Specificity and Origin of the Stability of the Sr Isotopic Ratio in Champagne Wines

The ⁸⁷Sr/⁸⁶Sr ratio of 39 Champagnes from six different brands, originating from the whole “Appellation d’Origine Contrôlée” (AOC) Champagne was analyzed to establish a possible relation with the geographical origin. Musts (i.e., grape juice) and base wines were also analyzed to study the evolution of the Sr isotopic ratio during the elaboration process of sparkling wine. The results demonstrate that there is a very homogeneous Sr isotopic ratio (⁸⁷Sr/⁸⁶Sr = 0.70812, n = 37) and a narrow span of variability (2σ = 0.00007, n = 37). Moreover, the Sr concentrations in Champagnes have also low variability, which can be in part explained by the homogeneity of the bedrock in the AOC Champagne. Measurements of the ⁸⁷Sr/⁸⁶Sr ratio from musts and base wines show that blending during Champagne production plays a major role in the limited variability observed. Further, the ⁸⁷Sr/⁸⁶Sr of the musts were closely linked to the ⁸⁷Sr/⁸⁶Sr ratio of the vineyard soil. It appears that the ⁸⁷Sr/⁸⁶Sr of the product does not change during the elaboration process, but its variability decreases throughout the process due to blending. Both the homogeneity of the soil composition in the Champagne AOC and the blending process during the wine making process with several blending steps at different stages account for the unique and stable Sr isotopic signature of the Champagne wines.     

ESI-QIMS Investigation of Sr,Rb, and Crown Ether Mixture Solutions

The isotope distribution of Sr, alternatively ⁸⁷Sr/⁸⁶Sr ratio frequently reported in geologic investigations, is obtained by direct electrospray ionization of aqueous samples containing Sr(II), Rb(I) with added 18-crown-6 (18c6) [1,4,7,10,13,16-Hexaoxacyclooctadecane C₁₂H₂₄O₆ m/z 264.3]. At relatively high concentrations of Sr and Rb, we observed favorable formation of Sr²⁺(18c6)₂ and Rb⁺(18c6) rather than Sr²⁺(18c6) complexes. Significant Sr²⁺(18c6)₂ suppression observed in post column addition of samples into water solvent disappeared when formic acid was present in the carrier solvent. Electrospray ionization-quadrupole-ion trap mass spectrometry (ESI-QITMS) successfully obtained the expected isotope distribution of Sr showing no interference from Rb without chromatographic separation of ⁸⁷Sr and ⁸⁷Rb necessary in ICP-MS studies.     

High-precision direct determination of the Sr/Sr isotope ratio of bottled Sr-rich natural mineral drinking water using multiple collector inductively coupled plasma mass spectrometry

We describe a precise and accurate method for the direct determination of the ⁸⁷Sr/⁸⁶Sr isotope ratio of bottled Sr-rich natural mineral drinking water using multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The method is validated by the comparative analysis of the same water with and without cation-exchange resin purification. The work indicates that isobarically interfering elements can be corrected for when ⁸⁷Rb/⁸⁶Sr < 0.05 (Rb/Sr < 0.015), and that the matrix elements (Ca, Mg, K and Na) have no significant effect on the accuracy of the Sr isotope data. The method is simple, rapid, eliminates sample preparation time, and avoids potential contamination during complicated sample-preparation procedures. Therefore, the high sample throughput inherent to the MC-ICP-MS can be fully exploited.     

Problems in obtaining precise and accurate Sr isotope analysis from geological materials using laser ablation MC-ICPMS

