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素，但也以高浓度和某些化学形式的水生生物有毒。因此，了解海水中铜的化学形式对于了解其在海洋生态系统中的影响很重要。主要研究者先前研究的研究北太平洋和北大西洋的铜的结果表明，海洋中大多数溶解的铜（CU）是惰性的，并且可能不会与海水中其他化合物进行化学交换。看来Cu仅从地表水中的惰性形式释放，在该水域被光介导的反应分解。在这个项目中，团队将确定来自太平洋和哥伦比亚河样品中海水中惰性和标签形式之间的交换速率和过程。该项目还旨在了解海水中溶解的有机物如何在海洋循环的时间尺度上与铜反应。该项目包括通过一项名为USC青年研究人员计划的计划，为学生提供整个夏季的精神，为洛杉矶中南部地区的高中生研究机会。将向大学生提供研究机会，以从事基于实验室的交换动力学工作。该研究项目挑战了当前的范式，即海水中的铜规格和分布由强，不稳定的有机络合物支配，这些复合物可以以热力学平衡为特征。该项目的目标包括：1）确定惰性和标签池之间Cu交换的速率，2）表征从太平洋和哥伦比亚河收集的样品中标记和惰性CU的稳定同位素组成，以及3）理解惰性Cu与溶解有机物之间的关系。该团队将努力重新评估对海水中铜化学的理解，并确定控制其循环和生物可用性的过程和机制。这项工作将扩展以前用于在反相列与色谱分离的反相列上隔离Cu的方法。结果将为更详细的结构表征提供基础，并为基于规范的自然同位素丰度数据包括在CU生物地球化学模型中。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响审查标准，通过评估来诚实地对支持进行评估。