Development of a Novel MALDI Mass Spectrometer and Technology for the Generation of Multiply Charged Ions at High Sensitivity

现代质谱（MS）可以与显微镜相比较，因为它对分析自然和物质的影响一直到分子（单个分子）水平，包括对生命的细胞过程和分子结构的分析。这些分析工具经常是重大科学突破的关键。特别是多发性硬化症，在生物医学和医疗保健等领域一直处于最新进展的前沿。在这个项目中，我们将开发一种新的仪器和相关的方法，为质谱及其应用迈出又一重要的一步。质谱法需要产生气相离子。现代质谱中两种主要的电离技术是电喷雾电离（ESI）和基质辅助激光解吸/电离（MALDI）。这两种技术之间有根本的区别。ESI能够完全从液体中形成离子，而MALDI主要使用固体样品。另一个显著的区别是它们产生多重带电离子的能力。对于多肽，MALDI通常产生单电荷，而ESI容易提供多电荷离子。重要的是，高电荷离子的产生是可取的，因为它允许使用高性能质谱仪，而这些质谱仪通常不能分析较大的单电荷离子。它还促进了更多的信息控制离子的破碎，从而有助于获得进一步的信息，如它们的分子结构。因此，使用ESI有一个明显的优势。尽管如此，MALDI具有更高的污染物耐受性，易于操作，高速自动化分析的潜力以及MS成像能力，使其成为一种电离技术，可以覆盖ESI不太适合的（生物）分析领域。如果这些优势能够与多重带电离子的分析能力相结合，使用MALDI MS进行新的仪器配置和新的大规模（生物）分析将变得可行。拟议的仪器和方法开发将导致一种新技术，该技术将能够以高灵敏度，即低分析物浓度和低样品消耗，生产稳定和高产的多电荷MALDI离子。它基于一种新的离子源设计，使用加热离子传递管将产生的离子转移到质谱仪的分析仪中，并采用新颖的液体样品制备方法，确保了类esi多电荷离子的稳定和高产率。因此，MALDI的两个主要缺点（没有/低产率的多电荷离子和高度可变的离子产量和信号质量）将在本项目中解决。最终，新开发的技术不仅应该成为ESI的真正竞争对手，而且应该开辟以前无法进入的分析新领域。简而言之，该项目将开发一种新的质谱技术，这将大大扩大MALDI质谱的应用范围，从而扩大一般的质谱，实现新的和更强大的分析策略。该项目将产生一种原型仪器和方法，可以很容易地商业化。由于MALDI MS已经在（生物）分析领域取得了巨大的进步，可以预见，该项目将在学术界、工业界、公共卫生部门乃至整个社会的许多领域产生重大影响。

Modern mass spectrometry (MS) can be compared to microscopy with its impact on analysing nature and materials down to the molecular (individual molecule) level, including the analysis of the cellular processes of life and the structure of molecules. These analytical tools have frequently been the key to major breakthroughs in science. MS in particular, has been at the forefront of recent advances in areas like biomedicine and healthcare. In this project we will develop a new instrument and the associated methodologies for another major step forward in MS and its application.MS requires the production of gas phase ions. The two major ionisation techniques in modern MS are electrospray ionisation (ESI) and matrix-assisted laser desorption/ionisation (MALDI). There are fundamental differences between these two techniques. ESI enables ion formation exclusively out of a liquid while MALDI uses predominantly solid samples. Another significant difference can be found in their ability to produce multiply charged ions. For peptides, MALDI typically generates singly charged while ESI easily provides multiply charged ions.Importantly, the production of highly charged ions is desirable as it allows the use of high-performance mass spectrometers, which typically cannot analyse the larger singly charged ions. It also facilitates more informative controlled fragmentation of the ions, thus helping to obtain further information such as their molecular structure. Consequently, there is a clear advantage of using ESI. Nonetheless, MALDI with its higher tolerance to contaminants, ease-of-operation, potential for high-speed automated analysis as well as its MS imaging capabilities makes it an ionisation technique that can cover (bio)analytical areas where ESI is less suitable. If these strengths could be combined with the analytical power of multiply charged ions, new instrumental configurations and new large-scale (bio)analyses using MALDI MS would become feasible.The proposed instrument and method development will lead to a new technology that will enable the production of stable and high yields of multiply charged MALDI ions at high sensitivity, i.e. low analyte concentration and low sample consumption. It is based on a new ion source design, using a heated ion transfer tube to transfer the produced ions into the analyser of the mass spectrometer, and novel liquid sample preparation methods, ensuring stable and high yields of ESI-like multiply charged ions. Thus, the two main disadvantages of MALDI (no/low yield of multiply charged ions and highly variable ion yield and signal quality) will be addressed within this project. Ultimately, the newly developed technology should not only become a real competitor for ESI but also open up new areas of analysis that have previously been inaccessible.In short, this project will develop a new MS technology that will significantly widen the application range of MALDI MS and thus MS in general, enabling new and more powerful analytical strategies. The project will result in a prototype instrument and methodology that can easily be commercialised. As MALDI MS is already making great strides within the (bio)analytical field it can be anticipated that this project will have significant impact in many areas from academia and industry to the public health sector and thus society at large.