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Titolo:
Rapid determination of Th-230 and Pa-231 in seawater by desolvated micro-nebulization Inductively Coupled Plasma magnetic sector mass spectrometry
Autore:
Choi, MS; Francois, R; Sims, K; Bacon, MP; Brown-Leger, S; Fleer, AP; Ball, L; Schneider, D; Pichat, S;
Indirizzi:
Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA Woods Hole Oceanog Inst Woods Hole MA USA 02543 Woods Hole, MA 02543 USA Korea Basic Sci Inst, Isotope Res Team, Taejon 305333, South Korea Korea Basic Sci Inst Taejon South Korea 305333 aejon 305333, South Korea Woods Hole Oceanog Inst, Dept Geol & Geophys, Woods Hole, MA 02543 USA Woods Hole Oceanog Inst Woods Hole MA USA 02543 Woods Hole, MA 02543 USA Ecole Normale Super Lyon, Lab Sci Terre, F-69364 Lyon, France Ecole Normale Super Lyon Lyon France F-69364 Terre, F-69364 Lyon, France
Titolo Testata:
MARINE CHEMISTRY
fascicolo: 1-2, volume: 76, anno: 2001,
pagine: 99 - 112
SICI:
0304-4203(200110)76:1-2<99:RDOTAP>2.0.ZU;2-T
Fonte:
ISI
Lingua:
ENG
Soggetto:
THORIUM ISOTOPES; WATER COLUMN; INTERGLACIAL CHANGES; ICP-MS; OCEAN; VENTILATION; SEDIMENTS; ATLANTIC; SAMPLES; RATES;
Keywords:
Th-230; Pa-231; seawater; ICP/MS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Physical, Chemical & Earth Sciences
Citazioni:
45
Recensione:
Indirizzi per estratti:
Indirizzo: Francois, R Woods Hole Oceanog Inst, Dept Marine Chem & Geochem, Woods Hole, MA 02543 USA Woods Hole Oceanog Inst Woods Hole MA USA 02543 MA 02543 USA
Citazione:
M.S. Choi et al., "Rapid determination of Th-230 and Pa-231 in seawater by desolvated micro-nebulization Inductively Coupled Plasma magnetic sector mass spectrometry", MAR CHEM, 76(1-2), 2001, pp. 99-112

Abstract

Difficulties in determining the Th-230 and Pa-231 concentration of seawater have hindered rapid progress in the application of these unique natural tracers of particle scavenging and ocean circulation. In response, we have developed an ICP/MS analytical procedure combining a degree of sensitivity, precision and sample throughput that can facilitate the systematic measurement of basin-scale changes in Th-230 and Pa-231 seawater concentration, andprovide important constraints on circulation and mixing rates in the deep ocean. Seawater samples are spiked with Th-229 and Pa-233 and equilibrated beforepre-concentration using conventional methods of Fe oxyhydroxide co-precipitation and anion exchange. Isotopic ratios are measured using a Finnigan MAT Element magnetic sector Inductively Coupled Plasma mass spectrometer (ICP/MS) equipped with a desolvating micronebulizer. Measurements are done on 10-20 1 seawater samples with an internal precision of similar to 2% and a reproducibility of similar to 5% (95% confidence intervals (CI)) in deep water. After correction for procedural blank, Th-232 tailing, and (ThH)-Th-232-H-1 interference, the detection limits are similar to 3 fg for Th-230 and similar to 0.4 fg for Pa-231. Applied to 20 1 volumes, these detection limits correspond to concentrations of 0.15 fg/kg for Th-230 and 0.02 fg/kg forPa-231, which are 5-15 times lower than typical concentrations in surface water. The capability of this method is illustrated by two seawater profiles from the Equatorial Atlantic region that show systematic variations in Th-230 and Pa-231 concentration consistent with patterns of deep water circulation. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 28/11/20 alle ore 00:04:48