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  • 1. Andren, Henrik
    et al.
    Baxter, Douglas
    Stenberg, Anna
    Luleå tekniska universitet.
    Malinovskiy, Dmitry
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Variations in instrumental mass discrimination2004In: 2004 Winter Conference on Plasma Spectrochemistry: [... Fort Lauderdale, FL, USA, January 5 - 10, 2004 ...], Cambridge: Royal Society of Chemistry, 2004, p. 329-Conference paper (Refereed)
  • 2. Andren, Henrik
    et al.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stenberg, Anna
    Luleå tekniska universitet.
    Malinovskiy, Dmitry
    Baxter, Douglas
    Sources of mass bias and isotope ratio variation in multi-collector ICP-MS: optimization of instrumental parameters based on experimental observations2004In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 19, no 9, p. 1217-1224Article in journal (Refereed)
    Abstract [en]

    In this work, several contributing factors to the observed mass bias in inductively coupled plasma mass spectrometry (ICP-MS) have been identified. Analyses of the isotopic compositions of B deposited on sampler and skimmer cones demonstrate enrichment of [1][0]B on the former and [1][1]B on the latter. Grounding the capacitive discharge system to enhance sensitivity also magnified the level of [1][1]B enrichment on the skimmer cone more than four-fold. This supersonic expansion of the ion beam behind the sampler is confirmed to be an important source of mass bias. Isotopic analyses of the Fe, Zn and Ti leached from used extraction lenses yielded a linear relationship between the levels of lighter isotope depletion and mass ratio. Although consistent with the space-charge effect, the fact that isotopically-heavy deposits were found demonstrates that the ion beam diverges into a relatively wide solid angle in the field-free region behind the skimmer. This severely impairs transmission of, in particular, the lighter isotopes. For a wide range of elements (Li, B, Fe, Ni, Cu, Sb, Ce, Hf and Re), the magnitude of the mass bias was found to be affected by the sample gas flow rate, as well as the distance between the sampler and the end of the torch, i.e., the sampling depth, employed in the Neptune multi-collector ICP-MS instrument. Mathematical analysis of the profiles of intensity variations as a function of these instrumental parameters revealed that the response peaks closer to the torch for the heavier isotopes of all studied elements. Owing to this spatial non-coincidence, tuning for maximum intensity on either isotope will result in sampling from a region where even slight plasma instabilities will be translated into substantial variations in mass bias. Therefore, in-plasma processes also contribute to the degree and temporal stability of mass bias. In light of these findings, recommendations for optimizing multi-collector ICP-MS with respect to obtaining the highest possible precision are presented.

  • 3.
    Appelblad, Petra
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    The use of Pt guard electrode in inductively coupled plasma sector field mass spectrometry: advantages and limitations2000In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 15, no 4, p. 359-364Article in journal (Refereed)
    Abstract [en]

    Performance characteristics of inductively coupled plasma sector field mass spectrometry (ICP-SFMS) were studied with a Pt guard electrode (GE) inserted between the torch and load coil. The importance of the optimisation procedure and the matrix effects caused by a seawater matrix were assessed for 20 elements. Oxide and doubly charged ion formation was also investigated. Use of the GE allows a significant increase in ion transmission, by a factor of three to 20, thus resulting in improved instrumental detection limits. The improvement in sensitivity is mass dependent, with the highest gain observed for lower mass elements. Since, for the majority of analytical applications, actual detection limits depend upon blank levels rather on instrumental sensitivity, the most important factor for the determination of elements at ultra-trace levels is the degree of contamination of reagents and containers used. At the same time, significantly greater oxide formation is observed when operating the GE grounded rather than in the floating mode. For example, the BaO+/Ba+ ratio is ten to twelve times higher in the grounded mode. This calls for compromised instrumental parameters and the potential for severe spectral interferences from oxide species, which are often unresolved, even in high-resolution mode. Furthermore, non-spectral interferences from the seawater matrix appear to be more pronounced with the grounded GE, yielding a recovery of Ni of 55% compared with 93% in the floating GE mode. Hence all possible advantages and limitations of the use of the GE should be carefully considered prior to the analysis of real samples.

  • 4. Appelblad, P.K.
    et al.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Sources of uncertainty in isotope ratio measurements by inductively coupled plasma mass spectrometry2001In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 73, no 13, p. 2911-2919Article in journal (Refereed)
    Abstract [en]

    A model is presented describing the effects of dead time and mass bias correction factor uncertainties, flicker noise, and counting statistics on isotope ratio measurement precision using inductively coupled plasma mass spectrometry (ICPMS) with a single collector. Noise spectral analysis is exploited to enable estimation of the flicker noise parameters. For the instrument used, the flicker noise component exhibited a fairly weak frequency (f) dependence ( f -0.33±0.12), but was directly proportional to the total number of counts, Q. As white noise, determined by counting statistics, is given by Q0.5, the isotope ratio measurement uncertainties will actually cease to improve when Q exceeds a certain threshold. This would suggest that flicker noise could become the limiting factor for the precision with which isotope ratios can be determined by ICPMS. However, under most experimental conditions, uncertainties associated with mass discrimination and dead time correction factors are decisive. For ratios up to ~22 (115In/113In), optimum major isotope count rates are generally below 0.3 MHz, for which precision in the mass discrimination factor is limiting. The model derived could be used as a starting point for determining optimum conditions and understanding the limitations of single-collector ICPMS for precise isotope ratio measurements.

  • 5.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Öhlander, Björn
    High spatial resolution analysis of ferromanganese concretions by LA-ICP-MS2002In: Geochemical Transactions, ISSN 1467-4866, E-ISSN 1467-4866, Vol. 3, no 5, p. 40-47Article in journal (Refereed)
    Abstract [en]

    A procedure was developed for the determination of element distributions in cross-sections of ferromanganese concretions using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The effects of carrier flow rates, rf forward power, ablation energy, ablation spot size, repetition rate and number of shots per point on analyte intensity were studied. It is shown that different carrier gas flow rates are required in order to obtain maximum sensitivities for different groups of elements, thus complicating the optimisation of ICP parameters. On the contrary, LA parameters have very similar effects on almost all elements studied, thus providing a common optimum parameter set for the entire mass range. However, for selected LA parameters, the use of compromise conditions was necessary in order to compensate for relatively slow data acquisition by ICP-MS and maintain high spatial resolution without sacrificing the multielemental capabilities of the technique. Possible variations in ablation efficiency were corrected for mathematically using the sum of Fe and Mn intensities. Quantification by external calibration against matrix-matched standards was successfully used for more than 50 elements. These standards, in the form of pressed pellets (no binder), were prepared in-house using

  • 6.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Determination of major and trace elements in sphalerite using laser ablation double focusing sector field ICP-MS2001In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 72, no 2, p. 81-89Article in journal (Refereed)
    Abstract [en]

    The analytical performance of laser ablation (LA) for the determination of Co, Fe, Cd, Ag, Mn, Cu and S in sphalerite was evaluated using double focusing sector field inductively coupled plasma mass spectrometry (ICP-SFMS). Samples were collected from Zinkgruvan, situated in the south central Sweden. The use of Zn for internal standardisation, together with correction for FeS impurities in sphalerite, allows straightforward quantification without using external methods for the determination of the actual Zn content. LA-ICP-SFMS results were compared with data obtained by conventional pneumatic nebulisation introduction of sample solutions following acid digestion. Good agreement between the two methods was obtained for homogeneously distributed elements. For the majority of the elements under consideration, LA-ICP-SFMS precision was better than 10% RSD.

  • 7.
    Axelsson, Mikael
    et al.
    Luleå tekniska universitet.
    Rodushkin, Ilya
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Multielemental analysis of Mn-Fe nodules by ICP-MS: optimisation of analytical method2002In: The Analyst, ISSN 0003-2654, E-ISSN 1364-5528, Vol. 127, no 1, p. 76-82Article in journal (Refereed)
    Abstract [en]

    Two acid digestion procedures (microwave-assisted and room temperature) were developed for the quantitative analysis of ferromanganese nodules by inductively coupled plasma double focusing sector field mass spectrometry (ICP-SFMS). Different compositions of the acid mixture, dilution factors and corrections for spectral interferences were tested. A combination of nitric, hydrochloric and hydrofluoric acids is necessary for complete sample digestion, with lowest acid to sample ratios (v/m) of 15 and 1.5. respectively, for the last two acids. Sample dilution factors higher than 2 X 104 should be used in order to decrease matrix effects and provide robust long-term instrumental operation. In spite of high dilution. method detection limits in the sub-mug g(-1) range were obtained for 54 out of 71 elements tested. due to the high detection capability of ICP-SFMS, as well as the special care taken to ensure the purity of reagents, to clean the instrument sample introduction system and to minimise sample handling. Owing to the presence of unresolved (at the resolution available) spectral interferences, accurate determination of Au, Hg, Os, Pd, Re and Rh is impossible without matrix separation. The accuracy of the entire analytical method was tested by the analysis of two nodule reference materials. The results generated agreed to within +/-2% for about 10, within +/-10% for more than 40 and within +/-20% for about 50 of 53 elements for which certified, recommended or literature values are available. A precision better than 3%, expressed as the between-digestion relative standard deviation (n=4). was obtained for the majority of elements, except in cases limited by low analyte concentrations

  • 8. Baxter, Douglas
    et al.
    Faarinen, Mikko
    ALS Scandinavia AB.
    Österlund, Helene
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Christensen, Morten
    ALS Scandinavia AB, Täby.
    Serum/plasma methylmercury determination by isotope dilution gas chromatography: inductively coupled plasma mass spectrometry2011In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 701, no 2, p. 134-138Article in journal (Refereed)
    Abstract [en]

    A method for the determination of methylmercury in plasma and serum samples was developed. The method uses isotope dilution with 198Hg-labelled methylmercury, extraction into dichloromethane, back-extraction into water, aqueous-phase ethylation, purge and trap collection, thermal desorption, separation by gas chromatography, and mercury isotope specific detection by inductively coupled plasma mass spectrometry. By spiking 2 mL sample with 1.2 ng tracer, measurements in a concentration interval of (0.007–2.9) μg L−1 could be performed with uncertainty amplification factors <2. A limit of quantification of 0.03 μg L−1 was estimated at 10 times the standard deviation of concentrations measured in preparation blanks. Within- and between-run relative standard deviations were <10% at added concentration levels of 0.14 μg L−1, 0.35 μg L−1 and 2.8 μg L−1, with recoveries in the range 82% to 110%. Application of the method to 50 plasma/serum samples yielded a median (mean; range) concentration of methylmercury of 0.081 (0.091; <0.03–0.19) μg L−1. This is the first time methylmercury has been directly measured in this kind of specimen, and is therefore the first estimate of a reference range.

