in the middle and lower basin of the Balsas River. This network is complemented by measurement points for surface water located in streams and in the upper basin of the river. Data collected in sensors installed in boreholes were compared to river level and precipitation data. Continuous water level recording sensors were installed at the monitoring points, and samples were collected for the determination of major ions and stable isotopes. The results indicate that in the mangroves of the lower basin and in the cativo forests of the middle basin levee there is a strong exchange of water between the river and the shallow groundwater. This water exchange is strongly influenced by the tide which spreads from the estuary to the continent through the river. Meanwhile, in the middle basin, mixed forests and orey forests developed on the alluvial plain exhibit a hydrological functioning that depends primarily on precipitation inputs. This study provides data that could serve as a basis for the management of this large tropical wetland that, despite having protection initiatives, could be hydrologically impacted by unsustainable socio-economic practices.

Accurate determination of stable silver isotopes in zinc-rich samples through effective separation of silver and zinc

A modified two-stage ion exchange procedure for the effective purification of silver from zinc-rich samples was presented, ensuring the accurate determination of stable silver isotopes.

Hydrogeochemical characteristics and evaluation of groundwater resources of Jilin Province, China

As one of China's nine border provinces, Jilin Province is an important window for China's “Belt and Road” to open up to the north, and an important channel for China's foreign trade and foreign exchanges. Therefore, understanding hydrogeochemical characteristics is very important for effective water resources management in Jilin Province. A total of 64 groundwater samples were collected from 32 monitoring Wells in Jilin Province. Use of hydrogeochemical analysis techniques, WQI index and human health risk index methods to assess hydrogeochemical processes and groundwater quality, including the determination of hydrogeochemical parameters, conventional ions, trace elements and stable isotopes (δD and δ18O). The results show that the groundwater is slightly alkaline, the cations are mainly Na+, Ca2+, Mg2+, and K+, and the anions are mainly HCO3-, Cl−, and SO42-. Most of the groundwater samples belong to Ca-HCO3 and Na-HCO3 types, which are formed by the dissolution of calcite, dolomite, gypsum, silicates and carbonates. Stable isotope analysis shows that groundwater recharge in Jilin mainly comes from atmospheric precipitation at an altitude of 1,430~2,348 m. The strong correlation between trace elements indicates a common source. Most of the groundwater quality index (WQI) in the study area is Class I to Class III, and hazard quotient (HQ) and hazard index (HI) are both below 1. This indicates excellent water quality and minimal health risks associated with human consumption. It is worth noting that trace elements are enriched in the Tanlu fault zone. It provides scientific guidance for the utilization and allocation of groundwater resources in Jilin Province.

“CROPPING THE MARGINS”: NEW EVIDENCE FOR URBAN AGRICULTURE AT MID-3RD MILLENNIUM B.C.E. TELL BRAK, SYRIA

The excavation of a large administrative building at the city of Tell Brak in northern Syria saw the recovery of a considerable quantity of charred cereals dated to the mid-third millennium B.C.E. This remarkable discovery provides a rare snapshot into the nature of agriculture in Upper Mesopotamia during the Early Bronze Age. The material has been studied using a combination of primary archaeobotanical analysis, crop stable isotope determinations, and functional weed ecology to deliver new insights into cultivation strategies at Tell Brak as well as to contribute to the wider debate regarding trade and crop importation in this region. Specific crop regime choices also reveal how the farmers of Tell Brak were able to reduce the overall risk of crop failure by careful water management, a vitally important factor in this semi-arid region, with potential implications for the analysis of other large-scale urban agro-economies in the Middle East and beyond.

