Physical Sciences and Mathematics Commons^™

Novel Applications Of Mass Spectrometry For Quantitation And Reaction Mechanism Elucidation, Pengyi Zhao

Dissertations

Mass spectrometry (MS) has been growing as one of the most widely used tools in the field of analytical chemistry. Various applications have been developed to harness the high sensitivity and specificity of mass spectrometric analysis. In this dissertation, two major challenges are addressed. By developing mass spectrometric-based methods, absolute quantitation of proteins/peptides have been achieved. Elucidation of various reaction mechanisms are also enabled. These are the focuses of this dissertation.

In Chapters 2 to 4, a novel quantitation method is developed, titled as coulometric mass spectrometry (CMS). The strength of this method is that no reference standard or isotope-labeled …

Observed Defects Of Swiss Cheese Based On The Microbiome Contribution To The Production Of Organic Acids, Vannessa D. Campfield

Boise State University Theses and Dissertations

The United States Department of Agriculture downgrades on the order of 17% of all Swiss cheese produced in the United States due to defects. Many of these defects are related to improper eye formation, number, distribution, or size; leading to an industry loss of over $69 million per annum. The microbiome in Swiss-type cheeses plays a significant role in eye development due to production of organic acids and gaseous emissions contingent on bacterial abundance and phenotype. The relationship between bacteria and the organic acids they produce leading to Swiss cheese defects can be correlated using Next-generation sequencing and high-performance liquid …

Isolation, Structure Elucidation, And Synthesis Of Natural Products From Marine Cyanobacteria, Keren Solomon

Electronic Theses and Dissertations

This thesis describes the isolation, structure elucidation, and synthesis of natural products from marine cyanobacteria. A crude extract from a cyanobacterium collected in Curacao showed selective affinity for the dopamine D₅ receptor in a screen against a panel of CNS receptors. Due to the high similarity of the D₅ and D₁ receptor, to date there are no known ligands that differentiate them. Attempts to purify the compound responsible for this affinity led to the isolation of the known compound caylobolide A. A second extract from a cyanobacterium collected in Panama underwent bioassay-guided fractionation and yielded the novel …

Iron In Urban Air Pollution, Joseph R. Salazar

Electronic Theses and Dissertations

The processes by which iron is solubilized are largely unknown. There are three hypotheses on how iron is soluble: 1) iron is thought to undergo an acid based solubilization process, 2) iron undergoes an oxidation/reduction process and reduces iron(III) to the more soluble iron(II), and 3) iron is bound to organic molecules, which solubilizes it. The 3 hypotheses on iron water-solubilized are explored by presenting two individual studies.

The first study investigates iron directly from car exhaust. Exhaust particles were collected from 32 vehicles. Iron solubility in these samples ranged from 0%-82% with the average iron solubility being 30%. X-ray …

Development Of A Method For The Detection And Quantification Of Various Benzodiazepines And Z-Drugs In Human Blood And Qualitative Identification In Urine Samples Using Liquid Chromatography Mass Spectrometry (Lc-Ms/Ms), Haley Michel

Williams Honors College, Honors Research Projects

This method developed in the toxicology department at the Cuyahoga County Medical Examiner’s Office (CCMEO) detects 40 benzodiazepines and metabolites along with several z-drugs in blood and urine by liquid chromatography tandem mass spectrometry. A sample amount of 0.5 mL was used to detect analytes in postmortem drug facilitated sexual assault and impaired driving cases. Twenty-nine analytes met criteria for quantification while the remaining 14 were used as qualitative indicators. Bias and precision results for quality controls met criteria, staying within ±15% except for clonazolam and etizolam which were within ±20%. Quantitative reporting criteria which included dilution integrity was met …

Applications Of Drones In Atmospheric Chemistry, Travis J. Schuyler

Theses and Dissertations--Chemistry

The emission of greenhouse gases (GHGs) has changed the composition of the atmosphere during the Anthropocene. A major technical and scientific challenge is quantifying the resulting fugitive trace gas fluxes under variable meteorological conditions. Accurately documenting the sources and magnitude of GHGs emission is an important undertaking for discriminating contributions of different processes to radiative forcing. Therefore, the adverse environmental and health effects of undetected gas leaks motivates new methods of detecting, characterizing, and quantifying plumes of fugitive trace gases. Currently, there is no mobile platform able to quantify trace gases at altitudes(UASs), or drones, can be deployed on-site in …