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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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Lepoupon, C; Lin, Rg; Benaim, Jy; Merks, Aga. |
The accurate classical batch method of Duursma (1961), based on the conversion of Dissolved Organic Nitrogen (DON) into NH3, is used as a basis for a new automatic DON analyser. After testing different possibilities through mechanical automation of the original batch technique, in which the conversion is preceded by the degassing of NH3 and drying of the sample, the procedure of autoanalyses has been selected. This procedure was simplified to the extent that a compact unit could be constructed, which would easily be applicable on board ship. The automatic method has a conversion phase in which in principle only DON is dissociated to NH4+, whereas both NO2- add NO3- are not reduced. This requires selective conditions and particularly high silver purity for... |
Tipo: Text |
Palavras-chave: Dissolved organic nitrogen; Analysis; Automation; Reduction; Total nitrogen. |
Ano: 1997 |
URL: http://archimer.ifremer.fr/doc/00093/20456/18128.pdf |
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Maestrini, S; Robert, J. |
Microalgal population of oyster ponds is dominated by several tychobenthic diatoms which provide a very good food to grow oysters. The mechanisms which allow them to dominate have been put under research. H.P.L.C. analysis demonstrated 17 amino acids amounted 10-17% of total DON, i.e. 0.6-11.5 mu g-at/l nitrogen. Serin and glycin were the most abundant. None of the substances was related to the presence of oyster. Glutamic acid, alanin and ornithin concentrations showed the greatest variations; they are suspected to play the major role as nutrient source. Screening of nutritional capabilities of ten local isolates of micro-algae to use 42 organic substances as sole source of nitrogen, demonstrated urea, glutamic acid and hypoxanthin are assimilated by all... |
Tipo: Text |
Palavras-chave: Bacillariophyceae; Bivalvia; Biomass; Pond culture; Algal settlements; Oyster culture; Nutritive value; Dissolved organic nitrogen. |
Ano: 1984 |
URL: http://archimer.ifremer.fr/doc/1984/acte-1531.pdf |
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