Language：English   Publishing type：Research paper (scientific journal)   Publisher：Springer Science and Business Media LLC  

DOI： 10.1007/s10872-012-0105-0

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

The distribution of Al, Mn, Fe, Co, Ni, Cu, Zn, Cd, and Pb in seawater was investigated on the Bering Sea shelf (56-64 degrees N, 165-169 degrees W) in September 2000. The unfiltered and filtered seawater samples were used for determination of total dissolvable (TD) and dissolved (D) metals (M), respectively. The TD-M concentrations were generally higher than in the Pacific Ocean. TD-Cd was highest in deep water of the outer shelf domain and dominated by dissolved species. The other TD-M were highest at stations close to the Yukon River delta and had higher fractions of labile particulate (LP) species that were obtained as the difference between TD-M and D-M. Dissolved Al, Ni, and Cu were characterized by input from the Yukon River. Dissolved Mn and Co showed maximums on the bottom of the coastal domain, suggesting influence of sedimentary Mn reduction. The correlations of D-Zn, D-Cd, and macronutrients indicated their distributions were largely controlled through uptake by microorganisms and remineralization from settling particles. All these three processes (river input, sedimentary reduction, and biogeochemical cycle) had an influence on the distribution of D-Fe. D-Pb was fairly uniformly distributed in the study area. The stoichiometry of D-M in the Bering Sea shelf showed enrichment of Co and Pb and depletion of Ni, Cu, Zn, and Cd compared with that in the North Pacific. The LP-M/LP-Al ratio revealed significant enrichment of the other eight metals relative to their crustal abundance, suggesting importance of formation of Fe-Mn oxides and adsorption of trace metals on the oxides.

DOI： 10.1007/s10872-011-0070-z

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURE PUBLISHING GROUP  

Understanding the circulation of water masses in the world's oceans is critical to our knowledge of the Earth's climate system. Trace elements and their isotopes have been explored as tracers for the movement of water masses(1). One type of candidate elements(2) are the high-field-strength elements zirconium (Zr), hafnium (Hf), niobium (Nb) and tantalum (Ta). Here we measure the distributions of dissolved Zr, Hf, Nb and Ta along two meridional sections in the Pacific Ocean that extend from 65 degrees to 10 degrees S and from 10 degrees to 50 degrees N. We find that all four elements tend to be depleted in surface water. In the deep oceans, their concentrations rise along our transects from the Southern Ocean to the North Pacific Ocean, and show strong correlations with the concentration of silicate. These results indicate that terrigenous sources are important to the budget of Zr, Hf, Nb and Ta in sea water, compared with hydrothermal input. Unexpectedly, the weight ratios for Zr/Hf fall between 45 and 350 and those for Nb/Ta between 14 and 85 in Pacific sea water, higher than the ratios observed in fresh water, in the silicate Earth or in chondritic meteorites. We conclude that the fractionation of Zr/Hf and Nb/Ta ratios will be useful for tracing water masses in the ocean.

DOI： 10.1038/NGEO1114

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Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

DOI： 10.14862/geochemproc.58.0.157.0

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：The Japan Society for Analytical Chemistry  

Bioactive trace metals are essential or highly toxic elements for organisms. The most important bioactive trace elements in the ocean environment are Al, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb, whose concentrations in seawater are generally less than tens of nmol kg⁻¹. In previous methods, there were problems, such as contamination, interferences by major constituents and a non-quantitative recovery of the target metals, especially Al and Mn. We developed a novel method for analyzing the 9 elements based on solid-phase extraction-inductively coupled plasma mass spectrometry (ICP-MS). In this method, a column packed with chelating absorbent, which had ethylenediaminetriacetic and iminodiacetic acid groups, was used in a closed concentration system. The proposed method was able to concentrate all of the 9 elements simultaneously and quantitatively, and to remove the major constituents in seawater. The procedural blanks for Mn, Co, Ni, Cu and Cd were less than the detection limits for ICP-MS (3 times the standard deviations of 1 mol L⁻¹ HNO₃), and those for Al, Fe, Zn and Pb were 0.14, 0.03, 0.07 and 0.003 nmol kg⁻¹, respectively. The overall detection limits for Al, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb were 0.24, 0.01, 0.04, 0.002, 0.01, 0.01, 0.06, 0.01 and 0.001 nmol kg⁻¹, respectively. In this paper, we review the development of this method and its application to international intercalibration using open-ocean seawater.

