Analytical Chemistry Commons^™

The Influence Of Fermentation Duration And Secondary Fermentation Conditions On The Bioactive Compound Profile Of Kombucha, Jordan Vereen

Honors Theses

Kombucha is a fermented sweet tea produced using a symbiotic culture of bacteria and yeast (SCOBY) and has gained widespread popularity due to its proposed health benefits. Kombucha has been studied to understand these advantages in cardiovascular support, improved metabolism, increased antioxidant effects, enhanced antimicrobial properties, and even potentially slowing the progression of certain diseases. Despite its increasing popularity, the way in which the specific bioactive compounds responsible for these effects and the fermentation conditions that influence their production remain unclear. The present study, conducted in collaboration with Dr. Budner, focuses on quantifying bioactive compounds in kombucha to better understand …

Urea-Based Boronium Salts As Antimicrobial Agents, Gabriel Allen Merchant

Honors Theses

Quaternary ammonium compounds (QACs) are widely used in disinfectants due to their ability to inhibit the growth of and eliminate microbes. The potency, broad-spectrum activity, and low cost of QACs have made them a cornerstone of modem hygiene. In recent years, QACs have garnered many health and safety concerns due to their overuse and subsequent accumulation in the environment. The increased use of QACs has further led to an increase in antimicrobial-resistant bacteria, making the synthesis of novel antibacterial compounds vital to combat this growing threat. Recent advances in boronium salts offer a unique alternative to address these adverse effects. …

Analysis Of The Flavonoid Composition Of Honey Using High-Performance Liquid Chromatography, Bryce Phillips

Honors Theses

Honey is a naturally occurring substance that has a complex composition including compounds such as flavonoids, that contribute to potential health benefits. Quantitative analysis of flavonoids in honey can be challenging due to their similar structural characteristics, matrix effects, and chromatographic peak separation issues. This study aimed to establish calibration curves for five flavonoids–kaempferol, luteolin, chrysin, myricetin, and quercetin– to estimate their concentrations in five honey samples from varying geographic origins. Liquid-liquid extraction was used to isolate the flavonoids from honey. High Performance Liquid Chromatography was utilized to establish calibration curves and analyze honey samples. The calibration curves assembled demonstrated …

A Spectroscopic Survey Of Atmospheres Of Super-Earths, Luke Brust

Honors Theses

Recent research has made it possible to use spectroscopy to analyze the composition of the atmospheres of exoplanets, planets that orbit other stars. Most projects thus far have focused on the atmospheres of gas giants, as it is less challenging to observe them with available equipment. This project studies the atmospheres of four Super- Earths, planets that have a mass greater than the Earth but smaller than Neptune. This is accomplished by processing the raw spectroscopic data from the Hubble Space Telescope and modeling the atmosphere using the program 𝝉-Rex3. This survey found clear results from two of the selected …

Characterization Of Aromatic Stationary Phases For Uses In High Performance Liquid Chromatography, Anastasia Davis

Honors Theses

High Performance Liquid Chromatography (HPLC) is an analytical chemist technique used to separate a sample into its components to characterize and study a specific molecule or compound. Traditionally, High-Performance Liquid Chromatography in different industries, such as the environmental and pharmaceutical fields, uses stationary phases that are already well characterized, such as the C18 stationary phase for separation. However, aromatic stationary phases have recently been produced, which have phenyl groups bonded to the interior surface of the column. Still, they have not been well characterized because of how modern they are. This project characterized several aromatic stationary phases (Biphenyl, pentafluorophenyl, and …

Investigation Of Zinc And Iron In Wildflower Honey, Savannah Simpson

Honors Theses

Honey acts as a valuable food source for both animals and humans. When found in contaminated environments, there is an increased likelihood that honey samples will have high metal concentrations. It has been discovered that honey concentrations in metals can be different based on location. This experiment aims to determine the amount of two valuable metals, zinc, and iron, in various honey sources. These metals can be important to the human body because they help boost immunity and allow the body to carry out the functions required for survival. However, if these elements are present in copious quantities, then it …

Investigating Reactivity Of Artificial Copper Peptides With Small Molecules, Allyson Bryant

Honors Theses

The design of artificial enzymes has been a topic of significant interest in the field of biochemistry, as they can provide new opportunities for catalytic processes and drug development. De novo protein design has emerged as a promising approach to create such enzymes, and the study of metalloproteins, particularly copper-binding peptides, has become a focus of this research. This thesis investigates the reactivity of a mutated copper-binding peptide, I5A-3SCC, with oxygen and its implications in the development of artificial enzymes.

