Analytical Chemistry Commons^™

Integration Of Raman Spectroscopy And Python-Based Data Analysis For Advancing Neurobiological Research, Natalie E. Dunn

Doctoral Dissertations

The field of Raman spectroscopy continues to expand into biological applications due to its usefulness as a non-invasive technique that can be utilized qualitatively and quantitatively. However, the inherent weakness of Raman scattering leads to the need for each collected spectra to undergo a preprocessing step to remove noise, background drift, and cosmic rays. Biological research in particular needs large datasets due to the increased variability in samples. As datasets grow, the need to perform preprocessing on each individual spectra becomes daunting. Often, these steps are done by hand with the help of specialized software programs. Preprocessing can be accelerated …

The Influence Of Ion-Ion Correlations On Conductivity In Concentrated Ionic Systems, Md Dipu Ahmed

Masters Theses

This study delves into the fascinating realm of concentrated ionic systems, such as ionic liquids, superionic materials, organic ionic plastic crystals, and polyelectrolytes, which hold immense potential for energy storage applications. The focus is on understanding the intricate role of ionic correlations in shaping their ionic conductivity behavior. These correlations can either boost or impede conductivity, yet their underlying mechanisms remain elusive. Through extensive investigation of various materials, including ionic liquids with differing anionic masses, pure organic ionic plastic crystals, and doped systems, this research employs advanced techniques like dielectric spectroscopy and innovative momentum conservation models to quantify these correlations. …

Women As A Force Multiplier For Bringing Nuclear Forensic Capabilities To The International Stage, Heather M. Dion, Caterina Fox, Kim Knight, Anne Phillip

International Journal of Nuclear Security

In 2009, the US Department of Energy National Nuclear Security Administration’s (NNSA’s) Defense Nuclear Nonproliferation Program initiated a new nuclear forensics outreach effort under its Confidence Building Measures Program. Little did they know that the timing could not have been better. This article focuses on the early years (2009–2015) of the NNSA’s international nuclear forensics outreach, specifically the efforts and experiences of the women who helped establish this program, building it from a fledgling, bilateral effort into an enduring technical capacity provider engaging with dozens of countries and multilateral organizations. At the onset of the program, nuclear forensics was an …

Chirality, Symmetry-Breaking, And Chemical Substitution In Multiferroics, Kiman Park

Doctoral Dissertations

Multiferroic materials attract significant attention due to their potential utility in a broad range of device applications. The inclusion of heavy metal centers in these materials enhances their magnetoelectric properties, yielding fascinating physical phenomena such as the Dzyaloshinskii–Moriya interaction, nonreciprocal directional dichroism, enhancement of spin-phonon coupling, and spin-orbit-entangled ground states. This dissertation provides a comprehensive survey of magnetoelectric multiferroics containing heavy metal centers and explores spectroscopic techniques under extreme conditions. A microscopic examination of phase transitions, symmetry-breaking, and structure-property relationships enhances the fundamental understanding of coupling mechanisms.

In A2Mo3O8 (A = Fe, Zn, Ni, and Mn), we use optical spectroscopy …

Synthesizing, Purifying, And Characterizing Molten Chloride Salts, Phillip W. Halstenberg

Doctoral Dissertations

Molten chloride salts have vast potential as heat transfer fluids with both nuclear and concentrated solar power applications. For application in energy systems, the characteristics that govern these systems must be well understood. This work focuses on inorganic molten chloride salts with a special emphasis on the experimental aspect of chemical research. Chapter 2 covers the synthetic approaches for the formation of molten chloride mixtures. Many salts can be purchased from industrial suppliers, but most must be purified therefore, Chapter 3 evaluates various methodology developed for removal of impurities in salt mixtures. Once the salt of proper content and purity …

Mechanochemical Synthesis Of Task-Specific Conjugated Porous Networks Towards Enhanced Energy Storage, Juntian Fan

