Analytical Chemistry Commons^™

Further Development Of Raman Spectroscopy For Body Fluid Investigation : Forensic Identification, Limit Of Detection, And Donor Characterization, Claire K. Muro

Legacy Theses & Dissertations (2009 - 2024)

The challenges to forensic body fluid analysis have placed limitations on the type of information that investigators can acquire and how that information can be collected. In recent years, Raman spectroscopy has proven itself useful for characterizing body fluids. In 2008, a large-scale investigation was undertaken to explore the use of Raman spectroscopy as a means of identifying body fluids. This work resulted in multidimensional Raman spectroscopic signatures for the five main body fluids: semen, peripheral blood, saliva, vaginal fluid, and sweat. These studies were incredibly successful and created the foundation for years of continued research. Accordingly, the studies included …

Structure And Characterization Of A Class 3b Proline Utilization A: Ligand-Induced Dimerization And Importance Of The C-Terminal Domain For Catalysis, David A. Korasick, Thameesha T. Gamage, Shelbi Christgen, Kyle M. Stiers, Lesa J. Beamer, Michael T. Henzl, Donald F. Becker, John J. Tanner

Department of Chemistry: Faculty Publications

The bifunctional flavoenzyme proline utilization A (PutA) catalyzes the two-step oxidation of proline to glutamate using separate proline dehydrogenase (PRODH) and L-glutamate-y-semialdehyde dehydrogenase active sites. Because PutAs catalyze sequential reactions, they are good systems for studying how metabolic enzymes communicate via substrate channeling. Although mechanistically similar, PutAs vary widely in domain architecture, oligomeric state, and quaternary structure, and these variations represent different structural solutions to the problem of sequestering a reactive metabolite. Here, we studied PutA from Corynebacterium freiburgense (CfPutA), which belongs to the uncharacterized 3B class of PutAs.A2.7A˚ resolution crystal structure showed the canonical arrangement of PRODH, L-glutamate-y-semialdehyde dehydrogenase, …

Impact Of Timber Harvest On Mercury Mobilization In A Mixed Pine And Hardwood Forest And Adjacent Lake In Mississippi, Mary Kristen Dickerson

Electronic Theses and Dissertations

With 65% of land area covered in forest, Mississippi is a leader in the timber industry. Whereas forestry provides numerous benefits for humans and wildlife, forest harvest has been hypothesized to increase mercury (Hg) mobilization to aquatic systems. In a forest, Hg mostly accumulates in the upper layer of soil, where associates with organic matter. This top soil is exposed after clear-cutting and thus more susceptible to runoff. Harvest may also change the net balance between Hg methylation and demethylation by microorganisms through changes in redox conditions and addition of carbon sources from decaying logging residues. To better understand the …

Nitric Oxide Release From Poly(Lactic-Co-Glycolic Acid) Nanoparticles And Titanium Alloy, Nina A. Reger

Electronic Theses and Dissertations

Current methods for the treatment of bacterial infection involve the use of systemic antibiotics, which are high concentrations of antibiotics delivered over a long period time. Unfortunately, the use of systemic antibiotics can cause harmful side effects to the patient and increases the possibility for antibiotic resistance. The delivery of antibiotics or alternative antimicrobial compounds, such as nitric oxide, directly to the site of infection would decrease the amount of antibiotic necessary to treat a bacterial infection.

Poly (lactic-co-glycolic acid)/polyvinyl alcohol nanoparticles and a titanium- aluminum-vanadium metal oxide alloy implant were surface functionalized to deliver nitric oxide. Polymer nanoparticles can …

Micro-Spectroscopy Of Bio-Assemblies At The Single Cell Level, Jeslin Kera

Honors Undergraduate Theses

In this thesis, we investigate biological molecules on a micron scale in the ultraviolet spectral region through the non-destructive confocal absorption microscopy. The setup involves a combination of confocal microscope with a UV light excitation beam to measure the optical absorption spectra with spatial resolution of 1.4 μm in the lateral and 3.6 μm in the axial direction. Confocal absorption microscopy has the benefits of requiring no labels and only low light intensity for excitation while providing a strong signal from the contrast generated by the attenuation of propagating light due to absorption. This enables spatially resolved measurements of single …

