Backtracking the movements of a migratory bird: a case study of a white-fronted goose (Anser albifrons)

The occurrence of avian influenza has brought attention to migrating birds and their migratory routes as possible carriers and gates, respectively, of the pathogenic influenza virus. There is a need to verify migration routes and to back-track the migration routes of infected animals. Stable isotope analysis of bird feathers is a valuable tool for studying the migratory pattern of birds, by gaining information about the environmental conditions during the growth of the feathers. Ideally, if different feathers that have grown during different periods are investigated, not only can information about the molting region be extracted, but also some clues can be obtained about stop-overs during the migration of individual animals, enabling the reconstruction of the pathway. In the presented case study the hydrogen, carbon nitrogen and sulfur stable isotope ratios of different types of feathers (primaries, down feathers and blood pinfeathers) from one white-fronted goose specimen have been determined. These ratios differ significantly for some elements. By taking into account the different time of growth of the respective feathers, the isotope data can be interpreted with respect to the animal migration route from the summer (and molting) to the wintering region. This is the first paper to attempt to map the migration pathway using different types of feather from a single individual.     

Phosphate oxygen isotope analysis on microsamples of bioapatite: removal of organic contamination and minimization of sample size

Modern and fossil teeth record seasonal information on climate, diet, and migration through stable isotope compositions in enamel and dentine. Climatic signals such as seasonal variation in meteoric water isotopic composition can be recovered through a microscale histology-based sampling and isotopic analysis of enamel phosphate oxygen. The phosphate moiety in bioapatite is particularly resistant to post mortem diagenesis. In order to determine the phosphate oxygen isotope composition of enamel, phosphate must be chemically purified from other oxygen sources in the enamel lattice and matrix, mainly hydroxyl and carbonate ions, and trace quantities of organics.We present a wet chemical technique for purifying phosphate from microsampled enamel and dentine. This technique uses a sodium hypochlorite oxidation step to remove interferences from residual organic constituents of the enamel and/or dentine scaffold, isolates phosphate as relatively large and easily manipulated Ag(3)PO(4) crystals by using a strongly buffered, moderate-temperature microprecipitation, and preserves the oxygen isotope composition of the initial tooth phosphate. The reproducibility of phosphate oxygen isotope compositions thus determined (measured as delta(18)O, V-SMOW scale) is typically 0.2-0.3 per thousand (1 s.d.) on samples as small as 300 microg of enamel or dentine, a considerable improvement over available techniques for analyses of bioapatite phosphate oxygen.     

梅花鹿茸多肽的化学结构及生物活性

在马鹿茸活性多肽结构与功能研究基础上, 从新鲜梅花鹿茸中分离纯化了活性单体多肽, 确定了其化学结构, 并与马鹿茸多肽进行结构与活性比较. 利用离子交换层析、 凝胶过滤层析及反相高效液相色谱层析等生物化学技术, 从梅花鹿茸中分离得到1个新多肽, SDS-PAGE电泳显示为一条带, HPLC图谱为单一峰, MALDI-TOF MS给出该多肽的精确分子量为3263.4, 其等电点pI=8.15. 一级结构研究表明, 该多肽是由32个氨基酸残基组成的直链多肽, 不含半胱氨酸, 富含缬氨酸、 赖氨酸、 亮氨酸和甘氨酸, 氨基酸序列为VLSATDKTNVLAAWGKVGGNAPAFGAEALERM. 生物活性检测结果表明, 该多肽可促进原代培养的表皮细胞和软骨细胞增殖, 也能刺激NIH3T3成纤维细胞株的分裂. 梅花鹿茸多肽与马鹿茸多肽在结构上均为32个氨基酸残基组成的直链多肽, 但第5, 8, 11和30位氨基酸残基不同. 2种多肽结构上的变化并未影响其促细胞增殖生物活性.     