This paper reviews the problems encountered in eleven studies of Sr isotope analysis using laser ablation multicollector inductively coupled plasma mass spectrometry (LA-MC-ICPMS) in the period 1995–2006. This technique has been shown to have great potential, but the accuracy and precision are limited by: (1) large instrumental mass discrimination, (2) laser-induced isotopic and elemental fractionations and (3) molecular interferences. The most important isobaric interferences are Kr and Rb, whereas Ca dimer/argides and doubly charged rare earth elements (REE) are limited to sample materials which contain substantial amounts of these elements. With modern laser (193 nm) and MC-ICPMS equipment, minerals with >500 ppm Sr content can be analysed with a precision of better than 100 ppm and a spatial resolution (spot size) of approximately 100 μm. The LA MC-ICPMS analysis of ⁸⁷Sr/⁸⁶Sr of both carbonate material and plagioclase is successful in all reported studies, although the higher ⁸⁴Sr/⁸⁶Sr ratios do suggest in some cases an influence of Ca dimer and/or argides. High Rb/Sr (>0.01) materials have been successfully analysed by carefully measuring the ⁸⁵Rb/⁸⁷Rb in standard material and by applying the standard-sample bracketing method for accurate Rb corrections. However, published LA-MC-ICPMS data on clinopyroxene, apatite and sphene records differences when compared with ⁸⁷Sr/⁸⁶Sr measured by thermal ionisation mass spectrometry (TIMS) and solution MC-ICPMS. This suggests that further studies are required to ensure that the most optimal correction methods are applied for all isobaric interferences.     

Evaluation of strontium isotope abundance ratios in combination with multi-elemental analysis as a possible tool to study the geographical origin of ciders

In order to evaluate alternative analytical methodologies to study the geographical origin of ciders, both multi-elemental analysis and Sr isotope abundance ratios in combination with multivariate statistical analysis were estimated in 67 samples from England, Switzerland, France and two Spanish regions (Asturias and the Basque Country). A methodology for the precise and accurate determination of the ⁸⁷Sr/⁸⁶Sr isotope abundance ratio in ciders by multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) was developed. Major elements (Na, K, Ca and Mg) were measured by ICP-AES and minor and trace elements (Li, Be, B, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Y, Mo, Cd, Sn, Sb, Cs, Ba, La, Ce, W, Tl, Pb, Bi, Th and U) were measured by ICP-MS using a collision cell instrument operated in multitune mode. An analysis of variance (ANOVA test) indicated that group means for B, Cr, Fe, Ni, Cu, Se, Cd, Cs, Ce, W, Pb, Bi and U did not show any significant differences at the 95% confidence level, so these elements were rejected for further statistical analysis. Another group of elements (Li, Be, Sc, Co, Ga, Y, Sn, Sb, La, Tl, Th) was removed from the data set because concentrations were close to the limits of detection for many samples. Therefore, the remaining elements (Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba) together with ⁸⁷Sr/⁸⁶Sr isotope abundance ratio were considered for principal component analysis (PCA) and linear discriminant analysis (LDA). Finally, LDA was able to classify correctly 100% of cider samples coming from different Spanish regions, France, England and Switzerland when considering Na, Mg, Al, K, Ca, Ti, V, Mn, Zn, As, Rb, Sr, Mo, Ba and ⁸⁷Sr/⁸⁶Sr isotope abundance ratio as original variables.     

Isotope analysis of strontium by multicollector inductively-coupled plasma mass spectrometry: High-precision combined measurement of 88Sr/86Sr and 87Sr/86Sr isotope ratios

The paper describes a new high-precision method for the simultaneous precise determination of ⁸⁸Sr/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr ratios in a single portion of a geological sample by multicollector inductively coupled mass spectrometry (MC-ICP-MS). The isotope analysis is carried out with mass bias effect correction by a combination of internal normalization to the standard Zr-isotope ratio and bracketing standard method (external normalization). Our results for geochemical IAPSO and BCR-1 standard samples are in a good agreement with the published data. The reproducibility of the ⁸⁸Sr/⁸⁶Sr ratio varies from ±0.015 to ±0.05?? (depending on the sample features) and, together with the analysis accuracy, is superior to the previously reported methods of MC-ICP-MS analysis. Still ahead is only double spike thermal ionization mass spectrometry with its ±0.02?? reproducibility. However, the new method allows the simultaneous determination of ⁸⁸Sr/⁸⁶Sr and ⁸⁷Sr/⁸⁶Sr ratios and its productivity is higher by 5 to 6 times. On the other hand, in sample preparation, it is necessary to strive for at least 95% Sr yield from the chromatographic column; otherwise the sorption-desorption process may lead to a 0.6?? ⁸⁸Sr/⁸⁶Sr ratio bias relative to the true value.     

