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| Registros recuperados: 32 | |
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| Baeyens, W.F.J.; Leermakers, M.; Molina, R.; Holsbeek, L.; Joiris, C.R.. |
| Aqueous distillation is a common initial step in the determination of monomethyl mercury (MMHg) in a variety of matrices. However, recently it was observed that during distillation, MMHg may be generated from inorganic mercury and induce in some cases significant analytical errors. Therefore we investigated a number of alternative analytical techniques for the determination of MMHg in sediments and biological tissues: (1) headspace-GC-AFS and some variants; (2) acid extraction-solvent extraction-GC-AFS; (3) acid extraction-solvent extraction-GC-ECD. Methods (2) and (3) showed MMHg generation when an inorganic Hg spike was added to the sediment sample. The headspace method yielded MMHg results in agreement with the reference values for biological and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=6829 |
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| Baeyens, W.F.J.; Dedeurwaerder, H.. |
| Heavy metal concentrations in total particulate suspended matter and size fractionated particulate suspended matter above the Southern Bight of the North Sea have been assessed. Most of the samples were collected from a light vessel; the total sampling period covered about 70 days at sea. Stringent precautions were taken during sampling, storage, handling and analysis of the samples. As a conclusion, we found that on a long-term basis the aerosol concentrations above the North Sea have a fairly homogeneous composition, but short-term variations probably resulting from point emissions were observed. The cascade impactor results indicated that Pb, Cu, Cd and Zu were carried by submicrometer aerosols, Na, Fe, Mn and Al by supermicrometer aerosols. Most of the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aerosols Air pollution Atmospheric particulates Meteorology Seasonal variations Statistical analysis Trace metals Troposphere Winds ANE; North Sea; Southern Bight. |
| Ano: 1991 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3106 |
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| Goeyens, L.G.; Stichelbaut, L.W.; Post, E.J.; Baeyens, W.F.J.. |
| A new procedure for the conversion of bound nitrogen into nitrogen gas, applicable to solid material, is described. It embodies two main stages: the catalytic ammonification of the sample and the consecutive transformation of ammonium to molecular nitrogen by the modified Dumas method. The first step of the preparation is carried out in a quartz reactor, filled with granular nickel, at a temperature of 700°C, the ammonia gas produced being trapped in sulphuric acid. In the second step, this solution is neutralised, dried and subjected to the Dumas combustion.The addition of reagents does not influence the results of the measurements. Spectrometric <sup>15</sup>N percentage abundances are converted into mass spectrometric "true"... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Emission spectroscopy. |
| Ano: 1985 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3279 |
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| Baeyens, W.F.J.; Parmentier, K.; Goeyens, L.; Ducastel, G.; De Gieter, M.; Leermakers, M.. |
| Cd, Cu, Zn and Pb concentrations in both dissolved and particulate phase were assessed during 1995. Data Quality Assurance was an integral part of this study and involved all major steps of the analysis procedure such as sampling, sample handling, preconcentration and determination. Desorption and redox processes clearly control the dissolved Cu and Cd profiles. Mobilisation of dissolved Zn is small and essentially restricted to the low salinity area and the late spring survey. Dissolved Pb shows the clearest dilution pattern. The parameters representative of these processes (dissolved oxygen and salinity) also correlate very well with the particulate metal profiles. In addition, the plankton activity (expressed by the chlorophyll-<i>a</i>... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7046 |
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| Baeyens, W.F.J.; Elskens, I.; Van Ryssen, R.; Leermakers, M.. |
| Offshore fluxes of Cu, Zn, Cd, Pb and Hg were calculated based on residual flow patterns and salinity gradients along the Belgian coast. The residual flow lines along the Belgian coast are more or less parallel to the coast except the area where the north-easterly flowing water mass coming from the Channel encounters the south-westerly-oriented Scheldt outflow, forming a residual hydrodynamical front. From the steady-state salinity pattern, diffusion coefficients perpendicular to the residual flow were deduced; they ranged from 21 to 108 m² s-¹ . Offshore fluxes of dissolved and particulate trace metals based on diffusive and mixing processes are calculated. The steady state profiles of dissolved metals show a dilution effect in the coastal waters,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1998 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=7055 |
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| Baeyens, W.F.J.; Gillain, G.; Ronday, F.; Dehairs, F.A.. |
| The residual flow lines of the Belgian coast are more or less parallel to the coast except in the area where the northeasterly flowing watermass coming from the Channel encounters the southwesterly-oriented Scheldt outflow. The result is a residual hydrodynamical front with, at the northern side, a less saline estuarine watermass, and at the southern side a more saline marine watermass. From the steady-state salinity pattern, diffusion coefficients perpendicular to the residual flow were deduced; they ranged from 21 to 108 m².s<sup>-1</sup>.The steady-state profiles of dissolved metals versus salinity indicate a dilution effect in the coastal-estuarine watermass and almost constant concentration in the marine watermass. Offshore fluxes of Cd,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Coastal zone Trace metals ANE; North Sea. |
| Ano: 1987 |
URL: http://www.vliz.be/nl/open-marien-archief?module=ref&refid=3156 |
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| Registros recuperados: 32 | |
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