Oxygen isotope corrections for online delta(34)S analysis

Elemental analyzers have been successfully coupled to stable-isotope-ratio mass spectrometers for online measurements of the delta(34)S isotopic composition of plants, animals and soils. We found that the online technology for automated delta(34)S isotopic determinations did not yield reproducible oxygen isotopic compositions in the SO(2) produced, and as a result calculated delta(34)S values were often 1-3 per thousand too high versus their correct values, particularly for plant and animal samples with high C/S ratio. Here we provide empirical and analytical methods for correcting the S isotope values for oxygen isotope variations, and further detail a new SO(2)-SiO(2) buffering method that minimizes detrimental oxygen isotope variations in SO(2).     

Intracrystalline oxygen isotope effects in CuSO4·5H2O and their dependence on crystallization temperature

In copper sulfate pentahydrate the water molecules occupy three different sites, connected with different oxygen isotope ratios. Results of measurements of the change of these isotope ratios with crystallisation temperature are reported. The temperature dependence found here provides the basis for the determination of crystallisation temperatures of hydrated crystals from such intracrystalline oxygen isotope fractionation. Suppositions necessary for the application of this method are discussed.     

Comparison of Structure and Biological Activity of Natural Polypeptide from Velvet Antlers of Cervus elaphus with Those of Synthesized Polypeptide

Biochemical techniques including ion-exchange chromatography, gel filtration chromatography and reversed-phase high-performance liquid chromatography(RP-HPLC) were used to isolate and purify the natural polypeptide from velvet antler(nVAP) of Cervus elaphus(C. elaphus), which has a molecular weight of 3215.8 and the primary structure of VLSAADKSNVKAAWGKVGGNAPAFGAEALLRM. The homology of the protein sequence in nVAP with known protein sequence is less than 50%, suggesting that nVAP appears to be a new bioactive substance. At a level of 0.4―50 μg/mL, nVAP promotes mitosis in epidermal cells, chondrocytes and NIH3T3 fibroblasts primarily cultured in a significant way. Given that a yield of high-purity nVAP isolated from C. elaphus is 0.001%, nVAP is artificially synthesized to prepare synthetic velvet antler polypeptide(sVAP) according to its primary structure. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) of sVAP shows a single band, and its HPLC spectrum displays a single peak. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry(MALDI-TOF-MS) was used to identify sVAP to be of a molecular weight of 3200 and the consistency between primary structures of sVAP and nVAP. Bioactivity test shows that at a dose of 5―40 μg/mL, sVAP promotes the proliferation of primarily cultured epidermal cells and NIH3T3 cell line. From the traditional Chinese medicine theory, velvet antler from Cervus nippon(C. nippon) and velvet antler from C. elaphus are considered as the same medicine, but differences between biochemical base and pharmacological effect of these two velvet antlers have been observed. We compared the total polypeptide mapping of the two velvet antlers, discovering that nVAP is active polypeptide and only exists in the velvet antler of C. elaphus. sVAP is similar to nVAP in physicochemical property and biological activity. These studies extend the possible utility of sVAP to be the promising compound to prepare velvet antler polypeptide of C. elaphus.     

Herkunft und Authentizität von Lebensmitteln: Stabilisotopenanalytik

The correlations between isotope ratios in water, organic mass, and trace elements of food and beverages, and the circumstances and sites of their origin and production are outlined, and the methods of mass spectrometric isotope ratio determination and the positional ²H analysis by quantitative NMR measurement are explained. In context with the application of these methods for origin and authenticity investigations of food, examples are given for the proof of watering or sugar addition to wine and fruit juices and methods for the identification of nondeclared additions of L‐malic and Lascorbic acids are described. The possibilities of multielement isotope ratio analysis for the identification of origin of animal products (eggs, milk products, meat) and methods for the discriminations between natural and nature identical aroma compounds are outlined. Finally, the possibilities of isotope ratio measurements for the discrimination between plant and animal food from conventional and organic production are discussed.     

