Analytical Chemistry Commons^™

Application Of Direct Analysis In Real Time-High Resolution Mass Spectrometry To Genus- And Species-Level Differentiation And Identification Of Coral, Jessica Mary Hayes

Legacy Theses & Dissertations (2009 - 2024)

Coral reefs are one of the most biologically diverse ecosystems, and the accurate identification of the species is essential for diversity assessment, species delimitation and conservation. Current species and genus determination approaches are time consuming, resource intensive and can be highly subjective. To explore the hypothesis that the small molecule profiles of coral are species and genus specific, and can be used as a rapid tool to catalogue, classify and identify coral genera and species, the small-molecule chemical fingerprints of coral belonging to the species Acanthastrea echinata, Catalaphyllia jardinei, Duncanopsammia axifuga, Echinopora lamellosa, Euphyllia divisa, Euphyllia paraancora, Euphyllia paradivisa, Galaxea …

Using Nmr Spectroscopy And Computational Chemistry To Confirm The Structure Of Novel Antibiotic Nocamycin O, Stephanie Lewis

CMC Senior Theses

In recent years, many medically promising antibiotics have been discovered in nature, especially in insect-microbe symbioses. One of the better-studied examples of this kind of defensive relationship is that of fungus-growing ants and the antibiotic-producing Actinobacteria. These bacteria produce several defensive chemicals with myriad uses, including one antibiotic that inhibits the growth of several bacterial strains, including other Actinobacteria. This antibiotic (known as nocamycin O) is a promising candidate for medicinal use due to its similarities to bacterial RNA polymerase inhibitors tirandamycin and streptolydigin, which inhibit several human pathogens. The determination of the structure of nocamycin O will be an …

A Dual Nanostructured Approach To Sers Substrates Amenable To Large-Scale Production, Kory Brian Castro, Cicely Rathmell, John Cooper

Chemistry & Biochemistry Faculty Publications

Surface enhanced Raman spectroscopy (SERS), although popular in research, has not yet been adopted in industrial applications. This is largely due to the challenge of manufacturing cost-effective, reproducible SERS substrates in volume that can be read by a compact reader for practical deployment in the field. Here we demonstrate and characterize a new dual-nanostructured SERS substrate approach that could be amenable to large-scale production. This dual-nanostructured surface combines long-range ordering of silver nanowires (AgNWs) with dense non-ordered decoration via silver nanoparticles (AgNPs) to improve on the SERS response characteristics of the individual structures, using fabrication methods that could be scaled …

High-Resolution Molecular Characterization Of Complex Environmental Mixtures: Aquatic Dissolved Organic Matter And Wildfire-Influenced Aerosol, Amna Ijaz

Dissertations, Master's Theses and Master's Reports

The natural environment is replete with organic matter of varying complexities. Whether it is particulate material in the atmosphere, decades old organic matter trapped within glaciers, or biological debris flowing with rivers and streams, natural organic matter (NOM) is exquisitely complex. High-resolution mass spectrometry allows us to have a glimpse of the molecular composition of NOM and delineate the elemental compositions of thousands of chemical species that form it. In this dissertation, the overarching aim was to explore the molecular diversity of complex mixtures from two sources: Surface water and atmospheric organic aerosol. The first objective of this dissertation was …

Cobalt, Molybdenum, And Nickel Complexes, Natural Zeolites, Epoxidation, And Free Radical Reactions, Nicholas K. Newberry

Dissertations, Master's Theses and Master's Reports

Chapter 2 is based on the synthesis and study of the compounds of the bidentate ligand ((5-phenyl-1H-pyrazol-3-yl)methyl)phosphine oxide with molybdenum and cobalt as the transition metal. The complexes were analyzed via FTIR, NMR, UV-Vis, Fluorescence Spectroscopy, TGA, DFT, and XRD. Chapter 3 resulted in the synthesis of the complexes [Ni(II)SSRRL](PF6)2 and [Ni(II)SRSRL](Cl)(PF6) of which [Ni(II)SRSRL](Cl)(PF6) had not been previously analyzed. Both products were analyzed via FTIR, NMR, UV-Vis, CV, DFT, and XRD. Chapter 5 contains the results of the characterization and modification of 4 natural zeolites (AZLB-Na, AZLB-Ca, NM-CA, NV-Na) from the United States in an attempt to increase the …

Continuing The Metalation And Ring Closure Of Biliazine, Joshua Villers

Williams Honors College, Honors Research Projects

Continuing previous research conducted by Dr. Ziegler and his Graduate Students in which different metals were selected to metalate the compound Biliazine as well as finding metals that could be used to close the ring system in Biliazine.

