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Venchiarutti, C.; Roy-barman, M.; Freydier, R.; Van Beek, P.; Souhaut, M.; Jeandel, C.. |
Dissolved and particulate excess (230)Th and (231)Pa concentrations (noted (230)Th(xs) and (231)Pa(xs) respectively) and (231)Pa(xs)/(230)Th(xs) activity ratios were investigated on and out of the Kerguelen plateau (Southern Ocean) in the framework of the Kerguelen Ocean and Plateau compared Study project in order to better understand the influence of particle flux and particle chemistry and advection on the scavenging of (231)Pa. In the wake of Kerguelen, particulate (231)Pa(xs) is relatively abundant compared to its content in the dissolved phase. This, together with the low fractionation observed between (230)Th and (231)Pa (F(Th/Pa) ranging from 0.06 +/- 0.01 to 1.6 +/- 0.2) reflects the domination of the biogenic silica in the particle pool. Along the... |
Tipo: Text |
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Ano: 2011 |
URL: https://archimer.ifremer.fr/doc/00228/33894/32272.pdf |
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Lacan, F.; Radic, A.; Jeandel, C.; Poitrasson, F.; Sarthou, Geraldine; Pradoux, C.; Freydier, R.. |
This work demonstrates for the first time the feasibility of the measurement of the isotopic composition of dissolved iron in seawater for a typical open ocean Fe concentration range (0.1-1 nM). It also presents the first data of this kind. Iron is preconcentrated using a Nitriloacetic Acid Superflow resin and purified using an AG1x4 anion exchange resin. The isotopic ratios are measured with a MC-ICPMS Neptune, coupled with a desolvator (Aridus II), using a Fe-57-Fe-58 double spike mass bias correction. Measurement precision (0.13%, 2SD) allows resolving small iron isotopic composition variations within the water column, in the Atlantic sector of the Southern Ocean (from delta Fe-57 = -0.19 to +0.32 parts per thousand). Isotopically light iron found in... |
Tipo: Text |
Palavras-chave: MC ICP MS; Chelating resin; Southern ocean; Fractionation; Seawater; Earth; Separation; Accuracy; Pacific; FE(III). |
Ano: 2008 |
URL: https://archimer.ifremer.fr/doc/00202/31374/29781.pdf |
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