New Solid-State NMR Techniques for Analyzing Insoluble Organic Matter

用于分析不溶性有机物的新型固态核磁共振技术

• 批准号: 0138117
• 负责人: Klaus Schmidt-Rohr
• 金额: $ 28.14万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-08-01 至 2006-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0138117&HistoricalAwards=false
• 关键词: New; Solid; State; NMR; Techniques

In this project supported by the Analytical and Surface Chemistry and the Geology and Paleontology Programs, Professor Klaus Schmidt-Rohr and coworkers at Iowa State University, advanced solid-state NMR methodologies will be developed and applied to identify at least 40 specific functional groups and estimate their concentrations in natural organic matter. This will be achieved by means of a set of efficient new spectral-editing pulse sequences based on heteronuclear dipolar couplings or chemical-shift anisotropies. Furthermore, the larger environment of a given functional group will be identified in two- and three-dimensional correlation experiments, and inhomogeneities on a 1- to 50-nm scale by spin diffusion. NMR dynamics measurements will enable the search for soft mobile regions that have been invoked to explain the partitioning of organic contaminants into soil organic matter. Near the end of the project, improved structural models for examples of soil and marine organic matter will be generated. Nuclear magnetic resonance spectroscopy will be used to elucidate the chemical and supramolecular structures of insoluble organic substances that are presented by the natural environment, such as soil and marine organic matter, kerogen, or bituminous materials. To this end, advanced solid-state nuclear magnetic resonance methods are being developed that can identify and quantify a large number of chemical groups in organic solids. In addition, nanometer-scale domains will be characterized. The NMR methods will be used to characterize the chemical binding sites of contaminants; to help understand nutrient release into soil; to indicate methods for enhanced carbon sequestration in soil to reduce "greenhouse gases" in the atmosphere; and to shed light on the chemical processes of soil, kerogen, and fossil-fuel formation. This will help to provide deeper insights into the chemical history of natural organic matter, its role in the global carbon cycle, and the results of human activities on the environment.

在该项目的支持和地面化学以及地质与古生物学计划的支持下，爱荷华州立大学的克劳斯·施密特·罗赫（Klaus Schmidt-Rohr）和同事，将开发高级固态NMR方法论，并应用于至少40个特定功能组，并在自然有机物中估算其浓度。这将通过一组有效的新光谱脉冲序列基于异核偶极耦合或化学转移各向异性来实现。 此外，将在两维相关实验中鉴定给定官能团的较大环境，并通过自旋扩散以1至50 nm的比例识别不均匀性。 NMR动力学测量将使搜索已调用的软移动区域，以解释有机污染物将有机污染物分配到土壤有机物中。在项目结束时，将产生改进的土壤和海洋有机物实例的结构模型。核磁共振光谱将用于阐明由自然环境呈现的不溶性有机物质的化学和超分子结构，例如土壤和海洋有机物，动质或沥青材料。为此，正在开发高级固态核磁共振方法，可以识别和量化有机固体中的大量化学基团。 另外，将表征纳米尺度的域。 NMR方法将用于表征污染物的化学结合位点。有助于了解养分释放到土壤中；指示在土壤中增强碳固相的方法，以减少大气中的“温室气体”；并阐明土壤，动元和化石燃料形成的化学过程。这将有助于更深入地了解自然有机物的化学史，其在全球碳周期中的作用以及人类活动对环境的结果。