Doctoral Dissertations

Conjugated scaffolds with high electronic conductivity, high surface area, etc. are promising materials for diverse technological applications, especially in the electrochemical field. However, the current synthesis methods are still limited to the traditional solution-based method or the ionothermal method, which always require an inert atmosphere shield, large amounts of organic solvents, noble catalysts, long reaction time up to days, and high temperatures, etc. Therefore, there is a common goal of developing conjugated scaffolds through facile, green, straightforward pathways. Mechanochemistry, which is an efficient, sustainable, solvent-free methodology, could provide a unique reaction environment to synthesize this kind of functionalized materials, resulting …

Utilizing Ultra-Performance Chromatography High-Resolution Mass Spectrometry To Investigate Fatty Acid Mediated Antibiotic Tolerance, Brittni Woodall

Doctoral Dissertations

The lipid membrane is the first component necessary to sustain life. To maintain homeostasis, segregate cellular machinery, provide protection from the environment, and reproduce, an organism must establish a boundary in which the processes can occur. Throughout the last two decades, research has propelled our knowledge of lipid membranes much beyond original hypotheses. Once thought of to be static and uniform, the understanding of the lipid membrane has evolved to encompass a structure that is responsive, unique, and intricately constructed by the organism itself. By chance or by choice, organisms adapt the lipid membrane according to the environment for which …

Intra-Skeletal Variation In Stable Isotopes Through Non-Destructive Approaches: Applications Of The Patterns Of Skeletal Remodeling To Biological Anthropology, Armando Anzellini

Doctoral Dissertations

Stable isotope analysis is a well-established method in biological anthropology used to deliver data on residence, diet, and life history. Samples for these analyses are often collected from the diaphyses of long bones with an assumption of an expected rate of turnover between five and ten years, depending on the skeletal element. However, the biological foundations of this assumption are still uncertain, especially concerning the intra-skeletal and intra-element variation of isotopic signatures that may relate to patterns of remodeling. Exploring these gaps in intra-element isotopic variation requires fine-grained work using multiple bones from multiple individuals, but such work is limited …

Light Matter Interactions: A Study Of Soft Materials Using Linear And Nonlinear Spectroscopy, Muhammad Redwan Hassan

Doctoral Dissertations

The adoption of complex fluids for various industrial applications is becoming normal. Complex fluids offer tunability, wide range solubility, and chemical and thermal stability which are the factors that conventional polar and non-polar solvents often lack. However, fundamental studies of these fluid systems are still lacking which is limiting the appropriate use of these complex fluids in many applications. The goal of this dissertation was to study and characterize complex fluids for application in electrolytes for redox flow batteries. Chapter 3 and chapter 4 feature the study of microemulsions and deep eutectic solvents (DES) by fluorescence techniques. Fluorescence studies of …

Analytical Techniques For The Analysis Of Uranium Bearing Materials, Nathaniel D. Fletcher

Doctoral Dissertations

The interest in the use of nuclear power has increased drastically in recent years. This is due to significantly increased efficiency at producing energy when compared to fossil fuels. With the increased use of nuclear power comes an increased need to for monitor for uranium bearing materials outside of regulatory control. This dissertation covers four projects aimed at improving the analysis of these materials. The first projects aims to develop a method that allows for the analysis of elements that exist in nature as anions by triple quadrupole ICP – MS. This would allow for the ability to measure more …

Development Of Raman Spectroscopic Methods For Detection Of Molecules Indicating Life In Extraterrestrial Environments, Grace Sarabia

Doctoral Dissertations

Mineral analysis is of great importance to the understanding of the world around us and worlds beyond. Geology, chemistry, and environmental studies all benefit from characterization of the structure and properties of minerals. While various techniques have been applied towards the study of minerals, we propose that Raman spectroscopy is specifically suited for the detection and study of minerals under various conditions, including for terrestrial and space applications.

