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dc.contributor.advisorLevis, Robert J.
dc.creatorShi, Fengjian
dc.date.accessioned2020-11-02T15:11:04Z
dc.date.available2020-11-02T15:11:04Z
dc.date.issued2017
dc.identifier.urihttp://hdl.handle.net/20.500.12613/2371
dc.description.abstractThis dissertation elucidates the instrumentation and application of a hybrid ambient ionization source, laser electrospray mass spectrometry (LEMS), for the direct analysis and molecular imaging of biological tissue without matrix deposition. In LEMS, laser pulses from a Ti:Sapphire laser amplifier (60 fs, 800 nm, and 1 mJ) interact with surface analytes and transfer them from the condensed phase into the gas phase without the requirement of either exogenous matrix or endogenous water in the sample. The laser vaporized analytes are captured and ionized by an electrospray source, and finally detected by a mass analyzer. It was found that a turn-key, robust femtosecond fiber laser with longer wavelength, longer duration, and lower pulse energy at 1042 nm, 425 fs, and 50 µJ, respectively, provided comparable results with the Ti:Sapphire laser. Vaporization of intact, dried or aqueous cytochrome c and lysozyme samples was demonstrated by the fiber laser. A charge states distribution at lower charge states indicating folded conformation of proteins and the hemoglobin α subunit-heme complex from whole blood was observed. Endogenous anthocyanins, sugars, and other metabolites were detected and revealed the anticipated metabolite profile for the flower petal and leaf samples by the fiber laser. Phospholipids, especially phosphatidylcholine, were identified from a fresh mouse brain section sample. These lipid features were suppressed in both the fiber laser and Ti:Sapphire LEMS measurement in the presence of optimal cutting temperature compounds which are commonly used in animal tissue cryosectioning. This dissertation also details the design of an automated mass spectrometry imaging source based on the Ti:Sapphire LEMS. The laser, translation stage, and mass analyzer are synchronized and controlled using a customized user interface to enable step-by-step scanning of the area of interest on a given tissue sample. The imaging source is coupled with a high resolution accurate mass quadrupole time-of-flight (QTOF) mass analyzer with tandem mass analysis capability. A lateral resolution of 60 µm was demonstrated on a patterned ink film by LEMS imaging. Plant metabolites including sugar and anthocyanins were directly imaged from a leaf sample. Small metabolites, lipids and proteins were simultaneously imaged from a single tissue section of a pig liver sample. Biomarkers of blood-brain barrier damage and traumatic brain injury (TBI) that occurred during the injury were detected and imaged from a TBI mouse brain. The loading values from principal component analysis (PCA) were shown to be useful for identification of features of interest from the large LEMS imaging dataset.
dc.format.extent220 pages
dc.language.isoeng
dc.publisherTemple University. Libraries
dc.relation.ispartofTheses and Dissertations
dc.rightsIN COPYRIGHT- This Rights Statement can be used for an Item that is in copyright. Using this statement implies that the organization making this Item available has determined that the Item is in copyright and either is the rights-holder, has obtained permission from the rights-holder(s) to make their Work(s) available, or makes the Item available under an exception or limitation to copyright (including Fair Use) that entitles it to make the Item available.
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/
dc.subjectChemistry, Analytical
dc.subjectChemistry, Physical
dc.subjectMedical Imaging
dc.subjectAmbient Ionization
dc.subjectBiological Tissue
dc.subjectElectrospray Ionization
dc.subjectFemtosecond Laser Desorption
dc.subjectMass Spectrometry
dc.subjectMass Spectrometry Imaging
dc.titleLASER ELECTROSPRAY MASS SPECTROMETRY: INSTRUMENTATION AND APPLICATION FOR DIRECT ANALYSIS AND MOLECULAR IMAGING OF BIOLOGICAL TISSUE
dc.typeText
dc.type.genreThesis/Dissertation
dc.contributor.committeememberLevis, Robert J.
dc.contributor.committeememberValentine, Ann M.
dc.contributor.committeememberStrongin, Daniel R.
dc.contributor.committeememberMcEwen, Charles N., 1942-
dc.description.departmentChemistry
dc.relation.doihttp://dx.doi.org/10.34944/dspace/2353
dc.ada.noteFor Americans with Disabilities Act (ADA) accommodation, including help with reading this content, please contact scholarshare@temple.edu
dc.description.degreePh.D.
refterms.dateFOA2020-11-02T15:11:04Z


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