  • 9. Baxter, Douglas
    et al.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Malinovskiy, Dmitry
    Revised exponential model for mass bias correction using an internal standard for isotope abundance ratio measurements by multi-collector inductively coupled plasma mass spectrometry2006In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 21, no 4, p. 427-430Article in journal (Refereed)
    Abstract [en]

    An internal standard (IS) can be used to account for moderate, matrix-related shifts in mass bias using multi-collector inductively coupled plasma mass spectrometry through the empirical, linear relationship between measured isotope abundance ratios for different elements in ln-ln space. Unfortunately, erroneous mass bias corrected isotope abundance ratios may be returned by the model, requiring artificial adjustment of the true isotope abundance ratio of the IS. Although inadequate correction for peak tailing has been convincingly used to explain this problem, our analysis of the literature describing the development of the mass bias correction model using an IS reveals the presence of a source of systematic error. The origin of this error is purely mathematical and is eliminated in the revised model presented, in which mass bias corrected isotope abundance ratios are independent of the isotopic composition of the IS. An expression for computing the total combined uncertainty in the corrected ratio, incorporating contributions from the linear model, the isotopic reference material, and measurements of analyte element and IS in the sample, is also derived.

  • 10. Baxter, Douglas
    et al.
    Rodushkin, Ilya
    ALS Scandinavia AB.
    Engström, Emma
    ALS Scandinavia AB.
    Isotope abundance ratio measurements by inductively coupled plasma-sector field mass spectrometry2012In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 27, no 8, p. 1355-1381Article in journal (Refereed)
    Abstract [en]

    This tutorial reviews fundamental aspects of isotope abundance ratio measurement by inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). After a synopsis of the scope of isotope abundance ratio measurement and a summary introduction to the factors affecting precision and accuracy, attention is turned to noise sources. Detailed theory behind Poisson or counting statistics and plasma flicker noise components is given, since much of the observed imprecision can be attributed to these sources. Using single collector instruments, ion beams from different isotopes are sampled in rapid sequence, and so ratioing of the signals will be subject to fluctuations derived from intensity variations, i.e., flicker noise. It is demonstrated that flicker noise can, under specified circumstances, become the limiting factor for the attainable precision. Furthermore, the practice of partitioning dwell times, ostensibly to optimize precision based on isotopic abundances and assumed Poisson statistics, is shown to be flawed and actually requires accounting for flicker noise. In addition to random uncertainty, various offset factors may contribute to systematic error in measured isotope abundance ratios. Two of these, namely mass scale shift and spectral interferences are ameliorated using ICP-SFMS. The former is eliminated when operating under conditions providing flat-topped peaks, such that the minor drift in mass calibration typical of the technique becomes inconsequential and the intensity remains the same. Isotope abundance ratio measurements are subject to three further important offset factors. First is abundance sensitivity, which quantifies the extent of peak tailing to neighboring masses and can present a considerable source of offset. Second is mass bias, resulting from the fact that all sector field devices exhibit increasing sensitivity with ion mass, and various empirical methods used to correct for this effect are compared and contrasted. Third is detector dead time, which affects mass spectrometers equipped with ion counting systems. Although a well-understood phenomenon, all current methods for determining the dead time on the basis of experimentally measured isotope abundance ratios are likely to yield biased estimates. Finally, the capabilities of ICP-SFMS for the determination of isotope abundance ratios are placed in perspective by making a brief comparison with other techniques.

  • 11. Baxter, Douglas
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Klockare, Dennis
    ALS Analytica AB, Luleå.
    Waara, Hans
    ALS Analytica AB, Luleå.
    Methylmercury measurement in whole blood by isotope-dilution GC-ICPMS with 2 sample preparation methods2007In: Clinical Chemistry, ISSN 0009-9147, E-ISSN 1530-8561, Vol. 53, no 1, p. 111-116Article in journal (Refereed)
    Abstract [en]

    Background: Despite its known toxicity, methylmercury is rarely measured directly in clinical studies; instead, conclusions are based on total mercury measurements. We have developed isotope-dilution-based methods for methylmercury-specific analysis of whole blood by coupled gas chromatography-inductively coupled plasma mass spectrometry (GC-ICPMS). Methods: We analyzed animal and human blood samples after alkaline digestion or extraction of methylmercury into dichloromethane and back extraction into water. Methylmercury was converted to the volatile ethyl derivative, purged, and trapped on a solid-phase collection medium, and then introduced into the GC-ICPMS system. Results: Limits of quantification were 0.4 and 0.03 mu g/L at a signal-to-noise ratio of 10 with the alkaline digestion and extraction methods, respectively. Extraction met our selected acceptable total error criterion, with an SD of 0.58 mu g/L at the critical maternal blood concentration of 5.8 mu g/L.Results obtained with alkaline digestion indicated the need for improved random analytical uncertainty, which was achieved by increasing the enrichment of the isotope dilution. For 37 blood samples, the mean (SD) proportion of total mercury present as methylmercury was 60 (27)%, range 6%-100%.Conclusions: The combination of extraction and isotope-dilution GC-ICPMS meets the requirements for use as a reference method for measuring methylmercury in whole blood.

  • 12.
    Boesen, Amanda H.
    et al.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Thiel, Alexandra
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Fuchs, Boris
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Evans, Alina L.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway.
    Bertelsen, Mads F.
    Center for Zoo and Wild Animal Health, Copenhagen Zoo, Frederiksberg, Denmark.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Scandinavia AB.
    Arnemo, Jon M.
    Department of Forestry and Wildlife Management, Faculty of Applied Ecology, Agricultural Sciences and Biotechnology, Inland Norway University of Applied Sciences, Koppang, Norway. Department of Wildlife, Fish and Environmental Studies, Faculty of Forest Sciences, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Assessment of the LeadCare® Plus for Use on Scandinavian Brown Bears (Ursus arctos)2019In: Frontiers in Veterinary Science, ISSN 2297-1769, Vol. 6, article id 285Article in journal (Refereed)
    Abstract [en]

    Lead (Pb) exposure is associated with adverse health effects in both humans and wildlife. Blood lead levels (BLL) of sentinel wildlife species can be used to monitor environmental lead exposure and ecosystem health. BLL analyzers, such as the LeadCare (R), are validated for use in humans, assessed for use in some avian species and cattle, and are increasingly being used on wildlife to monitor lead exposure. The LeadCare (R) analyzers use a technique called anodic stripping voltammetry (ASV). Species-specific conversion equations have been proposed to approximate the levels found with gold standard measuring methods such as inductively coupled plasma mass spectrometry (ICP-MS) because the ASV method has been shown to underestimate BLL in some species. In this study we assessed the LeadCare (R) Plus (LCP) for use on Scandinavian brown bears (Ursus arctos). LCP measurements were correlated with ICP-MS with a Bland-Altman analyzed bias of 16.3-22.5%, showing a consistent overestimation of BLL analyzed with LCP. Based on this analysis we provide conversion equations for calculating ICP-MS BLL based on the LCP results in Scandinavian brown bears. Our study shows that the LeadCare (R) Plus can be used for monitoring of lead exposure by approximating gold standard levels using conversion equations. This enables comparison with other gold standard measured BLL within the observed range of this study (38.20-174.00 mu g/L). Our study also found that Scandinavian brown bears are highly exposed to environmental lead.

  • 13.
    Boman, Anton
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Rodushkin, Ilya
    ALS Scandinavia AB.
    Åström, E.M.
    Linnaeus University, School of Natural Sciences, Kalmar.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Fe and Zn isotopic variations in Finnish acid sulfate soils2010In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 74, no 12/ Suppl 1, p. A102-Article in journal (Other academic)
  • 14. Boman, Anton
    et al.
    Engström, Emma
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Åström, Mats
    Linnéuniversitetet.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Isotopic variations of Fe and Zn in Finnish acid sulfate soils2010In: Proceedings of the 19th World Congress of Soil Science: Soil Solutions for a Changing World / [ed] RJ Gilkes; N Prakongkep, 2010, p. 1-4Conference paper (Refereed)
    Abstract [en]

    The use of a Neptune high-resolution MC-ICP-MS (Thermo Fisher Scientific) in this study has enabled high precision measurements of Fe and Zn isotopic ratios in Finnish acid sulfate soils in one near shore area (Vassor) and one inland area (Rintala).

