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| Registros recuperados: 43 | |
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| Aminot, Alain; Kerouel, Roger; Birot, Dominique. |
| A version of the orthophthaldialdehyde-fluorescence ammonium determination for flow injection analysis (FIA) is presented here, with a view to its use for in situ, low-power consumption systems, Thus, the reaction temperature was limited to 30 degreesC and FIA was used in stop-Bow mode (3 min stop). The calibration is linear up to 50 mu mol l(-1), but concentrations up to 100 mu mol l(-1) can be measured. Repeatability is around 1% in the range of 0.5-4 mu mol l(-1) and the detection limit is about 0.03 mu mol l(-1) Over the salinity range of 5-35 (seawater practical salinity scale) the salt effect is almost negligible (within +/- 2%); and below salinity of 5 it increases to a maximum of -9% in fresh water compared to seawater. Hydrogen carbonate,... |
| Tipo: Text |
Palavras-chave: In situ; Fluorometry; Flow injection analysis; Determination; Ammonium. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1722.pdf |
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| Coverly, Stephen; Kerouel, Roger; Aminot, Alain. |
| Modern instruments together with the use of standard reference materials have improved the accuracy and long-term reproducibility of the analysis of nutrients (ammonium, nitrate, nitrite, phosphate and silicate) in sea water using segmented-flow analysis, so that errors arising from matrix effects become more significant. Colorimetric detectors with bubble-through flowcells have become widely used for seawater analysis in recent years and their associated matrix effects are described. A re-examination of all categories of matrix effects, whose main origin is salinity, was thus undertaken to assess how much they are liable to alter the data. Interferences were classified into four types, each of which was examined in order to show its influence on the... |
| Tipo: Text |
Palavras-chave: Nutrient; Determination; Seawater; Estuarine water; Segmented-flow analysis; Matrix effects. |
| Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00057/16843/14530.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| A segmented flow automated method with on-line photo-oxidation for the determination of dissolved organic phosphorus + soluble reactive phosphorus (DOP + SRP) in seawater and fresh water is described here. A low-power lamp was used for a compact, easy-to-handle and low-ozone-producing manifold. The influence of seawater matrix components was studied in detail using natural seawater and salt solutions spiked with DOP model compounds. Bromide was found to be the most inhibitory species in seawater. The work shows that most salt solutions referred to as artificial seawater are not satisfactory model matrices to test the actual seawater matrix effect. Since DOP recovered in undiluted seawater samples was about half that obtained in fresh water samples, the... |
| Tipo: Text |
Palavras-chave: Measurement; Fresh water; Seawater; Total dissolved phosphorus; Dissolved organic phosphorus. |
| Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-1678.pdf |
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| El Sayed, Mohamed A.; Aminot, Alain. |
| Extractable organic copper using C18 Sep-Pak cartridges was investigated in seawater after laboratory experiment showed that the (C18 Sep-Pak) cartridges were reliable, in open and coastal waters with normal levels of dissolved organic carbon, for the separation of a specific fraction of organo-copper complexes.Given that the Sep-Pak cartridges retain the hydrophobic fraction of the dissolved organic matter, this extraction technique was applied for studying the characteristics of this particular hydrophobic dissolved organic copper fraction (hDOCu) in the north-western Mediterranean waters. Surface distribution of hDOC is influenced by organic matter input from the river Rhone and its estuary as well as the physical processes affecting the primary... |
| Tipo: Text |
Palavras-chave: Mediterranean sea; Seawater; Dissolved organic matter; Copper compounds. |
| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-1681.pdf |
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| Sarradin, Pierre-marie; Caprais, Jean-claude; Riso, Ricardo; Kerouel, Roger; Aminot, Alain. |
| Water samples were collected around the communities of a hydrothermal mussel, Bathymodiolus sp., in the Lucky Strike (1700 m depth) and Menez Gwen (850 m depth) areas, Mid Atlantic Ridge, and analysed for chemical constituents. The environment surrounding the organisms consists in sea water (88 to 100%) mixed with hydrothermal fluid with pH between 6.2 and 8, Sigma S (H2S + HS-) concentrations from 0 to 62 mu mol l(-1). High dissolved organic carbon (DOC) concentrations suggest a highly productive ecosystem. Production of ammonium and DOG, consumption of nitrate and sulfide in the vicinity of the organisms are among the environmental changes found in relation with local biological activity. Concentrations of Cu and Pb were high, implying that the organisms... |
