Semester

Summer

Date of Graduation

2022

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Stephen J. Valentine

Committee Co-Chair

Glen P. Jackson

Committee Member

Glen P. Jackson

Committee Member

Peng Li

Committee Member

Fabien Goulay

Committee Member

Rita Rio

Abstract

Advancing Compound Detection and Identification Using Vibrating Sharp-Edge Spray Ionization

Anthony Paul DeBastiani

‘Omics consists of various areas, including genomics, proteomics, lipidomics, and metabolomics with a goal of detection and identification of biomolecules present within each of these classes within an organism. Current omic analytical methods include the use of mass spectrometry (MS) coupled with various separation techniques, including liquid chromatography (LC), with the use of heated nebulization gas assisted electrospray ionization (HESI). Although the rapid progress in LC-MS platform development has lead to significant enhancements in omic studies, significant limitations in the detection and identification of low abundant species are still evident. Comparison of a novel MS ionization technique, field-enabled capillary vibrating sharp-edge spray ionization (cVSSI) with state-of-the-art HESI coupled to microflow LC separation shows a significant ionization efficiency enhancement for cVSSI with factors of 5±2 and 2±1 for negative and positive ion mode analyses, respectively, for a proteomic sample. In addition, a multiple cVSSI platform is demonstrated where intermittent in-droplet hydrogen-deuterium exchange (HDX) demonstrates the ability to distinguish between several sets of structural isomers unable to be differentiated through typical MS fragmentation techniques.

Another area of development is the use of cVSSI technology for the fabrication of a vibrating probe for the formation of gas-phase ions from a solid phase analyte/MALDI matrix mixture without the use of a laser. This platform, termed vibrating probe matrix-assisted ionization (VPMAI) is demonstrated for the surface analysis for compounds with various molecular weights and physiochemical properties. Through these experiments, where multiple matrix deposition methods were evaluated, six individual data points were detected by MS across an approximate 100 µm line of rhodamine utilizing this method.

Embargo Reason

Publication Pending

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