Collaborative Research: Comprehensive Chemical Characterization of Marine Dissolved Organic Matter using Efficient Isolation Coupled to Advanced Analytical Techniques

溶解有机质（DOM）是地球上最大的活性碳库之一，在海洋和全球生物地球化学过程中起着重要作用。确定DOM的详细组成和结构提供了无与伦比的回报，因为它们的信息丰富性代表了一套独特的生物地球化学示踪剂，能够为母水的起源以及在运输过程中在这些水中发生的成岩变化提供重要的见解。最近的分析突破有可能将海洋DOM的主要部分带入我们的分析窗口，从而极大地促进了DOM“分子信息”的阅读。此外，利用反渗透结合电渗析（RO/ED）分离DOM的能力也有了很大的提高，现在可以分离高达95%的海洋DOM，而以前的技术只有10-40%。在这项研究中，来自老道明大学的一位新研究员将领导一个包括佐治亚理工学院在内的团队，该团队将把改进的海洋DOM隔离与超高分辨率FT-ICR MS和先进的核磁共振波谱相结合，以获得对海洋DOM组成和控制其组成的生物地球化学过程的重要新见解。本研究的主要目的是：(1)对海洋DOM池中占主导地位的生物难降解DOM进行表征，特别是在深海中；(2)对上升流区新生成的DOM和亚热带低营养环流地表水中积累的半生物稳定性和光漂白DOM进行了表征；(3)将RO/ED分离的DOM与原始样品以及超滤和固相萃取（如XAD和C18）分离的DOM进行比较。就更广泛的影响而言，这项研究将为未来的海洋和全球生物地球化学研究奠定基础，这些先进的技术可以用来追踪化合物或DOM的成分类别，从它们的多种来源，沿着它们的各种成岩和运输路径，到它们的出口点，微生物吸收或矿化。此外，pi将为海洋生物地球化学界提供急需的前兆参考材料。拟议的研究将支持ODU的一名新助理研究教授和三名博士生。与WHOI、麻省理工学院和HOT网站的研究人员的合作关系将促进合作的实地研究。将设立一个专门的项目网站，并酌情通过公众和新闻媒介的相互作用，促进公众接触和信息传播。

Dissolved organic matter (DOM) plays major roles in oceanic and global biogeochemical processes as it is one of the Earth's largest active carbon pools. Determining the detailed composition and structure of DOM offers unparalleled rewards as their informational richness represents a unique set of biogeochemical tracers capable of providing important insights into the origins of their parent waters and the diagenetic alterations that have occurred within those waters during transport. Recent analytical breakthroughs have the potential to bring a major fraction of marine DOM within our analytical window, thus greatly facilitating the reading of DOM's "molecular messages". In addition, there has been promising improvement in the ability to isolate DOM using reverse osmosis coupled with electrodialysis (RO/ED) that can now isolate up to 95% of marine DOM compared to ~10-40% for previous techniques. In this research, a new investigator from Old Dominion University will lead a team that also includes Georgia Institute of Technology that will combine improved isolation of marine DOM with the unparalleled power of ultra-high resolution FT-ICR MS and advanced NMR spectroscopy to gain major new insights into the composition of marine DOM and the biogeochemical processes controlling its composition. The main goals of this proposed study are to: (1) characterize bio-refractory DOM that dominates the marine DOM pool especially in the deep sea; (2) characterize newly produced DOM in an upwelling region and the semi-biolabile and photobleached DOM that accumulates in oligotrophic, subtropical gyre surface waters; and (3) compare RO/ED isolated DOM to the original sample and to DOM isolated using ultrafiltration and solid-phase extraction (e.g., XAD and C18). In terms of broader impacts, this research will lay the foundations for future oceanic and global biogeochemical studies where these advanced techniques can be used to trace compounds or component classes of DOM from their multifarious sources, along their various paths of diagenesis and transport, to their points of export, microbial uptake or mineralization. In addition, the PIs will provide critically needed precursory reference material for the marine biogeochemical community. The proposed study will support a new Assistant Research Professor at ODU and three doctoral students. Collaborative ties with investigators from WHOI, MIT and the HOT site will foster cooperative field-based research. Public outreach and information dissemination will be facilitated by creation of a dedicated project website and through public and news media interactions, as appropriate.