Methods for the Determination of Stable Isotopes of Carbon and Nitrogen Directly in Valine, Proline, Glutamine, and Glutamic Acid

Methods for the Determination of Stable Isotopes of Carbon and Nitrogen Directly in Valine, Proline, Glutamine, and Glutamic Acid

Ban‐1 Zircon: A New Natural Zircon Reference Material for LA‐MC‐ICP‐MS Zr and Hf Isotopic Determinations

New zircon reference materials for in situ zircon radiogenic Hf isotope and stable Zr isotopic determinations made by laser ablation multi‐collector inductively coupled plasma‐mass spectrometry (LA‐MC‐ICP‐MS) are required due to high data productivity and consequently high reference material consumption rate. This study examines a new natural zircon for Zr isotope ratios by double spike thermal ionisation mass spectrometry (TIMS), and for Hf isotopes by bulk solution nebuliser (SN)‐MC‐ICP‐MS with both Zr and Hf determined by LA‐MC‐ICP‐MS. A total of five zirconium isotope measurements from drilled zircons, determined by TIMS, yield a mean δ94/90ZrIPGP‐Zr value of ‐0.09 ± 0.06‰ (2s). Five and eight hafnium isotope measurements for powders from the drilled zircons and Ban‐1‐4 by SN‐MC‐ICP‐MS, yield mean 176Hf/177Hf ratios of 0.282985 ± 0.000011 (2s) and 0.282982 ± 0.000007 (2s), respectively. The mean δ94/90ZrIPGP‐Zr value and 176Hf/177Hf ratio determined by LA‐MC‐ICP‐MS analyses are ‐0.06 ± 0.09‰ (2s, n = 504) and 0.282985 ± 0.000035 (2s, n = 327), respectively. The isotopic homogeneities suggest that the Ban‐1 zircon is a suitable reference material for microbeam Zr and Hf isotopic measurements.

Simultaneous analysis of stable and radiogenic strontium isotopes in reference materials, plants and modern tooth enamel

Radiogenic strontium isotopes (87Sr/86Sr) are a useful tool in forensics, ecology, bioarcheology and paleoanthropology allowing investigation of present and past migration and landscape use. The measurement of the 87Sr/86Sr ratio traditionally assumes a constant stable (88Sr/86Sr) isotope ratio. However, some studies indicate that these stable Sr isotopes may display mass-dependent fractionation, suggesting that the 88Sr/86Sr ratio may fingerprint previously unknown dietary and physiological information. Here we present a survey of the variability of δ88Sr values, along with the 87Sr/86Sr ratios, in fourteen reference materials of geological and biological origin using MC-ICPMS. The measurements employ a simple sample-standard bracketing method and zirconium external correction. Comparisons with double-spiked δ88Sr TIMS analyses show a very good agreement (0.014 ‰; n = 10). We then applied this method to explore the fractionation of the 88Sr/86Sr ratio in tooth enamel of mammals from two modern food-chains (Kruger National Park and Western Cape, South Africa), and from modern South African chacma baboon populations. Clear differences in the δ88Sr values are observed between plants and teeth of herbivores (~ −0.26 ‰; n = 5), but the distinction between herbivores and carnivores requires further investigation. Variations between tooth enamel of young and adult baboons suggests that the δ88Sr is a promising indicator of weaning behaviors. Our method implementation and preliminary results highlight the importance of coupled radiogenic and stable Sr isotope determination in extant and extinct vertebrates.

Subnanomolar Sensitive Stable Isotopic Determination in CO2 by Tunable Infrared Laser Absorption Spectroscopy.

Oxygen and carbon stable isotope ratios (18O/16O, 13C/12C, and 17O/16O) of CO2 have been crucial in helping us understand Earth and planetary systems. These ratios have also been used in medicine for the noninvasive diagnosis of diseases from exhaled breath and for quantifying biochemical or metabolic reactions and in determining the production area of agricultural products. The current method for measuring the stable isotope ratios of CO2 is primarily gas-source isotope ratio mass spectroscopy (IRMS). Due to the recent demand for isotopic microanalysis of carbonates and organic compounds, the sample size required for isotopic measurements has been reduced to approximately 2 nmol CO2 (equivalent to 0.2 μg CaCO3 and 24 ng carbon) by using high-precision IRMS. We report a novel method using tunable mid-infrared laser direct absorption spectroscopy (TILDAS) for sensitive measurements of 18O/16O and 13C/12C in subnanomolar CO2. This method can accurately measure 18O/16O and 13C/12C in CO2 with a repeatability of less than 0.03‰ (n = 28) in a range of 0.3 nmol (equivalent to 0.03 μg CaCO3 and 3.8 ng carbon) to 30 nmol. This is a sample size 1 order of magnitude smaller than currently available sensitive analytical techniques. In addition, the TILDAS system measures 17O/16O simultaneously with a repeatability of less than 0.06‰ (n = 28). Our method is a major advance in supersensitive CO2 stable isotopic analyses for various fields.