DOI： 10.2116/bunsekikagaku.59.1087

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Other Link： https://jlc.jst.go.jp/DN/JALC/00362207383?from=CiNii

Language：English   Publishing type：Research paper (scientific journal)  

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Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

DOI： 10.14862/geochemproc.56.0.335.0

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Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

The major activity of the international program GEOTRACES is to elucidate the global oceanic distribution of key parameter, such as trace elements Al, Mn, Fe, Cu, Zn, Cd, and stable isotopic compositions. We are targeting

DOI： 10.14862/geochemproc.56.0.331.0

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Publisher：GEOCHEMICAL SOCIETY OF JAPAN  

DOI： 10.14862/geochemproc.55.0.60.0

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Language：English   Publisher：SPRINGER  

Dissolved and labile particulate Zr, Hf, Nb, Ta, Mo and W were determined at stations K1 (51 degrees N, 165 degrees E), K2 (47 degrees N, 160 degrees E), KNOT (44 degrees N, 155 degrees E) and 35N (35 degrees N, 160 degrees E) in the western North Pacific Ocean. A portion of seawater for dissolved species (D) was passed through a 0.2 mu m Nuclepore filter and acidified to pH 2.2 with HCI and HE A portion of seawater for acid-dissolvable species (AD) was acidified without filtration. Labile particulate (LP) species is defined as AD minus D, which represents a chemically labile fraction of particulate species. D-Zr, Hf and Ta increase with depth, Nb shows a slight depletion in surface water, whereas Mo and W have a conservative vertical profile. The concentration range of D-Zr, Hf, Nb, Ta and W is 31-275, 0.14-0.95, 4.0-7.2, 0.08-0.29 and 40-51 pmol kg(-1), respectively, whereas that of Mo is 97-105 nmol kg(-1). LP-species of Zr, Hf and Ta account for 10-14% of AD in average and increase up to 25% below 4000 m, whereas those for Mo and W are negligible. In contrast, LP-Nb shows maxima (up to 27%) in surface water, We also found that D-Zr/Hf, Nb/Ta and Mo/W mole ratios generally increase in the order continental crust < river water < coastal sea < open ocean.

DOI： 10.1007/s10872-008-0019-z

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Language：Japanese   Publisher：Japan Society for Biomedical Research on Trace Elements  

Solid phase extraction with chelating adsorbents is useful for the preconcentration of trace metals in seawater. We have examined a number of chelating adsorbents and developed simultaneous determination methods for trace metals in seawater on the basis of preconcentration by solid phase extraction and determination by ICP-MS. Here we review the results on the determination of trace bioactive metals(Fe, Co, Ni, Cu, Zn, Cd and Pb)using fluoride-containing metal alkoxide glass immobilized 8-hydroxyquinoline(MAF-8HQ)and the determination of the second and third transition series metals(Zr, Hf, Nb, Ta, Mo and W)using vinyl polymer resin immobilized 8-hydroxyquinoline(TSK-8HQ).

DOI： 10.11299/brte.18.319

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

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Language：English   Publisher：ELSEVIER SCIENCE BV  