| Tipo: Text |
Palavras-chave: Environment; Sea water; Hydrothermal vents; Mussels. |
| Ano: 1999 |
URL: http://archimer.ifremer.fr/doc/00147/25847/23968.pdf |
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| Hydes, D; Aoyama, M; Aminot, Alain; Bakker, K; Becker, S; Coverly, S; Daniel, Anne; Dickson, A; Grosso, O; Kerouel, Roger; Van Ooijen, J; Sato, K; Tanhua, T; Woodward, M; Zhang, J. |
| The Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) brings together scientists with interests in physical oceanography, the carbon cycle, marine biogeochemistry and ecosystems, and other users and collectors of ocean interior data to develop a sustained global network of hydrographic sections as part of the Global Ocean Climate Observing System. A series of manuals and guidelines are being produced by GO-SHIP which update those developed by the World Ocean Circulation Experiment (WOCE) in the early 1990s. Analysis of the data collected in WOCE suggests that improvements are needed in the collection of nutrient data if they are to be used for determining change within the ocean interior. Production of this manual is timely as it... |
| Tipo: Text |
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| Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00020/13141/10182.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| Dissolved organic carbon (DOC), dissolved organic nitrogen (DON) and dissolved organic phosphorus (DOP) measured in deep profiles in the N-E Atlantic and in the N-W Mediterranean in the period 1984-2002 are described. After accurate validation, they show close agreement with those previously published. Classic profiles were obtained, with concentrations decreasing in deep waters. In the Mediterranean and in the Atlantic comparable concentrations were found in the 1500-2000 m waters, 44-46 mumol 1(-1) DOC, 2.6-2.8 mumol 1(-1) DON and 0.02-0.03 mumol 1-1 DOP. In the surface layers, DOC concentrations were higher, but DON and DOP concentrations lower, in the Mediterranean than in the Atlantic, leading to higher element ratios in the Mediterranean. In autumn,... |
| Tipo: Text |
Palavras-chave: N W Mediterranean; N E Atlantic; Mineralization; Non refractory; Refractory; Dissolved organic phosphorus; Dissolved organic nitrogen; Dissolved organic carbon. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-472.pdf |
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| Aminot, Alain; Kerouel, R.. |
| The determination of urea in sea water was performed by an automated method based on the reaction of urea with diacetyl-monoxime. The sensitivity, which has been greatly enhanced compared to previous methods, by using reagents containing thiosemicarbazide and iron III, is 0.044 absorbance units/ g-at urea-N/L with the 50 mm flow cell. The precision is 0.01 g-at urea-N/L and the limit of detection (2 SD) is 0.02 g-at urea-N/L. The absorbance-concentration relationship is linear up to 15 g-at urea-N/L. The analytical blanks have been strictly determined and the interferences studied. Citrulline is the main compound that interferes. However, in attempting to remove this compound from the samples by a chelating resin. we demonstrated its absence from... |
| Tipo: Text |
Palavras-chave: Histoire Ifremer. |
| Ano: 1982 |
URL: http://archimer.ifremer.fr/doc/1982/publication-5350.pdf |
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| Savoye, N; Aminot, Alain; Treguer, Paul; Fontugne, M; Naulet, N; Kerouel, Roger. |
| Two cruises (April and June 1997) were carried out in the Bay of Seine, a nitrate- and ammonium-enriched ecosystem of Western Europe, to identify the major mechanisms that control delta(15)N and VC in spring particulate organic matter (POM). Particulate organic nitrogen (PON) delta(15)N ranged between 0.8 and 5.2parts per thousand in April and between 2.2 and 6.2parts per thousand in June, while particulate organic carbon (POC) delta(13)C ranged between -24.3 and -19.7parts per thousand, and between -20.0 and -16.2parts per thousand during the same periods. During spring 1997, POM was highly dominated by autochthonous phytoplankton. It is shown that the variation of PON delta(15)N is due to both nitrate mixing between river and marine waters and... |
| Tipo: Text |
Palavras-chave: C and N stable isotopes; Phytoplankton; Coastal ecosystem; Nitrate utilization; Bay of Seine. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/00000/10645/7593.pdf |
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| Aminot, Alain; Kerouel, Roger; Joanny, Michel; Le Guellec, Anne-marie. |
