2020年11月
Determination of the tungsten isotope composition in seawater: The first vertical profile from the western North Pacific Ocean
CHEMICAL GEOLOGY
- ,
- ,
- ,
- 巻
- 555
- 号
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1016/j.chemgeo.2020.119835
- 出版者・発行元
- ELSEVIER
The stable isotope ratio of W is a new tracer in oceanographic studies and a new proxy in paleoceanographic studies; however, precise data for modern seawater have not been reported to date. Because the concentration of W in seawater is as low as 49 pmol kg(-1), an similar to 3000-fold preconcentration is necessary prior to measurement by multicollector inductivity coupled plasma mass spectrometry (MC-ICP-MS). For the preconcentration, we investigated solid-phase extraction using chelating resins, namely, NOBIAS Chelate-PA1 with ethylenediaminetriacetic acid groups and TSK-8HQ with 8-hydroxyquinolie groups. We report that TSK-8HQ is useful because the effects of the seawater matrix are minor thermodynamically and kinetically. We present a novel method for analysis of the concentrations and isotope ratios of W and Mo in seawater, consisting of solid phase extraction, chromatographic separation using anion exchange resin AG1 X8, and measurement by MC-ICP-MS. Both W and Mo are quantitatively recovered by this method, which was applied to seawater samples collected from the North Pacific Ocean. The measured concentration of W and the concentration and isotope ratio of Mo are consistent with those in the literature. The isotope ratio of W is found to be uniform throughout the water column in the western North Pacific Ocean; delta W-186/184 is +/- 0.12 parts per thousand (ave +/- 2sd, n = 7) using NIST SRM 3163 as a reference for W. On the basis of this data, we determined that the isotopic difference in delta W-186/184 is similar to 0.49 parts per thousand between seawater and oxic sediments in the modern ocean. This value accords with the reported experimental data for the isotope fractionation of W during adsorption on manganese and iron (oxyhydr)oxides, suggesting the validity of our data.
- リンク情報
-
- DOI
- https://doi.org/10.1016/j.chemgeo.2020.119835
- Web of Science
- https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000580660000010&DestApp=WOS_CPL
- Scopus
- https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85090049241&origin=inward
- Scopus Citedby
- https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85090049241&origin=inward
- ID情報
-
- DOI : 10.1016/j.chemgeo.2020.119835
- ISSN : 0009-2541
- eISSN : 1872-6836
- ORCIDのPut Code : 105671962
- SCOPUS ID : 85090049241
- Web of Science ID : WOS:000580660000010