Oceanographic Testing and Verification of an Iron-Selective Electrode

海水中有效铁（Fe）的缺乏被广泛认为是限制大面积高营养、低叶绿素（HNLC）海洋区域以及一些沿海上升流区域浮游植物生长的一个因素。 最近，铁已被证明会影响生态和物种分布的分层贫营养制度以及。 在这些铁有限区域的规模上，生产力（或缺乏生产力）对全球海洋碳预算至关重要。 一个可靠的，船舶部署的铁传感器的可用性将允许高分辨率的数据集，以获得常规的基础上，从而提高对全球地球化学相互作用的理解。 该提案旨在采取具体步骤，通过开发一种可用于大大扩大建模者可用数据的实地工具，提高测量覆盖率。该项目将为研究生和本科生提供培训，并在斯克里普斯新开的斯克里普斯创客空间开设本科工程课程。该项目将硫属化物Fe 3+离子选择性电极（Fe-ISE）集成到正在进行的和原位的自主测量系统中。 研究人员将通过以下方式校准和测试这些系统：1）将Fe-ISE测量的Fe 3+离子活性与通过竞争性配体交换-吸附阴极溶出伏安法（CLE-ACSV）独立测定的可溶性无机铁浓度进行比较，以及2）在人工海水介质中校准Fe-ISE，其中溶解的有机配体背景作为模拟校准系统。该提案的第二个目的是提高我们对存在于非均相溶解有机物池（例如海水）的硫属化物伊势的表面处的复杂化学的理解。预计该项目将产生适合长期自主使用的改进的Fe-ISE方法。 预计该项目还将描述/开发一套仪器，适用于长期监测码头位置的海洋学变量、船上航行系统和潜在的自主系泊和剖面系统。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The lack of available iron (Fe) in seawater is widely accepted as a factor that limits phytoplankton growth in extensive high nutrient, low chlorophyll (HNLC) ocean areas, as well as some coastal upwelling regions. More recently, iron has been shown to impact the ecology and species distribution of stratified oligotrophic regimes as well. Productivity (or lack thereof) at the scale of these iron limited areas is significant to the global marine carbon budget. The availability of a reliable, ship-deployable Fe sensor would permit high resolution datasets to be obtained on a routine basis, resulting in improved understanding of global biogeochemical interactions. This proposal is designed to make concrete steps toward improving measurement coverage by developing a field instrument that could be used to greatly expand the data available to modelers. This project will provide training for graduate and undergraduate students and an undergraduate engineering class in the newly opened Scripps Makerspace at Scripps. This project will integrate the chalcogenide Fe3+ ion selective electrode (Fe-ISE) into underway and in situ autonomous measuring systems. The researchers will calibrate and test these systems through: 1) comparison of the Fe3+ ion activity measured by the Fe-ISE to the concentration of soluble inorganic iron determined independently by competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-ACSV), and 2) calibration of the Fe-ISE in an artificial seawater medium with a well-understood dissolved organic ligand background serving as a mimetic calibration system. A secondary objective of this proposal is to enhance our understanding of the complex chemistry that exists at the surface of the chalcogenide ISE in the presence of a heterogeneous dissolved organic matter pool, such as seawater. It is expected that this project will yield an improved Fe-ISE methodology that is suitable for long term autonomous use. It is also expected that this project will describe/develop an instrument package suitable for long term monitoring of oceanographic variables at pier locations, shipboard underway systems, and potentially autonomous moored and profiling systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.