  • 15.
    Conrad, Sarah
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gelting, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordblad, Fredrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden .
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden .
    Andersson, Per S.
    Department of Geosciences, Swedish Museum of Natural History, Stockholm, Sweden.
    Porcelli, Don
    Department of Earth Sciences, Oxford University, Oxford, UK.
    Gustafsson, Örjan
    Department of Environmental Science and Analytical Chemistry, Stockholm University, Stockholm, Sweden.
    Semiletov, Igor
    International Arctic Research Center (IARC), University of Alaska, Fairbanks, AK, USA. Pacific Oceanological Institute (POI), Far Eastern Branch of the Russian Academy of Sciences (FEBRAS), Vladivostok, Russia. Tomsk National Research Politechnical University, Arctic Seas Carbon International Research Laboratory, Tomsk, Russia.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Distribution of Fe isotopes in particles and colloids in the salinity gradient along the Lena River plume, Laptev Sea2019In: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 16, no 6, p. 1305-1319Article in journal (Refereed)
    Abstract [en]

     Riverine Fe input is the primary Fe source for the ocean. This study is focused on the distribution of Fe along the Lena River freshwater plume in the Laptev Sea using samples from a 600 km long transect in front of the Lena River mouth. Separation of the particulate ( >  0.22 μm), colloidal (0.22 μm–1 kDa), and truly dissolved (<  1 kDa) fractions of Fe was carried out. The total Fe concentrations ranged from 0.2 to 57μM with Fe dominantly as particulate Fe. The loss of >  99% of particulate Fe and about 90% of the colloidal Fe was observed across the shelf, while the truly dissolved phase was almost constant across the Laptev Sea. Thus, the truly dissolved Fe could be an important source of bioavailable Fe for plankton in the central Arctic Ocean, together with the colloidal Fe. Fe-isotope analysis showed that the particulate phase and the sediment below the Lena River freshwater plume had negative δ56Fe values (relative to IRMM-14). The colloidal Fe phase showed negative δ56Fe values close to the river mouth (about -0.20 ‰) and positive δ56Fe values in the outermost stations (about +0.10 ‰). We suggest that the shelf zone acts as a sink for Fe particles and colloids with negative δ56Fe values, representing chemically reactive ferrihydrites. The positive δ56Fe values of the colloidal phase within the outer Lena River freshwater plume might represent Fe oxyhydroxides, which remain in the water column, and will be the predominant δ56Fe composition in the Arctic Ocean.

  • 16. Engström, Emma
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Förekomst av osmium och osmiumtetroxid i Norrbottens län2007Report (Other (popular science, discussion, etc.))
  • 17.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Öhlander, Björn
    Characterization of the silicon isotopic composition of the terrestrial biogenic output from a boreal forest in Northern Sweden2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 15s, p. A256-Article in journal (Other academic)
    Abstract [en]

    During the last decade, the potential plant impact on the biogeochemical cycle of Si via the large terrestrial biogenic Si reservoir formed by vegetation has attracted considerable interest. It has been concluded that the release of silicic acid from dissolution of soil phytoliths might exceed the Si mobilized by weathering of Si-containing primary minerals, which implies that the biogenic contribution to the total content of Si in the soil profile must be considered in weathering studies. Information about Si isotopes can potentially be used for differentiation between relative contributions from biogenic and mineral sources in natural waters, soil solutions and plants. This would, however, require thorough characterization of the terrestrial biogenic Si reservoir, a task that received somewhat limited attention to date. The aim of the present study was to characterize the Si isotopic composition of a boreal forest, with bedrock consisting of dolomitic limestone, in Northern Sweden. Representative biomass from the forest area exhibited a surprisingly homogenous Si isotopic composition, ranging from δ29Si (-0.14 ± 0.05)‰ (2σ) to (0.13 ± 0.04)‰. Further, a change in the Si isotopic composition of (+0.39 ± 0.04)‰ has been detected in Leymus arenarius, indicating predominant accumulation of heavier isotopes from spring to autumn. Recent studies of Si isotopic composition in plants have been focused on the root uptake of dissolved silicic acid as the only Si accumulation path. Results acquired during the present study provide compelling evidence to suggest that exogenous Si is also incorporated in the surface structure of the plant material. A surface contribution in excess of 5% of the total Si would introduce a significant shift in the bulk isotopic composition (>0.1‰) assuming that the exogenous material differed by 2‰ from the biogenic Si. This strongly suggests that the surface contribution must be carefully considered during in situ uptake studies.

  • 18.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Öhlander, Björn
    Chromatographic purification for the determination of dissolved silicon isotopic composition in natural waters by high-resolution multicollector inductively coupled plasma mass spectrometry2006In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 78, no 1, p. 250-257Article in journal (Refereed)
    Abstract [en]

    A procedure is described for accurate Si isotope ratio measurements by multicollector inductively coupled plasma mass spectrometry (MC-ICPMS). Dissolved silicon was preconcentrated and separated from other elements present in natural surface waters using anion-exchange chromatography. The optimized procedure provides virtually complete elimination of major inorganic constituents while maintaining Si recovery in excess of 97%. High-resolution capabilities of MC-ICPMS used in this study allow interference-free measurements of 28Si and 29Si isotopes using conventional solution nebulization sample introduction without aerosol desolvation. Owing to the magnitude of polyatomic ion contributions in the region of mass 30, mostly from 14N16O+, measurements of the 30Si isotope can be affected by tailing of the interference signals, making exact matching of analyte and nitric acid concentrations in all measurement solutions mandatory. Isotope abundance ratio measurements were performed using the bracketing standards approach and on-line correction for mass-bias variations using an internal standard (Mg). Uncertainties, expressed as 95% confidence intervals, for replication of the entire procedure are better than ±0.18" for δ29Si and ±0.5" for δ30Si. For the first time with MC-ICPMS, the quality of Si isotope abundance ratio measurements could be verified using a three-isotope plot. All samples studied were isotopically heavier than the IRMM-018 Si isotopic reference material.

  • 19. Engström, Emma
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Baxter, Douglas
    Ecke, Frauke
    Österlund, Helene
    Öhlander, Björn
    Temporal isotopic variations of dissolved silicon in a pristine boreal river2009In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Suppl. S, p. A333-Article in journal (Other academic)
    Abstract [en]

    Interest in quantifying the biogenic impact on the terrestrial biogeochemical Si cycle has increased significantly since biological control has been suggested. Previous observations of isotopic fractionation of Si during biogeochemical and geochemical processes imply that seasonal dissolved Si isotopic patterns in rivers have the potential for use in extracting information about the riverineand terrestrial biogeochemical Si cycles.Therefore, variations in the isotopic composition of dissolved riverine Si were investigated for the Kalix River, Northern Sweden, one of the largest pristine rivers in Europe, based on high-frequency sampling during a period of 25 weeks from early April to early October 2006. Temporal variations spanning 0.4. for δ29Si and 0.8. for δ30Si of dissolved Si in the Kalix River were observed during the period, suggesting that the riverine Si input to the oceans cannot be considered to have a constant Si isotopic composition even on a short time scale. The results implicate biogeochemical Si-cycling via formation and dissolution of biogenic silica as major processes controlling the Si transport in boreal systems. The Si budget in the river system appeared to be controlled by relative Si accretions during high discharge events and relative Si depletions in the subarctic mountainous and lake dominated areas. There were also temporal variations in Si isotopic composition with accretion (relative Si contribution), accompanied by depletion of the heavier Si isotopes, while the opposite trend was observed during periods of riverine Si depletion. These isotope variations can be explained by release of plant derived silica, depleted in heavier Si isotopes, during the spring snowmelt. Further, increased volumetric contribution from the headwater and losses of Si due to biogenic silica formation by diatoms in the subarctic lakes at a later period are expected to be responsible for the preferential losses of lighter isotopes. These conclusions are further verified by land cover analysis.

  • 20.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Baxter, Douglas
    Ecke, Frauke
    Österlund, Helene
    Öhlander, Björn
    Temporal isotopic variations of dissolved silicon in a pristine boreal river2010In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 271, no 3-4, p. 142-152Article in journal (Refereed)
    Abstract [en]

    It has previously been concluded that the stable Si isotopes are fractionated during geochemical and biogeochemical elemental transfers, such as weathering and precipitation of clays and biogenic Si, which has opened up the possibility of using Si as a tracer in natural terrestrial ecosystems. Furthermore, quantification of the biogenic impact on the biogeochemical Si cycle has attracted significant scientific interest since biological control has been suggested. Previous observations of seasonal variations in the dissolved Si isotopic pattern further imply that high-frequency riverine sampling during main hydrological events might provide important information about natural processes governing the fluvial biogeochemical Si cycle.Therefore, temporal variations in the isotopic composition of riverine dissolved Si were investigated for the Kalix River, Northern Sweden, the largest pristine river system in Europe, based on high-frequency sampling during a period of 25 weeks from early April to early October 2006. Temporal variations spanning 0.4‰ for δ29Si and 0.8‰ for δ30Si of dissolved Si in the Kalix River were observed during the period, suggesting that the riverine dissolved Si input to the oceans cannot be considered to have a constant Si isotopic composition even on a short time scale.The results implicate biogeochemical Si-cycling via formation and dissolution of biogenic silica as processes significantly affecting the dissolved Si transport in boreal systems during April to early October. The Si budget in the river system appeared to be controlled by relative Si enrichment during high discharge events and relative Si depletions in the subarctic mountainous and lake dominated areas. The Si enrichments and depletions were accompanied by decreasing and increasing riverine δ29Si and δ30Si, respectively. These isotope variations can be explained by release of plant derived silica, depleted in heavier Si isotopes, during the spring snowmelt. Further, increased volumetric contribution from the headwater and losses of dissolved Si due to biogenic silica formation by diatoms in the subarctic lakes at a later period are expected to be responsible for the preferential losses of lighter isotopes, as further verified by land cover analysis