Activity Of Saccharomyces Cerevisiae By Single Entity Electrochemistry, John Lutkenhaus

Graduate Research Posters

According to the Centers of Disease Control and Prevention, antibiotics decrease in effectiveness as bacteria gain resistance for previously treatable illnesses. Currently, antibiotic susceptibility is typically carried out via the Kirby-Bauer method. Even with automation, this process requires two incubation periods so a less time-consuming technique is desirable. Single entity electrochemistry (SEE) detects changes in current when collisions of individual particles at an ultramicroelectrode (UME) are linked with an electrochemical event. Our group has obtained step-like and spike-like responses of Saccharomyces cerevisiae at the UME surface as a result of adsorption and desorption, respectively. This response is due to the …

Collisions Or Adsorption: An Electrochemical Random Walk Decides, Junaid U. Ahmed, Julio C. Alvarez

Graduate Research Posters

Current-time recordings of toluene microdroplets emulsified in water and containing 20 mM Ferrocene (Fc), show multiple electrochemical peaks from oxidation of Fc on disk microelectrodes (5μm-diameter). The average droplet diameter (~0.7 μm) determined from area integration of the peaks was close to Dynamic Light Scattering measurements (~1 μm). Random walk simulations were performed deriving equations to simulate droplet electrolysis using the diffusion and thermal velocity expressions established by Einstein. The simulations show that multiple droplet-electrode collisions, lasting ~0.11 μs each, occur before a droplet wanders away. Updating the Fc-concentration at every collision shows that a droplet only oxidizes ~0.58 % …

Advanced Raman Spectroscopy Detection Of Oxidative Damage In Nucleic Acid Bases: Probing Chemical Changes And Intermolecular Interactions In Guanosine At Ultralow Concentration, Francesca Ripanti, Claudia Fasolato, Flavia Mazzarda, Simonetta Palleschi, Marina Ceccarini, Chunchun Li, Margherita Bignami, Enrico Bodo, Steven E.J. Bell, Filomena Mazzei, Paolo Postorino

Bioelectrics Publications

DNA/RNA synthesis precursors are especially vulnerable to damage induced by reactive oxygen species occurring following oxidative stress. Guanosine triphosphates are the prevalent oxidized nucleotides, which can be misincorporated during replication, leading to mutations and cell death. Here, we present a novel method based on micro-Raman spectroscopy, combined with ab initio calculations, for the identification, detection, and quantification of oxidized nucleotides at low concentration. We also show that the Raman signature in the terahertz spectral range (<100 >cm(-1)) contains information on the intermolecular assembly of guanine in tetrads, which allows us to further boost the oxidative damage detection limit. Eventually, we …

Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mass Spectrometry (MS) is one of the widely used tools for chemical detection down to attomole concentrations for certain proteins. Ionization sources are a critical component for MS analysis. One of the major ionization methods is electrospray ionization (ESI), which remains a gold standard for proteins and peptides. ESI uses voltages up to ~4 kV to produce ions from solubilized molecules. Recently, a novel ionization method termed vibrating sharp-edge spray ionization (VSSI) that nebulizes liquids efficiently at the edge of a vibrating glass slide has been reported. The work in this thesis leverages the capabilities of VSSI for continuous flow-based …

Enhancing Negative-Ion Native Mass Spectrometry With Field-Assisted Capillary Vibrating Sharp-Edge Spray Ionization (Cvssi), Kushani Udeshika Attanayake

Graduate Theses, Dissertations, and Problem Reports (ETD)

Although the birth of native mass spectrometry (native MS) occurred only several years after the development of electrospray ionization (ESI), it is yet considered an emerging technique for MS-based studies. This stems in part from challenges associated with efficient ionization of biopolymers. Although steady gains in ion production for native structure characterization have been secured primarily with the use of nanoelectrospray ionization (nESI), under negative polarity, the ionization efficiency can be extensively reduced due to an effect called “corona discharge”. The corona discharge occurs at the tip of ESI emitters because of free electron acceleration in the high-field region produced …

Unique Biological Applications Of Charge Transfer Dissociation Mass Spectrometry, Halle M. Edwards

Graduate Theses, Dissertations, and Problem Reports (ETD)

The ever-changing landscape of mass spectrometry is driven by gaps in knowledge, and one of the biggest driving forces is the desire to understand the structure and dynamics of biomolecules in living organisms. New and better methods of tandem mass spectrometry are often at the heart of technological developments. Some fragmentation methods are limited to expensive FTICR instruments, some techniques are limited multiply charged precursors, and others are limited to breaking only the weakest bonds in precursor ions; all of which support the pursuit of new activation methods. Charge transfer dissociation (CTD) addresses some of these concerns by providing structurally …

Improving Characterization Of Small Molecules Using Enhanced Molecular Reaction And Ionization Techniques, Sandra N. Majuta

Graduate Theses, Dissertations, and Problem Reports (ETD)

Metabolomics is an emerging “omics” field, which is comprised of the study of small molecule metabolites in biological systems. It can be argued that the abundances of metabolites within biological samples, such as tissue and plasma, are indicative of various physiological states. Thus, metabolomics analysis has the potential in the clinical scientific field to be an effective tool for early disease diagnosis as well as for proposing and monitoring new treatments for diseases. However, full characterization of the metabolome complement is often hampered by the wide diversity of metabolites, which also exhibit an extremely large concentration range in biological samples. …

Harnessing Acoustic Streaming For Bioanalysis In Microfluidics, Xiaojun Li

Graduate Theses, Dissertations, and Problem Reports (ETD)