Determination of Stable Chlorine Isotopes by Isotopic Preparative Chromatography (IPC) with Positive–Thermal Ionization Mass Spectrometry (P-TIMS)

A novel approach to chlorine isotope analysis is presented to overcome many drawbacks of existing methods. Contemporary methods often require several laborious off-line procedures prior to instrumental determination; interfering ions (SO4 2- and NO3 -) in real samples are difficult to completely remove, especially when the concentrations of those ions are equal to that of the Cl- ion. This study was aimed to develop an automatic sample preparation method with chromatographic purity for determination of chlorine isotopes using isotopic preparative chromatography (IPC), which was a modified ion chromatograph and a fraction collector. An AS19 chromatographic column was employed to separate chlorine from interference ions using an eluent, flow rate, and suppressor current of 30 mM NaOH, 1 mL/min, and 70 mA, respectively. After the original solutions introduced into the IPC, eluted pure chlorine in the form of HCl was collected in an automated procedure from the outlet of the detector for 6 to 10 mins. The recoveries of chlorine were more than 95% with the relative standard deviation (RSD) of the separation less than 1.8%. After transforming the HCl into CsCl with a resin and concentration in a super-clean laboratory, the samples were sent to the thermal ionization mass spectrometer. The present method was validated by certified reference materials and real samples. The precision of 37Cl/35Cl ratio value was generally below 0.20 ‰. This method provides a potential approach for the analysis of samples with low chlorine concentrations.

Olive Oil Traceability Studies Using Inorganic and Isotopic Signatures: A Review.

The olive oil industry is subject to significant fraudulent practices that can lead to serious economic implications and even affect consumer health. Therefore, many analytical strategies have been developed for olive oil’s geographic authentication, including multi-elemental and isotopic analyses. In the first part of this review, the range of multi-elemental concentrations recorded in olive oil from the main olive oil-producing countries is discussed. The compiled data from the literature indicates that the concentrations of elements are in comparable ranges overall. They can be classified into three categories, with (1) Rb and Pb well below 1 µg kg−1; (2) elements such as As, B, Mn, Ni, and Sr ranging on average between 10 and 100 µg kg−1; and (3) elements including Cr, Fe, and Ca ranging between 100 to 10,000 µg kg−1. Various sample preparations, detection techniques, and statistical data treatments were reviewed and discussed. Results obtained through the selected analytical approaches have demonstrated a strong correlation between the multi-elemental composition of the oil and that of the soil in which the plant grew. The review next focused on the limits of olive oil authentication using the multi-elemental composition method. Finally, different methods based on isotopic signatures were compiled and critically assessed. Stable isotopes of light elements have provided acceptable segregation of oils from different origins for years already. More recently, the determination of stable isotopes of strontium has proven to be a reliable tool in determining the geographical origin of food products. The ratio 87Sr/86Sr is stable over time and directly related to soil geology; it merits further study and is likely to become part of the standard tool kit for olive oil origin determination, along with a combination of different isotopic approaches and multi-elemental composition.

New method for simultaneous determination of dissolved organic carbon and its stable carbon isotope ratio in liquid samples: environmental applications

ABSTRACT This study reports the development of an all-in-one elemental analyser isotope ratio mass spectrometry (EA-IRMS) system modified for simultaneous analysis of dissolved organic carbon (DOC) concentration and its stable carbon isotope footprint (δ 13CDOC) in aqueous samples. The method involves a quantitative oxidation of DOC in a 200 µL liquid sample to CO2, after sample acidification and stripping by nitrogen. The detection limit of the method for DOC quantification was 0.2 mg C/L with an analytical precision of 12 %. Uncertainty of stable isotope determinations was 2 % at 0.2 mg DOC/L, while decreasing to 0.3 % at 20 mg DOC/L. Quantitative oxidation of DOC in aqueous samples was validated by using ring test water samples and Deep Sea reference seawater. The method performances of isotope analysis were evaluated by analysing different isotopic standard solutions. The applicability of the method was tested through the analysis of different environmental types of water, showing that δ 13CDOC ranged from – 23.30 to –31.85 ‰, allowing to characterize samples of different environmental origin. The developed method offers several advantages including rapidity, use of small sample volumes and minimal sample pre-treatment, making it a valuable tool for routine DOC concentration measurements paired with isotopic characterization.

