Chemistry proposal defense — Nate Buzitis, chemistry PhD student

About the event

Title: Probing Native Liquid-Phase Ion Distributions using Gas-Phase Separation Techniques

Abstract: Recent developments in the production of microdroplets have demonstrated that chemical reactions can be accelerated by orders of magnitude. While the exact reasoning of kinetic increase is not fully known, very little research has occurred for inorganic reactions within microdroplets. In conjunction with a recently constructed ion mobility-mass spectrometry (IM-MS) system, kinetic information and stability constants can be determined for the products of microdroplet reactions. IM-MS allows for increased confidence in the determination of the collisional-cross section (CCS) as well as the mobility of the ion. Additionally, the coupling of IM-MS allows for the precise determination of reactions and their intermediates by changing the drift time of the ion through the drift region. While a variety of methods are currently in use to produce droplets (Leidenfrost effect, ultrasonic generation, etc.), electrospray ionization (ESI) is one of the most widespread. However, ESI suffers from the integral nature of the ionization process during the nebulization of droplets. This applied voltage potential can cause oxidative effects with inorganic analytes and conformational changes within protein complexes. A new droplet production source, capillary vibrating sharp-edge spray ionization (cVSSI), allows for voltage-free droplet production and provides increased signal when compared to ESI for aqueous solvents. The integration of cVSSI with IM-MS will allow for microdroplet production without any applied voltage potential. The nebulized microdroplets will therefore be in their most native state for analysis.