A new technique for the determination of suspended particulate trace metals (P-metals > 0.2 mu m), such as Co, Ni, Cu, Zn, Cd and Pb, in open ocean seawater has been developed by using microwave digestion coupled with flow injection inductively coupled plasma mass spectrometry (FI-ICP-MS). Suspended particulate matter (SPM) was collected from 500 mL of seawater on a Nuclepore filter (0.2 mu m) using a closed filtration system. Both the SPM and filter were completely dissolved by microwave digestion. Reagents for the digestion were evaporated using a clean evaporation system, and the metals were redissolved in 0.8 M HNO3. The solution was diluted with buffer solution to give pH 5.0 and the metals were determined by FI-ICP-MS using a chelating adsorbent of 8-hydroxyquinoline immobilized on fluorinated metal alkoxide glass (MAF-8HQ). The procedure blanks with a filter were found to be 0.048 +/- 0.008, 10.3 +/- 0.3, 0.27 +/- 0.05, 3.3 +/- 1.8, 0.02 +/- 0.03 and 0.85 +/- 0.09 ng L-1 for Co, Ni, Cu, Zn, Cd and Pb, respectively (n = 14). Detection limits defined as 3 times the standard deviation of the blanks were 0.023, 0.90, 0.14, 5.3, 0.078 and 0.28 ng L-1 for Co, Ni, Cu, Zn, Cd and Pb, respectively. Accuracy was evaluated using certified reference materials of chlorella (NES CRM No. 3) and marine sediment (HISS-1). The method was applied to the determination of vertical distributions for P-Co, Ni, Cu, Zn, Cd and Pb in the Western North Pacific. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.aca.2007.04.057

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Language：English   Publisher：ELSEVIER SCIENCE BV  

Here, we present the first simultaneous preconcentration and determination of ultratrace (pmol kg(-1) level) Zr, Hf, Nb, Ta and W in seawater, both in the form of dissolved and acid-dissolvable species. 8-Hydroxyquinoline (8HQ) bonded covalently to a vinyl polymer resin, TSK-8HQ, was used in a chelating adsorbent column to concentrate the metals. The greatest advantage of this resin is its endurance to 5 M HF, since this is an effective eluent for all five metals. The analytes were successfully concentrated from 250 mL seawater with a 50-fold concentration factor through the column extraction and evaporation. The detection limit was 0.009-0.15 pmol kg(-1). The procedure blank determined using ultra pure water as a sample was 0.005-0.37 pmol kg(-1). The five metals were quantitatively recovered from seawater with good precision (2-4%). The effect of sample pH, sample flow rate, eluent composition and sample pretreatment were carefully studied. This method was applied to seawater. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.aca.2006.10.033

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Here we present the first vertical distribution of dissolved (D) and acid-dissolvable (AD) bioactive trace metals (Fe, Co, Ni, Cu, Zn and Cd) in the Sulu Sea and the South China Sea, together with those observed previously by the same method in the western North Pacific. At a depth of 50-75 m, concentration minima of some trace metals were observed in the Sulu Sea (D-Zn, Cu and Fe) and the South China Sea (D-Zn), which coincided with the Chl a maximum, indicating scavenging of these metals including biological uptake. Above 150 m in the South China Sea, elevated concentrations of D-Co and Cu were observed, which could result from fluvial/coastal waters and/or shelf-sedimentary sources. In the surface mixed layer in the Sulu Sea, D-Fe concentrations were high (2 nM), presumably due to the flowing of waters across the Philippine Archipelago.
Except for Fe, concentrations of D and AD species at each corresponding depth were not significantly different. Concentrations of AD-Fe (6.8-17 nM), below 500 m in the Sulu Sea were much higher than those of D-Fe (0.2-1.7 nM), indicating that particulate Fe is abundant in the basin, probably coming from nearby sedimentary sources.
The vertical distributions of D-Ni, Cu, Zn and Cd in the South China Sea were nutrient-like and deviated slightly from those in the western North Pacific. This is caused by a rapid flushing of waters from the Philippine Sea coupled with vertical mixing within the South China Sea. The distribution of these metals in the Sulu Sea was more uniform below 500 m. The average concentrations of D-Ni, Cu, Zn and Cd in the deep water of the Sulu Sea were 6.1, 1.5, 3.3 and 0.5 nM, significantly lower than those of the western North Pacific (9.6, 2.8, 10.1 and 1.0 nM, respectively). We also found lower D-Cd/PO4, Ni/PO4 and Zn/Si(OH)(4) ratios in the Sulu Sea than those of the Pacific. The depletion of these concentrations and the D-Cd/PO4 and Ni/PO4 ratios in the Sulu Sea is probably because the deep water of the basin is rapidly exchanged with shallow waters but isolated from nutrient-rich deep waters derived from the North Pacific, due to the surrounding topographic barriers including the islands and the shallow sills ( < 420 m). The lower D-Zn/Si(OH)(4) ratios in the Sulu Sea are probably due to the relatively low D-Zn/Si(OH)(4) ratios in the upper water coupled with the preferential supply of Si(OH)(4) relative to Zn at depth.
While subsurface waters were flowing along density surfaces (sigma- T values of similar to 26) from the South China Sea to the Sulu Sea, the concentrations of macronutrients, D-Ni, Cu, Zn and Cd increased due to the regeneration from biogenic particles. The increases in the concentrations of bioactive elements relative to that Of PO4 were N: P: Si: Ni: Cu: Zn: Cd = 15: 1: 40: 2.4 x 10(-3) :0.6 x 10(-3) : 2.7 x 10(-3) : 0.03 x 10(-3) in a molar unit. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.dsr2.2006.04.019