Isolation of strontium pools and isotope ratios in modern human hair

The elements of human hair record specific information about an individual's health, diet, and surrounding environment. Strontium isotope ratios of human hair have attracted interest as they potentially record an individual's environment. Yet, separating the external environmental signals from the internal dietary indicators has remained a challenge. Here, we examined the effects of five different hair-cleaning methodologies to determine the extent that internal and external strontium signals can be isolated from human hair. In the first study of its kind, we employed an in-line strontium purification methodology and a multi-collector inductively coupled plasma mass spectrometer to obtain high-precision strontium isotope ratio of human hair and of leachates of the different washing treatments. We found that the different applications of an individual treatment removed a consistent amount of strontium from hair and that replicate analyses showed each treatment altered the strontium isotope ratios of hair consistently. A mass-balance approach was applied to demonstrate that strontium was quantitatively removed and was accounted for in either the treated hair or the leachate. We observed that strontium isotope ratio varied as a function of treatment aggressiveness so as to suggest that there was a fine-scale structuring of strontium within hair (transverse cross-sectional variations); these variations existed as differences in strontium concentrations and isotope ratios. As a result, the Sr isotope ratio of hair and hair leachates treated with the most aggressive cleaning methods reflected the isotope ratios of the interior and total exterior strontium signatures, respectively. The results of this study indicate that external environmental strontium signals can be distinguished from the internal signals and therefore permit the application of strontium isotope ratios of modern human hair for geospatial applications.     

delta34S measurements on organic materials by continuous flow isotope ratio mass spectrometry

Sulfur (S) isotope ratios of thoroughly dried organic samples were measured by direct thermal decomposition in an elemental analyzer coupled to an isotope ratio mass spectrometer in continuous flow mode (EA-CF-IRMS). For organic samples of up to 13 mg weight and with total S contents of more than 10 microg, the reproducibility of the delta34S(organic) values was +/-0.4 per thousand or better. However, the delta34S values of organic samples measured directly by online EA-CF-IRMS analysis were between 0.3 and 2.9 per thousand higher than those determined on BaSO4 precipitates produced by Parr Bomb oxidation from the same sample material. Our results suggest that structural oxygen in organic samples influences the oxygen isotope ratios of the SO2 produced from organic samples. Consequently, SO2 generated from organic samples appears to have different 18O/16O ratios than SO2 generated from BaSO4 precipitates and inorganic reference materials, resulting in a deviation from the true delta34S values because of 32S16O18O contributions to mass 66. It was shown that both the amount of structural oxygen in the organic sample, and the difference of the oxygen isotope ratios between organic samples and tank O2, influenced the magnitude of the observed deviation from the true delta34S value after direct EA-CF-IRMS analysis of organic samples. Suggestions are made to correct the difference between measured delta34S(organic) and true delta34S values in order to obtain not only reproducible, but also accurate S isotope ratios for organic materials by EA-CF-IRMS.     

Sorption and transport mechanism of gases in polycarbonate membranes

The transport phenomena of oxygen and nitrogen across a pure polycarbonate (PC) and a cobalt(III) acetylactonate (Co(acac)₃) containing PC membrane was studied. Co(acac)₃ was added into a polycarbonate membrane to enhance its oxygen solubility. The oxygen sorption isotherms was measured. It was found that the oxygen solubility decreased sharply as pressure increased, especially at low pressure region. On the contrary, the oxygen permeability increased slightly with respect to pressure. Both the solution-diffusion model and traditional dual mobility model were unable to explain the inconsistent pressure dependency between solubility and permeability. Instead of adopting Langmuir-Henry sorption model, a modified dual mobility model which incorporates BET-type isotherm to describe oxygen sorption. The diffusivity of molecules moving at the first adsorbed layer was assumed to be different from those moving at higher layers. This modified dual mobility model satisfactorily described both the pressure dependency of oxygen solubility and permeability. It was also found that the increase of oxygen/nitrogen selectivity was not due to the elevation of oxygen to nitrogen solubility ratio but due to the mobility ratio of oxygen to nitrogen at the higher adsorption layers.     

