Direct measurement of dissolved organic nitrogen concentration and 15N/14N ratio

直接测量溶解有机氮浓度和15N/14N比值

• 批准号: 0933076
• 负责人: Dennis Hansell
• 金额: $ 35.63万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2013-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0933076&HistoricalAwards=false
• 关键词: Direct; measurement; dissolved; organic; nitrogen

Dissolved organic nitrogen (DON) plays a significant role in terrestrial, marine, and atmospheric environments, but is a poorly understood part of the earth's nitrogen cycle. The concentration and isotopic composition of DON can be measured accurately in waters where minimal concentrations of inorganic nitrogen exist; however, there are currently no methods that can directly measure the concentration or isotopic composition of DON in aqueous samples where dissolved inorganic forms of nitrogen are present. Traditionally, the concentration of DON is estimated from the measurement of total dissolved nitrogen, but when DON makes up only a small fraction of the total dissolved nitrogen, it is difficult to accurately estimate the DON concentration with certainty. To address this issue, scientists from the University of Miami Rosenstiel School of Marine and Atmospheric Science are developing a new and potentially transformative method for studying organic nitrogen in the ocean. By developing such a technique scientists will be able to directly measure dissolved organic nitrogen, as well as the nitrogen isotopic composition, which will provide scientists with a better understanding of the global nitrogen cycle. Upon successful development of this new method of measuring oceanic nitrogen, scientists will be able to differentiate between natural and anthropogenic sources and sinks of DON, which will enhance our understanding of the controls on the fertility of the ocean, as well as its potential to sequester CO2 from the atmosphere. This research will also provide support for a postdoctoral researcher and a graduate student.

溶解有机氮(DON)在陆地、海洋和大气环境中发挥着重要作用，但在地球氮循环中却知之甚少。在无机氮浓度最低的水域中，DON的浓度和同位素组成可以准确测量；但是，在存在溶解的无机氮的水样中，目前还没有直接测量DON浓度或同位素组成的方法。传统上，DON的浓度是通过测定总溶解氮来估算的，但当DON只占总溶解氮的一小部分时，很难准确地估计出DON的浓度。为了解决这个问题，迈阿密大学罗森斯蒂尔海洋和大气科学学院的科学家们正在开发一种新的、可能具有变革性的方法来研究海洋中的有机氮。通过开发这种技术，科学家将能够直接测量溶解的有机氮以及氮的同位素组成，这将使科学家更好地了解全球氮循环。在成功开发这种测量海洋氮的新方法后，科学家将能够区分DON的自然和人为来源和汇，这将增强我们对海洋肥力的控制以及海洋从大气中隔离二氧化碳的潜力的理解。这项研究还将为博士后研究员和研究生提供支持。