Characterization of the distribution and properties of inert copper in seawater

海水中惰性铜的分布和性质表征

• 批准号: 2343416
• 负责人: James Moffett
• 金额: $ 55.03万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2343416&HistoricalAwards=false
• 关键词: Characterization; distribution; properties; inert; copper

Copper is an important nutrient but also toxic to aquatic organisms at high concentrations and in certain chemical forms. Understanding the chemical forms of copper in seawater is therefore important to understanding its effect in ocean ecosystems. Results from the principal investigator’s previous research investigating copper in the North Pacific and North Atlantic Oceans indicated that most dissolved copper (Cu) in the ocean is inert and likely does not undergo chemical exchange with other compounds in seawater. It appears that Cu is only released from the inert form in surface waters, where it is decomposed by light-mediated reactions. In this project, the team will determine the rates and processes of exchange between inert and labile forms of copper in seawater in samples from the Pacific Ocean and Columbia River. The project also aims to understand how dissolved organic matter in seawater will react with copper over the timescales of ocean circulation. The project includes summer research opportunities for high school students in the South Central Los Angeles Area through a program known as USC Young Researchers Program that provides students with a mentor throughout the summer. Research opportunities will be provided to undergraduate students to work on laboratory-based exchange kinetics work. This research project challenges the current paradigm that copper speciation and distribution in seawater is dominated by strong, labile organic complexes that can be characterized by thermodynamic equilibria. The objectives of this project include: 1) determining rates of exchange of Cu between inert and labile pools, 2) characterizing the stable isotope composition of labile and inert Cu from samples collected from the Pacific Ocean and Columbia River, and 3) understanding the relationship between inert Cu and dissolved organic matter. The team will work to reassess the understanding of the chemistry of copper in seawater and determine the processes and mechanisms that control its cycling and biological availability. The work will expand the methodology utilized previously to isolation of inert Cu on reverse phase columns coupled with chromatographic separation. The results will provide a basis for more detailed structural characterization and provide a basis for including speciation-based natural isotope abundance data into models of Cu biogeochemistry.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.

铜是一种重要的营养物质，但在高浓度和某些化学形式下对水生生物有毒，因此了解海水中铜的化学形式对于了解其对海洋生态系统的影响非常重要。北太平洋和北大西洋表明，海洋中大多数溶解的铜 (Cu) 是惰性的，很可能不会与海水中的其他化合物进行化学交换，看来铜仅以惰性形式释放到表层水中。分解为在该项目中，该团队将确定太平洋和哥伦比亚河样本中惰性和不稳定形式的铜之间的交换速率和过程。该项目还旨在了解海水中有机物的溶解情况。该项目包括通过南加州大学青年研究人员计划为洛杉矶中南部地区的高中生提供夏季研究机会，该计划为学生提供整个夏季的导师研究机会。提供给本科生进行基于实验室的工作该研究项目挑战了当前的范式，即海水中铜的形态和分布由强的、不稳定的有机配合物主导，该配合物可以通过热力学平衡来表征。该项目的目标包括：1）确定铜之间的交换率。惰性和不稳定池，2）表征从太平洋和哥伦比亚河收集的样品中不稳定和惰性铜的稳定同位素组成，以及3）了解惰性铜和溶解有机物之间的关系。重新评估对海水中铜的化学性质的了解，并确定控制其循环和生物利用度的过程和机制。这项工作将扩展之前使用的反相柱分离惰性铜的方法，并结合色谱分离。为更详细的结构表征提供基础，并为将基于形态的天然同位素丰度数据纳入铜生物地球化学模型提供基础。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。