Role of rock glaciers and other high-altitude depositional units in the hydrology of the mountain watersheds of the Northern Patagonian Andes

Mountain depositional landforms are important units for freshwater supply in regions with water deficits and significant droughts during the summer season. In the Northern Patagonian Andes, the cold climatic events during the Pleistocene period left a large number of glacial and periglacial depositional landforms, among which a glacial cirque called La Hoya stands out. An analysis of geomorphological landforms, climatic data, soil temperature, flows in springs and streams, electrical conductivity measurements, and stable isotope determination of water, were made to study the hydrological role of these depositional mountain landforms. In this region, precipitations are concentrate during the winter season when an important snow cover accumulates and persists until spring. During winter and spring seasons, part of the snowmelt infiltrates, being kept in solid states inside the depositional landforms, and part of it contributes to the runoff between winter and summer. At the ends of spring and early summer, the snowmelt is the main water contribution to the La Hoya watershed. During late summer and autumn, the most important water contribution is from groundwater discharge. Where glacial ice is absent and the presence of permafrost is limited or non-existent, morphosedimentary units are important landforms for water storage and streams sustenance. This is the case of the city of Esquel, which depends exclusively on the “Los Bandidos” stream for water supply, which is sustained throughout the year by these landforms. The increase in temperature and the decrease in precipitation in this region highlights the importance of the high-altitude depositional landforms for the capture, storage, and distribution of water resources in the Northern Patagonian Andes.

UHAS-MIDA Software Package: Mass Isotopomer Distribution Analysis-Applying the Inverse Matrix for the Determination of Stable Isotopes of Chromium Distribution during Red Blood Cell Labelling

Clinical assessment of fluid volume status in children during malaria can be taxing and often inaccurate. During malaria, changes in fluid volume are rather multifarious and estimating this parameter, especially in sick children is very challenging for clinicians who frequently rely on indices such as long capillary refill times, tachycardia, central venous pressure and decreased urine volume as guides. Here, we present the UHAS-MIDA, an open-source software tool that calculates the red blood cell (RBC) concentration and blood volume during malaria in children determined using a stable isotope of chromium (53Cr as the label) by gas chromatography-mass spectrometry in selective ion monitoring (GC/MS-SIM) analysis. A key component involves the determination of the compositions of the most abundant naturally occurring isotopes of Cr (50Cr, 52Cr, 53Cr), and converting the proportions into a 3 × 3 matrix. To estimate unknown proportions of chromium isotopic mixtures from the measured abundances of three ions, an inverse matrix was calculated. The inverse together with several inputs is then used to calculate the corrected MS ion abundances. Thus, we constructed the software tool UHAS- MIDA using HTML, CSS/Bootstrap, JavaScript, and PHP scripting languages. The tool enables the user to efficiently determine RBC concentration and fluid volume. The source code, binary packages and associated materials for UHAS-MIDA are freely available at https://github.com/bentil078/Abaye-et-al_UHASmida

Diagenesis and the Conditions of Deposition of the Middle Jurassic Siderite Rocks from the Northern Margin of the Holy Cross Mountains (Poland)

