Isotope Ratio Analysis Research Articles

Analysis of Isotopic Abundance Ratio of Consciousness Energy Healing Treated Metronidazole Using LC-MS and GC-MS Spectrometry

Metronidazole is an antibiotic and useful for the antibacterial and antiprotozoal medication. This study was performed to investigate the impact of the Trivedi Effect®-Biofield Energy Healing Treatment on the structural properties and the isotopic abundance ratio of metronidazole using LC-MS and GC-MS spectroscopy. Metronidazole sample was divided into two parts, one part of metronidazole was considered as control (no Biofield Energy Treatment was provided), while the second part was treated with the Trivedi Effect®-Consciousness Energy Healing Treatment remotely by a renowned Biofield Energy Healer, Alice Branton and termed as a treated sample. The LC-MS spectra of both the samples of metronidazole at the retention time (Rt) 2.61 minutes exhibited the mass of the protonated molecular ion peak at m/z 172 M+H+ (calculated for C6H10N3O3+, 172.07). The LC-MS based isotopic abundance ratio of PM+1/PM (2H/1H or 13C/12C or 15N/214N or 17O/16O) in the treated metronidazole was significantly increased by 8.24% compared with the control sample. Thus,13C, 2H, 15N,and17O contributions from (C6H10N3O3)+ to m/z 173 in the treated sample were significantly increased compared with the control sample. The GC-MS based isotopic abundance ratio of PM+1/PM in the treated metronidazole was significantly increased by 5.92% compared with the control sample. Hence,13C, 2H, 15N, and217O contributions from (C6H9N3O3)+ to m/z 172 in the Biofield Energy Treated sample were significantly increased compared with the control sample. However, the isotopic abundance ratio of PM+2/PM in the treated metronidazole was significantly decreased by 18.2% compared with the control sample. Hence,18O contributions from (C6H9N3O3)+ to m/z 173 in the treated sample were significantly decreased compared with the control sample. The isotopic abundance ratio of PM+1/PM (2H/1H or 13C/12C or 15N/14N or 17O/16O) and PM+2/PM (18O/16O) in the treated metronidazole was significantly altered compared to the control sample. From the results, it can be hypothesized that the changes in isotopic abundance and mass peak intensities could be due to changes in nuclei possibly through the interference of neutrino particles via the Trivedi Effect® - Consciousness Energy Healing Treatment. The new form of treated metronidazole would be better designing novel pharmaceutical formulations that might offer better therapeutic response against bacterial and protozoal infection in the vagina (bacterial vaginosis), stomach (giardiasis, trichomoniasis, pseudomembranous colitis), joints (pelvic inflammatory disease), liver, skin, brain, and respiratory tract, aspiration pneumonia, rosacea, intra-abdominal infections, lung abscess, fungating wounds, periodontitis, amoebiasis, oral infections, etc.

Simultaneous Analysis of the Stable Carbon Isotope Ratios of Acetoin and Acetic Acid by GC-C-IRMS for Adulteration Detection in Brewed Rice Vinegar Products.

In this study, we developed a method to simultaneously measure the stable carbon isotope ratio for acetic acid (δ 13Caceticacid) and acetoin (δ13Cacetoin) in rice vinegar by gas chromatography-combustion-isotope ratio mass spectrometry. The method showed good precision and accuracy. With this method, data from 16 brewed rice vinegars and 10 acetic acid samples were used to evaluate the feasibility of adulteration detection. On the basis that all δ13Cacetoin values of brewed rice vinegars are nearly constant, a characteristic pattern of the stable carbon isotope in rice vinegar was built with the 95% confidence intervals for δ13Caceticacid (-26.97 to -25.38‰), δ13Cacetoin (-28.14 to -27.09‰), and Δδ13C (0.61 to 2.27‰). An adulteration detection curve of Δδ13C was proposed based on the results of vinegar and acetic acid samples and confirmed by vinegar spiked with different amounts of acetic acid. This method could be useful in estimating the blending ratio of adulterated rice vinegar products. Products containing more than 10% of synthetic acetic acid could be possibly identified.

