Microwave-Enhanced Ionization Techniques for Mass Spectrometry

在化学系化学测量和成像项目的支持下，纽约州立大学布法罗分校的Steven Ray和他的研究小组正在努力提高质谱（MS）的能力，这是一种重要的化学分析工具。特别是，Ray小组正在开发一种新的策略，使用高度聚焦的微波辐射来增强和控制质谱分析的第一步-从感兴趣的样品中形成带电粒子（离子）。如果成功，这项研究将对质谱中最重要的现代方法产生广泛的科学影响，包括电喷雾电离（ESI）和基质辅助激光解吸电离（MALDI）质谱方法。Ray博士还创建了本科分析化学实验室实验，使用简单的微波辅助技术来演示绿色分析化学和生物分析方法。在这个项目中，Steven Ray和他的研究团队将致力于利用精细调谐的微波辐射来改进质谱中的电离方法。例如，频率为2.45 GHz的微波辐射可以通过直接电介质加热来影响携带电荷的分子，这种加热方式与传统的传导传热方式不同，可以实现能量传递。在质谱应用中，微波偶极子极化和离子传导可以促进ESI-MS相关的液滴脱溶过程，以及MALDI-MS中自由气相离子的形成。微波辐射还可以通过影响电离反应的速率来加速电荷分离和挥发，并可以加速用于生物分析质谱的酶介导的蛋白质水解反应。专门的波导结构正在通过计算机模拟和构建来将微波聚焦到定义良好的电离体积中，在那里能量转移可以被测量、控制和调制。深入了解微波如何影响离子形成的机制正在被开发，以改善现有的电离源。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support from the Chemical Measurement and Imaging Program in the Division of Chemistry, Steven Ray and his research group at the State University of New York at Buffalo are working to improve the capabilities of mass spectrometry (MS) – an important tool for chemical analysis. In particular, the Ray group is developing a new strategy that uses highly-focused microwave radiation to enhance and control the initial step in MS analysis – formation of charged particles (ions) from samples of interest. If successful, this research could have broad scientific impact, on the most important modern methods utilized in mass spectrometry, including electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) MS methods. Dr. Ray is also creating undergraduate analytical chemistry laboratory experiments that use simple microwave-assisted techniques to demonstrate green analytical chemistry and bioanalytical methodologies. In this project, Steven Ray and his research team will work to exploit finely tuned microwave radiation to refine ionization methods in mass spectrometry. Microwave radiation at the 2.45 GHz frequency, say, can influence charge-carrying molecules by direct dielectric heating, which achieves energy transfer in ways different from conventional conductive heat transfer. In MS applications, microwave dipole polarization and ionic conduction can facilitate droplet desolvation processes associated with ESI-MS, as well as formation of free gas-phase ions in MALDI-MS. Microwave radiation also can accelerate charge separation and volatilization by impacting the rates of ionization reactions, and can accelerate enzyme-mediated proteolytic reactions used in bioanalytical mass spectrometry. Specialized waveguide structures are being modeled by computer simulation and constructed to focus microwaves into well-defined ionization volumes, where energy transfer can be measured, controlled, and modulated. Insight into how microwaves influence the mechanism of ion formation is being exploited to improve extant ionization sources.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.