In the past few decades, microfluidic technology has been developed rapidly in both fabrication methods and multifunctionality integrations, making it a powerful tool for a wider variety of biological applications. The device fabrication method has expanded from conventional polymer-based micro devices to 3D-printed micro devices, and allows multiple functions such as electric, optic, magnetic and acoustic to be integrated on a single platform. This dissertation focuses on method development of acoustic streaming-based microfluidics in bioanalysis such as immunoassay, enzyme kinetics and DNA fragmentation analysis. In this dissertation, a micromixer was developed based on acoustic streaming generated from sharp-edge structure vibration …

Advanced Analytical Techniques For The Analysis Of Therapeutics Of Toxic Inhalation Agents And Pharmacokinetic Investigation, Subrata Bhadra

Electronic Theses and Dissertations

Toxic inhalation agents (TIAs), (i.e., cyanide (CN) and reduced sulfur compounds (RSCs)), including hydrogen sulfide (H2S) and methanethiol (MT)) are extremely poisonous upon exposure. Many TIAs act by inhibiting mitochondrial cytochrome c oxidase, resulting in cellular hypoxia, cytotoxic anoxia, apnea, respiratory failure, cardiovascular collapse, seizure and potentially death. CN is generated in structural fires and cigarette smoke as well as in mining, electroplating and polymer processing, whereas H2S and MT are found in petroleum, oil and natural gas, waste treatment facilities and decaying organic matter. All are common occupational gas exposure hazards in chemical industries and for first responders, including …

Absorbent Household Materials For The Collection Of Ignitable Liquid Residues From Surfaces Of Varying Porosity, Jessica Carlotti

Online Theses and Dissertations

Ignitable liquids (ILs) are used as accelerants to burn items at a faster rate and the presence of an IL indicates that arson has occurred. Upon arrival to an arson scene, fire investigators access the scene and collect substrates containing ILs. The substrates, such as concrete and wood, are removed from the scene by methods that are time consuming, and require heavy machinery and tools. The evidence is transported in air-tight containers to the laboratory where analysts identify the chemical classification of the IL using gas chromatography mass spectrometry (GC-MS). In this work, readily available absorbent household materials such as …

Determination Of Molecular Markers Of Vaccinium Berry Standard Reference Materials Through Differential Analysis With Ultrahigh Resolution Lc/Ms, Abby Mikolitis

Dissertations, Master's Theses and Master's Reports

Blueberries and cranberries have vastly different flavor profiles despite both being a part of the Vaccinium genus. Their high content of phenolics makes them subjects of interest in preventative medicine, especially research in illnesses such as heart disease and cancer. Analysis has primarily focused on the identification and characterization of polyphenols, primarily anthocyanins which are a subclass of polyphenols, with ultra-high performance liquid chromatography coupled with electrospray ionization high resolution mass spectrometry (UHPLC-ES/HRMS). This study aims to develop a novel method of non-targeted UHPLC-ES/MS analysis with post processing and formula assignment performed with MZmine 2.53 and MFAssignR software tools. Pairing …

Development Of Poly (Methyl Methacrylate-Co-Methacrylic Acid) Based Electrolytes With Synthesized And Commercial Ionic Liquids For Dye Sensitized Solar Cells, Vhaissnavin Sundararajan

Student Works (2020-2029)

A persistent challenge for expanding global population and soaring economic progress has always been ensuring everyone has enough access to energy supply. At present, the high dependency on fossil fuel derived energy has led to a crisis that necessitated a shift of attention towards greener energy sources like solar. Solar energy serves as the most consistent back up energy and the best option for environmental conservation. Among the listed solar harvesters, dye sensitized solar cells (DSSCs) bring about vast potential in efficient conversion of solar to electrical energy. The fact that this discovery has not reached its pinnacle and every …

Strategies For Resolution Enhancement In Liquid Chromatography, Shelby Lynn Weatherbee

Theses and Dissertations

Recent research in liquid chromatography (LC) has led to the development of new methodologies to further improve sample analysis. Non-uniform stationary phases are one such area that focuses on developments in selectivity and efficiency of stationary phases. Within this subset of stationary phases are two major focuses: two-dimensional liquid chromatography (2D-LC) and continuous stationary phase gradients that are the basis of this work.

In this work, LC simulation software was adapted to simulate chromatograms based on experimental and modeled injection profiles. This was done by measuring the injection profiles from a 2D-LC active solvent modulation valve using a variety of …

Multiplexed Nucleic Acid Sensing With Single Molecule Fret, Anisa Kaur

Theses and Dissertations

In recent years, biomarkers have drawn tremendous interest in the fields of clinical diagnostics and biotechnology. In fact, recent quests for biomarker analyses have discovered a myriad of disease-related biomarkers spanning a wide variety of biomolecules such as proteins, nucleic acids, and small molecule ligands. While the detection of only one target at a time is the most common practice in biosensing today, it has been shown that the accuracy of diagnosis increases significantly by measuring the level of multiple biomarkers instead of just one due to the possible overlap of certain biomarkers in more than one disease. However, currently …