Caffeine Used As A Tracer Of Wastewater Contamination In South Florida, Stephanie Spence

Honors Program Theses

In this study, a method was developed to analyze caffeine levels of water samples collected in Miami, Florida. The method was used to determine caffeine concentrations in reclaimed water samples and environmental water samples using on-line solid phase extraction (SPE) high pressure liquid chromatography (HPLC) high resolution mass spectrometry (HRMS). The rising use and disposal of pharmaceuticals and personal care products are becoming a concern as contaminants increasingly enter lakes, streams, and rivers without proper removal by traditional wastewater treatment processes. Caffeine may be used as a chemical tracer to indicate the presence of contamination in water samples and to …

Self-Assembled Architecture Of Natural Organic Matter, Cynthia Johnson-Edler

Electronic Theses and Dissertations

This investigation focuses on the determination of the architecture of the natural organic matter (NOM) contained within a soft coal-like material, an agricultural soil and a peat material. NOM has been extracted from bulk materials, fractionated, reassembled, then characterized by ¹³C Solid State NMR, Pulsed-Field Gradient NMR (PFG-NMR), and Small Angle Neutron Scattering (SANS). Interpretation of the data obtained by SANS has established that the majority of the components of NOM are mass fractals in solution and surface fractals in the solid state. Surface-to-volume ratios calculated with PFGNMR data indicate the NOM components studied have varying disk-like shapes. These …

Application Of Factorial Design In The Analysis Of Factors Influencing Textile Dye Adsorption On Activated Carbon, Eid A. Alkhatib, Penny A. Snetsinger, Ahmad Alanazi, Sarah Aanonsen

Chemistry & Physics Faculty Publications

In this study, the use of factorial design software is applied to evaluate efficiently factors influencing the adsorption capacity of activated carbon in treating textile dyes. Activated carbon is usually used to treat wastewater effluents from textile industries in order to remove textile dyes before discharge into the environment. Most treatment facilities, particularly large industrial or wastewater treatment facilities use continuous flow reactors or packed columns to treat the dye. Due to the limited residence time in these types of reactors, adsorption equilibrium is not necessarily reached, and the absorption rate becomes an important factor in this treatment process. Other …

Bioavailable Iron In Equatorial Pacific Ocean Aerosol Samples, Hsiang T Teng

All Master's Theses

Oceanic iron (Fe) fertilization experiments performed in remote regions have established that Fe additions draw carbon into the ocean, at least over the months-long time frame of the experiments. However, the mechanisms that control Fe speciation in atmospheric aerosol particles before and after deposition into the surface ocean remain largely unknown. This is in part due to the analytical challenge of quantifying Fe at environmentally significant sub-nano molar levels. The flow injection analysis method combined with the luminol chemiluminescence analytical system allows us to explore the near-real time determination of pico-molar levels of both Fe(II) and H₂O_{2 …}

Influence Of Magnetic Nanoparticles And Magnetic Stress On An Ionic Liquid Electrospray Source, Kurt Joseph Terhune

Dissertations, Master's Theses and Master's Reports

Two electrospray sources were developed to operate on an ionic liquid ferrofluid; one source was a pressure‑fed capillary electrospray source and the other was a novel electrospray source which used a magnetically‑induced instability to produce a peak from which an electric field could extract electrospray. Multiple characteristics of electrospray operation were examined for both sources using faraday plates/cups, a quartz crystal microbalance, a retarding potential analyzer, and a time-of-flight mass spectrometer. The ILFF electrosprays for a capillary source were shown to operate in a mixed ion/droplet regime. The mass flow of the electrospray beam was primarily transported by larger particles …

Drinking Water Disinfection By-Products Detection, Formation And The Precursors Removal Study, Runmiao Xue

