| 1. |
- Szefer, P, et al.
(author)
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Heavy-metal pollution of sediments from the Polish exclusive economic zone, southern Baltic Sea
- 2009
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In: Environmental Geology. - Berlin / Heidelberg : Springer. - 0943-0105 .- 1432-0495. ; 57:4, s. 847-862
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Journal article (peer-reviewed)abstract
- Analysis of 59 surface sediment samples from the Polish exclusive economic zone (EEZ) shows that Szczecin Lagoon sediments are the most polluted by heavy metals and that the degree of heavy-metal pollution decreases substantially on passing from the Szczecin Lagoon to the Pomeranian Bay and the inner shelf area and then on passing to the Bornholm Deep and Słupsk Furrow. Heavy-metal pollution in the sediments of the western part of the Polish EEZ therefore appears to follow the dispersion of the Oder River. Fluffy material from the Oder estuary appears to be the main source of heavy metals in the muddy sediments of the Bornholm Deep. The formation of sulphides is therefore not the principal factor controlling the enrichment of heavy metals in the sediments of this anoxic basin, although it may be responsible for the uptake of Mo, Sb and As. Two main factors control the distribution of the rare earth elements (REE) in sediments of the Polish EEZ: the input of Fe-organic colloids from rivers and the presence of detrital material in the sediments.
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| 2. |
- Kumar, Sunil J., et al.
(author)
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A simple method for synthesis of organotin species to investigate extraction procedures in sediments by isotope dilution-gas chromatography-inductively coupled plasma mass spectrometry : Part 2. Phenyltin species
- 2004
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In: Journal of Analytical Atomic Spectrometry. - London : Royal Society of Chemistry. - 0267-9477 .- 1364-5544. ; 19:3, s. 368-372
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Journal article (peer-reviewed)abstract
- A rapid method for the synthesis of phenyltin species based on the phenylation of tin iodide was developed and a standard of 124Sn, enriched monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TPhT) was produced. Isotope enriched species were added to and equilibrated with the certified reference material BCR 646 to evaluate different extraction procedures currently in use for the determination of organic tin species in sediments. Samples were measured by gas chromatography-inductively coupled plasma mass spectrometry (GC-ICP-MS) with species specific isotope dilution (SSID) calibration. For TPhT measurement results agreed with the certified values for extraction methods using tropolone in diethyl ether alone or in the presence of NaCl and HCl as well as with 50% HBr. However, with 50% HBr, concentrations obtained for DPhT and MPhT were above the upper limit (2) of the certification. The stability of phenyltin species was studied by comparing their signal magnitudes in spike solutions generated directly after derivatisation with those obtained after applying the extraction–derivatisation procedures. Degradation of phenyltin species was matrix dependent and appeared for most of the extraction methods investigated. For water standards and BCR 646, extraction with methanol combined with dichloromethane or methanol combined with acetic acid gave no degradation when applied with less than 20 min ultrasonication. Extraction efficiencies for these two methods were however low for the BCR 646 matrix, in particular for DPhT and MPhT.
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| 3. |
- Snell, James P, et al.
(author)
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Investigation of errors introduced by the species distribution of mercury in organic solutions on total mercury determination by electrothermal vaporisation-inductively coupled plasma mass spectrometry
- 2000
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In: JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. - : Royal Society of Chemistry (RSC). ; 15:4, s. 397-402
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Journal article (peer-reviewed)abstract
- This paper presents an investigation into the potential and limitations of an ETV system for the determination of total mercury, present as different species, in organic solution. The thermal and chemical stability of four mercury species in an electrothermal vaporiser, ETV, coupled to an inductively coupled plasma (ICP-MS) mass spectrometer was investigated when samples of hydrocarbon products were introduced. Calibration by the method of isotope dilution was tested with an isotopically enriched standard of mercury diethyldithiocarbamate, (HgDDTC)-Hg-201, in toluene. Sulfur-containing compounds, different palladium solutions and gold metals were investigated for use as matrix modifiers. A combination of Pd(NO3)(2) in propanol with stabilising additives applied as a permanent modifier (A. Asheim, poster presentation, 3rd European Furnace Symposium, Prague, 1998) and thionyl chloride injected with each sample gave the most effective stabilisation of mercury species and reproducible signals with a relative standard deviation of 3% for 5 mu g l(-1) HgCl2. The recoveries, by isotope dilution, of HgCl2 and CH3HgCl in natural gas condensates ranged between 100 and 115%, while for Hg-0 and (CH3)(2)Hg only 48-65% was recovered with optimised conditions. Losses of the latter two species occurred on drying of the sample in the furnace prior to heating to the pyrolysis temperature. Systematic errors in total mercury determination were, therefore, found to occur for samples containing Hg-0 or (CH3)(2)Hg, even with isotope dilution calibration. The detection limit, based on 3s of 10 replicate measurements of the Hg-202(+) signal for toluene spiked with 6 mu g l(-1 201)HgDDTC, was 0.19 mu g l(-1).
