Application of cross‐flow filtration for determining the solubility of iron species in open ocean seawater
Application of cross‐flow filtration for determining the solubility of iron species in open ocean seawater
复制标题
应用错流过滤测定公海海水中铁物质的溶解度
DOI：
10.4319/lom.2008.6.630
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
P. Croot
中科院分区：
文献类型：
--
作者：
C. Schlosser;P. Croot
可溶性铁物种（有机和无机）的测量对于了解铁在海洋中的运输及其生物利用度非常重要。超滤设备和分析检测技术在低水平铁测定中的最新发展已将焦点转向获得可溶性铁物种的数据。然而，到目前为止，很少有研究已经表征了超滤系统相对于充分描述的可溶性铁络合物的性能。在目前的工作中，我们描述了一种方法学研究，通过将交叉流超滤系统（Vivaflow 50™）与放射性同位素（55 Fe）相结合，表征海水中可溶性和胶体铁物种的行为。在本研究期间，我们能够通过包括所有组分来保持良好的质量平衡：不仅包括溶液相（渗余物和渗透物），还包括通过酸冲洗步骤回收的壁吸附和过滤吸附铁。当溶液中Fe′饱和时，吸附不可避免。然而，在不饱和溶液中，如过量的去铁胺B，壁和过滤器吸附最小化，表明这些影响对于铁结合配体过量的天然样品应该是轻微的。我们的研究结果具有重要的意义，使用超滤膜的开放海洋铁地球化学研究。
Measurements of soluble iron species (organic and inorganic) are important for understanding the transport of iron within the ocean and its bioavailability. Recent developments in ultrafiltration equipment and analytical detection techniques for low level Fe determination has turned the spotlight on obtaining data on soluble iron species. However there have, until now, been few studies that have characterized the performance of an ultrafiltration system with respect to well described soluble iron complexes. In the present work, we describe a methodological study characterizing the behavior of soluble and colloidal iron species in seawater by combining a cross‐flow ultrafiltration system (Vivaflow 50™) with a radioisotope (55Fe). During this study, we were able to maintain excellent mass balances by including all components: not only the solution phases (retentate and permeate) but wall‐adsorbed and filter‐adsorbed iron, which were recovered by an acid‐rinsing step. Wall and filter adsorption were unavoidable when solutions were saturated with respect to Fe′. However in undersaturated solutions, such as with an excess of desferrioxamine B, wall and filter adsorption were minimized, indicating that these effects should be slight for natural samples where iron‐binding ligands are in excess. Our results have important implications for the use of ultrafiltration membranes for open ocean iron biogeochemical studies.