Development of a Novel Atmospheric Pressure Glow Discharge for Ambient Mass Spect

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DESCRIPTION (provided by applicant): The overall objective of this Phase II STTR project is the commercialization of a new ionization source for ambient mass spectrometry based on the flowing afterglow of an atmospheric pressure glow discharge. This technology promises to have significant impact in pharmaceutical, clinical and biomedical research. Ultimately, we envision commercial ion sources that can be easily switched among several atmospheric pressure ionization techniques and can be retro-fitted to several different types of mass spectrometers or ion mobility spectrometers. Phase I of this project was highly successful. Alpha prototypes were developed, tested and feasibility proven. Optical spectroscopy measurement revealed novel species (He2+), which are implicated in the ionization mechanism. Further, the plume temperature measurements revealed "hot spots' within the afterglow where thermal desorption is most efficient and results in higher sensitivity. We demonstrated that the ion source could directly desorb and ionize a variety of chemical species and further tested the method in the direct analysis of mycobacterium smegmatis cells. Finally, the coupling of the ion source to a laser ablation cavity proved to yield molecular information with high spatial resolution. The phase II specific aims are as follows: 1. Prototype Development. Beta prototypes of the FAPA ion source will be designed and built based on the criteria defined at the conclusion of the Phase I grant. The sources will include the development of an optimized FAPA discharge cell and a mass spectrometer mounting system with computer controlled sample positioning system. Additionally, prototype support electronics, including the constant current, high voltage DC power supply, a discharge gas temperature controller, and a discharge gas flow controller. Finally, software will be developed to control these elements and automate sample collection. There will be a minimum two beta prototypes built for testing and validation simultaneously at Indiana University and Prosolia. 2. Characterization and Optimization of the sampling process at atmospheric pressure: We will use schlieren photography in combination with mass spectrometry and computer simulations to provide the ideal sampling environment at the interface between the reagent ion gas plume and the vacuum inlet to the mass spectrometer. 3. Source Characterization and applications development: Our approach is three-fold: 1) to test and characterize the beta prototype FAPA source developed in Aim 1 by examining neat samples while varying the gas flow, heater temperature, and device impact angle and assessing the usual figures of merit, detection limits, precision, accuracy, carry-over, and throughput; 2) examining the effects of modifying gas phase chemistries to effect atmospheric pressure fragmentation reactions for generating NIST searchable spectra; and 3) to apply the optimal device parameters, gas-phase chemistry and sampling conditions to a combinatorial study of one hundred "drug-like" molecules of various properties and compare the results to the same study by DESI. We believe it is important to show our customers a range of molecules in size and hydrophobicity to make it easier for them to assess the likelihood their proposed application will be successful. Upon successful completion of the proposed aims, Prosolia will proceed into phase III commercialization where FAPA ion source products (hardware and software) and services will be commercialized. Further, strategic licensing and partnerships will be secured to commercialize the technology as an add-on accessory to laser ablation cavities, gas chromatographs and/or liquid chromatographs.