A bio‐available strontium isoscape for eastern Beringia: a tool for tracking landscape use of Pleistocene megafauna

ABSTRACTNumerous paleoecological questions concern the mobility of ancient fauna in eastern Beringia. Strontium (Sr) isotope ratio (87Sr/86Sr) analysis has emerged as a powerful tracer for determining the provenance of ancient biological materials. However, it is important to characterize 87Sr/86Sr variation across a landscape. We measured the 87Sr/86Sr composition of teeth from present‐day, herbivorous rodents (n = 162) sampled from across eastern Beringia to estimate bio‐available 87Sr/86Sr values. We compiled these data with the very limited number of previously published 87Sr/86Sr values from the region. We then used this dataset and a machine learning, random‐forest regression to predict bio‐available 87Sr/86Sr variations across eastern Beringia. As a case study using our new 87Sr/86Sr map (isoscape), we measured the 87Sr/86Sr and oxygen stable isotope values (δ18O) of five radiocarbon‐dated steppe bison from eastern Beringia and compared these to our 87Sr/86Sr isoscape and a δ18O isoscape to estimate the probable landscape use of these ancient fauna. Our model and isoscape provide important foundations for a wide range of additional applications, including studies of the paleo‐mobility of other fauna, ancient people and present‐day fauna in eastern Beringia.

Stable isotope fractionation of cadmium in the soil-rice-human continuum

Consumption of rice (Oryza sativa) grain is a major pathway by which humans are exposed to Cd, especially in non-smoking Asian populations. Although the stable isotope signatures of Cd offer a potential tool for tracing its sources, little is known about the isotopic fractionation of Cd across the entire soil-rice-human continuum. Cadmium isotope ratios were determined in field soils, rice grain, and human urine collected from two Cd-contaminated regions in southern China. Additionally, Cd isotopic fractionation in rice plants was investigated using two transgenic plants differing in Cd uptake and accumulation. Analysis of isotope ratios revealed a preferential enrichment of the heavy Cd isotopes from soil to rice grain (δ114/110Cdgrain-soil = +0.40‰) and from grain to urine (δ114/110Cdurine-grain = +0.40‰) in both regions. The first increase was mainly caused by partitioning between the soil solid phase and the soil solution, with heavier Cd preferentially enriching in the soil solution. Within the rice plant, we identified multiple processes that alter the isotope ratio, but the net effect throughout the plant was comparatively small. Cd fractionation in humans is presumably due to the preferential enrichment of heavier Cd isotopes by metal transporters DMT1 and ZIP8 (responsible for the absorption of Cd into body from the foods). These findings provide important insights into the Cd isotopic fractionation through the soil-rice-human continuum and are helpful for tracing the sources of Cd.

Cadmium transfer in contaminated soil-rice systems: Insights from solid-state speciation analysis and stable isotope fractionation.

Initial Cadmium (Cd) isotope fractionation studies in cereals ascribed the retention of Cd and its light isotopes to the binding of Cd to sulfur (S). To better understand the relation of Cd binding to S and Cd isotope fractionation in soils and plants, we combined isotope and XAS speciation analyses in soil-rice systems that were rich in Cd and S. The systems included distinct water management (flooded vs. non-flooded) and rice accessions with (excluder) and without (non-excluder) functional membrane transporter OsHMA3 that transports Cd into root vacuoles. Initially, 13% of Cd in the soil was bound to S. Through soil flooding, the proportion of Cd bound to S increased to 100%. Soil flooding enriched the rice plants towards heavy isotopes (δ114/110Cd=-0.37 to-0.39%) compared to the plants that grew on non-flooded soils (δ114/110Cd=-0.45 to-0.56%) suggesting that preferentially light Cd isotopes precipitated into Cd sulfides. Isotope compositions in CaCl2 root extracts indicated that the root surface contributed to the isotope shift between soil and plant during soil flooding. In rice roots, Cd was fully bound to S in all treatments. The roots in the excluder rice strongly retained Cd and its lights isotopes while heavy isotopes were transported to the shoots (Δ114/110Cdshoot-root 0.16-0.19‰). The non-excluder rice accumulated Cd in shoots and the apparent difference in isotope composition between roots and shoots was smaller than that of the excluder rice (Δ114/110Cdshoot-root-0.02 to 0.08‰). We ascribe the retention of light Cd isotopes in the roots of the excluder rice to the membrane transport of Cd by OsHMA3 and/or chelating Cd-S complexes in the vacuole. Cd-S was the major binding form in flooded soils and rice roots and partly contributed to the immobilization of Cd and its light isotopes in soil-rice systems.