  • 21. Engström, Emma
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Ingri, Johan
    Baxter, Douglas
    Silicon isotopic composition of boreal forest vegetation in Northern Sweden2008In: Chemical Geology, ISSN 0009-2541, E-ISSN 1872-6836, Vol. 257, no 3-4, p. 247-256Article in journal (Refereed)
    Abstract [en]

    Thorough characterization of the Si isotopic composition of the terrestrial biogenic pool could potentially allow Si isotope information to be used when assessing the relative contributions from biogenic and mineral sources to soil water, plants and surface waters. In the present study, the Si isotopic compositions of major biomass components in a boreal forest in Northern Sweden were investigated, along with the relative contributions from exogenous Si incorporated in the plant structure. This was achieved using chemical purification and high-resolution multi-collector inductively coupled mass spectrometry (MC-ICP-MS) for the precise and accurate determination of the Si isotopic composition of plants. The technique, which relies on multi-elemental analysis of plant ashes and sample-specific HF-dissolution followed by strong-anion exchange chromatography, allows efficient separation of Si from matrix and interfering elements, while recovering in excess of 99% Si. The long-term instrumental reproducibility, expressed as two standard deviations (2σ), for the isotopic reference material NBS28 (n=12) was 0.06‰ for δ29Si and 0.12‰ for δ30Si. Results for the analyses of composite plant samples for the eight most prolific species in the boreal forest yielded a surprisingly homogenous Si isotopic composition, expressed as δ29Si (±expanded combined uncertainty) and δ30Si, ranging from (-0.15±0.11)‰ to (0.13±0.06)‰ and (-0.31±0.08)‰ to (0.22±0.13)‰, respectively. Isotopic and elemental analyses of local airborne particulate material suggest that the exogenous Si contribution varies between >1% and >70%, indicating that the potential surface contribution must be considered during Si uptake studies. The present study thus provides evidence that thorough appreciation of the forms of Si in plants is an absolute requirement when assessing the plant impact on the Si cycle via the difference in dissolution kinetics for phytoliths and lithogenic Si.

  • 22.
    Engström, Emma
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Stenberg, Anna
    Luleå tekniska universitet.
    Baxter, Douglas
    Malinovskiy, Dmitry
    Irma, Mäkinen
    Finnish Environment Institute.
    Pönni, Seppo
    Pirkanmaa Regional Environment Centre.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Effects of sample preparation and calibration strategy on accuracy and precision in the multi-elemental analysis of soil by sector field ICP-MS2004In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 19, p. 858-866Article in journal (Refereed)
    Abstract [en]

    Soil samples were prepared for multi-element analysis using HNO3 leaching or pseudo-total digestion with HNO3, HCl and HF in a microwave oven, both methods requiring 70 min heating time. Two calibration approaches for the soil characterization were also compared: external calibration, combined with internal standardization, and isotope dilution (ID) after appropriate spiking of the soils with a stable isotope mixture prior to sample preparation. Analyses were performed using inductively coupled plasma sector field mass spectrometry (ICP-SFMS). Accurate total elemental concentrations were only obtained for Cd and P using both sample preparation methods in two certified reference materials, NIST SRM 2709 and CCRMP SO-2, as well as comparable values for a Finnish inter-laboratory soil. The pseudo-total digestion method also provided accurate results for As, Be, Co, Fe, Mn, Ni, Pb, Sb, Ti, V and Zn. For Cu in SO-2 and Cr in both certified reference materials, incomplete recoveries were always obtained. In the case of Cr, this is due to difficulties associated with the complete solubilization of refractory minerals.For a given final dilution factor, external calibration provides better limits of detection (LODs) than ID. As both methods of quantification yield results of essentially equivalent accuracy and precision, external calibration is to be preferred as a greater number of elements are amenable to analysis in a shorter measurement time. On the other hand, ID can be combined with matrix separation (NH3 precipitation was used here), allowing lower dilution factors to be used without deleterious effects on the instrumental performance. In particular, improved LODs could be obtained for Cd, Cu and Hg, primarily as a result of being able to introduce ten-fold more concentrated solutions from which the bulk of the matrix had been removed. For Cu and Ni, matrix separation almost eliminated Ti, and thus the formation of spectrally interfering TiO+ was completely suppressed. Potentially, the combination of ID and matrix separation would allow these elements to be determined without resorting to medium resolution measurement mode, again improving the LODs for the determination by ID-ICP-SFMS.

  • 23. Engström, Emma
    et al.
    Stenberg, Anna
    Luleå tekniska universitet.
    Senioukh, Svetlana
    ALS Analytica AB, Luleå.
    Edelbro, Roland
    ALS Analytica AB, Luleå.
    Baxter, Douglas
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Multi-elemental characterization of soft biological tissues by inductively coupled plasma-sector field mass spectrometry2004In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 521, no 2, p. 123-135Article in journal (Refereed)
    Abstract [en]

    The performance of double-focusing, sector field ICP-MS (ICP-SFMS) for the multi-elmental analysis of soft tissues following microwave-assisted digestion with nitric acid was eveluated and factors affecting method limits of detection discussed. Accuracy was assessed by replicate analyses of certified reference materials and by participation in performance evaluation programs; the precision was better than 5% relative standard deviation (RSD) for the majority of elements. Cl was the only element for which ICP-SFMS data consistently deviated from certified concentrations in the reference materials tested. Comparison between results obtained by ICP-SFMS and ICP optical emission spectrometry showed good agreement for elements present in tissues at concentrations above 2 μg g-1. The concentrations of 68 elements in different fish and animal soft tissues (muscle, liver, kidney, lung and brain) are presented, and, where possible, compared to previously published data.

  • 24.
    Entwistle, Jane A.
    et al.
    Department of Geography and Environmental Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Amaibi, Patrick M.
    Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Dean, John R.
    Department of Applied Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Deary, Michael E.
    Department of Geography and Environmental Sciences, Northumbria University, Ellison Building, Newcastle upon Tyne NE1 8ST, UK.
    Medock, Daniel
    Toxicology Department, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxon OX11 0RQ, UK.
    Morton, Jackie
    Health and Safety Executive, Harpur Hill, Buxton SK17 9JN, UK.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Global Scandinavia, Aurorum 10, 977 75 Luleå, Sweden.
    Bramwell, Lindsay
    Institute of Health and Society, Medical Faculty, Newcastle University, Newcastle upon Tyne NE2 4AX, UK.
    An apple a day? Assessing gardeners' lead exposure in urban agriculture sites to improve the derivation of soil assessment criteria2019In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 122, p. 130-141Article in journal (Refereed)
    Abstract [en]

    Globally, many of our urban agriculture sites (UAS) contain high levels of lead (Pb), a contaminant of toxicological concern to humans. To improve the derivation of soil assessment criteria at UAS, and avoid inappropriate closure of these valuable community spaces, we sampled nearly 280 paired soil and crop samples across 31 UAS gardens. This sampling was coupled with an exposure and food frequency questionnaire and participants blood Pb levels (BLL), (43 gardeners and 29 non-gardening neighbours). In 98% of the sampled soils, Pb concentrations were above the current UK soil guideline for UAS (80 mg/kg), however despite the high soil Pb (geometric mean: 324 mg/kg), and high soil bioaccessible Pb (geometric mean: 58.7%), all participants BLL were <4.1 μg/dL (range: 0.6–4.1 μg/dL). Indeed, there was no statistically significant difference between the BLL of the UAS gardeners and those of their non-gardening neighbours (p = 0.569).

    Pb uptake, however, varied with crop type and our study highlights the suitability of certain crops for growing at UAS with elevated Pb (e.g. tubers, shrub and tree fruit), whilst limiting the consumption of others (selected root vegetables, such as rhubarb, beetroot, parsnips and carrots, with observed Pb concentrations > 0.1 mg/kg FW).

    The importance of defining the exposure scenario of a specific sub-population (i.e. UAS gardeners) is highlighted. Our preferred models predict site specific assessment criteria (SSAC) of 722–1634 mg/kg. We found fruit and vegetable consumption rates by all participants, and not just the UAS gardeners, to be considerably higher than those currently used to derive the UK's category 4 screening levels (C4SLs). Furthermore, the soil to plant concentration factors (SPCFs) used to derive the UAS C4SL significantly over predict Pb uptake. Our study indicates it may be appropriate to develop a distinct exposure dataset for UAS. In particular we recommend the derivation of SPCFs that are reflective of urban soils, both in terms of the range of soil Pb concentrations typically observed, but also the sources (and hence human oral bioaccessibility and plant-availability) of this Pb.