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Language：Japanese   Publisher：海洋出版  

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DOI： 10.1007/s10967-006-0026-8

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DOI： 10.1007/s10201-003-0111-4

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DOI： 10.2343/geochemj.38.535

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

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Language：English   Publisher：CHEMICAL SOC JAPAN  

The sample, preparation and analytical methodology are described for determining minor and trace elements (Al, As, Ba, Cd, Co, Cr, Fe, Mg, Mn, Mo, Ni, Sb, Sr, U, V, W, Y and Zn) in biogenic carbonate minerals of coccolithophores. Coccolith particles isolated from cultivated coccolithophores were purified by centrifugation and resuspension with 0.5 mM sodium hydrogencarbonate solutions (1 M = 1 mol L-1). The concentrations of the elements in the final solutions were determined by high-resolution inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. The analytical results of coccolith particles suggest that the molar ratios of the minor and trace elements in coccoliths vary with the compositions of the medium in which the coccolithophores are grown.

DOI： 10.1246/bcsj.76.115

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Language：English   Publishing type：Research paper, summary (international conference)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

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Language：English   Publisher：Institute for Chemical Research, Kyoto University  

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Language：English   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Arsenic transformations by freshwater algae have been studied under laboratory conditions. By the use of a new analytical method, we identified methylarsenic(III) species in the growth medium of green-alga Closterium aciculare incubated under axenic conditions. The arsenate concentration in the experimental medium began to decrease just after inoculation, and the levels of arsenite and methylarsenicals increased with the growth of C. aciculare. Initially, most of the arsenate was converted into arsenite, which peaked in concentration during the exponential phase. Methylarsenicals accumulated rapidly in the stationary phase. DMAA(V) production was enhanced when the ratio of phosphate to arsenate decreased in the culture medium. The levels of DMAA(V) increased continuously toward the end of the experiment. On the other hand, methylarsenic(III) species remained relatively steady during the stationary phase. Methylarsenic(III) species accounted for 0-35% of methylarsenicals. These results suggest that arsenite and methylarsenicals (containing methylarsenic(III) species) are supplied by phytoplankton, and serve as evidence of the origin of methylarsenic(III) species in natural waters. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0045-6535(00)00137-5

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Language：English   Publisher：ELSEVIER SCIENCE BV  

A method for preconcentrating Zr from large volumes of seawater using MnO2-impregnated fibers is described. The manganese dioxide-impregnated fibers were synthesized from polypropylene cartridge filters by a redox reaction between KMnO4 and MnCl2. Seawater samples were introduced into an extraction system and Zr was extracted from the samples by the MnO2-impregnated fibers. Zirconium was recovered from the fibers through two steps of elution into aqueous solutions and measured by inductively coupled argon plasma atomic emission spectrometry. The average extraction efficiency for Zr was 59% on a single pass of 50-1000 l sample at flow rates of 8.1-15 l min(-1), and 100% on continuous circulation of 200 l sample at 15 l min(-1). The results indicate that Zr can be rapidly and easily preconcentrated onto MnO2-impregnated fibers from large volumes of seawater. This simple method can be applied to the preconcentration of trace dissolved Zr in natural water and removal of radiozirconium from radioactive waste fluid. (C) 2000 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0039-9140(00)00548-8

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