Calcium tungstate coprecipitation for removal of Sr interference with determination of Rb by ID-ICP-MS

A coprecipitation method using calcium tungstate was developed to remove ⁸⁷Sr isobaric interference with ⁸⁷Rb prior to measurement of Rb by ID-ICP-MS. Precipitation of calcium tungstate was obtained by adding Ca(NO₃)₂ solution and (NH₄)₂WO₄ solution to the sample, where (NH₄)₂WO₄ was added more than the stoichiometric proportion to precipitate Ca(NO₃)₂ completely and remove Sr effectively. Furthermore, in order to reduce matrix burden to the ICP-MS instrument, the residual (NH₄)₂WO₄ was removed by adding conc. HNO₃. Prior to the application, thorough purification of coprecipitant reagent was carried out to reduce the blank. The effectiveness of the present method was verified by analyzing two brown rice flour certified reference materials (CRMs), NIES CRM 10a and NIES CRM 10b. Finally, the present method was applied to the measurement of Rb in a white rice flour RM sample being developed by National Institute of Metrology of Japan.     

HAc溶解碳酸盐岩测定87Sr/86Sr值实验方法研究

传统的碳酸盐岩的sr同位素比值测定因为采用HCl溶样,往往导致非碳酸盐组分的溶解,引起测定值偏高,采用HAc溶样可以防止样品中非碳酸盐组分的溶解,同时也避免过多的杂质离子进入溶解液,从而使^87Sr／^86Sr测定值趋于准确和可靠;通过2.5mol/L HAc溶解碳酸盐矿样和4.0mol/L HCl溶解残渣样的最后质谱测定的^87Sr／^86Sr值比较,证实碳酸盐岩中非碳酸盐组分的^87Sr／^86Sr值较碳酸盐组分高。     

Identification of Marchfeld asparagus using Sr isotope ratio measurements by MC-ICP-MS

This work focuses on testing and application of Sr isotope signatures for the fast and reliable authentication and traceability of Asparagus officinalis originating from Marchfeld, Austria, using multicollector inductively coupled plasma mass spectrometry after optimised Rb/Sr separation. The major sample pool comprises freeze-dried and microwave-digested asparagus samples from Hungary and Slovakia which are compared with Austrian asparagus originating from the Marchfeld region, which is a protected geographical indication. Additional samples from Peru, the Netherlands and Germany were limited in number and allowed therefore only restricted statistical evaluation. Asparagus samples from Marchfeld were harvested within two subsequent years in order to investigate the annual variation. The results show that the Sr isotope ratio is consistent within these 2 years of investigation. Moreover, the Sr isotope ratio of total Sr in soil was found to be significantly higher than in an NH₄NO₃ extract, reflecting the mobile (bioavailable) phase. The isotope composition in the latter extract corresponds well to the range found in the asparagus samples in Marchfeld, even though the concentration of Sr in asparagus shows no direct correlation to the concentration of Sr in the mobile phase of the soil. The major question was whether the ‘Marchfelder Spargel’ can be distinguished from samples from the neighbouring countries of Hungary and Slovakia. According to our findings, they can be clearly (100%) singled out from the Hungarian samples and can be distinguished from the Slovakian asparagus samples with a probability of more than 80%.     

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.

     

Simultaneous determination of Ca,Rb, Sr and Ce in environmental materials by photon activation analysis using the stable isotope dilution method

In order to study further the applicability of the newly developed stable isotope dilution method, simultaneous determination of Ca, Rb, Sr and Ce in three kinds of environmental materials has been tried by means of photon activation using isotopically enriched⁴⁸Ca,⁸⁷Rb,⁸⁶Sr and¹⁴²Ce as spikes. All determinations were demonstrated to be sensitive, highly specific and reasonably accurate.     