The Use of Stable Isotope Ratio Analysis to Trace European Sea Bass (D. labrax) Originating from Different Farming Systems.

Simple SummaryEuropean sea bass is one of the most economically important fish species in the Mediterranean area. The potential effects of farming systems on the final quality of this product and the recent popular demand for labels to certify the animal rearing origin, which is increasingly used as a marketing tool, have raised the use of analytical techniques that make it possible to differentiate this fish product according to the rearing farming system and authenticate their geographical origin. The aim of this study was to determine whether isotopic ratio mass spectrometry (IRMS) can discriminate farmed European sea bass according to different farming systems (concrete tank inland, sea cages, and extensive methods in valleys or salt works) and geographic origins (different locations scattered throughout Italy). The results of this study showed the viability of δ13C and δ15N to discriminate cultured sea bass from different farming systems (extensive vs. intensive) reared at different geographical sites in Italy. Meanwhile, the measurement of δ18O and δ2H made it possible to distinguish the geographical origin of the sea bass farmed extensively and intensively (in cages).This study aimed to determine whether isotopic ratio mass spectrometry (IRMS) can discriminate farmed European sea bass according to different farming systems and geographic origins. Dicentrarchus labrax of commercial size from three different rearing systems (concrete tank inland, sea cages, and extensive methods in valleys or salt works) were collected at the trading period (autumn–winter). For each farming type, different locations spread over Italy were monitored. Once the fish were harvested, the muscle and feed were sampled. For both muscle and feed, δ13C and δ15N were measured by continuous flow elemental analyzer isotope ratio mass spectrometry (CF-EA-IRMS) with the goal of discriminating samples based on the rearing system. Additional δ2H and δ18O measurements of fish samples were performed by continuous flow total combustion elemental analyzer isotope ratio mass spectrometry (CF-TC/EA-IRMS) to track the geographical origin. The measurements of δ13C and δ15N made it possible to discriminate cultured sea bass from different farming systems (extensive vs. intensive) reared at different geographical sites in Italy. Additional information was obtained from δ18O and δ2H, which enabled the geographical areas of origin of the sea bass farmed extensively and intensively (in cages) to be distinguished.

Natural abundance carbon isotope ratio analysis and its application in the study of diet and metabolism.

Due to differences in carbon assimilation pathways between plants, there are subtle but distinct variations in the carbon isotope ratios of foods and animal products throughout the food supply. Although it is well understood that the carbon isotope ratio composition of the diet influences that of the consumers' tissues, the application of natural abundance carbon isotope ratio analysis in nutrition has long been underappreciated. Over the past decade, however, several studies have investigated the utility of carbon isotope ratio analysis for evaluation of nutritional biomarker status, primarily focusing on its application as an objective indicator of sugar and animal protein intake. More recently, research investigating the application of natural abundance measurements has been extended to study fatty acid metabolism and has yielded encouraging results. Collectively, data from large-scale observational studies and experimental animal studies highlight the potential for carbon isotope ratio analysis as an additional and effective tool to study diet and metabolism. The purpose of this review is to provide an overview of natural abundance carbon isotope ratio analysis, its application to studying nutrition, and an update of the research in the field.

Stratospheric Incursion as a Source of Enhancement of the Isotopic Ratios of Atmospheric N2O at Western Pacific

