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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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| FERREIRA, E. C.; NOGUEIRA, A. R. de A.; SOUZA, G. B. de; BATISTA, L. A. R.. |
| Total phenols and condensed tannins in Pigeon pea seeds were determined by flow injection spectrophotometry. Folin-Denis and vanillin assays were used for total phenol and condensed tannin, respectively. Three Pigeon pea accessions were cultivated in a greenhouse. After harvesting, one access was separated into two aliquots. One aliquot was freeze-dried (-196 C), and the other was dried in a forced air oven at 50 C, like the other access samples, to evaluate drying temperature interference. The seeds were initially analyzed and then stored at around -10 C, 16 C or at ambient temperature (25 10 C). The stored samples were analysed every 30 days, for a 90 day period. A significant difference (P < 0:05) occurred between the drying methods for condensed... |
| Tipo: Artigo de periódico |
Palavras-chave: Condensed tannims; Total phenols; Pigeon pea seeds; Flow injection analysis; Storage. |
| Ano: 2004 |
URL: http://www.alice.cnptia.embrapa.br/alice/handle/doc/46838 |
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| Laes, Agathe; Vuillemin, Renaud; Leilde, Bernard; Sarthou, Géraldine; Bournot Marec, Claudie; Blain, Stéphane. |
| A sensitive method for iron determination in seawater has been adapted on a submersible chemical analyser for in situ measurements. The technique is based on flow injection analysis (FIA) coupled with spectrophotometric detection. When direct injection of seawater was used, the detection limit was 1.6 nM, and the precision 7%, for a triplicate injection of a 4 nM standard. At low iron concentrations, on line preconcentration using a column filled with 8-hydroxyquinoline (8HQ) resin was used. The detection limit was 0.15 nM (time of preconcentration = 240 s), and the precision 6%, for a triplicate determination of a I nM standard, allowing the determination of Fe in most of the oceanic regimes, except the most depleted surface waters. The effect of... |
| Tipo: Text |
Palavras-chave: Temperature and pressure effects; Submersible chemical analyser; Seawater; In situ measurements; Iron; Flow injection analysis. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-1209.pdf |
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