87Sr/86Sr measurements on marine sediments by inductively coupled plasma-mass spectrometry

The application of inductively coupled plasma-mass spectrometry (ICP-MS) is documented for the study of the strontium isotopic composition (⁸⁷Sr/⁸⁶Sr) in geological samples, i.e. in the marine lithic fraction of core sediments. Methods for the determination of the isotopic composition, its accuracy and precision are reported. The results obtained simultaneously on 11 samples by both ICP-MS and thermal ionization mass spectrometry (TIMS) reveal a very good correlation (r² = 0.955). Received: 24 February 1997 / Revised: 26 May 1997 / Accepted: 30 May 1997     

87Sr/86Sr measurements on marine sediments by inductively coupled plasma-mass spectrometry

The application of inductively coupled plasma-mass spectrometry (ICP-MS) is documented for the study of the strontium isotopic composition (⁸⁷Sr/⁸⁶Sr) in geological samples, i.e. in the marine lithic fraction of core sediments. Methods for the determination of the isotopic composition, its accuracy and precision are reported. The results obtained simultaneously on 11 samples by both ICP-MS and thermal ionization mass spectrometry (TIMS) reveal a very good correlation (r² = 0.955). Received: 24 February 1997 / Revised: 26 May 1997 / Accepted: 30 May 1997     

Uranium from German Nuclear Power Projects of the 1940s— A Nuclear Forensic Investigation

Here we present a nuclear forensic study of uranium from German nuclear projects which used different geometries of metallic uranium fuel. 3b , 3d , 4 Through measurement of the ²³⁰Th/²³⁴U ratio, we could determine that the material had been produced in the period from 1940 to 1943. To determine the geographical origin of the uranium, the rare‐earth‐element content and the ⁸⁷Sr/⁸⁶Sr ratio were measured. The results provide evidence that the uranium was mined in the Czech Republic. Trace amounts of ²³⁶U and ²³⁹Pu were detected at the level of their natural abundance, which indicates that the uranium fuel was not exposed to any major neutron fluence.     

Separation of 82Sr from rubidium target for preparation of 82Sr/82Rb generator

Summary ⁸²Rb is a generator produced positron-emitting isotope (T_1/2 = 75 s) that is increasingly being used in positron emission tomography for the characterization of myocardial perfusion. The parent radionuclide of ⁸²Rb, strontium ⁸²Sr, is produced mainly by a (p, 4n) reaction induced by >40 MeV protons on rubidium (⁸⁵Rb) target. In the present work we propose a new fast and simple procedure for ⁸²Sr separation from the target, based on selective adsorption of rubidium on the inorganic ion-exchanger: cryptomelane MnO₂.     

Radiochemical separation of 82Sr and the preparation of a sterile 82Sr/82Rb generator column

Summary Ion-exchange chromatography using the chelating resins Purolite S950 and Chelex 100 was investigated for the radiochemical separation of ⁸²Sr from a RbCl target. 0.25M NH₄Cl solution was employed for the retention of Sr and elution of Rb, and 2M HCl for the elution of Sr. Although both resins showed very similar results, the conditions for adsorption of Sr were different. The ammonium chloride solution was directly used with Purolite S950 while it was necessary to adjust the pH between 9 and 10 with Chelex 100. Purolite S950 was, therefore, selected for routine production of ⁸²Sr. A procedure has been introduced for the preparation of a hydrous tin dioxide as supporting material for the ⁸²Sr/⁸²Rb generator column. All components of the generator column were made up of stainless steel. The column was 4 cm long, 9.5 mm O.D. and 7.1 mm I.D. Using isotonic saline (0.9% NaCl) for elution of ⁸²Rb, elution curves with different flow rates ranging from 5 to 20 ml/min were obtained. Maximum available ⁸²Rb was eluted in the first 20 ml. The column generator provided a sterile ⁸²Rb in isotonic saline. The breakthrough of ⁸²Sr over 4 weeks of elution using 7 liter of saline was on average 4.5 ^. 10^-5% (based on the first 20 ml eluate).     

利用锶特效树脂分离富集岩石样品中的锶及测定~(87)Sr/~(86)Sr

本研究以Sr-Spec树脂作为分离锶的特效树脂,以HNO3为淋洗液,通过改变HNO3的浓度,将地质岩石样品中的锶分离富集.实验结果表明,Sr与基质元素和Rb能很好地分离.利用Sr-Spec树脂分离国际标准物质SRM607、日本岩石标样JA-2、JB-2、JF-2和国家标准物质GBW04111后, 测得同位素比值87Sr/86Sr结果及误差(2σ)分别为1.200660±22, 0.706350±17, 0.703640±16, 0.709692±22和0.700008±23.相对于常规的阳离子树脂分离方法,此方法所用淋洗试剂量少,分离流程短,可以降低实验空白并提高工作效率.因此,Sr-Spec树脂分离法是快速分离富集不同岩性地质样品的Sr并测定87Sr/86Sr的有效方法.     

