Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 14 of 14 for “"ion suppression"”.
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High performance liquid chromatography-tandem mass spectrometry of pharmaceuticals and personal care products in environmental and biological matrices
… sensitive and specific techniques for detection of these compounds at very low concentrations, liquid chromatography-tandem mass spectrometry (LCMS/ MS) has emerged as the new technique of choice. This work describes methods for screening and quantification of various pharmaceutical and …
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Laser Electrospray Mass Spectrometry: Mechanistic Insights and Classification of Inorganic-Based Explosives and Tissue Phenotypes Using Multivariate Statistics
This dissertation elucidates a greater understanding of the vaporization and electrospray post-ionization mechanisms when using femtosecond laser pulses for desorption of surface molecules and electrospray ionization for capture and mass analysis of the gas phase ions. The internal energy …
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The synthesis and characterization of alginate-melanin hydrogels for applications in forensic science
… moieties for subsequent click chemistry reactions with the alginate polymer backbone. UV-VIS spectroscopy showed broadband absorption in the visible region consistent with melanin compounds. ATR-FT-IR, 1H-NMR, and 13C-NMR analyses indicated alkynyl group incorporation, and DART-MS showed …
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LC-MS/MS determination of various drugs of abuse and metabolites in municipal wastewater effluent samples
… mass spectrometry (LC-MS/MS) for the quantification and confirmation of 8 drugs of abuse (cocaine, codeine, MDMA, methadone, methamphetamine, morphine, nicotine, and oxycodone) and their various metabolites (acetylmorphine, cotinine, EDDP, amphetamine and benzoylecgonine) in municipal wastewater …
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The factors and protocols that influence, accuracy, precision and uncertainty of accurate mass measurements by FT-ICR ms to validate the assignment of elemental composition
… is becoming more demanding with the expansion of the number of compounds in need of correct identification and with the limits of elemental analysis; a fast, robust analytical solution is sought. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) is a very powerful tool …
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New liquid chromatographic methods for the analysis of cationic tensides
Cationic tensides are important oleochemicals that are used to prevent adulteration of pharmaceutical preparations and personal care products, as well as being the conditioning agents in domestic fabric softeners. The widespread use of these materials requires quantitative methods for …
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Proteomic Analysis of Three Dimensional Organotypic Liver Models
… are central for understanding hepatic functions and intercellular communication processes. Bottom-up shotgun proteomic analysis of the hepatic cells can lend insight into such processes. This technique employs liquid chromatography-tandem mass spectrometry (LC-MS/MS) for relative …
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Development of Amine Containing Polymer Modified MALDI Targets for Complex Peptide and Protein Mixture Fractionation Prior to MALDI Mass Spectrometry Analysis
AN ABSTRACT OF THE DISSERATION OF STEPHANIE EASTWOOD, for the Doctor of Philosophy degree in CHEMISTRY, presented on the DATE OF DEFENSE, at Southern Illinois University Carbondale. TITLE: DEVELOPMENT OF AMINE CONTAINING POLYMERIC MODIFIED MALDI TARGET SUBSTRATES FOR COMPLEX MIXTURE FRACTIONATION …
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DEVELOPMENT AND OPTMIZATION OF POLYELECTROLYTE POLYMER BRUSHES FOR THE FRACTIONATION OF PEPTIDE AND PROTEIN MIXTURES PRIOR TO MALDI MASS SPECTROMETRY ANALYSIS
The focus of this dissertation is the synthesis, development and application of polymer brushes for the fractionation of complex mixtures of peptides and digested proteins prior to MALDI-MS analysis. Even though MALDI-MS analysis is increasingly used in proteomic applications, this method of …
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MATRIX-ASSISTED LASER DESORPTION/IONIZATION (MALDI) TARGET MODIFICATION FOR ENHANCED PROTEOMICS ANALYSIS AND PLASMA POLYMER CHARACTERIZATION BY MALDI MASS SPECTROMETRY
The work described in this dissertation is divided into three sections. In the first section three surface modifications are used to produce MALDI targets having reduced surface-protein binding affinity with a goal of increasing peptide/protein MALDI ion signals and lowering the limits of detection …
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Hyphenation of analytical techniques to single cell capillary electrophoresis-mass spectrometry
… technologies require low limits of detection, accurate quantitation, confident identity assignment, and ability to process complex chemical mixtures. Heterogeneity in nucleic acids, proteins, peptides, metabolites, lipids, and more result in functionally significant differences between …
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Detection of human salivary α-Defensins by LC-ESI-MS and evaluation of levels in athletes after physical stress
… G1 (Q-TOF-ESI-MS), was used for the separation and detection of HNP1-4. The need for solid phase extraction (SPE) was established. An LC-MS optimisation, focusing on mobile phases, column performances, and ion intensities, was carried out in order to enhance the detection of individual HNPs …
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Discovery of Quinic Acid Derivatives as Oral Anti-inflammatory Agents
… activity through mechanisms involving inhibition of the pro-inflammatory transcription factor nuclear factor kappa B (NF-κB). Herein, we described the synthesis and biological testing of novel QA derivatives. Inhibition of NF-κB was assessed using A549 (Type II alveolar epithelial-like) cells …
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Secondary ion mass spectrometry imaging of surface-bound microbial communities
… unseen, and often undiscovered, microbial population. In order to understand how the microbial dimension influences our own we must first understand the microbes themselves. Far from existing as a collection of single cells floating about aimlessly, bacteria largely reside in highly cooperative …