Stable oxygen isotopes from theropod dinosaur tooth enamel: interlaboratory comparison of results and analytical interference by reference standards

Although previous work has demonstrated that biological phosphates ('biophosphates') record significant changes in delta18O associated with variations in local climate and seasonality, the repeatability of these analyses between laboratories has not previously been tested. We serially sampled enamel on four Cretaceous dinosaur teeth for phosphate delta18O analysis at up to three different facilities. With the exception of one set of unprocessed enamel samples, the material supplied to each laboratory was chemically processed to silver phosphate. Each laboratory analyzed sample sets by pyrolysis (thermochemical decomposition) in a ThermoFinnigan TC/EA attached to a ThermoFinnigan Delta Plus mass spectrometer. Significant interference between phosphate samples and the NIST reference material 8557 barium sulfate (NBS 127) distorts some of the results. Samples analyzed immediately following NBS 127 may be depleted by 6 per thousand isotopically and in instrument peak amplitude response by 80%. Substantial interference can persist over the subsequent 20 silver phosphate samples, and can influence the instrument peak amplitude response from some organic standards. Experiments using reagent-grade silver phosphate link these effects to divalent cations, particularly Ca2+ and Ba2+, which linger in the reactor and scavenge oxygen evolved from pyrolysis of subsequent samples. Unprocessed enamel includes 40 wt% calcium and self-scavenges oxygen, disrupting the isotopic measurements for the first half of a set and depleting subsequent organic standards by up to 9 per thousand. In sets without NBS 127 or calcium, such interference did not occur and an interlaboratory comparison of results from enamel shows reproducible, significantly correlated peaked delta18O patterns with a 2-3 per thousand dynamic range, consistent with previous results from contemporaneous teeth. Whereas both unprocessed enamel and the NBS 127 barium sulfate should be applied to biological phosphate ('biophosphate') stable isotope research with caution, seasonal variations in enamel phosphate delta18O are a paleoecologically valuable, reproducible phenomenon in theropod dinosaur teeth.     

Tracing the geographical origin of beefs being circulated in Korean markets based on stable isotopes

We have examined the carbon, nitrogen and oxygen isotopic compositions of American, Mexican, Australian, New Zealand and Korean beefs, which are currently being circulated in Korean markets, to check whether stable isotope ratios can identify their country of origin. Each beef exhibited statistically distinct isotopic compositions, especially in oxygen and carbon, because of the different isotopic compositions of their water and cattle feeds. Nevertheless, their isotopic compositions still showed some overlap, especially among USA, Australian, and Korean beefs, which sometimes resulted in significant misidentification when a single isotope was considered. However, the discrimination was generally successful when both the carbon and the oxygen isotopes were used. Copyright © 2009 John Wiley & Sons, Ltd.     

High accuracy isotope dilution analysis for the determination of ethanol using gas chromatography-combustion-isotope ratio mass spectrometry

A procedure was established for the determination of ethanol in water samples by isotope dilution analysis. After spiking the sample with labelled [13C2]ethanol, it was analysed by gas chromatography-combustion-isotope ratio mass spectrometry. Results are reported for two certified reference materials and also ethanol solutions prepared for a CITAC (Co-operation on International Traceability in Analytical Chemistry) interlaboratory comparison. The certified reference materials were certified using the dichromate titration method at nominal levels of 80 and 200 mg per 100 mL. The CITAC solutions were prepared gravimetrically at nominal levels of 50, 80 and 200 mg per 100 mL. The results of the analysis agree well to within 0.5% of the gravimetric values of the different samples. The relative expanded standard uncertainties (with a coverage factor equal to 2) associated with the results varied between 0.18 and 0.37%, a range that encompassed the gravimetric values for the different samples. A complete uncertainty budget was also drawn up so that the different contributions could be identified and quantified. The main contributions were due to variations in the measured isotope amount ratios and a 'between' blend component introduced to quantify the contribution of factors such as the degree of matching of the isotope amount ratios between standards and samples used in the isotope dilution analysis.     