In our terrestrial studies, we explored the polymorphs of calcium carbonate within freshwater mollusk shell matrices with Raman spectroscopy. We found that aragonite was the main calcium carbonate polymorph present in the …

Validation Of A Method For Pantoprazole And Its Sulfone Metabolite In Goat Plasma Using High Performance Liquid Chromatography, Sherry Cox, Lainey Harvill, Sarah Bullock, Joseph Smith, Joan Bergman

Faculty Publications and Other Works -- Large Animal Clinical Sciences

No abstract provided.

Elucidating Molecular Structure And Interactions Of Disease-Related Noncovalent Assemblies Through Ion Mobility Spectrometry - Mass Spectrometry, Amber Leann Hope Gray

Doctoral Dissertations

Ion mobility spectrometry – mass spectrometry (IMS-MS) is a powerful gas-phase technique that is routinely employed in the investigations of amyloid oligomers and conformational studies due to its ability to separate isobaric and isomeric species with the same mass-to-charge ratio (m/z). The goal of this dissertation is to use IMS-MS as a primary platform to probe the conformational landscape of a macrocyclic protein, Cyclosporin A (CycA), and to characterize interactions of amyloidogenic assemblies. Through five independent studies presented within document, the limits of IMS-MS are pushed by employing conditions which mimic biological environments.

Chapter 2 focused on how …

Unraveling The Molecular Foundations Behind The Diverged Behaviors Of Mouse Insulin 1 And Insulin 2, Connecting Diabetes Risk With Glucocorticoid Treatment And Chronic Migraine Through The Analysis Of Islet Chemistry, And Capturing Key Posttranslational Modifications All Through The Application Of A Novel Lc-Ims-Ms Workflow, Connor Christopher Long

Select or Award-Winning Individual Scholarship

We display the capabilities of our established liquid chromatography-ion mobility spectrometry-mass spectrometry (LC-IMS-MS) workflow in the investigations of islet chemistry at the sub-single-islet level. We begin by characterizing the structural differences of Ins1 and Ins2 to present novel insights as to why their behaviors diverge. We then examine the effects of the stress hormone corticosterone, the rodent equivalent of human cortisol that is often used as a therapeutic, on pancreatic peptide hormone secretion. We also uncover the molecular connection behind the inverse relationship between type 2 diabetes (T2D) risk and chronic migraine via the neuropeptides CGRP and PACAP. Lastly, we …

Total Internal Reflection: Applications In Nonlinear Microscopy And Fluorescence Anisotropy, Brandon Colon

Doctoral Dissertations

As technology advances to harness new energies and to create new cures, the sophistication of analysis grows not only in depth but in efficiency. Total internal reflection (TIR) has been coupled to microscopy leveraging its unique optical phenomenon on a breadth of topics. In this dissertation, the work presented will show how TIR was applied in two different instrumental analyses to evaluate two unique and complex systems. The first project features TIR paired with the transient absorption microscopy (TAM), a nonlinear optical technique, to gauge solvent mixing and diffusion in microreactors. Microreactors gained acclaim for their ability to produce high …

Instrument Development For High Sensitivity Size Characterization Of Lipid Vesicles And Other Biological Macromolecules Via Taylor Dispersion Analysis, Meagan Moser

Doctoral Dissertations

Just as humans communicate with other humans, the cells in our bodies communicate with each other through various, often complex, mechanisms. Cell-to-cell transmission of small molecules, lipids, proteins, peptides, or nucleic acids can be mediated by extracellular lipid vesicles called exosomes. Exosomes have been found to play a role in the delivery of regulatory molecules from one cell to another, serving as a universal communication mechanism. Currently, there is an emerging focus on characterizing exosome communication dynamics. Understanding exosome mechanisms of cell-to-cell communication requires accurate measurements of the spatiotemporal and chemical dynamics of exosome secretion. No current analytical approach offers …

Ultrasound-Driven Fabrication Of Nanosized High-Entropy Materials For Heterogeneous Catalysis, Francis Uchenna Okejiri

Doctoral Dissertations

High-entropy materials (HEMs) have emerged as a new class of multi-principal-element materials with great technological prospects. As a unique class of concentrated solid-solution materials, HEMs, formed on the premise of incorporating five or more principal elements into a single crystalline phase, provide an excellent opportunity to access superior catalytic materials ‘hiding’ in the unexplored central regions of a multicomponent phase space of higher orders.