The parent peptide, 3SCC, was mutated by replacing Isoleucine residues with smaller Alanine side chains, which was hypothesized to enhance …

Deposited Cigarette Smoke As A Driver Of Oxidation And Partitioning Processes On Indoor Surfaces, April Hurlock

Honors Theses

Despite the large amount of time that individuals spend indoors during their lives, very little attention was paid to the chemistry that occurs on indoor surfaces until recently. Although not visible to the naked eye, physical and chemical processes, such as partitioning and oxidation, are occurring on virtually every indoor surface in a typical household. Indoor pollutants, ranging from skin oils to environmental cigarette smoke, drive a lot of these processes. The transformation of indoor surfaces by indoor pollutants can increase chemical exposure risks as new irritants or carcinogens can be introduced to the surfaces. In this thesis, I describe …

Collision-Induced Dissociation And Ion Mobility Mass Spectrometry Of Au30(S-Tbu)18 Nanoclusters, Christopher Hood

Honors Theses

Collision Induced Dissociation (CID) and Ion Mobility Mass Spectrometry (IM-MS) are methods used to understand the structural arrangement and stability of large molecules. In this study, the gold nanocluster Au₃₀(S-tBu)₁₈ was dissociated at varying Trap collision energies, and drift time vs mass spectrometry data was plotted to determine the order of cluster fragmentation. Comparing Au₃₀(S-tBu)₁₈ data to that of Au₂₅(SCH₂CH₂Ph)₁₈, the only current nanocluster published with IM-MS data, two distinctly different dissociation patterns were seen. Unlike the linear CID fragmentation of Au …

Fast Photochemical Oxidation And Footprinting Of Proteins Via Trifluoromethyl Radical Chemistry, Elaine Morrow

Honors Theses

Fast photochemical oxidation of proteins (FPOP) is a useful tool in proteomics because of the ability for modifications to occur on the scale of microseconds which reduces the modifications to tertiary and quaternary structure allowing for more accurate labeling of the protein. Labels for FPOP are generated from various radicals in our experiments which include hydroxyl radicals and trifluoromethyl radicals. Hydroxyl radicals are easily generated by using an excimer laser (KrF laser, 248 nm) or a UV flash lamp (as a part of the Fox™ System) by the photolysis of hydrogen peroxide. Trifluoromethyl radicals, however, need hydroxyl radicals to be …

Initial Investigation Of Wildflower Honey Using Headspace Solid-Phase Microextraction Coupled With Gas Chromatography-Mass Spectrometry For Geographical Information, Tyra Countiss

Honors Theses

Honey has been used as a food, sugar substitute, and flavor enhancer forever. The uses for honey are extremely varied from food to medicine. It is widely touted that you can address seasonal allergies, especially those following a move, by eating local honey. For this to be true the composition of the local honey, including trapped pollen, would allow allergy symptoms to be eliminated. In this project, the volatile and semi-volatile aroma compounds in wild flower honey from several different locations were analyzed. Headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to help develop the …

Determination Of Metals And Microplastics In Sediment From Oyster Reefs In The Mississippi Sound, Shelby Goza

Honors Theses

This research centers on the determination of metals (Cd, Pb, V, Cr, Mn, Fe, Co, Ni, Cu) and microplastics (MPs) in marine sediment from oyster reefs in the Mississippi Sound Estuary. Oysters (Crassostrea virginica) are a vital part of the Gulf Coast economy, but their population has dramatically declined in recent years due to multiple stressors, including oil spills and fluctuations in salinity from flooding. Increasingly frequent flooding events also introduce high loads of MPs and sediments containing heavy metals from the Mississippi River. These pollutants can have deleterious effects on oyster biology; however, they have not been adequately …

Effects Of Halogen Bonding On 13c Nmr Shifts Of Various Tolan Species, Anthony Lybrand

Honors Theses

Halogen bonding is slowly becoming a more and more useful part of the world of chemistry and is beginning to be incorporated into various aspects of the chemical industry. This study’s purpose is to determine whether or not halogen bonding can cause any effect in the 13C NMR shifts. The specific purpose of this study is to determine whether these chemical shifts change when a Lewis Base is added to the dissolved sample. In order to do this, the tolan species (4-iodotolan and 4-chlorotolan) had to be synthesized. Once synthesized, the tolan species were analyzed via NMR. NMR data indicated …

Lc-Ms/Ms Method Development And Analysis Of Tricyclic Antidepressants In Human Plasma, Shahbaz Gul