AbstractWe present analyses of nitrogen and oxygen isotopic ratios and site‐preference (SP) values of atmospheric nitrous oxide samples obtained from Taiwan in west Pacific. Air samples were collected during September 2013 to January 2016 from Taipei and during November 2011 to December 2014 from Keelung, located in the northeastern coast of Taiwan. The average values of δ15N, δ18O, and SP are 6.4 ± 0.3 ‰, 44.0 ± 0.4 ‰, and 17.1 ± 1.0 ‰, respectively, at Taipei and 6.4 ± 0.2 ‰, 44.6 ± 0.4 ‰, and 17.9 ± 1.3 ‰, for δ15N, δ18O, and SP respectively, at Keelung, comparable to the average values (6.6 ± 0.2, 44.2 ± 0.2, and 18.1 ± 0.5 ‰, scaled to year 2014) from Hateruma, an open ocean station in western Pacific. Strong temporal variations in the delta values, however, are seen. During a subtropical jet‐strengthening period in October to mid‐December 2014, the δ15N, δ18O and SP values increased at the rate of 0.006 ± 0.002 ‰/day, 0.010 ± 0.002 ‰/day and 0.008 ± 0.002 ‰/day, respectively at Taipei and 0.013 ± 0.005 ‰/day, 0.011 ± 0.005 ‰/day and 0.011 ± 0.027 ‰/day at Keelung. This suggests intrusion of air to the lower troposphere from the stratosphere where δ15N, δ18O and SP values are higher. This is consistent with earlier observations of oxygen isotope anomaly in atmospheric CO2 and elevated 35S in sulfate aerosols, indicating frequent stratospheric intrusions in this region. The observed δ15N and δ18O values, along with the oxygen isotope anomaly in CO2 and multiple sulfur isotopes in sulfate, can be used to constrain local emissions from the surface, improving our knowledge of anthropogenic contribution to the global budget of N2O.

Laboratory-based validation of a passive sampler for determination of the nitrogen stable isotope ratio of ammonia gas

Nitrogen stable isotope ratio (δ15N) analysis of ammonia gas (NH3) by using a passive sampler is expected to be useful for determining sources of NH3 and for examining environmental dynamics. However, the use of passive samplers for determining the δ15N values of NH3 obtained has not been well validated in laboratory. Here, we evaluated the reliability of the passive sampler under various simulated environmental conditions in the chamber. When the amount of NH3 collected by the sampler was <70 μg, the δ15N value obtained was approximately 10–15‰ lighter than the δ15N value of a reference NH3 gas value regardless of type of passive sampler, the temperature, or sampling chamber size. Thus, when using a passive sampler to collect NH3, if the amount of NH3 collected is < 70 μg, it is necessary to add approximately 10–15‰ to the measured value. This finding will enable determination of more accurate δ15N values, which will be meaningful for future air research.

The identification of selenopolythionates in aqueous solutions by electrospray ionization-Fourier transform-ion cyclotron resonance-mass spectrometry

Selenosulfate (SeSO32−) has been shown to occur in certain industrial process waters, and selenopolythionates (SenSxO62−) can be suspected to form from SeSO32− via oxidative or addition reactions. We report here the first observation of selenopolythionates in waters by mass spectrometry. The high mass accuracy and ultra-high resolution of Fourier transform-ion cyclotron resonance-mass Spectrometry with electrospray ionization (ESI-FT-ICR-MS) were used to analyze the isotope patterns of selenium (Se), sulfur (S), and oxygen (O) satellites, in order to provide unequivocal determination of the molecular sum formula of three different selenopolythionates. An aged aqueous solution of SeSO32− was shown to contain the sodium adducts of selenotrithionate (NaSeS2O6−), diselenotetrathionate (NaSe2S2O6−), and triselenopentathionate (NaSe3S2O6−). The identity of these ions was confirmed by accurate mass determination (Δ m/z < 3 ppm error) and by isotopic intensity ratio analysis of the [MIS+2] satellites. Furthermore, Collision Induced Dissociation (CID) was applied to selenotrithionate to distinguish between isomers, and the fragmentation mass spectrum reveals that the Se atom in NaSeS2O6− is located in the middle of the chalcogen chain. Ion chromatographic analysis of the analyzed selenosulfate solutions indicates that selenopolythionates are not suitable for determination by common separations employed for Se speciation analysis, which emphasizes the value of ESI-FT-ICR-MS for complete qualitative characterization of trace element speciation in solution.

Effects of Aphid Density and Plant Taxa on Predatory Ladybeetle Abundance at Field and Landscape Scales.

