| 1. |
- Pallavicini, Nicola, et al.
(författare)
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Ranges of B, Cd, Cr, Cu, Fe, Pb, Sr, Tl, and Zn Concentrations and Isotope Ratios in Environmental Matrices from an Urban Area
- 2018
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Ingår i: Journal of Spectroscopy. - : Hindawi Publishing Corporation. - 2314-4920 .- 2314-4939. ; , s. 1-17
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Tidskriftsartikel (refereegranskat)abstract
- Isotopic information may provide powerful insight into the elemental cycling processes which occur in natural compartments. Further implementation of isotopic techniques in natural sciences requires a better understanding of the range of elemental and isotopic compositional variability in environmental matrices. This study assesses the local-scale concentration and isotopic composition variability of nine elements: boron (B), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), lead (Pb), strontium (Sr), thallium (Tl), and zinc (Zn) in lysimetric waters, mushrooms, litter, needles, leaves, and lichens. Sequential extractions were also performed on soil samples from 6 depth profiles providing more detailed information on the variability of elemental concentrations and isotope ratios between the elemental pools present in soil. For most of the sample types studied the range of isotopic variability between samples spans almost the entire ranges reported in the literature for natural samples. These results represent a starting point for discussing the role of natural variability in isotopic studies (for example, as a limiting factor in the use of isotopic mixing models) and a baseline for future in-depth studies examining the controls on isotope fraction in natural systems
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| 2. |
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| 3. |
- Rodushkin, Ilya, et al.
(författare)
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Uptake and Accumulation of Anthropogenic Os in Free-Living Bank Voles (Myodes glareolus)
- 2011
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 0049-6979 .- 1573-2932. ; 218:1-4, s. 603-610
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Tidskriftsartikel (refereegranskat)abstract
- Osmium tetroxide (OsO4) is one of the most toxic air contaminants but its environmental effects are poorly understood. Here, for the first time, we present evidence of osmium uptake in a common herbivore (bank vole, Myodes glareolus) in boreal forests of northern Sweden. Voles (n = 22) and fruticose arboreal pendular lichens, the potential main winter food source of the vole, were collected along a spatial gradient to the west of a steelwork in Tornio, Finland at the Finnish-Swedish border. Os-187/Os-188 isotope ratios increased and osmium concentrations decreased in lichens and voles along the gradient. Osmium concentrations in lichens were 10,000-fold higher than those in voles. Closest to the steelwork, concentrations were highest in kidneys rather than skin/fur that are directly exposed to airborne OsO4. The kidney-to-body weight ratio was higher at the two localities close to the steelwork. Even though based on a small sample size, our results for the first time demonstrate that osmium is taken up, partitioned, and accumulated in mammal tissue, and indicate that high kidney-to-body weight ratios might be induced by anthropogenic osmium.
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| 4. |
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| 5. |
- Malinovskiy, Dmitry, et al.
(författare)
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Determination of the isotopic composition of molybdenum in the bottom sediments of freshwater basins
- 2007
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Ingår i: Geochemistry International. - 0016-7029 .- 1556-1968. ; 45:4, s. 381-389
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
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| 7. |
- Axelsson, Mikael D., et al.
(författare)
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Determination of major and trace elements in sphalerite using laser ablation double focusing sector field ICP-MS
- 2001
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Ingår i: Journal of Geochemical Exploration. - 0375-6742 .- 1879-1689. ; 72:2, s. 81-89
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 8. |
- Axelsson, Mikael D., et al.
(författare)
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Multielemental analysis of Mn–Fe nodules by ICP-MS: optimisation of analytical method
- 2002
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Ingår i: The Analyst. - 0003-2654 .- 1364-5528. ; 127:1, s. 76-82
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Tidskriftsartikel (refereegranskat)abstract
- 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
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| 9. |
- Baxter, Douglas, et al.
(författare)
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Methylmercury measurement in whole blood by isotope-dilution GC-ICPMS with 2 sample preparation methods
- 2007
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Ingår i: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 53:1, s. 111-116
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 10. |
- Baxter, Douglas, et al.
(författare)
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Serum/plasma methylmercury determination by isotope dilution gas chromatography : inductively coupled plasma mass spectrometry
- 2011
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Ingår i: Analytica Chimica Acta. - : Elsevier BV. - 0003-2670 .- 1873-4324. ; 701:2, s. 134-138
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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