Depth-specific and spatiotemporal variation of δ13C and δ15N in Charophytes of Lake Constance: implications for food web studies

Macrophytes are at the base of many lake food webs providing essential food resources for animals at higher trophic level, such as invertebrates, fish and waterbirds. However, data regarding the spatiotemporal variation in isotopic composition of macrophytes are generally missing. We measured the carbon and nitrogen stable isotope ratios of Charophytes at Lake Constance, where they constitute a major food source for waterbirds. Our data reveal seasonal and site-specific differences as well as depth-specific variations in isotopic carbon values within the littoral zone. Charophytes were enriched in (13)C at sites of higher productivity: the δ(13)C values were high in summer, at shallow and at relatively nutrient-rich sites, and comparatively low in winter, and in deeper and nutrient-poorer sites. In contrast, no temporal or spatial trend was found to explain the variability in the isotopic nitrogen values. These results imply that the seasonal timing of food intake (relative to turnover rates of consumers tissue) and the potential depth of foraging need to be taken into account when calculating the relative contribution of energy sources to diets of consumers such as waterbirds.     

Lattice dynamics to trigger low temperature oxygen mobility in solid oxide ion conductors

SrFeO(2.5) and SrCoO(2.5) are able to intercalate oxygen in a reversible topotactic redox reaction already at room temperature to form the cubic perovskites Sr(Fe,Co)O(3), while CaFeO(2.5) can only be oxidized under extreme conditions. To explain this significant difference in low temperature oxygen mobility, we investigated the homologous SrFeO(2.5) and CaFeO(2.5) by temperature dependent oxygen isotope exchange as well as by inelastic neutron scattering (INS) studies, combined with ab initio (DFT) molecular dynamical calculations. From (18)O/(16)O isotope exchange experiments we proved free oxygen mobility to be realized in SrFeO(x) already below 600 K. We have also evidence that low temperature oxygen mobility relies on the existence of specific, low energy lattice modes, which trigger and amplify oxygen mobility in solids. We interpret the INS data together with the DFT-based molecular dynamical simulation results on SrFeO(2.5) and CaFeO(2.5) in terms of an enhanced, phonon-assisted, low temperature oxygen diffusion for SrFeO(3-x) as a result of the strongly reduced Fe-O-Fe bond strength of the apical oxygen atoms in the FeO(6) octahedra along the stacking axis. This dynamically triggered phenomenon leads to an easy migration of the oxide ions into the open vacancy channels and vice versa. The decisive impact of lattice dynamics, giving rise to structural instabilities in oxygen deficient perovskites, especially with brownmillerite-type structure, is demonstrated, opening new concepts for the design and tailoring of low temperature oxygen ion conductors.     

Determination of 13C/12C-ratios of anthropogenic organic contaminants in river water samples by GC-irmMS

This study describes the application of a common analytical procedure adapted for compound-specific stable carbon isotope analyses of riverine contaminants. To evaluate the sensitivity of the analytical method and the precision of the isotopic data obtained, a set of numerous substances at different concentration levels were measured. For most of the anthropogenic contaminants investigated (including chlorinated aliphatics and aromatics, musk fragrances, phthalate-based plasticizers and tetrabutyl tin) acceptable carbon isotope analyses could be obtained down to amounts of approximately 5?ng absolutely applied to the gas chromatograph. These amounts correspond to concentrations in water samples at a natural abundance level of approximately 50–200?ng?L^?1 (low to medium contaminated river systems). However, it has to be considered that the precision and the sensitivity of the analytical method depend partially on the chemical properties of the substances measured. Five recovery experiments were conducted to assess changes in carbon isotope ratios during sample preparation and measurement. The compounds selected for these experiments are known riverine contaminants. Isotopic shifts or higher variations of the isotope ratios as a result of the analytical procedures applied were observed only for a couple of contaminants. Furthermore, compound-specific carbon isotope analyses were performed on eight water extracts of the Rhine river. By comparing the variation of the data of several individual compounds with the deviations obtained from the recovery experiments, it was possible to differentiate contaminants with unaffected isotope ratios and substances with significant alterations of the δ¹³C-values.     