  • 25.
    Filella, Montserrat
    et al.
    Department F.-A. Forel, University of Geneva, Geneva, Switzerland..
    Reimann, Clemens
    Geological Survey of Norway, Trondheim, Norway..
    Biver, Marc
    Bibliothèque Nationale de Luxembourg, Luxembourg, Luxembourg.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden..
    Rodushkina, Katerina
    ALS Laboratory Group, ALS Scandinavia AB, Luleå, Sweden.Ghent University, Department of Chemistry, Atomic and Mass Spectrometry Research Group, Campus Sterre, Ghent, Belgium.
    Tellurium in the environment: current knowledge and identification of gaps2019In: Environmental Chemistry, ISSN 1448-2517, E-ISSN 1449-8979, Vol. 16, no 4, p. 215-228Article in journal (Refereed)
    Abstract [en]

    Tellurium has recently become a ‘technology-critical element’ increasingly used in new applications. Thus, potential environmental impacts need to be evaluated. This, in turn, requires knowledge of its typical concentrations in the environment along with better understanding of the chemical processes governing its environmental behaviour. We evaluate the current situation of our understanding of tellurium in the environment and identify the areas where improvements in measurement technology are most needed. The comprehensive evaluation of published data described in this study shows that values for tellurium concentrations in the different environmental compartments are scarce, particularly in the case of natural waters where reliable estimates of tellurium concentrations in seawater and freshwater cannot even be produced. Data in air are even less abundant than for natural water. Concentration data do exist for soils suggesting a predominant geological origin. Some urban soil surveys and lake sediment data close to tellurium contamination sources point to possible effects on the element’s distribution as a result of human activity; long-range atmospheric transport remains to be proved. Current knowledge about tellurium behaviour in the environment is strongly hindered by analytical difficulties, with insufficiently low analytical detection limits being the main limitation. For instance, ‘dissolved’ concentrations are well below current analytical capabilities in natural water and often require pre-concentration procedures that, for the moment, do not provide consistent results; solid samples require complex mineralisation procedures that often exclude tellurium from routine multielement studies. In general, the use of available measuring techniques is far from straightforward and needs particular expertise. Overcoming the current analytical limitations is essential to be able to progress in the field.

  • 26.
    Filella, Montserrat
    et al.
    Department F.-A. Forel, University of Geneva.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    A concise guide for the determination of less-studied technology-critical elements (Nb, Ta, Ga, In, Ge, Te) by inductively coupled plasma mass spectrometry in environmental samples2018In: Spectrochimica Acta Part B - Atomic Spectroscopy, ISSN 0584-8547, E-ISSN 1873-3565, Vol. 141, p. 80-84Article in journal (Refereed)
    Abstract [en]

    There is an increasing demand for analytical techniques able to measure so-called ‘technology-critical elements’, a set of chemical elements increasingly used in technological applications, in environmental matrices. Nowadays, inductively coupled plasma-mass spectrometry (ICP-MS) has become the technique of choice for measuring trace element concentrations. However, its application is often less straightforward than often assumed. The hints and drawbacks of ICP-MS application to the measurement of a set of less-studied technology-critical elements (Nb, Ta, Ga, In, Ge and Te) is discussed here and concise guidelines given.

  • 27.
    Genuis, Stephen J.
    et al.
    University of Alberta.
    Birkholz, Detlef
    University of Alberta.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Beesoon, Sanjay
    Department of Laboratory Medicine, University of Alberta, Edmonton.
    Blood, urine, and sweat (BUS) study: monitoring and elimination of bioaccumulated toxic elements2011In: Archives of Environmental Contamination and Toxicology, ISSN 0090-4341, E-ISSN 1432-0703, Vol. 61, no 2, p. 344-357Article in journal (Refereed)
    Abstract [en]

    There is limited understanding of the toxicokinetics of bioaccumulated toxic elements and their methods of excretion from the human body. This study was designed to assess the concentration of various toxic elements in three body fluids: blood, urine and sweat. Blood, urine, and sweat were collected from 20 individuals (10 healthy participants and 10 participants with various health problems) and analyzed for approximately 120 various compounds, including toxic elements. Toxic elements were found to differing degrees in each of blood, urine, and sweat. Serum levels for most metals and metalloids were comparable with those found in other studies in the scientific literature. Many toxic elements appeared to be preferentially excreted through sweat. Presumably stored in tissues, some toxic elements readily identified in the perspiration of some participants were not found in their serum. Induced sweating appears to be a potential method for elimination of many toxic elements from the human body. Biomonitoring for toxic elements through blood and/or urine testing may underestimate the total body burden of such toxicants. Sweat analysis should be considered as an additional method for monitoring bioaccumulation of toxic elements in humans

  • 28.
    Genuis, Stephen John
    et al.
    Faculty of Medicine, University of Alberta, Edmonton.
    Schwalfenberg, Gerry K.
    Faculty of Medicine, University of Alberta, Edmonton.
    Siy, Anna Kristen J.
    Faculty of Medicine, University of Alberta, Edmonton.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Toxic element contamination of natural health products and pharmaceutical preparations2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 11Article in journal (Refereed)
    Abstract [en]

    Background: Concern has recently emerged regarding the safety of natural health products (NHPs)-therapies that are increasingly recommended by various health providers, including conventional physicians. Recognizing that most individuals in the Western world now consume vitamins and many take herbal agents, this study endeavored to determine levels of toxic element contamination within a range of NHPs. Methods: Toxic element testing was performed on 121 NHPs (including Ayurvedic, traditional Chinese, and various marine-source products) as well as 49 routinely prescribed pharmaceutical preparations. Testing was also performed on several batches of one prenatal supplement, with multiple samples tested within each batch. Results were compared to existing toxicant regulatory limits. Results: Toxic element contamination was found in many supplements and pharmaceuticals; levels exceeding established limits were only found in a small percentage of the NHPs tested and none of the drugs tested. Some NHPs demonstrated contamination levels above preferred daily endpoints for mercury, cadmium, lead, arsenic or aluminum. NHPs manufactured in China generally had higher levels of mercury and aluminum. Conclusions: Exposure to toxic elements is occurring regularly as a result of some contaminated NHPs. Best practices for quality control-developed and implemented by the NHP industry with government oversight-is recommended to guard the safety of unsuspecting consumers

  • 29.
    Gonfiantini, Roberto
    et al.
    Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR.
    Tonarini, Sonia
    Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR.
    Gröning, Manfred
    International Atomic Energy Agency, Division of Physical and Chemical Sciences, Vienna.
    Adorni-Braccesi, Alessandra
    Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR.
    Al-Ammar, Assad S
    Department of Chemistry, University of Massachusetts.
    Astner, Marcus
    Departement für Chemie und Biochemie, Universität Bern.
    Bächler, Sebastien
    Departement für Chemie und Biochemie, Universität Bern.
    Barnes, Ramon M.
    Department of Chemistry, University of Massachusetts.
    Bassett, Randy L.
    Geochemical Technologies Corporation, Wheat Ridge, Colorado.
    Cocherie, Alain
    Bureau de Recherches Géologiques et Minières, Orléans.
    Deyhle, Annette
    GEOMAR, Kiel.
    Dini, Andrea
    Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR.
    Ferrara, Giorgio
    Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR.
    Gaillardet, Jérôme
    Institut de Physique du Globe, Université de Paris.
    Grimm, Judith
    Departement für Chemie und Biochemie, Universität Bern.
    Guerrot, Catherine
    Bureau de Recherches Géologiques et Minières, Orléans.
    Krähenbühl, Urs
    Departement für Chemie und Biochemie, Universität Bern.
    Layne, Graham
    Woods Hole Oceanographic Institution, Woods Hole, Massachusetts.
    Lemarchand, Damien
    Institut de Physique du Globe, Université de Paris.
    Meixner, Anette
    GeoForschungsZentrum Potsdam.
    Northington, Jack
    West Coast Analytical Services, Santa Fe Springs.
    Pennisi, Maddalena
    Istituto di Geoscienze e Georisorse, Area di Ricerca del CNR.
    Reitznerová, Eva
    Department of Chemistry, University of Massachusetts.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Sugiura, Naoji
    Department of Earth and Planetary Science, University of Tokyo.
    Zack, Thomas
    Department of Earth Science, Memorial University of Newfoundland.
    Intercomparison of boron isotope and concentration measurements: Part II: Evaluation of results2005In: Geostandards Newsletter, ISSN 0150-5505, Vol. 27, no 1, p. 41-57Article in journal (Refereed)
    Abstract [en]

    The Istituto di Geoscienze e Georisorse (IGG), on behalf and with the support of the International Atomic Energy Agency (IAEA), prepared eight geological materials (three natural waters and five rocks and minerals), intended for a blind interlaboratory comparison of measurements of boron isotopic composition and concentration. The materials were distributed to twenty seven laboratories - virtually all those performing geochemical boron isotope analyses in the world - which agreed to participate in the intercomparison exercise. Only fifteen laboratories, however, ultimately submitted the isotopic and/or concentration results they obtained on the intercomparison materials. The results demonstrate that interlaboratory reproducibility is not well reflected by the precision values reported by the individual laboratories and this observation holds true for both boron concentration and isotopic composition. The reasons for the discrepancies include fractionations due to the chemical matrix of materials, relative shift of the zero position on the δ11 B scale and a lack of well characterized materials for calibrating absolute boron content measurements. The intercomparison materials are now available at the IAEA (solid materials) and IGG (waters) for future distribution.