Honors Theses

Depression has become one of the most prominent problems in society, disrupting both personal and social lives. Tricyclic antidepressants (TCAs) were first developed in the 1950’s and became some of the leading anti-depressant medications on the market later that decade. Today, newer anti-depressants have risen to the forefront, being safer and having a lower side-effect probability. Nonetheless, TCAs continue to be prescribed for severe depression, especially in cases where the newer anti-depressants have failed. However, TCAs are still highly potent, the toxicity associated with these compounds cannot be ignored. They have considerable cardiovascular and neurological toxicity, and in the event …

Determination Of Metals In Whey And Vegan Protein Supplements Using Inductively Coupled Plasma Mass Spectrometry, Megan Lofaso

Honors Theses

Driven by a demand for health and wellness products worldwide, the dietary supplement industry continues to expand with an economic impact >$100 billion in the USA alone. However, the industry is plagued by a lack of regulation and incidents of contamination, including with toxic heavy metals that can put consumers at potential risk. In this study, eight trace elements (Cd, Pb, Fe, Co, Mn, V, Cu, and Cr), including heavy metals (Cd and Pb), were determined in whey and vegan protein powder by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted digestion using nitric acid and hydrogen peroxide. Samples were …

A Conductivity Analysis Of A Newly Synthesized Poly(Ethylene Glycol) Methyl Ether Hydroxide Electrolyte, Sarah Marie Peterson

Honors Theses

This thesis investigates the synthesis and conductive properties of a Poly (ethylene glycol) methyl ether-based polymer electrolyte. The goal of the synthesis is to enhance the hydroxide ion conduction properties of the polymer with its cationic groups attached. The MePEG backbone contained seven ethylene glycol groups and was modified to substitute the hydroxide group in the MePEG with trimethylamine. In addition, the bromide added in the synthesis was exchanged for hydroxide ions to allow for the transportation of hydroxide ions in polymeric electrolytes that can be used in Anion Exchange Membrane Fuel Cells. The newly synthesized polymer was compared to …

The Quantitative Assessment Of Pond Scum: An Examination Of The Biogeochemistry Of Phosphorus Cycling In The Belgrade Lakes, Abbey M. Sykes

Honors Theses

The internal recycling phosphorus in freshwater lake bottom sediments represents a significant source of hypolimnetic phosphorus (P) release for many of Maine’s lakes. In summer months, Maine lakes often thermally stratify and the lake hypolimnion develops anoxia, leading to a reduction in redox potential at the sediment-water interface. These reducing conditions facilitate the reductive dissolution of ferric iron, and, since phosphorus is often present in freshwater lake sediments as solid FeOOH-PO₄ complexes, results in release of soluble phosphorus into the water column. Our current study presents field and laboratory data from sediment fractionation extractions designed to quantify concentrations of …

The Synthesis Of A Mepeg-Based Hydroxide Conducting Electrolyte And The Optimization Of The Mepeg-Tosylation Reaction, Andrew Ladner

Honors Theses

As society is becoming increasingly aware of the effects of climate change and the ever-looming threat of a fuel shortage, exploring green and renewable alternative energy production, such as fuel cells, is paramount. This project investigates the synthesis of a polyethylene glycol monomethyl ether (MePEG_n) based polymer as well as the optimization of the MePEG Tosylation reaction. The MePEG explored contains seven polymerized ethoxy groups (MePEG₇). The MePEG₇ polymer was modified by substituting a positively-charged trimethylamine group in the place of the alcohol functional group at the end of the PEG chain. The reason for …

Intrinsic Buffer Hydroxyl Radical Dosimetry For Hydroxyl Radical Protein Footprinting, Addison Roush

Honors Theses

Hydroxyl radical protein footprinting (HRPF) coupled to mass spectrometry is a powerful technique for the analysis of protein topography as it generates covalent mass labels that can survive downstream sample handling, and it is sensitive to the solvent accessibility of amino acid sidechains. Of the multiple platforms for HRPF, fast photochemical oxidation of proteins (FPOP) utilizes a pulsed 248 nm KrF excimer laser to label proteins by photolyzing hydrogen peroxide. FPOP is the most widely used HRPF platform because it labels proteins faster than unfolding can occur. Variations in FPOP sample conditions make it difficult to compare results between experiments …

Investigation Of The History Of Fingerprinting, Advancements In The Field, And Development Of Potential Methods That Could Improve The Detection Of Endogenous And Exogenous Drugs In Latent Prints, Kristen Malloy