Doctoral Dissertations

"Haloacetic acids (HAAs) and trihalomethanes (THMs) are two groups of commonly found disinfection by-products (DBPs). Iodinated THMs and HAAs were observed after disinfection of water containing high level of iodide and are proved to be more toxic than their corresponding chlorinated and brominated species. In the presented dissertation, a novel rapid and sensitive high performance ion chromatography-tandem mass spectrometry (HPIC-MS/MS) method has been developed for simultaneous analysis of all these HAAs, bromate, bromide, iodide, and iodate, seventeen compounds in total, without any tedious sample preparation. Besides an efficient analytical method for the detection of DBPs, seeking for a green disinfectant …

Latent Fingerprint Enhancement On A Brass Metal Surface Using Paint Electrodeposition, Reika D. Haskell

Online Theses and Dissertations

Fingerprint evidence recovered at a crime scene plays a key role in apprehending a suspect. Cyanoacrylate fuming is one the most successful methods of enhancing fingerprints from metallic surfaces. Despite the success of cyanoacrylate fuming, fingerprint recovery on fired cartridge casings is rarely successful. Therefore, a new fingerprint development method is needed to enhance fingerprint evidence that may still be present on fired cartridge casings. The aim of this research project is to study the use of metal and paint electrodeposition to enhance fingerprints on a brass metal surface.

High throw power paint was used in the initial study; high …

Metabolomic Profiling Of Chiari Malformation Type I: Comparison Of Bioinformatic Programs For Untargeted Analysis, Hunter W. Korsmo

Williams Honors College, Honors Research Projects

Chiari Malformation Type I is a neurodegenerative trait that can result from disease or from acquiring. Metabolomic analysis was done on normal pressure hydrocephalous and Chiari CSF samples using LC-MS and multiple bioinformatic programs. After analysis from multiple programs, we were able to analyze the stringency in statistical algorithms done by each program and determined qualities that are shared between programs that offer multiple details. We identified dysregulation in glucuronated metabolites in CSF of Chiari versus NPH. Using LC-MS, we established the experimental MS/MS of glucuronic acid in attempt to identify similarities in mass-to-charge features primarily identified. We could not …

Transcriptional And Antagonistic Responses Of Biocontrol Strain Lysobacter Enzymogenes Oh11 To The Plant Pathogenic Oomycete Pythium Aphanidermatum, Yangyang Zhao, Guoliang Qian, Yuan Chen, Liangcheng Du, Fengquan Liu

Department of Chemistry: Faculty Publications

Lysobacter enzymogenes is a ubiquitous, beneficial, plant-associated bacterium emerging as a novel biological control agent. It has the potential to become a new source of antimicrobial secondary metabolites such as the Heat-Stable Antifungal Factor (HSAF), which is a broad-spectrum antimycotic with a novel mode of action. However, very little information about how L. enzymogenes detects and responds to fungi or oomycetes has been reported. An in vitro confrontation bioassay between the pathogenic oomycete Pythium aphanidermatum and the biocontrol bacterial strain L. enzymogenes OH11 was used to analyze the transcriptional changes in the bacteria that were induced by the oomycetes. Analysis …

Separation Of Transition And Heavy Metals Using Stationary Phase Gradients And Chelation Thin Layer Chromatography / Evaluation Of The Effectiveness Of Pogil-Pcl Workshops, Stacy L. Stegall

Theses and Dissertations

Gradient surfaces exhibit a variation in functionality along the length of the surface. One method for preparing gradients is controlled-rate infusion (CRI). In Part 1 of this work, CRI was used to prepare gradients for the purpose of separating transition and heavy metals. Initial work on this project was focused on controlling the retention of the metal ions by varying the number of amine groups, aminoalkoxysilane concentration, and the infusion time. The retention factors of four metal ions varied predictably with increasing number of amine groups, increasing aminoalkoxysilane concentration, and increasing infusion time, producing small but useful changes in the …

Quantitative Analysis Of Tobacco-Specific Nitrosamines And Their Precursor Alkaloids In Tobacco Extracts, Celeste T. Wilkinson