Simple SummaryIn agroecosystems, predatory ladybeetles play an important role in suppressing aphid populations. How ladybeetles make use of host plant diversity in multicropping landscapes has rarely been documented in China. In this study, we examined the relationship between aphid densities and ladybeetle densities at both the local field and landscape scales. Overall, we found that there was a positive correlation between aphid densities and ladybeetle densities. However, plant taxa had no significant influence on predatory ladybeetle abundance at the local field scale. In addition, the effect of aphids on ladybeetles abundance was influenced by the crop type and growing season at the regional landscape scale. There was a significant positive correlation between aphid and ladybeetle populations on cotton only in July and August, whereas the correlation was significant for maize throughout the whole growing season. The δ13C value indicated that most prey aphids for ladybeetles originated from crops where aphids are abundant (cotton in June and July; both maize and cotton in August). These findings improved our understanding of the migration and dispersal of ladybeetles among different habitats and plant species and provided insight into the promotion of regional conservation and pest control of natural enemies in Northern China.In agroecosystems, predatory ladybeetles play an important role in restraining aphid population growth and suppressing aphid populations. They can adapt to various habitats and make use of various aphid species associated with multiple host plants during their life cycle. Agricultural landscapes in China are composed of a mosaic of small fields with a diverse range of crops, and how ladybeetles make use of host plant diversity in such landscapes has rarely been documented. In this study, we examined the relationship between aphid densities and ladybeetle densities in two different settings: (i) on the majority of plant species (including crops, trees, and weeds) at a local field scale in 2013 and 2014, and (ii) in paired cotton and maize crop fields at a regional landscape scale in 2013. Overall, we found that aphid abundance determined predatory ladybeetle abundance at both the local field and landscape scales, and there was a positive correlation between aphid densities and ladybeetle densities. However, plant taxa had no significant influence on the predatory ladybeetle abundance at the local field scale. In addition, the effect of aphids on ladybeetles abundance was influenced by the crop type and growing season at the regional landscape scale. There was a significant positive correlation between aphids and ladybeetles populations on cotton only in July and August, whereas the correlation was significant for maize throughout the whole growing season. We also conducted an analysis of the stable carbon isotope ratios of the adult ladybeetles caught in cotton and maize fields (C3 and C4 crops, respectively) in a regional landscape-scale survey in 2013. The δ13Cvalue indicated that most prey aphids for ladybeetles originated from crops where aphids are abundant (cotton in June and July; both maize and cotton in August).These findings improved our understanding of the migration and dispersal of ladybeetles among different habitats and plant species and provided insight into the promotion of the regional conservation and pest control of natural enemies in northern China.

Simultaneous determination of stable chlorine and bromine isotopic ratios for bromochlorinated trihalomethanes using GC-qMS

Bromochlorinated compounds are organic contaminants originating from different natural and anthropic sources and increasingly found in different environmental compartments. This work presents an online approach for compound specific stable isotope analysis of chlorine and bromine isotope ratios for bromochlorinated trihalomethanes using gas chromatography coupled to quadrupole mass spectrometry (GC-qMS). An evaluation scheme was developed to simultaneously determine stable chlorine and bromine isotope ratios based on the mass spectral data of two target compounds: dibromochloromethane and dichlorobromomethane. The analytical technique was optimized by assessing the impact of different instrumental parameters, including dwell time, split ratios, and ionization energy. Successively, static headspace samples containing the two target compounds at aqueous concentrations ranging from 0.1 mg/L to 5 mg/L were analyzed in order to test the precision and reproducibility of the proposed approach. The results showed a good precision under the optimized instrumental conditions, with relative standard deviations ranging between 0.05% and 0.5% for chlorine and bromine isotope analysis. Finally, the method was tested in a source identification problem in which the simultaneous determination of chlorine and bromine stable isotope ratios allowed the clear distinction of dibromochloromethane from three different manufacturers.

Persistent pollutants in Northern Gannet Morus bassanus eggs in Ireland: Levels and colony differences.

