Collaborative Research: Molecular Level Characterization of Organic Matter in Ice Cores using High-resolution FTICR mass spectrometry

该奖项支持一个项目，该项目旨在充分开发分析冰芯样品中可溶性有机物的相对较新的技术所需的分析方案。 该技术将电喷雾电离与高分辨率傅里叶变换离子回旋共振质谱 (ESI-FTICR-MS) 结合起来。 样品体积将减少，预浓缩步骤将被取消。在方法优化之后，将对来自南极和格陵兰岛多个地点的一组冰芯样本进行研究，以解决几个假设驱动的研究问题。 初步结果表明，冰芯样本中存在大量相对高分子量有机物质，一些样本的有趣结果值得进一步研究。将解决与更好地了解冰芯中有机物的性质和古记录有关的几个重要问题。其中包括更好地了解工业化前与现代样品中氮和硫同位素的起源，开发将有机地球化学家通常用于沉积物分析的分子生物标记技术应用于冰芯有机物分析的方法，跟踪同系化合物的氧化水平并将其用作过去大气氧化剂水平的代理，并确定高分辨率 FTICR 质谱分析是否可以为冰芯社区提供可靠的分析方法分子水平的有机材料。 这项工作的智力价值在于，这种分析方法将为冰中有机物的性质提供新的认识，可能导致发现表明全球变化过程的多种分子物种，其丰度可以与其他变化代理进行比较。 拟议的研究具有探索性，并且对冰芯研究和低温生物学领域具有潜在的变革性。 这些研究更广泛的影响是，它们应该提供关于有机物来源、大气处理和极地冰的人为输入以及这些随时间变化的令人信服的证据。这里提出的合作工作将把大气化学/极地冰化学专业知识与有机地球化学专业知识结合起来，从而对这两个研究领域做出重大贡献，并在冰芯分析方面取得重大进展。研究生和本科生的培训将是该项目的关键组成部分，学生将参与使用先进分析仪器的合作研究，在全国会议上展示研究成果，并参与手稿准备。

This award supports a project to fully develop the analytical protocols needed to exploit a relatively new technique for the analysis of soluble organic matter in ice core samples. The technique couples Electrospray ionization to high resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). Sample volume will be reduced and pre-concentration steps will be eliminated. Following method optimization a suite of ice core samples will be studied from several Antarctic and Greenland locations to address several hypothesis driven research questions. Preliminary results show that a vast record of relatively high molecular weight organic material exists in ice core samples and intriguing results from a few samples warrant further investigation. Several important questions related to developing a better understanding of the nature and paleo record of organic matter in ice cores will be addressed. These include developing a better understanding of the origin of nitrogen and sulfur isotopes in pre-industrial vs. modern samples, developing the methods to apply molecular biomarker techniques, routinely used by organic geochemists for sediment analyses, to the analysis of organic matter in ice cores, tracking the level of oxidation of homologous series of compounds and using them as a proxy for atmospheric oxidant levels in the past and determining whether or not high resolution FTICR mass spectral analysis can provide the ice core community with a robust method to analyze organic materials at the molecular level. The intellectual merit of this work is that this analytical method will provide a new understanding of the nature of organic matter in ice, possibly leading to the discovery of multitudes of molecular species indicative of global change processes whose abundances can be compared with other change proxies. The proposed studies are of an exploratory nature and potentially transformative for the field of ice core research and cryobiology. The broader impacts of these studies are that they should provide compelling evidence regarding organic matter sources, atmospheric processing and anthropogenic inputs to polar ice and how these have varied over time. The collaborative work proposed here will partner atmospheric chemistry/polar ice chemistry expertise with organic geochemistry expertise, resulting in significant contributions to both fields of study and significant advances in ice core analysis. Training of both graduate and undergraduate students will be a key component of the project and students will be involved in collaborative research using advanced analytical instrumentation, presentation of research results at national meetings, and will participate in manuscript preparation.