  • 30. Heghe, Lana Van
    et al.
    Engström, Emma
    Rodushkin, Ilya
    ALS Scandinavia AB.
    Isotopic analysis of the metabolically relevant transition metals Cu, Fe and Zn in human blood from vegetarians and omnivores using multi-collector ICP-mass spectrometry2012In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 27, p. 1327-1334Article in journal (Refereed)
    Abstract [en]

    Multi-collector ICP-mass spectrometry (MC-ICP-MS) was used for the isotopic analysis of Cu, Fe and Zn, isolated from human whole blood. For chromatographic isolation of these elements, the method first described by Maréchal, Telouk and Albarède (Chem. Geol., 1999, 156, 251–273) and relying on the use of AG MP-1 strong anion exchange resin was further tailored and subsequently validated. It was shown that all three target elements could be obtained in pure form and with quantitative recovery from Seronorm whole blood reference material. MC-ICP-MS isotope ratio measurement conditions were optimized so as to avoid the influence of spectral overlap and the capabilities of several methods to correct for instrumental mass discrimination were compared. The method developed was then applied to a set of whole blood samples from supposedly healthy volunteers (reference population). For Fe, the by now well-known difference in isotopic composition between blood from male and female individuals was confirmed. The isotopic composition of Zn in whole blood was assessed to be governed by the diet as a significant difference could be established between blood from vegetarians and from omnivores, respectively. For the isotopic composition of Cu, interpretation of the results is more challenging, as neither gender, nor diet seems to have a significant influence, but the combined influence of both factors may show an effect.

  • 31.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Conrad, Sarah
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Lidman, Fredfrik
    Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå.
    Nordblad, Fredrik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Engström, Emma
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering. ALS Laboratory Group, ALS Scandinavia AB.
    Rodushkin, Ilia
    ALS Laboratory Group, ALS Scandinavia AB.
    Porcelli, Don
    Department of Earth Sciences, University of Oxford.
    Iron isotope pathways in the boreal landscape: Role of the riparian zone2018In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 239, p. 49-60Article in journal (Refereed)
    Abstract [en]

    Stable Fe isotope compositions have been measured in water samples of the subarctic Kalix River, a first-order stream, and soil water samples from a riparian soil profile adjacent to the first-order stream (Northern Sweden). In the first-order stream, dominated by forest, both the particulate (>0.22 µm) and dissolved (<0.22 µm) phase showed negative δ56Fe values (relative to IRMM-014) during base flow and meltwater discharge in May (−0.97 to −0.09‰). The Fe isotope composition in the water from the riparian soil profile varied between −0.20 and +0.91‰ with sharp gradients near the groundwater table. A linear correlation between the δ56Fe values and the TOC/Febulk ratio was measured during snowmelt in the unfiltered river waters (δ56Fe from −0.02 to +0.54‰), suggesting mixing of two Fe components. Two groups of Fe aggregates, with different Fe isotope compositions, are formed in the boreal landscape. We propose that carbon-rich aggregates, Fe(II)(III)-OC, have negative δ56Fe values and Fe-oxyhydroxides have positive δ56Fe values. A mixture of these two components can explain temporal variations of the Fe isotope composition in the Kalix River. This study suggests that stable Fe isotopes can be used as a tool to track and characterize suspended Fe-organic carbon aggregates during transport from the soil, via first-order streams and rivers, to coastal sediment. Furthermore, the differences in Fe isotope values in the Kalix River and the first-order stream during base flow conditions suggest that the primary Fe sources for river water change throughout the year. This model is combining the Fe isotope composition of first-order streams and rivers to weathering and transport processes in the riparian soil.

  • 32.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Gelting, Johan
    Nordblad, Fredrik
    Engström, Emma
    Rodushkin, Ilya
    Andersson, P.S.
    Oxford University.
    Porcelli, D.
    Oxford University.
    Gustafsson, O.
    Stockholms Universitet.
    Semiletov, I.
    University of Alaska.
    Öhlander, Björn
    Fractionation of iron isotopes during estuarine mixing in Ob, Yenisey and Lena freshwater plumes2009In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, no 13, Suppl. S, p. A569-Article in journal (Other academic)
    Abstract [en]

    Iron isotopes were measured in suspended matter (>0.2 µm) in the Ob, Yenisey and Lena River freshwater plumes during the International Siberian Shelf Study 2008 (ISSS-08). The δ56Fe value was around zero within the Lena River and close to the river mouth, but changed to more negative values in the outer parts of the plume. In both the Ob and Yenisey plumes suspended matter in the surface water had clearly negative values whereas samples close to the bottom showed values close to zero.It has previously been suggested that total Fe in river suspended matter (>0.2µm) in boreal regions is roughly a mixture of three phases, detrital particles (δ56Fe around zero), oxyhydroxide particles (δ56Fe positive) and C-Fe particles (δ56Fe negative). We suggest that the δ56Fe pattern observed in this study is the result of relatively rapid removal of detrital particles and Fe-oxyhydroxides, leaving a suspended fraction with negative values in the surface water in the outer parts of the freshwater plumes. Hence, during estuarine mixing of suspended particles heavy iron isotopes are deposited close to the river mouth, whereas light isotopes are exported to open ocean water.

  • 33.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Malinovskiy, Dmitry
    Rodushkin, Ilia
    Baxter, Douglas
    Widerlund, Anders
    Andersson, Per
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Gustafsson, Örjan
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Forsling, Willis
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Iron isotope fractionation in river colloidal matter2006In: Earth and Planetary Science Letters, ISSN 0012-821X, E-ISSN 1385-013X, Vol. 245, no 3-4, p. 792-798Article in journal (Refereed)
    Abstract [en]

    Temporal variations in the iron isotopic composition, δ56Fe between − 0.13‰ and 0.31‰, have been measured in the suspended fraction in a Boreal river. The major mechanism behind these variations is temporal mixing between two types of particles–colloids, Fe-oxyhydroxides and Fe–C colloids. Data in this study indicate that these two types of colloids have different Fe-isotope composition. The Fe–C colloid has a negative δ56Fe value whereas the Fe-oxyhydroxide colloid is enriched in 56Fe. These two types of colloidal matter have different hydrogeochemical origin. The Fe–C colloid reaches the river during storm events when the upper sections of the soil profile (O and E horizons) are flooded by a rising water table. Colloidal Fe-oxyhydroxides reach the river via inflow and subsequent oxidation of groundwater enriched in dissolved Fe(II).

  • 34.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Nordling, Susanna
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Larsson, Jenny
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Rönnegård, Jenny
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Nilsson, Nina
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Rodushkin, Ilia
    Dahlqvist, Ralf
    Department of Geology and Geochemistry, Stockholm University.
    Andersson, Per
    Laboratory for Isotope Geology. Swedish Museum of Natural History, Stockholm.
    Gustafsson, Örjan
    Institute of Applied Environmental Research (ITM), Stockholm University.
    Size distribution of colloidal trace metals and organic carbon during a coastal bloom in the Baltic Sea2004In: Marine Chemistry, ISSN 0304-4203, E-ISSN 1872-7581, Vol. 91, no 1-4, p. 117-130Article in journal (Refereed)
    Abstract [en]

    The physico-chemical speciation of organic carbon and selected metals was measured during a coastal bloom in Ekhagen Bay, Baltic Sea, using ultrafiltration.One important objective with the study was to see if any depletion of trace metals could be measured in the directly bioavailable fraction (<1000 Da, the soluble low molecular weight fraction, LMW) during a plankton bloom. Filters with five different cut-offs were used (1 kD (1000 Da), 5 kD, 10 kD, 100 kD and 0.22 μm) in order to delineate the size distribution of colloidal organic carbon (COC) and trace metals. During the bloom in May, LMW Al, Co, Cu, Mn and Ni concentrations decreased although the colloidal and particulate concentrations were relatively high. Data show that desorption of colloidal and particulate bound trace metals to the LMW fraction was slower than the process depleting the LMW fraction. Estimates of the maximum active uptake of Cu, Ni and Mn by the phytoplankton, and the loss of non-bioactive Al from the LMW fraction, indicate that processes other than active uptake by phytoplankton must contribute to the observed depletion of trace metals in the LMW fraction. Hence, in order to estimate the bioavailable pool of trace metals for plankton during bloom conditions, these other processes must be understood and quantified. Transparent Exopolymeric Particles (TEP, reflecting sugar-rich phytoplankton exudates) increased around eight times during the plankton bloom. We hypothesize that the formation of TEP is a process that might be important for the transfer of trace metals from the LMW to the particulate fraction during the phytoplankton bloom, but the significance of TEP for this depletion in Baltic Sea surface water remains to be shown.

  • 35.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Pekka, L.
    Luleå tekniska universitet.
    Dauvalter, V.
    Institute of Problems of Industrial Ecology of the North, Kola Scientific Center, Russian Academy of Sciences.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Peinerud, E.
    ALS Laboratory Group.
    Manganese redox cycling in Lake Imandra: Impact on nitrogen and the trace metal sediment record2011In: Biogeosciences Discussions, ISSN 1810-6277, E-ISSN 1810-6285, Vol. 8, no 1, p. 273-321Article in journal (Refereed)
    Abstract [en]

    Sediment and water samples from the mine-polluted Yokostrovskaya basin in Lake Imandra have been analysed. Three major processes have influenced the accumulation and distribution of metals in the sediment: (1) Development of the apatite-nepheline and the sulfide ore mining industries. (2) Secondary formation of sulphides in the upper sediment column. (3) Redox cycling of Mn in the surface sediment and in the bottom water. This study demonstrate the dominant role of the Mn redox cycling in controlling distribution of several major and trace elements, especially during the winter stratification period. Mn oxides act as a major scavenger and carrier for the non-detrital fraction of Al, Ca, K, Mg, P, Ba, Co, Cu, Ni, Mo and Zn in the bottom water. Aluminium, Ca, K, Mg, P, Cu, Ni and Zn are mainly sorbed at the surface of the particulate Mn phase, while Ba and Mo form a phase (or inner sphere complex) with Mn. Co is associated with the Mn-rich phase, probably by oxidation of Co(II) to a trivalent state by the particulate Mn surface. Formation and dissolution of Mn particles most likely also control anoxic ammonium oxidation to nitrate and reduction of nitrate to N2. It is shown that secondary sulphides in Lake Imandra sediments are fed with trace metals primarily scavenged from the dissolved phase in the water column. This enrichment process, driven by the Mn-redox cycle, therefore changes the sediment record by the transfer of a dissolved pollution signal to the particulate sediment record, thus making it more complicated to trace direct influence of particles from different pollution sources.

