Microwave-Assisted Electrospray Ionization for LC/MS

描述（由申请人提供）：这个小企业创新研究第一阶段项目将测试一种新方法的可行性，该方法通过微波诱导热化电喷雾电离（ESI）质谱法实现增强汽化。将采取两种方法来诱导加热从毛细管流出的废水。第一种策略是将微波腔（艾文森型腔）直接放置在色谱柱的尖端，产生必要的功率（约8 W）来增强所产生的液滴流的汽化。这项技术的优点是微波驱动器已经经过测试，并证明可以提供足够的能量。要测试的第二个微波策略是将毛细管尖端放置在rf驱动线圈（也约为8 W）上方。这种射频线圈设计已被发现是可行的，能够提供可调谐的射频能量，也可以脉冲，以更好地控制加热过程。在通过微波场之前和之后对颗粒直径进行实时分级，以便更好地了解微波辐射对液滴干燥过程的影响。

DESCRIPTION (provided by applicant): This Small Business Innovation Research Phase I project will test the feasibility of a new method for achieving enhanced vaporization via microwave-induced thermalization for electrospray ionization (ESI) mass spectrometry. Two approaches will be taken to induce heating of the effluent from the capillary. The first strategy is the placement of a microwave cavity (Evenson-type cavity) directly to the tip of the column, generating the necessary power (ca. 8 W) to enhance vaporization of the resulting droplet stream. The advantage of this technology is that the microwave driver has been previously tested and demonstrated to provide sufficient energy. A second microwave strategy to be tested is the placement of the capillary tip just above an RF-driven coil (also ca. 8 W). This RF-coil design has been found to be feasible, capable of supplying tuneable RF-energy that can also be pulsed to better control the heating process. Real- time sizing of particle diameter both before and after passage through the microwave field will be taken, allowing for a better understanding of the affects of microwave radiation on the drying process of the droplet. PUBLIC HEALTH RELEVANCE: The field of LC/MS using the ESI sprayer as a source is extensive, providing analytical support for diverse fields within industries such as pharmacology, medical, immunological, petrol and proteomics. Especially within the pharmacological industry, there have been attempts to enhance LC/MS analysis to extend the traditionally polar-only detection capabilities of ESI to include low- to non-polar compounds. This has resulted in the recent incorporation of photoionization (PI) sources with ESI, also termed ESPI. One challenge to this newly emerging multimode source is the requirement of a highly efficient drying process for effective PI; however, the current ESI sprayer technology is limited in the extent to which the resulting stream can be heated. This has led our group to investigate the possibility of microwave-assisted techniques to overcome this challenge. The proposed activity will have a broad and profound impact on society as a whole by providing valuable information that can lead to improved analytical detection of compounds using ESI LC/MS. The practical outcome is to improve both fundamental academic research and industry-wide detection of socially significant compounds. This work also involves an academic collaboration and will promote teaching, training, and learning of graduate students. Finally this project has the potential for explosive commercial growth, which will stimulate economic development.