Automated on-line flow-injection ICP-MS determination of trace metals (Mn, Fe, Co, Ni, Cu and Zn) in open ocean seawater: Application to the GEOTRACES program
Automated on-line flow-injection ICP-MS determination of trace metals (Mn, Fe, Co, Ni, Cu and Zn) in open ocean seawater: Application to the GEOTRACES program
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DOI：
10.1016/j.marchem.2013.06.001
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发表时间：
2013-09-20
期刊：
影响因子：
3
通讯作者：
Sherrell, R. M.
中科院分区：
文献类型：
--
作者：
Lagerstroem, M. E.;Field, M. P.;Sherrell, R. M.
化学海洋学的大型项目目前需要测定数百至数千个公海海水样品中的多种微量元素。例如，国际GEOTRACES计划将大大受益于对海水中多种痕量金属的快速、精确、自动化、多元素分析方法。建立了一种在线自动萃取-流动注射-电感耦合等离子体质谱（ICP-MS）法同时测定大洋海水样品中Mn、Fe、Co、Ni、Cu和Zn的分析方法。一个全自动的市售系统在线缓冲样品的pH值，并从9 mL海水中提取感兴趣的金属到螯合树脂柱上，然后洗脱（1.6 M HNO 3）直接进入磁扇区ICP-MS。（类似于30 s），产生类似于200的预浓缩因子，并且总分析周期需要每个样品8.75 min。使用同位素稀释和基质匹配标准曲线的组合，从积分峰面积计算元素浓度。在每次取样过程中，以定期间隔（每10个样品）测定的程序空白用于空白校正和计算检测限（这些元素的范围为0.3至16 pmol kg（-1）海水）。罗斯海内部一致性标准和四种GEOTRACES参考海水材料的重复分析（大西洋和太平洋，表层和深层水）用于证明1-3%（RSD）的精度，以及除Co外所有元素与参考共识值的良好一致性。确定的Co浓度比共识值低40%，与海水中存在强Co配体一致，以及在该方法中不存在UV氧化步骤。正如GEOTRACES大西洋和太平洋基线站的海洋学一致剖面图所示，这种方法可以高度精确地测量全球海洋中各种浓度范围内的痕量金属。此外，完整的方法，包括流动注射硬件和控制软件，很容易转移到其他用户。(C)2013爱思唯尔有限公司版权所有。
Large programs in chemical oceanography currently require the determination of multiple trace elements in hundreds to thousands of open ocean seawater samples. For example, the international GEOTRACES program would benefit greatly from rapid, precise, automated, multi-element analytical methods for multiple trace metals in seawater. An automated, on-line extraction, flow-injection ICP-MS method is presented here for simultaneous determination of Mn, Fe, Co, Ni, Cu and Zn in open ocean seawater samples. A fully automated commercially available system buffers the pH of the samples on-line and extracts the metals of interest from 9 mL of seawater onto a chelation resin column, which is then eluted (1.6 M HNO3) directly into a magnetic sector ICP-MS. The resulting transient peaks elute in 45 mu L (similar to 30 s) yielding a preconcentration factor of similar to 200, and the total analysis cycle requires 8.75 min per sample. Elemental concentrations are calculated from integrated peak areas using a combination of isotope dilution and matrix-matched standard curves. Procedural blanks determined at periodic intervals (every 10 samples) throughout each sample run are used for blank correction and for calculating detection limits (range 0.3 to 16 pmol kg(-1) seawater for these elements). Replicate analyses of a Ross Sea in-house consistency standard and four GEOTRACES reference seawater materials (Atlantic and Pacific, surface and deep water) are used to demonstrate precision of 1-3% (RSD) and very good agreement with reference consensus values for all elements except Co. Determined Co concentrations are similar to 40% lower than consensus values, consistent with the presence of strong Co ligands in seawater, and the absence of a UV-oxidation step in this method. As illustrated by oceanographically consistent profiles at the GEOTRACES Atlantic and Pacific baseline stations, this method provides highly precise measurement of trace metals over the full range of concentrations occurring in the global ocean. Moreover, the full methodology, including flow-injection hardware and control software, is readily transferable to other users. (C) 2013 Elsevier B.V. All rights reserved.