  • 36.
    Ingri, Johan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rodushkin, Ilya
    Malinovskiy, Dmitry
    Hålenius, U.
    Swedish Museum of Natural History.
    Baxter, Douglas
    Andersson, P.S:
    Swedish Museum of Natural History.
    Fractionation of iron isotopes in shallow-marine ferromanganese concretions2007In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 71, no 15S, p. A428-Article in journal (Other academic)
  • 37. Malinovskiy, Dmitry
    et al.
    Baxter, Douglas
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ion-specific isotopic fractionation of molybdenum during diffusion in aqueous solutions2007In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 41, no 5, p. 1596-1600Article in journal (Refereed)
    Abstract [en]

    Experiments modeling diffusion of Mo in aqueous solutions have been performed and, using multicollector ICP-MS, the ratios of the diffusivities of Mo isotopes, D97Mo/D95Mo, in aqueous solutions have been determined. Diffusion of MoO42- ions in solution was concomitant with Mo isotopic fractionation with D97Mo/D95Mo = 0.99988 ± 0.00004 (2σ for n = 3). In contrast, during diffusion of Mo polyanions, such as Mo7O246- and Mo8O264-, no measurable isotope fractionation has been found with D97Mo/D95Mo = 1.00000 ± 0.00002 (2σ for n = 3). These results indicate the need for due consideration to Mo speciation when attempting to interpret the role of diffusive fluxes in the formation of Mo isotopic signatures in nature. They also raise the possibility that the various chemical forms of other transition metals may be characterized by species-specific isotopic fractionation effects during physicochemical reactions.

  • 38. Malinovskiy, Dmitry
    et al.
    Dahlqvist, Ralf
    Swedish Museum of Natural History.
    Baxter, Douglas
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Rodushkin, Ilya
    Performance of diffusive gradients in thin films for measurements of the isotopic composition of soluble Zn2005In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 537, no 1-2, p. 401-405Article in journal (Refereed)
    Abstract [en]

    The application of diffusive gradients in thin films (DGT) samplers for measurements of the isotopic composition of soluble Zn by multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) was tested under laboratory conditions. The effect of diffusion in hydrogels as a possible source of fractionation was investigated by measuring Zn isotope ratios for different fractions of Zn accumulated by DGT and comparing with the bulk isotope composition of the solution. An important finding of this study is that, provided quantitative elution is obtained, no fractionation of Zn isotopes due to the diffusion process is detectable within the reported precision of MC-ICPMS measurements. Consequently, DGT samplers are suitable for studies of the Zn isotopic composition in natural waters.

  • 39. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Axelsson, Mikael D.
    SGAB Analytica, Luleå.
    Baxter, Douglas
    Determination of rhenium and osmium concentrations in molybdenite using laser ablation double focusing sector field ICP-MS2004In: Journal of Geochemical Exploration, ISSN 0375-6742, E-ISSN 1879-1689, Vol. 81, no 1-3, p. 71-79Article in journal (Refereed)
    Abstract [en]

    A technique for the in situ determination of Re and Os in molybdenite samples using direct solid sampling by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is described. The sample preparation is limited to molybdenite separation followed by grinding and pressing to pellets. For Re determination, the best results were obtained using external calibration in conjunction with internal standardization. Isotopes of both molybdenum and sulphur could be used as internal standards. This quantification approach provides precision levels generally better than 10% the relative standard deviation (RSD) with similar levels of accuracy. Os concentrations were derived from Re concentrations and measured isotopic ratios of intensities measured at masses 187 and 185, using W isotopes for on-line mass bias correction. As a rule, LA-ICP-MS results for Os agree with corresponding isotope dilution ICP-MS data to within 30%. Reproducibility is strongly dependent on the age of the molybdenite as well as on the precision of isotope ratio measurements, which in turn depend on Re and W concentrations. The proposed technique provides a rapid estimation of Re and Os concentrations for subsequent precise analysis by isotope dilution ICP-MS.

  • 40. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilia
    Baxter, Douglas
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Simplified method for the Re-Os dating of molybdenite using acid digestion and isotope dilution ICP-MS2002In: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 463, no 1, p. 111-124Article in journal (Refereed)
    Abstract [en]

    An analytical method was developed for Os-Re dating of molybdenite. The method is based on determination of Os and Re concentrations in molybdenite by isotope dilution inductively-coupled plasma mass spectrometry (ID-ICP-MS). Sample digestion and sample/spike equilibration were achieved by a two-stage autoclave-based procedure using a mixture of nitric and sulphuric acids. Os was separated from the sample digest by modified single-stage distillation of osmium tetraoxide (OsO4) using elevated temperature and on-line addition of hydrogen peroxide. OsO4(g) was trapped in a mixture of 0.05% thiourea in 0.05 M sodium hydroxide. An anion-exchange column was used to separate Re from excess Mo in the solution remaining after distillation. Os and Re isotope ratio measurements were performed by single-collector, double focusing inductively-coupled plasma mass spectrometry (ICP-MS) with on-line mass-bias correction. Typical instrumental precision was in the range 0.02-0.2% relative standard deviation (R.S.D.) depending on the analyte concentrations. Notorious Os memory effects in the ICP-MS introduction system were eliminated using 5% ammonia solution, both as matrix for final dilution of the trap mixture as well as for washing between the samples. The reproducibility of the entire analytical procedure was accessed by replicate dating of two molybdenite standards and three molybdenite separates, and was found to be in the range 0.87-1.52% R.S.D. Though accuracy of the method is limited by difficulties in evaluating exact concentration of Os in spike solution, ages obtained in the course of these work agrees well with previously published data.

  • 41. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Öhlander, Björn
    Ingri, Johan
    Fe isotope fractionation during redox cycling of Fe in lake water2004In: Vol. 68, no 11, Special suppl.Article in journal (Refereed)
  • 42. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Forsberg, Jerry
    Pekka, Larisa
    Luleå tekniska universitet.
    Andren, Henrik
    Stenberg, Anna
    Baxter, Douglas
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Forsling, Willis
    Pontér, Christer
    Kinetic and equilibrium Fe isotope fractionation during redox cycling of Fe in seasonally anoxic lake water2004In: 2004 Winter conference on plasma spectrochemistry: : [... Fort Lauderdale, FL, USA, January 5 - 10, 2004 ...], Cambridge: Royal Society of Chemistry, 2004Conference paper (Refereed)
  • 43. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Baxter, Douglas
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Molybdenum isotope ratio measurements on geological samples by MC-ICPMS2005In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 245, no 1-3, p. 94-107Article in journal (Refereed)
    Abstract [en]

    A method using multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) for the precise measurement of Mo isotopic composition in geological samples has been developed. Purification of Mo for isotope ratio measurements was realized by ion-exchange chromatography using the chelating resin Chelex-100. This technique allows an efficient separation of Mo from an excess of Fe in samples and at the same time provides quantitative recovery of Mo. Instrumental mass discrimination is corrected by using Pd spiking and normalization to the 105Pd/104Pd ratio. Mo isotope ratios of samples are expressed in per mil relative to those of the bracketing in-house Mo standard. The long-term reproducibility at the two standard deviation level is 0.04, 0.06, 0.08 and 0.14‰ for 96Mo/95Mo, 97Mo/95Mo, 98Mo/95Mo and 100Mo/95Mo ratio measurements, respectively. The technique has been applied to measurement of the Mo isotopic composition of freshwater sediments and molybdenites. Mass-dependent variations in the isotopic composition of Mo spanning the range of 2.2‰ in terms of the 97Mo/95Mo ratio for two sediment columns from different redox environments have been resolved. These results show that Mo isotope effects induced by geochemical processes operating during weathering and transport of Mo to the oceans should be quantified in order to interpret global Mo isotope budget and make use of stable Mo isotopes as proxy for redox conditions in the geological past.