Seabird eggs are considered a favourable matrix for monitoring marine pollutants and are widely used as higher trophic level indicators. Persistent organic pollutants such as polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other organochlorine compounds (OCs) as well as metals have been shown to have deleterious impacts on seabirds. The Northern Gannet Morus bassanus is an avian sentinel; the largest breeding seabird in Ireland and an obligate piscivore. Gannet eggs were collected from two island colonies off the east coast of Ireland in locations with divergent history of industrialisation. Contaminant levels were measured and differences in concentrations between colonies compared. Stable isotope ratios of carbon (δ13C) and nitrogen (δ15N) were measured in each egg to understand the influence of diet and trophic position on contaminant levels detected. Significantly higher levels of Σ14PCBs, Σ7PBDEs and total mercury were detected in Gannet eggs from Lambay Island near Dublin (Ireland's industrialised capital city) compared to Great Saltee Island. No differences were observed in levels of other OCs (HCB, ΣHCH, ΣCHL, ΣDDT) between the two colonies. Though Gannets travel significant distances when foraging for food, tracking studies have demonstrated that birds from proximal breeding colonies maintain exclusive feeding areas. Stable isotope ratio analysis in this study demonstrated that Gannets at both locations occupy similar dietary niches, indicating that dietary differences may not be the driver of differing contaminant levels between colonies. Levels of persistent pollutants in the Gannet eggs fall below most existing thresholds for adverse effects and are within internationally reported values. Recent population growth and range expansion of Gannets in Ireland suggest that persistent pollutants are not having an immediate impact on the Gannet population. This study will inform potential monitoring programmes that can help Ireland achieve good environmental status under the European Union's Marine Strategy Framework Directive.

The oxygen isotopic signature of soil- and plant-derived sulphate is controlled by fertilizer type and water source.

The oxygen isotope signature of sulphate (δ18 Osulphate ) is increasingly used to study nutritional fluxes and sulphur transformation processes in a variety of natural environments. However, mechanisms controlling the δ18 Osulphate signature in soil-plant systems are largely unknown. The objective of this study was to determine key factors, which affect δ18 Osulphate values in soil and plants. The impact of an 18 O-water isotopic gradient and different types of fertilizers was investigated in a soil incubation study and a radish (Raphanus sativus L.) greenhouse growth experiment. Water provided 31-64% of oxygen atoms in soil sulphate formed via mineralization of organic residues (green and chicken manures) while 49% of oxygen atoms were derived from water during oxidation of elemental sulphur. In contrast, δ18 Osulphate values of synthetic fertilizer were not affected by soil water. Correlations between soil and plant δ18 Osulphate values were controlled by water δ18 O values and fertilizer treatments. Additionally, plant δ34 S data showed that the sulphate isotopic composition of plants is a function of S assimilation. This study documents the potential of using compound-specific isotope ratio analysis for investigating and tracing fertilization strategies in agricultural and environmental studies.

Determination of Cu, Zn, Ga, Ag, Cd, In, Sn and Tl in Geological Reference Materials and Chondrites by Isotope Dilution ICP‐MS

Mass fractions of Cu, Zn, Ga, Ag, Cd, In, Sn and Tl were determined via isotope dilution quadrupole ICP‐MS in twenty‐one geological reference materials (RMs) and the carbonaceous chondrites Orgueil (CI1), Murchison (CM2) and Allende (CV3). The RMs comprise basaltic/mafic (BCR‐2, BE‐N, BHVO‐1, BHVO‐2, BIR‐1, BRP‐1, JB‐2, OKUM, W‐2, WS‐E), intermediate/felsic (AGV‐2, G‐2, JA‐2, RGM‐1), ultramafic (DTS‐2b, MUH‐1, PCC‐1, UB‐N) and sedimentary (MAG‐1, OU‐6) rocks. Pressure digestion was applied for nonbasaltic samples to ensure effective sample digestion. For basaltic RMs, hot plate digestion was found to be sufficient for a quantitative recovery of the target elements. To minimise interferences and increase ion beam intensities during isotope ratio analyses by ICP‐MS, separation of the target elements was carried out from single sample aliquots using a novel anion exchange procedure. The intermediate precision (2s) estimated from two to four replicate analyses was usually &lt; 4% and results are in agreement with literature data, where available. Especially for Ag and Tl, the intermediate precision was compromised, likely due to low ion beam intensities and, hence, higher background and blank contributions. For ultramafic RMs, nugget effects and incomplete digestion might compromise the intermediate precision. Results for the carbonaceous chondrites Orgueil (CI1), Murchison (CM2) and Allende (CV3) agree well with previously reported data.