| Les éléments nutritifs (N-NH4 +, N-N02-, N-NO3, P-PO4 3- et Si-Si(OH) 4) et la matière organique dissoute (COD, NOD, POD, urée, amines primaires libres) mesures en septembre 1984 en Méditerranee nord-occidentale sont interprétés en fonction de l'hydrologie. Les résurgences d'eaux subsuperficielles influencent plus les concentrations des éléments nutritifs que celles de la matière organique. La composition globale (en C, N et P) de la matière organique a pu être donnée : on note des différences entre les masses d'eau. |
| Tipo: Text |
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| Ano: 1986 |
URL: http://archimer.ifremer.fr/doc/00082/19288/16883.pdf |
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| Lunven, Michel; Guillaud, Jean-francois; Crassous, Marie Pierre; Youenou, Agnes; Gohin, Francis; Huret, Martin; Danielou, Marie-madeleine; Kerouel, Roger; Labry, Claire; Aminot, Alain. |
| Inscrite dans le cadre du Grand Défi Golfe de Gascogne, la campagne VILOIR a été réalisée du 19 au 26 Juin 2003 à bord du Côtes de la Manche avec pour objectif l’étude en période estivale des structures hydrologiques et phytoplanctoniques des panaches de la Loire et de la Vilaine. Elle fait suite, sur la même thématique, à la campagne hivernale NUTRIGAS (2001) et à la campagne printanière GASPROD (2002). |
| Tipo: Text |
Palavras-chave: Surveillance; Littoral; Phytoplancton; Phycotoxines; Bretagne; Pays de Loire. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/00144/25494/23648.pdf |
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| Del Amo, Yolanda; Le Pape, Olivier; Treguer, Paul; Queguiner, Bernard; Menesguen, Alain; Aminot, Alain. |
| The chemical factors (inorganic nitrogen, phosphate, silicic acid) that potentially or actually control primary production were determined for the Bay of Brest, France, a macrotidal ecosystem submitted to high-nitrate-loaded freshwater inputs (winter nitrate freshwater concentrations >700 mu M, Si:N molar ratio as low as 0.2, i.e. among the lowest ever published). Intensive data collection and observations were carried out from February 1993 to March 1994 to determine the variations of physical [salinity, temperature, photosynthetically active radiation (PAR), freshwater discharges] and chemical (oxygen and nutrients) parameters and their impacts on the phytoplankton cycle (fluorescence, pigments, primary production). With insufficient PAR the winter... |
| Tipo: Text |
Palavras-chave: Coastal ecosystem; Phytoplankton dynamics; Macrotidal; Nutrient limitation; Silicon; Eutrophication. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00337/44782/44588.pdf |
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| Aminot, Alain; Kerouel, Roger. |
| La préparation de matériaux de référence pour des exercices d'intercomparaison pour les eaux de mer a été pratiquée à plusieurs reprises par notre laboratoire au cours des années passées, soit au niveau français (cas de la salinité pour le RNO) soit au niveau international (cas des nutriments). Ainsi, pour les nutriments, deux exercices du CIEM (Conseil International pour l'Exploration de la Mer) ont été préparés, lesquels ont été suivis du programme européen d'assurance qualité QUASIMEME comportant six exercices en trois ans. Nous avons également contribué à l'exercice concernant l'agrément des laboratoires type 8 « eaux marines » du Ministère de l'Environnement en 1998. Les résultats de ces exercices et les méthodes de préparation des matériaux de... |
| Tipo: Text |
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| Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/00018/12912/9868.pdf |
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| Aminot, Alain; Guillaud, Jean-francois; Kerouel, Roger. |
| The data of hydrology, nutrients and chlorophyll obtained in the Bay of Seine over the period 1978-1994, from 14 océanographie cruises, are synthetised and illustrated by an atlas. The Bay is a typical example of a coastal area influenced by a large river. In winter, the nutrient input is drained off into the eastern Channel. In spring, nutrients are consumed intensively. Silicate is the first that drops to limiting levels. The spring bloom generally begins in the centre-east of the Bay. Chlorophyll a can reach up to 40-70 µg/l during the year, values typical of eutrophic coastal areas. Despite the regular increase of nitrogen inputs, the biomass (as chlorophyll) has not significantly changed over a fifteen year period. |
| Tipo: Text |
Palavras-chave: Chlorophyll; Nutrients; Hydrology; Bay of Seine; Chlorophylle; Nutriments; Hydrologie; Baie de Seine. |
| Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/1997/rapport-1428.pdf |
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| Registros recuperados: 43 | |
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