  • 44. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilya
    Moiseenko, T.
    Institute of Water Problems. Russian Academy of Science.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Aqueous transport and fate of pollutants in mining area: a case study of Khibiny apatite-nepheline mines, the Kola Peninsula, Russia: a case study of Khibiny apatite-nepheline mines, the Kola Peninsula, Russia2002In: Environmental Geology, ISSN 0943-0105, E-ISSN 1432-0495, Vol. 43, no 1-2, p. 172-187Article in journal (Refereed)
    Abstract [en]

    Seven decades of mining activity on the Khibiny apatite-nepheline ore deposits and current large excavation volumes have resulted in elevated concentrations of total dissolved solids and metals in various waters near the mines. To assess the major sources of pollution inputs and fate of pollutants in watercourses draining the mine workings, snow cover, surface waters, and deposited and suspended sediments were sampled and analyzed. Water chemistry data showed that discharges of the mine wastewater are the main contributor to solute and metal loads in the streams. Atmospheric transport of metals and their accumulation in the snowpack account for a sharp increase in metal concentrations in stream waters during spring snowmelt. Data on bed and suspended sediments indicated that the streams have a low capacity of immobilization of metals. The dominant mechanism responsible for decrease in solutes in watercourses is dilution. The results demonstrated the necessity for remediation actions to address pollutant loads due to wastewater discharges

  • 45. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Shcherbakova, Elena
    Ponter, Christer
    Analytica AB.
    Öhlander, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Ingri, Johan
    Fractionation of Fe isotopes as a result of redox process in a basin2005In: Geohimiâ, ISSN 0016-7525, Vol. 43, no 8, p. 878-885Article in journal (Refereed)
    Abstract [en]

    This paper presents the results of a study of Fe isotope fractionation due to seasonal redox variations in water and bottom sediments (BS) of fresh-water basins. Fe isotopic ratios were measured using multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS). The investigation of suspended matter (SM) at the oxic-anoxic interface showed a significant positive shift in δ56Fe values between anoxic waters with dissolved Fe(II) and SM after Fe(II) oxidation and precipitation of Fe(III) oxides. Data on Fe content and isotope composition suggest that Fe(II) oxidation is accompanied by equilibrium Fe isotope fractionation. Potentials and limitations of the use of Fe isotope data for the reconstruction of pre-existing geochemical conditions in basins are outlined

  • 46. Malinovskiy, Dmitry
    et al.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Determination of the isotopic composition of molybdenum in the bottom sediments of freshwater basins2007In: Geochemistry International, ISSN 0016-7029, E-ISSN 1556-1968, Vol. 45, no 4, p. 381-389Article in journal (Refereed)
    Abstract [en]

    This paper presents the results of measurements of the Mo isotopic composition in the bottom sediments (BS) of freshwater basins. Mo isotopic ratios were measured using a multicollector inductively coupled plasma mass spectrometer (MC ICP MS). Efficient methods were used in this study for Mo separation from the elements of the sample matrix and correction for instrumental mass discrimination. This allowed us to achieve a high accuracy of 0.06, 0.08, and 0.14‰ (2 σ) for the measurement of 97Mo/95Mo, 98Mo/95Mo, and 100Mo/95Mo, respectively. The range of variations in Mo isotope ratios observed in the collected BS columns was ∼2.2‰ in terms of δ97Mo/95Mo. The results obtained here suggest that geochemical processes occurring during Mo migration with land water can change the isotopic composition of Mo. It is pointed out that the potential use of Mo isotopic systematics for reconstructions of redox conditions in seawater over the geologic past requires the quantification of isotopic effects of Mo accompanying its migration on land and the extent of possible variations in the isotopic composition of Mo entering the ocean.

  • 47. Malinovskiy, Dmitry
    et al.
    Stenberg, Anna
    Luleå tekniska universitet.
    Rodushkin, Ilia
    Andren, Henrik
    Ingri, Johan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Öhlander, Björn
    Baxter, Douglas
    Performance of high resolution MC-ICP-MS for Fe isotope ratio measurements in sedimentary geological materials2003In: Journal of Analytical Atomic Spectrometry, ISSN 0267-9477, E-ISSN 1364-5544, Vol. 18, no 7, p. 687-695Article in journal (Refereed)
    Abstract [en]

    High resolution MC-ICP-MS is used for the precise measurement of variations in the isotopic composition of Fe in ferromanganese concretions and sediments relative to IRMM-014 standard. The sensitivity for 56Fe in high resolution mode was 3 V per mg lm1 Fe, a figure that is comparable to those from other MC-ICP-MS instruments operated at low resolution. Incorporation of a guard electrode and the efficient ion transmission capabilities of the Neptune MC-ICP-MS instrument are responsible for the high sensitivity. It was observed that the use of HCl resulted in the formation of ClOH+, causing interference with 54Fe in particular. This acid has been preferred in some cases over HNO3 to minimize formation of ArN+, the major interferent for 54Fe. Using the high resolution mode of the Neptune, the nature of spectral interferences is unimportant as all are completely resolved and will not affect the accuracy of the determined Fe isotope ratios. As the instrument also provides flat-topped peaks, high resolution operation does not necessarily result in impaired precision, providing that higher concentrations are used to compensate for the loss in sensitivity compared with the low resolution mode. In the present work, external reproducibilities of 56Fe/54Fe and 57Fe/54Fe isotope ratios were better than 50 ppm (one standard deviation) at a concentration of 5 mg lm1. The level of instrumental mass discrimination observed for raw ratios drifted by as much as 0.09% per mass unit over a measurement session, but could be corrected on-line by simultaneous monitoring of the 62Ni/60Ni isotope ratio. Variations in the Fe concentrations or the acid strength of measurement solutions were found to affect the apparent mass discrimination. Increasing the Fe concentration caused a relative decrease in the raw 56Fe/54Fe and 57Fe/54Fe isotope ratios, thus ruling out the space charge effect as the explanation for this phenomenon. Instead, it is suggested that the larger dry aerosol particles formed at higher Fe concentrations are not completely vaporized until later in the plasma, thus reducing the relative rate of diffusional losses of lighter 54Fe from the central channel. However, application of on-line correction using Ni could adequately account for this effect. From the results for a variety of sedimentary geological materials, analysis of three-isotope data revealed that equilibrium fractionation of Fe occurred during deposition. To be able to distinguish between equilibrium and kinetic fractionation processes, it is imperative to collect accurate and precise data for the 56Fe/54Fe and 57Fe/54Fe isotope ratios. These requirements are readily fulfilled by applying high resolution MC-ICP-MS and on-line correction for instrumental mass discrimination using Ni.

  • 48.
    Marinov, A.
    et al.
    Racah Institute of Physics, Hebrew University of Jerusalem.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kashiv, Y.
    Racah Institute of Physics, Hebrew University of Jerusalem.
    Halicz, L.
    Geological Survey of Israel.
    Segal, I.
    Geological Survey of Israel.
    Pape, A.
    IPHC-UMR7178, IN2P3-CNRS/ULP, BP 28, F-67037 Strasbourg.
    Gentry, R.V.
    Earth Science Associates, P.O. Box 12067, Knoxville, Tennessee.
    Miller, H.W.
    P. O. Box 1092, Boulder, Colorado.
    Kolb, D.
    Department of Physics, University GH Kassel.
    Brandt, R.
    Kernchemie, Philipps University, D-35041 Marburg.
    Reply to "Comment on `Existence of long-lived isomeric states in naturally-occurring neutron-deficient Th isotopes'"2009In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 79, no 4, p. 49802-Article in journal (Other academic)
  • 49.
    Marinov, A.
    et al.
    Racah Institute of Physics, Hebrew University of Jerusalem.
    Rodushkin, Ilya
    Kolb, D.
    Department of Physics, University GH Kassel.
    Pape, A.
    IPHC-UMR7178, IN2P3-CNRS/ULP, BP 28, F-67037 Strasbourg.
    Kashiv, Y.
    Racah Institute of Physics, Hebrew University of Jerusalem.
    Brandt, R.
    Kernchemie, Philipps University, D-35041 Marburg.
    Gentry, R V
    Earth Science Associates, P.O. Box 12067, Knoxville, Tennessee.
    Miller, H W
    Evidence for the possible existence of a long-lived superheavy nucleus with atomic mass number A=292 and atomic number Z congruent to 122 in natural Th2010In: International Journal of Modern Physics E, ISSN 0218-3013, Vol. 19, no 1, p. 131-140Article in journal (Refereed)
    Abstract [en]

    Evidence for the possible existence of a superheavy nucleus with atomic mass number A = 292 and abundance of about 1 x 10(-12) relative to Th-232 has been found in a study of natural Th using inductively coupled plasma-sector field mass spectrometry. The measured mass is different from any species with molecular mass of 292, but it matches the predictions for the mass of an isotope with atomic number Z = 122 or a nearby element. Its deduced half-life of t(1/2) >= 10(8) y suggests that a long-lived isomeric state exists in this isotope. The possibility that it might belong to a new class of long-lived high spin super- and hyperdeformed isomeric states is discussed.

  • 50.
    Marinov, Amnon
    et al.
    Racah Institute of Physics, Hebrew University of Jerusalem.
    Rodushkin, Ilya
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Kashiv, Y
    Racah Institute of Physics, Hebrew University of Jerusalem.
    Halicz, L
    Geological Survey of Israel.
    Segal, I
    Geological Survey of Israel.
    Pape, A
    IPHC-UMR7178, IN2P3-CNRS/ULP, BP 28, F-67037 Strasbourg.
    Gentry, RV
    Earth Science Associates, P.O. Box 12067, Knoxville, Tennessee.
    Miller, HW
    Kolb, D
    Department of Physics, University GH Kassel.
    Brandt, R
    Kernchemie, Philipps University, D-35041 Marburg.
    Existence of long-lived isomeric states in naturally-occuring neutron-deficient Th isotopes2007In: Physical Review C. Nuclear Physics, ISSN 0556-2813, E-ISSN 1089-490X, Vol. 76, no 2Article in journal (Refereed)
    Abstract [en]

    Four long-lived neutron-deficient Th isotopes with atomic mass numbers 211 to 218 and abundances of (1-10)x10(-11) relative to Th-232 have been found in a study of naturally-occurring Th using inductively coupled plasma-sector field mass spectrometry. It is deduced that long-lived isomeric states exist in these isotopes. The hypothesis that they might belong to a new class of long-lived high spin super- and hyperdeformed isomeric states is discussed.

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