Theses and Dissertations

Tobacco-specific nitrosamines (TSNA) are carcinogenic constituents derived from alkaloids in tobacco. Researchers are actively exploring several avenues to reduce TSNA levels in tobacco products like moist snuff tobacco. The focus of the research presented within is the quantitative analysis of TSNA in tobacco, specifically N’-nitrosonornicotine (NNN), 4-(methylnitrosamino)-1(3-pyridyl)-1-butanone (NNK), N’-nitrosoanatabine (NAT), and N’-nitrosoanabasine (NAB).

Tobacco alkaloids and nitrosamines in tobacco are currently analyzed by different instrumentation due to orders of magnitude difference in their concentrations, chromatographic separation challenges due to structural similarities, and similar mass fragmentation patterns. An analytical column using silica and 1,2-bis(siloxy)ethane hybrid particles of 1.7 µm size is …

Approaches Toward Novel 1,2,3-Triazole Sensors For The Detection Of Anions And Heavy Metal Cations, Richard D. Govan

College of Graduate Studies: Theses & Dissertations

Cations and anions play pivotal roles in biological and physiological processes, however an imbalance in concentration of any ion can be detrimental. Therefore, research into the selective recognition of anions and heavy metal cations has acquired much attention. One approach involves the use of chemosensors. Upon interaction with targeted analytes, chemosensors produce a distinct response, in some cases a fluorescent or colorimetric signal. The 1,2,3-triazole unit has much potential as a chemical sensor due to its unique photophysical properties. The specificity, selectivity, and signaling mechanism of triazole sensors can be tuned with conjugation in the motif and choice and placement …

Development Of General Purpose Liquid Chromatography Simulator For The Exploration Of Novel Liquid Chromatographic Strategies, Lena N. Jeong

Theses and Dissertations

The method development process in liquid chromatography (LC) involves optimization of a variety of method parameters including stationary phase chemistry, column temperature, initial and final mobile phase compositions, and gradient time when gradient mobile phases are used. Here, a general simulation program to predict the results (i.e., retention time, peak width and peak shape) of LC separations, with the ability to study various complex chromatographic conditions is described. The simulation program is based on the Craig distribution model where the column is divided into discrete distance (Δz) and time (Δt) segments in a grid and is …

Energetic Effects Of Hole Transporting Materials On The Performance Of Organometal Halide Perovskite Photovoltaic Cells, So Min Park

Theses and Dissertations--Chemistry

Efficient, inexpensive, lightweight and flexible solar cells are desired to help meet the world’s growing energy needs. Organometal halide perovskite (OMHP) photovoltaic (PV) cells have shown dramatic increases in solar cell efficiencies increase over the last 5 years. OMHP PV cells have attracted significant attention due to their broad absorption spectra, high electron and hole mobility, and low production cost. The interface between hole transporting layer (HTL) and perovskite thin films have a significant influence on charge transfer and overall solar cell performance. 2,2’,7,7’-tetrakis(N,N-di-p-methoxyphenylamine)9,9’-spirobifluorene (Spiro-OMeTAD) is a small molecule largely used as HTL in perovskite solar cells. However, this material …

Mechanisms Of Heterogeneous Oxidations At Model Aerosol Interfaces By Ozone And Hydroxyl Radicals, Elizabeth A. Pillar-Little

Theses and Dissertations--Chemistry

Atmospheric aerosols play an important role in climate by scattering and absorbing radiation and by serving as cloud condensation nuclei. An aerosol’s optical or nucleation properties are driven by its chemical composition. Chemical aging of aerosols by atmospheric oxidants, such as ozone, alters the physiochemical properties of aerosol to become more hygroscopic, light absorbing, and viscous during transport. However the mechanism of these transformations is poorly understood. While ozone is a protective and beneficial atmospheric gas in the stratosphere, it is a potent greenhouse gas in the troposphere that traps heat near the Earth’s surface. It also impacts human heath …