High-resolution Nuclear Magnetic Resonance and Mass spectrometry methodology for the analysis of complex mixtures

拟议研究的背景。我们身边到处都是复杂的混合物，对我们的日常生活有很大的影响。土壤、河流、海洋或气溶胶、食品和饮料、生物流体或生物医疗产品中的天然有机物都是非常复杂混合物的例子。目前化合物鉴定的现状是花费大量精力与热力学第二定律作斗争，试图从混合物中分离出单个化合物。然而，如果我们不必经历如此艰难的过程，而能够简单地绕过传统的净化步骤，那不是很好吗？这是特别相关的，因为从数千个分子的混合物中分离单个化合物超出了当今色谱方法的能力。我的目标是开发与环境问题，食品和药品生产和监管相关的方法。核磁共振波谱和质谱是两种最先进的高分辨率技术，有可能在分子水平上处理复杂混合物的分析核磁共振和质谱仪的硬件和软件能力不断提高，为新方法的发展打开了大门。爱丁堡大学化学学院是英国仅有的两所拥有尖端核磁共振和质谱仪（800 MHz核磁共振冷冻探针仪器和12 T FT-ICR质谱仪）的大学之一。这里的研究人员还可以使用美国太平洋西北国家实验室（PNNL）世界领先的核磁共振和质谱设备。因此，我研究的一个总体目标是通过开发数据采集、处理和分析的新方法，推进核磁共振和质谱方法对复杂混合物的分析。我的目标。应用开发的方法来回答有关现实生活中复杂混合物的重要问题：(i)饮用水中的消毒副产物（DBPs） （ii）苏格兰威士忌（iii）生物医学研究问题和假设。以上每个目标都提出了一个独特的研究问题，在以下段落中简要阐述。(i)饮用水生产过程中产生的dbp的特征。当可以使用微生物消毒剂时，需要进行广泛的物理和化学处理，以将溶解的有机物（DOM）水平降低到2mg/l以下。在苏格兰，这涉及氯化/氯胺化。除了处理微生物外，涉及DOM分子的自由基反应还会产生数百个氯化分子，这些分子成为饮用水的一部分目前，由于绝大多数dbp的结构尚不清楚，其中只有少数受到调控。如果我们要确定dbp对人类健康的潜在影响，了解dbp的结构是必不可少的。单个氟原子用作DOM组成分子（代表不同类别的DOM分子）的标签，将允许通过新开发的核磁共振和质谱方法确定dbp的结构。这种方法是必要的，因为Cl不是“核磁共振友好核”，这与19F完全相反，19F具有100%的天然丰度，高灵敏度，大化学位移范围和与1H和13C的远耦合，便于结构测定。另一方面氯的同位素是a

Background behind the proposed research. Complex mixtures are all around us and have a greatimpact on our daily lives. Natural organic matter of soils, rivers, oceans or aerosols, food andbeverages, bio-fluids or biologic medical products are all examples of very complex mixtures. Thestatus quo in compound identification is to expend lots of energy combating the second law ofthermodynamics to try to isolate individual compounds from a mixture. However, wouldn't it bewonderful if we did not have to go through such an arduous process and were able to simply bypassthe customary purification step? This is particularly relevant, as the separation of individualcompounds from a mixture of thousands of molecules is beyond the capability of today'schromatographic methods.2The methodology I aim to develop will be relevant to environmental issues, food and medicineproduction and regulation.Methodology. NMR spectroscopy and mass spectrometry are the two state-of-the-art highresolutiontechniques that have the potential to tackle the analysis of complex mixtures at amolecular level.3,4 The hardware and software capabilities of NMR and MS spectrometers areconstantly improving, opening doors for the development of new methodology. The School ofChemistry of the University of Edinburgh is one of only two UK universities that houses both cuttingedge NMR and MS spectrometers (800 MHz NMR cryoprobe instrument and 12 T FT-ICR massspectrometer). Researchers here also have access to the world-leading NMR and MS equipment ofthe Pacific Northwest National Laboratory (PNNL), USA.An overarching aim of my research thus is to advance NMR and MS methodology for theanalysis of complex mixtures by developing new methods for data acquisition, processingand analysis.My objectives. To apply the developed methodology to answer important questions concerning reallife complex mixtures:(i) Disinfection by-products (DBPs) in drinking water(ii) Scotch whisky(iii) Biological medicinesResearch questions and hypotheses. Each of the above objectives poses a unique researchquestion that is briefly elaborated on in the following paragraphs.(i) Characterisation of DBPs generated during the production of potable water. Extensive physicaland chemical treatment is required to reduce the levels of dissolved organic matter (DOM) below 2mg/l when microbial disinfectant can be applied. In Scotland, this involves chlorination/chloramination. In addition to dealing with microbes, radical reactions involving DOM moleculesproduce hundreds of chlorinated molecules that become part of potable water.5 At present only ahandful of these is regulated, as the structures of a vast majority of DBPs are unknown. Knowingstructures of DBPs is essential if we are to determine their potential effects on human health.Hypothesis. A single fluorine atom used as a tag on DOM constituent molecules (representingdifferent classes of DOM molecules) will allow structure determination of DBPs through newlydeveloped NMR and MS methodology. This approach is necessary since Cl is not "a NMR friendlynucleus", which is in complete contrast to 19F that has 100% natural abundance, high sensitivity,large chemical shift range and far reaching couplings with 1H and 13C, facilitating structuredetermination. Chlorine isotopes on the other hand a