Identification of energy consumption and nutritional stress by isotopic and elemental analysis of urine in bonobos (Pan paniscus)

A mounting body of evidence suggests that changes in energetic conditions like prolonged starvation can be monitored using stable isotope ratios of tissues such as bone, muscle, hair, and blood. However, it is unclear if urinary stable isotope ratios reflect a variation in energetic condition, especially if these changes in energetic condition are accompanied by shifts in dietary composition. In a feeding experiment conducted on captive bonobos (Pan paniscus), we monitored urinary δ(13)C, δ(15)N, total C (carbon), total N (nitrogen), and C/N ratios and compared these results with glucocorticoid levels under gradually changing energy availability and dietary composition. Measurements of daily collected urine samples over a period of 31 days showed that while shifts in urinary isotope signatures of δ(13)C and δ(15)N as well as total C were best explained by changes in energy consumption, urinary total N excretion as well as the C/N ratios matched the variation in dietary composition. Furthermore, when correcting for fluctuations in dietary composition, the isotope signatures of δ(13)C and δ(15)N as well as total C correlated with urinary glucocorticoid levels; however, the urinary total N and the C/N ratio did not. These results indicate for the first time that it is possible to non-invasively explore specific longitudinal records on animal energetic conditions and dietary compositions with urinary stable isotope ratios and elemental compositions, and this research provides a strong foundation for investigating how ecological factors and social dynamics affect feeding habits in wild animal populations such as primates.     

Intra‐ and inter‐tooth variation in strontium isotope ratios from prehistoric seals by laser ablation multi‐collector inductively coupled plasma mass spectrometry

Rationale

Strontium isotope ratios (⁸⁷Sr/⁸⁶Sr) in modern‐day marine environments are considered to be homogeneous (~0.7092). However, in the Baltic Sea, the Sr ratios are controlled by mixing seawater and continental drainage from major rivers discharging into the Baltic. This pilot study explores if variations in Sr can be detected in marine mammals from archaeological sites in the Baltic Sea.

Methods

⁸⁷Sr/⁸⁶Sr ratios were measured in tooth enamel from three seal species by laser ablation multi‐collector inductively coupled plasma mass spectrometry (LA‐MC‐ICP‐MS). The method enables micro‐sampling of solid materials. This is the first time that the method has been applied to marine samples from archaeological collections.

Results

The analyses showed inter‐tooth ⁸⁷Sr/⁸⁶Sr variation suggesting that different ratios can be detected in different regions of the Baltic Sea. Furthermore, the intra‐tooth variation suggests possible different geographic origin or seasonal movement of seals within different regions in the Baltic Sea through their lifetime.

Conclusions

The method was successfully applied to archaeological marine samples showing that: (1) the ⁸⁷Sr/⁸⁶Sr ratio in marine environments is not uniform, (2) ⁸⁷Sr/⁸⁶Sr differences might reflect differences in ecology and life history of different seal species, and (3) archaeological mobility studies based on ⁸⁷Sr/⁸⁶Sr ratios in humans should therefore be evaluated together with diet reconstruction.

     

Stable isotope compositions of CO(2) in background air and at polluted sites in Hungary

CO(2) samples were collected from air at three sites in Hungary for comparison of polluted and background areas. In order to reduce the uncertainties caused by the varying amount of N(2)O, a gas chromatography (GC)-based vacuum separation was applied. The reliability of the procedure was demonstrated by careful standardization and comparison with global network data. The stable isotope data show complex diurnal and seasonal variations that can be explained by fractionations during photosynthesis and respiration. The isotopic characteristics of pollution-derived (anthropogenic) and biogenic CO(2) appear to be indistinguishable at the study sites. However, the sites at unpolluted areas reveal a seasonal variation in the carbon isotope composition of biogenic CO(2) that may be related to changes in soil biogenic activities. The atmospheric background CO(2) shows constant delta(13)C in the region. Finally, the study demonstrates the need for careful standardization of sampling in order to make the data obtained from different sampling systems comparable.     

不同赋存形态土壤铅同位素比值用于判别地域性差异的研究

由于各地区地质结构不同,造成了铅同位素组成具有地域特征。本研究利用电感耦合等离子体质谱测定了福建不同茶园土壤的铅同位素比值,比较了土壤全消解和残渣态两种赋存形态的铅同位素比值的差异,发现残渣态的铅的地域性特征较强,可用来作为地区土壤的判别依据。