However, the fabrication of HEMs is energy-intensive, typically requiring extreme temperatures and/or pressures under which agglomeration of particles occurs with a commensurate decrease in surface area. For most catalytic applications, non-agglomerated particles with high surface areas …

Analytical Considerations And Methods For Comprehensive Analysis Of Bacterial Phospholipidomics Using Hilic-Ms/Ms, David Thomas Reeves

Doctoral Dissertations

Omics technologies have rapidly evolved over the last half century through vast improvements in efficient extraction methodologies, advances in instrumentation for data collection, and a wide assortment of informatics tools to help deconvolute sample data sets. However, there are still untapped pools of molecules that warrant further analytical attention. As the frontline defense of the cell against exterior influences, the phospholipid membrane is key in structure, defense, and signaling, but current omics studies are only just now catching up to the potential hidden within cellular lipid profiles. Examination of shifts in phospholipid speciation and character could provide researchers with a …

Characterization Techniques And Cation Exchange Membrane For Non-Aqueous Redox Flow Battery, Kun Lou

Doctoral Dissertations

The motivation of this work comes from one of the major problems of emerging non-aqueous flow battery (NAFB) that a separator or membrane which facilitates conductivity and blocks redox species crossover does not exist. Although many aspects of principles can be mirrored from mature fuel cell and aqueous flow battery, it is found that some well-defined membrane properties in aqueous systems such as swelling, transport and interactions are different in non-aqueous solvents to some extent. However, the approach of this work does follow the way perfluorosulfonate ion exchange membrane (PFSA) facilitated development of fuel cell and aqueous flow battery in …

Using Second Harmonic Generation To Study Gram-Positive Bacterial Membranes, Lindsey N. Miller

Doctoral Dissertations

Understanding how small-molecules, such as drugs, interact with bacterial membranes can quickly unravel into much more perplexing questions. No two bacterial species are alike, especially when comparing their membrane compositions which can even be altered by incorporating fatty acids from their surrounding environment into their lipid-membrane composition. To further complicate the comparison, discrete alterations in small-molecule structures can result in vastly different membrane-interaction outcomes, giving rise to the need for more "label-free" studies when analyzing drug mechanisms. The work presented in this dissertation highlights the benefits to using nonlinear spectroscopy and microscopy techniques for probing small-molecule interactions in living bacteria. …

Utilization Of Raman Spectroscopic Techniques For Forensic Science Applications, Alyssa Rose Daniel

Masters Theses

In the field of forensic science, it is important to have reliable, accurate, and nondestructive testing methods for evidence collection and testing. Current methods, such as gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC), are destructive to evidence and require lengthy sample preparation. Because of its nondestructive nature, specificity, and portability, Raman spectroscopy has been increasingly improving forensic science. The goal of this work is to expand on the growing pool of knowledge of forensics related Raman applications.

One problem that has plagued forensic scientists for years is how to accurately identify the time since death, or post-mortem interval. …

Bioanalytical Applications Of Digital Imaging: Applications To Organ-On-Chip And Point-Of-Care Analysis Systems, Amirus Saleheen

Doctoral Dissertations

Qualitative and quantitative analysis through digital imaging has significant potential in several scientific applications including bioanalytical applications. In this document, the implication of digital imaging to validate and characterize a novel microfluidic organ-on-chip device and establish a point-of-care method to estimate epinephrine concentrations in expired and degraded autoinjectors have been described in chapter 2 and 3 respectively. Chapter 4 includes description of the principle and methodology of strong cation exchange-based immunoassay for oxytocin and β-endorphin.