The aim of the present study is to reconstruct sedimentary conditions of Middle Jurassic rocks that contain siderites to identify the mineral composition of the inserbeds and to recognize the origin of the siderite. Thin inserbeds of siderite rocks occur most frequently within Bajocian siliciclastic deposits and, more rarely, Aalenian and Bathonian. The research material comes from 11 boreholes located in the north and northeastern margins of the Holy Cross Mountains. The research methods included sedimentological analyses, and studies in polarizing and scanning electron microscopes, staining of carbonates, cathodoluminescence, X-ray structural analysis, and stable carbon and oxygen isotopic determinations were used. Middle Jurassic sideritic rocks are most often represented by clayey siderites, which also include muddy and sandy varieties and siderite sandstones. There are also local occurrences of coquinas, claystones, mudstones, and siderite conglomerates. The main component of sideritic rocks is sideroplesite. Berthierine, pistomesite, calcite, and ankerite are important components, too. The action of diagenetic processes of cementation, compaction, replacement, and alteration within the Middle Jurassic deposits was most intense during the eo- and mesodiagenesis. The sedimentological analysis showed that most of the studied siderites were formed in a low-oxygenated marine environment, mainly in the transition zone between the normal and storm wave bases and in the lower and middle shoreface zones. The results of the petrographic, mineralogical, and geochemical studies indicated the origin of the sideritic rocks mainly in the marine environment, with the participation of meteoric water. There were slight differences in the chemical composition of sideroplesite depending on the environment it crystallized in. There was no correlation between the values of the carbon isotope determinations in the sideroplesite and the environmental conditions of its crystallization. Slight differences were visible in the case of the average values of δ18O in the sideroplesite.

Measurement and Traceability Issues in Isotope Amount Ratio Determination of Stable Isotopes

Measurement and Traceability Issues in Isotope Amount Ratio Determination of Stable Isotopes

GESTIÓN DE LA PROCEDENCIA Y LA TRAZABILIDAD DE PRODUCTOS ORGÁNICOS DE EXPORTACIÓN EN PERÚ

The objective of the study was to explain through a model, the influence of chemical compounds in determining the origin and traceability of organic export products, to generate confidence and security in the choice of organic food in consumers, tracing it as purpose the determination of stable isotopes to know the origin and traceability of organic export products, in order to generate confidence and security in the choice of food in consumers. The research methodology was quasi-experimental - descriptive - correlational – explanatory, in addition, data from experiments carried out were used, where the surveys and questionnaires applied in the interview have provided the information that was processed through SPSS program and LISREL for factor analysis. It has been proven that in the studied model the influencing factors originality, traceability and the composition of the food

Doubly substituted isotopologues of methane hydrate (13CH3D and 12CH2D2): Implications for methane clumped isotope effects, source apportionments and global hydrate reservoirs

Recently developed methane clumped isotope techniques provides fresh and novel insights into methane biogeochemistry, which have been unobtainable through other techniques such as conventional stable isotope determinations and molecular composition measurements of hydrocarbons. Nonetheless, the governing processes and mechanisms which control the clumped isotope signatures (Δ13CH3D and Δ12CH2D2) of natural methane samples remain an active area of investigation. Here, we present paired clumped isotope measurements in methane hydrate, which is a major methane reservoir widely distributed along the continental margins and which plays an important role in the global carbon cycle and climate system. Our study aims to shed new light into the fundamental processes of methane clumped isotope effects and their potential to answer fundamental questions regarding the source and migration of methane found in naturally occurring gas hydrate accumulations.Gas hydrate samples were recovered from five shallow marine sediment sites on the eastern margin of the Japan Sea and most of them present Δ13CH3D and Δ12CH2D2 temperatures ranging from ∼15 to ∼170 °C that apparently match expected methane formation temperatures. The distribution of these clumped isotope signatures along the equilibrium line is best explained by the mixing effect of equilibrated thermogenic methane formed at temperatures of 165 ± 15 °C and biogenic methane equilibrated at 1–2 °C, which may result from slow methanogenesis, anaerobic oxidation of methane (AOM), or their combination. The influences of gas migration/diffusion, hydrate formation and dissociation on Δ13CH3D and Δ12CH2D2 values are insignificant. By combining clumped isotope results with other traditional approaches, a thermogenic and two microbial end-members as well as their isotopic compositions were identified and the relative contribution of each end-member was also quantified. The results not only demonstrate the applicability of methane clumped isotope data to identify potential end-members in natural methane samples, but also reveal that more conventional carbon isotope approaches may significantly underestimate the fraction of thermogenic methane present in global gas hydrate reservoirs. Improvements in the accuracy of source apportionment enable us to better understand the formation history and mechanisms of gas hydrate accumulation, as well as the role played by gas hydrate dissociation in past geological events. The estimated formation temperatures of thermogenic end-member can be further applied in reconstruction of the paleo geothermal gradient at the time when the thermogenic methane was formed at marine sedimentary environment.