Honors Theses

When someone thinks of fingerprinting, they are most likely going to picture how a latent print is matched to the fingerprint of a suspect based on ridge pattern analysis. However, there is much more information that can be obtained from a latent print. The work performed in this thesis focuses the detection of exogenous and endogenous drugs in latent prints. The experiments performed analyzed fingerprints from volunteers that were contaminated with one of three common painkillers: acetaminophen, acetylsalicylic acid (ASA), and ibuprofen. Three different instruments were tested for this purpose: MALDI-MS, ATR-FTIR, and LC-MS. Based on the results gathered, it …

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized heating, …

Glucose Oxidase And Prussian Blue Nanoparticles Encapsulated Within A Xerogel For Electrochemical Detection Of Glucose, Daniel Baker

Honors Theses

Recent literature reports examples of electrochemical biosensor systems based on the encapsulation of enzymes and metal nanoparticles into a xerogel for the detection of biologically important compounds, such as glucose. While these systems are very successful with acceptable detection limits and linear ranges. However, Prussian Blue modified electrodes have been shown to be better than metal electrodes for the detection of hydrogen peroxide. Here, a biosensor system where a xerogel in formed with both glucose oxidase and Prussian Blue nanoparticles.

Gold Nanoparticles: Core Conversion Of Au144(Sch2ch2ph)60 To Au99(Sph-Ch3)42 Using Aromatic Thiolate Ligands And Crystallization Of Au99(Sph-Ch3)42, Elizabeth Turnage

Honors Theses

The purpose of this thesis is to synthesize Au₁₄₄(SCH₂CH₂Ph)₆₀ using a two-step synthesis reaction, and then using this product to conduct a core conversion from Au₁₄₄(SCH₂CH₂Ph)₆₀ to Au₉₉(SPh-CH₃)₄₂. The Au₉₉(SPh-CH₃)₄₂ product will then be used to attempt to form crystals using five different crystal set-up methods. Au₁₄₄(SCH₂CH₂Ph)₆₀ is made with aliphatic thiolate ligands, and when it is placed in a mixture containing excess para-methyl benzenethiol, it undergoes a …

Detecting Cyanobacteria Toxins: The Human Health Impact Of An Environmental Problem, Lillian E. Naimie

Honors Theses

Cyanobacteria blooms are a growing concern in the world, as they can form a dense and sometimes toxin scum on water bodies. This paper will outline and discuss the environmental conditions that produce cyanobacteria bloom with a focus on the toxins produced by blooms and specifically the detection of these toxins through two analytical methods. Of the various toxins cyanobacteria are capable of producing, this paper will focus on microcystins and BMAA, a family of hepatotoxins and a specific neurotoxin respectively. The two analytical methods discussed are liquid chromatography coupled mass spectrometry and ELISA kit techniques. The advantages and drawbacks …

Photoelectrochemical Investigations On Novel Earth Abundant Solid State Catalysts For Solar Water Oxidation, Nathaniel Branimir Kurtz

Honors Theses

In light of a looming fossil fuel scarcity, many forms of alternative, clean energy production are being researched in order to provide a more sustainable source of energy production for the future. One area of research is on using novel, abundant catalytic materials in conjunction with semiconducting materials to drive the splitting of water in order to produce hydrogen gas, an energy-rich fuel. Currently, efficiency is limited by the energy bottleneck posed by the oxygen evolution reaction (OER) half of water splitting. In this work, cobalt selenide (CoSe) catalyst paired with the semiconductor iron oxide (Fe2O3) has been identified as …

A Novel Method For Determination Of Ammonium Isotope Ratios With Electrospray Ionization Mass Spectrometry, Rebecca J. Chmiel

Honors Theses

Nitrogen (¹⁵N) isotope tracer studies are an invaluable tool for understanding the rate of N transformations in the environment. A mechanistic understanding of N cycling is critical to management of excess N availability in freshwater and marine ecosystems. Conventional methods for measuring ¹⁵N:¹⁴N of dissolved inorganic nitrogen species are time consuming and require large sample volumes. Here, we present a technique for measuring ¹⁵N:¹⁴N in ammonium (NH₄⁺) using electrospray ionization mass spectrometry (ESI-MS). NH₄⁺ present in small volumes of sample (3 ml) is complexed with phenol via …

Automation And Analysis Of Thermometric Titrations, Russel P. Linneman Ii

Honors Theses

Over the past three years, I have been involved in the development and testing of an automated thermometric titration system for chemical research. There were three major phases in this process. The first phase consisted of modernizing the equipment and software. The second phase consisted of testing the software and equipment with a known chemical system. The third phase consisted of original research.