Microwave-Assisted Electrospray Ionization for LC/MS

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 spectrome try. 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 v aporization 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 an d 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 exten d 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 so urce 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 microw ave-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 practic al 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 thi s project has the potential for explosive commercial growth, which will stimulate economic development.