Source apportionment of cadmium pollution in agricultural soil based on cadmium isotope ratio analysis

Anthropogenic activities, especially industrial production and agricultural practices have led to Cd accumulation in the agricultural soil locating near to the industrial areas of China threatening soil environmental quality and food security. In this study, the sources of Cd pollution were accurately analyzed, which may lead to efficiently control the Cd content in the soil. The samples of agricultural topsoil, four possible pollution sources such as smelter dust, automobile exhaust, cement factory dust and agricultural fertilizer were collected, and the Cd concentrations and Cd isotope ratios were analyzed using the instrument of Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Multi-collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS). The results indicated that the Cd concentration of agricultural topsoil (11.72 ± 0.30 mg kg−1) was much higher than the recommended value (0.6 mg kg−1). The highest δ114/110CdNIST3108 value (−0.15 ± 0.14‰) was observed for smelter dust and the lowest δ114/110CdNIST3108 value (−0.64‰) was found in cement factory dust. Similarly, the highest Cd concentration was found in smelter dust and it was clearly distinguishable from the other samples based on δ114/110CdNIST108 values. Cd isotope analysis suggested that smelter along with agricultural fertilizer were the major sources of Cd accumulation in agricultural topsoil. In addition, based on the IsoSource software, the relative Cd contribution rates due to automobile exhaust, cement factory, agricultural fertilizer, and smelter dust were 14%, 7%, 20%, and 59%, respectively, demonstrating that smelter dust is the main pollution source of Cd in the study area. Cd isotope analysis is a promising tool to accurately identify the heavy metal pollution sources.

Stable isotope profile (C, N, O, S) of Irish raw milk: Baseline data for authentication

Grass-based milk production is a major contributor to Irish agricultural output. The study characterized the Irish milk pool using stable isotope ratio analysis of carbon, nitrogen, oxygen and sulphur. Authentic raw milk samples were collected from 50 farms on five occasions over 13 months. Mean values of −27.11, 6.79, −3.27 and 6.16‰ were obtained for δ13C, δ15N, δ18O and δ34S, respectively. δ13C values reflected a high level of grass input and values increased with increasing cereal concentrate feed input (P < 0.001). δ18O values were most negative in spring. There was a significant interaction between feed and season for δ13C and δ15N values (P < 0.05), with the impact of concentrate feeding most evident in spring. δ34S values were lowest at the highest level of concentrate input (P < 0.05). The isotopic values reported here describe the Irish milk pool and may offer the potential to discriminate Irish milk and dairy products from similar commodities from other countries.

An isotope ratio mass spectrometry-based method for hydrogen isotopic analysis in sub-microliter volumes of water: Application for multi-isotope investigations of gases extracted from fluid inclusions.

The study of multi-isotope systematics of fluid inclusions is of great importance for understanding of the sources and evolution of fluid phases in mantle rocks and ore deposits. The most appropriate technique for such investigations is a (stepwise) crushing method that is widely used for noble gases and nitrogen. However, because of the possible influence of mechanochemical reactions and back sorption, analyses of the isotope composition of water extracted by crushing from fluid inclusions are challenging. An isotope ratio mass spectrometry (IRMS)-based method for hydrogen (and oxygen) isotopic analysis in sub-microliter volumes of water extracted from fluid inclusions by crushing is presented. The verification of the possible influence of adsorption processes and mechanochemical reactions on the results of isotope analysis was performed for the first time. For that a series of parallel analyses of hydrogen isotopic ratios from water inclusions in quartz applying physically different extraction methods (crushing and thermodecrepitation) was conducted. Four series of quartz aliquots were analyzed: three series extracting water by crushing (two series for δ2 H values and one for δ18 O values) and one by thermodecrepitation. The mean value for the crushing results is δ2 H = -85.3 ± 3.6 ‰ (1σ, n = 11), which coincides well with the thermodecrepitation data (-86.3 ± 2.0 ‰, 1σ, n = 5), suggesting that our methodological approach allows the influence of back sorption or mechanochemical reactions during the crushing experiment to be minimized. The reproducibility of the oxygen isotopic ratios is ±0.9 ‰ (1σ, n = 5). The conducted experiments have shown that the influence of back sorption or mechanochemical reactions during crushing on isotopic results is not crucial for our method. The developed IRMS-based method for hydrogen (and oxygen) isotopic analysis in sub-microliter volumes of water is well applicable for multi-isotope investigations of gases extracted from fluid inclusions. As an application a well-defined 40 Ar/36 Ar-δ2 H correlation in mantle rocks is presented for the first time.

