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Vong, Lilita; Laes, Agathe; Blain, Stéphane. |
A new method for the non-specific determination of iron-porphyrin-like complexes in natural waters has been developed. It is based on the chemiluminescent oxidation of the luminol in the presence of dioxygen (O-2) at pH 13. The method has been implemented in a FIA manifold that allowed the direct injection of seawater. The limit of detection is 0.11 nM of equivalent hemin (Fe-protoporphyrin IX). Fe2+, Fe3+, H2O2, siderophore (deferoxamin mesylate), humic acid and phytic acid did not interfere when the), were present at the concentrations expected in seawater. Metal free porphyrin and Mg, Cu, Co porphyrin complexes did not induce a significant chemiluminescent signal. Poisoned unfiltered samples could be stored for several weeks before analyses. The new... |
Tipo: Text |
Palavras-chave: Chemiluminescence; Complexation; Flow injection; Seawater; Porphyrin; Iron. |
Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/2007/publication-3298.pdf |
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Ramalhosa, Elsa; Río-Segade, Susana; Pereira, Eduarda; Vale, Carlos; Duarte, Armando. |
Dissolved reactive mercury was determined in water samples from Ria da Aveiro, a coastal lagoon contaminated by mercury. Concentrations increased with acid dilution to a maximum of 193% in samples containing organic matter with high aromaticity, as inferred from absorbances at 250, 280 and 365 nm. Laboratory experiments with potassium hydrogenoftalate and humic acids solutions proved the influence of aromaticity in complexing mercury, how acid dilution protonates the aromatic Hg-complexes and consequent release of labile forms of mercury to solution. On the basis of these results it is proposed that natural waters from mercury contaminated ecosystems should be analysed without dilutions, otherwise additional studies should be performed to access the... |
Tipo: Article |
Palavras-chave: Reactive mercury; Organic matter; Flow injection; Cold vapour atomic Fluorescence Spectrometry; Natural waters. |
Ano: 2003 |
URL: http://hdl.handle.net/10198/3954 |
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