Collaborative Research: Nanoscale Investigations of Marine Organic Matter Diagenesis

对于海洋有机化学家来说，对海洋溶解有机质的未表征部分的化学结构的ABSTRACTOCE-0221295OCE-0221029OCE-0221336Investigation仍然是一个难以实现的目标。这项工作中使用的一种方法是通过在微米到纳米尺度上评估海洋有机物结构的微观异质性来直接处理超分子尺度的海洋有机物结构。使用扫描透射式X射线显微镜(STXM)，这是一种允许记录近边X射线吸收精细结构(NEXAFS)谱的技术，将允许量化不同官能团和元素键合类型的相对丰度。这种介于整体化学分析和分析、单个分子或分子类之间的大分子组合的化学空间图谱为海洋化学提供了一种重要的新分析工具的能力。在调查模式中，将使用这些技术对来自世界海洋不同地区的几名研究人员收集和贡献的一系列有机材料进行检查。这一方法将推广到收集的沉积物和悬浮(捕获)颗粒物的更多样本。使用整个浮游植物和细菌培养的实验室实验将被用来提供适合有机质成岩作用早期阶段的材料。

ABSTRACTOCE-0221295OCE-0221029OCE-0221336Investigation of the chemical structures of the uncharacterized fraction of marine dissolved organic matter remains an elusive goal for marine organic chemists. An approach to be used in this work is to directly address supramolecular size scales of marine organic matter structures by assessing their microheterogeneity on micro to nanoscales. Using Scanning Transmission X-ray Microscopy (STXM), a technique that allows the registration of Near Edge X-ray Absorption Fine Structure (NEXAFS) spectra, will allow the quantification of the relative abundance of different functional groups and element bonding types. This spatial mapping of the chemistry of macromolecular assemblages at scales intermediate between bulk chemical analysis and analysis individual molecules or molecular classes offers the capabilities of a important new analytical tool to marine chemistry. In a survey mode, a range of organic materials collected and contributed by several researchers from different parts of the world's oceans will be examined using these techniques. This approach will be extended with additional samples of collected sediment and suspended (trapped) particulates. Laboratory experiments using whole phytoplankton and bacterial cultures will be used to provide materials appropriate to the earlier stages of organic matter diagenesis.