A comparison of sulfur isotope measurements of geologic materials by inductively coupled plasma and gas source mass spectrometry

Sulfur isotope measurements by multi collector-inductively coupled plasma-mass spectrometry (MC-ICP-MS) require up to one hundred times less sulfur than traditional measurements via elemental analyzer isotope ratio mass spectrometry (EA-IRMS). Here, we report an improved MC-ICP-MS protocol for measuring δ34S values in different natural samples, specifically, calcium-sulfate minerals, carbonate associated sulfate, and dissolved sulfate in water. Sample preparation and subsequent anion exchange chromatography quantitatively recovers sulfur as sulfate. However, for samples with high and complex anion budgets, such as meteoric water, a stronger retention of sulfate on the anion exchange resin is observed relative to samples that contain sulfur as pure sulfate such as calcium-sulfate minerals and carbonate associated sulfate. An extended elution scheme with HNO3 is therefore required to achieve full recovery of sulfur, and thus accurate and reproducible δ34S values for the different materials investigated. Sulfur isotope measurements were performed on a Neptune Plus MC-ICP-MS coupled to an Apex-Ω desolvator, resulting in a “dry” plasma, negligible level of isobaric interferences, a sensitivity of >40 V ppm−1 sulfur, and a precision of 0.2‰ (2 S.D.) for δ34S for as little as 70 ng sulfur of a pure sulfate solution. The accuracy of the procedure was tested against duplicate δ34S EA-IRMS measurements for eleven different geologic samples. The EA-IRMS and MC-ICPMS values generally agree well within analytical uncertainty. However, procedural blank levels are on the order of a few tens of nanogram sulfur, and are thus the main limiting factor for accurate low-level sulfur isotope measurements with MC-ICP-MS.

Effects of soil moisture, needle age and leaf morphology on carbon and oxygen uptake, incorporation and allocation: a dual labeling approach with 13CO2 and H218O in foliage of a coniferous forest.

The carbon and oxygen isotopic composition of water and assimilates in plants reveals valuable information on plant responses to climatic conditions. Yet, the carbon and oxygen uptake, incorporation and allocation processes determining isotopic compositions are not fully understood. We carried out a dual-isotope labeling experiment at high humidity with 18O-enriched water (H218O) and 13C-enriched CO2 (13CO2) with attached Scots pine (Pinus sylvestris L.) branches and detached twigs of hemiparasitic mistletoes (Viscum album ssp. austriacum) in a naturally dry coniferous forest, where also a long-term irrigation takes place. After 4h of label exposure, we sampled previous- and recent-year leaves, twig phloem and twig xylem over 192h for the analysis of isotope ratios in water and assimilates. For both species, the uptake into leaf water and the incorporation of the 18O-label into leaf assimilates was not influenced by soil moisture, while the 13C-label incorporation into assimilates was significantly higher under irrigation compared with control dry conditions. Species-specific differences in leaf morphology or needle age did not affect 18O-label uptake into leaf water, but the incorporation of both tracers into assimilates was two times lower in mistletoe than in pine. The 18O-label allocation in water from pine needles to twig tissues was two times higher for phloem than for xylem under both soil moisture conditions. In contrast, the allocation of both tracers in pine assimilates were similar and not affected by soil moisture, twig tissue or needle age. Soil moisture effects on 13C-label but not on 18O-label incorporation into assimilates can be explained by the stomatal responses at high humidity, non-stomatal pathways for water and isotope exchange reactions. Our results suggest that non-photosynthetic 18O-incorporation processes may have masked prevalent photosynthetic processes. Thus, isotopic variation in leaf water could also be imprinted on assimilates when photosynthetic assimilation rates are low.