In chapter 2, fabrication of a novel microfluidic organ-on-chip device capable of culturing rodent SCN slices has been discussed. Characterization of the aCSF media droplets …

Sustained Release Of Persulfate And Iron(Ii) Ions From Inert Inorganic Materials For Groundwater Remediation, Peter Pham

Masters Theses

Contamination of groundwater, initiated from years of human negligence, continues to persist despite major advancements in water remediation technologies. The generated groundwater plumes can continuously replenish contaminants such as dense nonaqueous phase liquids (DNAPLs) through the aid of slow-moving water. Thus, long-term treatment of this flow system has proven to be problematic. A selection of sophisticated sustained diffusion technologies is needed to help prevent further damage to this prominent freshwater source.

Here, a novel in-situ chemical oxidation (ISCO) method was designed to incorporate persulfate into silica mediums such as zeolite, diatom, and silica flour for the treatment of groundwater contaminants …

Python Script For Homogeneous Aqueous Chemical Reaction Analysis And Associated Data Related To Radiolysis Simulations, Peter James Doyle, David Bartels

Faculty Publications and Other Works -- Nuclear Engineering

No abstract provided.

A Raman Spectroscopic Investigation Of Neurotransmitters And Photon Migration, Ian C. Bennie

Chancellor’s Honors Program Projects

No abstract provided.

Neurological Disease Detection Using Surface Enhanced Spatially Offset Raman Spectroscopy (Sesors), Taylor D. Payne

Chancellor’s Honors Program Projects

No abstract provided.

Design And Development Of A Quartz Crystal Microbalance Immunosensor For Exosomes, Wesley Cox

Chancellor’s Honors Program Projects

No abstract provided.

Analysis Of Primary Stripper Foils At The Spallation Neutron Source By An Electron Beam Foil Test Stand, Eric Paul Barrowclough

Doctoral Dissertations

Diamond films are used at the Spallation Neutron Source (SNS) as the primary charge exchange foils (i.e., stripper foils) of the accelerated 1 GeV (Gigaelectron volts) hydride ions. The most common type of film used is a nanocrystalline diamond film, typically 17 mm x 45 mm (millimeter) with an aerial density of 350 μg/cm² (microgram per square centimeter). The diamond film is deposited on a corrugated silicon substrate using plasma-assisted chemical vapor deposition. After the growth of the diamond film, 30 mm of the silicon substrate is etched away, leaving a freestanding diamond foil with a silicon handle that …

New Optical And Electrochemical Probes For Trace Chemicals With Health And Environmental Impacts, Thomas Stewart Carpenter

Doctoral Dissertations

The work in this dissertation focuses on the development of probes for the analysis of trace chemicals in samples with health and environmental impacts. A paper, Cu(copper)-based colorimetric probe was developed for the detection of toxic hydrogen sulfide (H₂S) gas. A modified Kipp’s apparatus was used to generate desired concentrations of H₂S in a total volume of 1.35 L (liters). The probe shows a qualitative response down to 60 ppb (parts per billion), indicating its ability to be used in industrial settings as a replacement for the commonly used lead acetate strips. When used in conjunction …

Improved Sample Utilization In Thermal Ionization Mass Spectrometry Isotope Ratio Measurements: Refined Development Of Porous Ion Emitters For Nuclear Forensic Applications, Matthew Louis Baruzzini

Doctoral Dissertations

The precise and accurate determination of isotopic composition in nuclear forensic samples is vital for assessing origin, intended use and process history. Thermal ionization mass spectrometry (TIMS) is widely accepted as the gold standard for high performance isotopic measurements and has long served as the workhorse in the isotopic ratio determination of nuclear materials. Nuclear forensic and safeguard specialists have relied heavily on such methods for both routine and atypical efforts. Despite widespread use, TIMS methods for the assay of actinide systems continue to be hindered by poor ionization efficiency, often less than tenths of a percent; the majority of …