What’s in a wine? – A spot check of the integrity of European wine sold in China based on anthocyanin composition, stable isotope and glycerol impurity analysis

ABSTRACT The international wine market has been repeatedly hit by cases of fraud in recent decades. While several studies attested a special vulnerability of the fast growing wine business in China, reports on chemical analyses of commercial wine samples are rare. We examined 50 predominantly red wines with European labelling, which were purchased on the Chinese market, for fraud-relevant parameters. More than 20% of the tested samples revealed anomalies in relation to the stable isotope ratios of D/H, 18O/16O and 13C/12C, contents of technical glycerol by-products or anthocyanin composition. These results strongly suggested watering of the wines, chaptalisation, glycerol addition or the use of non-Vitis anthocyanin sources, respectively. Some of these samples also showed suspicious spelling errors or other irregularities in the labelling, but the majority appeared genuine to the eye. Hence, this spot check demonstrates the importance of chemical authenticity analysis of market samples in order to detect fraudulent products. Moreover, we used the same sample set for an evaluation of the Chinese standard method for carbon stable isotope determination of wine ethanol in comparison to the current OIV (International Organisation of Vine and Wine) standard method. The results of a Bland-Altman analysis indicated that the methods can be applied interchangeably. As the two methods differ in their workflow and in the requested equipment, this might eventually enable more laboratories to perform 13C/12C analysis of wine and spirits.

Speciated Collection of Nitric Acid and Fine Particulate Nitrate for Nitrogen and Oxygen Stable Isotope Determination.

Stable isotopic composition of atmospheric nitrate (nitric acid (HNO3) + particulate nitrate (pNO3-)) provides a higher-order dimensional analysis of critical atmospheric components, enabling a process-level understanding of precursor emissions, oxidation chemistry, aerosol acidity, and depositional patterns. Current methods have not been evaluated for their ability to accurately speciate and determine nitrogen (δ15N) and oxygen (δ18O and Δ17O) isotope compositions for gaseous and particle phases. Suitability of a denuder-filter sampling system for the collection of speciated HNO3(g) and pNO3- for off-line concentration and isotopic determination was tested using both laboratory and field collections. Honeycomb denuders coated with either NaCl or Na2CO3 solutions were used to collect HNO3(g). Laboratory experiments found that both coating solutions quantitatively collected HNO3(g), with the Na2CO3 solution demonstrating a higher operative capacity (>1470 μg of HNO3; n = 25) compared to the NaCl solution (∼750 μg of HNO3; n = 25). The precision values for laboratory-tested HNO3(g) collections are ±0.6‰ and ±1.2‰ for δ15N and δ18O for the NaCl solution and ± 0.8‰ and ±1.2‰ for the Na2CO3 solution. Replicate (urban) samples indicate that the Na2CO3 solution is significantly less selective for HNO3(g) collection than the NaCl solution. Nylon filters were found to collect efficiently and retain laboratory-generated NaNO3 and NH4NO3 particles, with maximum standard deviations for δ15N and δ18O of ±0.3‰ and ±0.3‰, respectively. Field replicates, while predictably more variable, also show consistency for δ15N and δ18O of ±0.6‰ and ±1.3‰ for particulate species, respectively. Recommended methods for field collections of speciated HNO3(g) and pNO3- for isotopic measurements would best utilize the NaCl solution and Nylon filters.

The agroecology of an early state: new results from Hattusha

The discovery of a large underground silo complex with spectacular intact grain stores at the Late Bronze Age Hittite capital of Hattusha in Turkey provides a unique snapshot of the mobilisation of crop production by the Hittite state. A combination of primary archaeobotanical analysis, crop stable isotope determinations and functional weed ecology reveals new insights into Hittite cultivation strategies, featuring a range of relatively low-input, extensive production regimes for hulled wheats and hulled barley. Taxation of extensively produced grain in the sixteenth century BC reveals how an ancient state sought to sustain itself, providing wider implications for the politics and ecology of territorially expansive states in Western Asia and beyond.