肉类制品中微量锶的分离及^87Sr/^86Sr同位素比值测定

利用87Sr/86Sr同位素比值进行生物和古人类源区与迁徙的示踪是Sr同位素技术应用的新领域,也是考古研究和肉类食品溯源研究的新尝试。本研究对牛肉干粉采用酸溶、微波消解和灰化后硝酸提取等不同方法进行消解,比较了它们的离子交换分离效果和Sr同位素测定结果;用石英、石墨和瓷坩埚3种器皿对牛肉干粉进行灰化,检测了灰化器皿对87Sr/86Sr同位素比值的影响,从而确定了石英坩埚灰化的消解方法,建立了适合于肉类制品微量Sr的化学分离方法与87Sr/86Sr同位素比值测定方法。本方法包括肉类制品的石英坩埚灰化、离子交换分离和87Sr/86Sr比值的热离子化质谱测定。所建方法对肉类食品溯源和考古研究等领域富含有机质样品的Sr同位素比值测定具有普适性。     

Rapid determination of 90Sr/90Y in water samples by liquid scintillation and Cherenkov counting

Strontium-90 (⁹⁰Sr) is a ubiquitous contaminant at nuclear facilities, found at high concentrations in spent nuclear fuel and radioactive waste. Due to its long half-life and ability to be transported in groundwater, an accurate method for measuring ⁹⁰Sr in water samples is critical to the monitoring program of any nuclear facility. To address this need, a rapid procedure for sequential separation of Sr/Y was developed and tested in groundwater samples collected from an area of riverbed affected by a ⁹⁰Sr groundwater plume. Sixteen samples, plus spike and water blanks, were analyzed. Five different measurements were performed to determine the ⁹⁰Sr and yttrium-90 (⁹⁰Y) activities in the samples: direct triple-to-double-coincidence ratio (TDCR) Cherenkov counting of ⁹⁰Y, liquid scintillation (LS) counting for ⁹⁰Sr following radiochemical separation, LS counting for ⁹⁰Y following radiochemical separation, Cherenkov counting for ⁹⁰Y following radiochemical separation and LS counting of the Sr samples for ⁹⁰Y in-growth. The counting was done using a low-level Hidex 300SL TDCR counter. Each measurement method was compared for accuracy, sensitivity and efficiency. The results following Cherenkov counting and radiochemical separation were in very good agreement with one another.     

Rapid and precise determination of Sr and Nd isotopic ratios in geological samples from the same filament loading by thermal ionization mass spectrometry employing a single-step separation scheme

Thermal ionization mass spectrometry (TIMS) offers the excellent precision and accuracy of the Sr and Nd isotopic ratio analysis for geological samples, but this method is labour intensive, expensive and time-consuming. In this study, a new analytical protocol by TIMS is presented that aims at improving analytical efficiency and cutting down experimental cost. Using the single-step cation exchange resin technique, mixed Sr and rare earth elements (REEs) fractions were separated from matrix and evaporated to dryness. Afterwards, mixed Sr + REEs fractions were dissolved and loaded onto the same Re filament using 1 μL of 2 M HCl. Then, Sr and Nd were sequentially measured without venting using TIMS. In contrast to conventional TIMS methods, the merits of this analytical protocol are its cost- and time-saving adaptations. The applicability of our method is evaluated by replicated measurements of ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd for nine international silicate rock reference materials, spanning a wide range of bulk compositions. The typical internal precision in this study is ca. 0.001% (RSE) for ⁸⁷Sr/⁸⁶Sr and ¹⁴³Nd/¹⁴⁴Nd; the analytical results obtained for these standard rocks show a good agreement with reported values, indicating the effectiveness of the proposed method.