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| 4. |
- Snell, James P., et al.
(author)
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Preparation and certification of ERM-AE670, a 202Hg enriched methylmercury isotopic reference material
- 2004
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In: JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. - : Royal Society of Chemistry (RSC). - 0267-9477. ; 19:10, s. 1315-24
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Journal article (peer-reviewed)abstract
- The need for comparability of methylmercury, noted MeHg, measurement results and for the reduction of their associated uncertainties is hampered by the lack of suitable calibration materials. An isotopic certified reference material, ICRM, of MeHg containing isotopically enriched Hg has the potential to answer these problems, in combination with the isotope dilution mass spectrometry, IDMS, strategy. The objective of this work was to produce such a material, of demonstrated stability and carrying certified values traceable to the SI accompanied by combined uncertainty statements. Mercury oxide enriched in 202Hg was used for the preparation of a solution of 202Hg enriched CH3HgCl. The starting material had previously been employed for the preparation of ERM-AE640; a 202Hg enriched inorganic mercury ICRM. The CH3HgCl was synthesised by reaction with a Grignard reagent and a subsequent comproportionation reaction between (CH3)2Hg and HgCl2. The process was optimised to give a high yield of the product, minimise contamination with naturalHg and additional steps were applied to purify the material from other Hg species and by-products of the synthesis reaction. Aliquots of 5 g of the solution were sealed in quartz ampoules for later distribution as a reference material, named ERM-AE670. Using gas chromatography inductively coupled plasma mass spectrometry, only MeHg and inorganic Hg was detectable in the finished reference material with inorganic Hg in <2% of the total amount. The isotopic composition of Hg in the form of MeHg was confirmed to be identical to that of ERM-AE640, within enlarged uncertainty statements. The Hg amount content in the form of MeHg was obtained by subtraction of the inorganic Hg amount content from the total Hg amount content (determined by IDMS in the digested material). The final uncertainty on the Hg amount content in the form of MeHg (3.5% relative, k= 2) included a contribution covering for potential changes over 2 years of shelf-life. This contribution was estimated from the results of a 1 year isochronous stability study.
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| 5. |
- Snell, James P, et al.
(author)
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Species specific isotope dilution calibration for determination of mercury species by gas chromatography coupled to inductively coupled plasma- or furnace atomisation plasma ionisation-mass spectrometry
- 2000
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In: JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY. - : Royal Society of Chemistry (RSC). ; 15:12, s. 1540-5
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Journal article (peer-reviewed)abstract
- Standard solutions of(CH3)(2)Hg, CH3HgCl and HgCl2 were prepared in toluene from isotopically enriched mercury. Methods for synthesising (CH3)(2)Hg and CH3HgCl, from HgCl2, were developed with reaction yields of 95.2% and 92.7%. respectively, without noticeable loss of isotope. Isotopically enriched species standards were then used for species specific isotope dilution calibration and method assurance tests for mercury species determination. An interface was built to couple a gas chromatograph (GC) to an inductively coupled plasma mass spectrometer (ICP-MS) that resulted in rapid and efficient transfer of organic mercury compounds eluted from, natural gas condensates. Oxygen, introduced to the plasma auxiliary gas, reduced matrix interferences and improved sensitivity by a factor of two. The GC-ICP-MS method with species specific isotope dilution calibration gave recovery values of 97.7 +/- 2.0, 104.1 +/- 0.7 and 106.6 +/- 2.1% for (CH3)(2)Hg, CH3HgCl and HgCl2 respectively, in natural gas condensate compared to a standard solution of the species in toluene. Detection limits of the three species, calculated from 3s of the peak areas derived from 20 pg of the species (as Hg) in solution, were 8, 2 and 3 pg. Furnace atomisation plasma ionisation mass spectrometry (FAPIMS) was also evaluated as a detector with the GC methodology. When the plasma was operated with optimised conditions for the generation of elemental ions, recoveries were 100.0 +/- 2.9, 98.3 +/- 1.5 and 97.5 +/- 1.2% for (CH3)(2)Hg, CH3HgCl and HgCl2 in a 10% condensate solution, and a detection limit of 33 pg was obtained for methylmercury. A plasma was also generated and sustained with reduced rf power and graphite furnace temperature so that molecular ions and fragments were produced and detected by the same spectrometer, which demonstrated the potential of FAPIMS as a sensitive elemental detector additionally capable of providing molecular mass spectra for the identification of species eluted from a GC column.
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