Analytical Chemistry Commons^™

Information Theory Analysis Of Water Vapor Stable Isotopes From The Sail Campaign, Matthew John Rybecky

Earth and Planetary Sciences ETDs

Understanding the processes that control water vapor isotopic composition in mountain environ- ments is essential for interpreting isotope records and predicting water resource responses to cli- mate change. This thesis applies information theory to continuous, high-resolution water vapor stable isotope measurements from the Surface Atmosphere Integrated Field Laboratory (SAIL) campaign in the East River watershed of Colorado’s Upper Gunnison Basin, spanning the winter- to-spring transition of 2022–2023. The analysis employs Shannon entropy, mutual information, transfer entropy, and joint transfer en- tropy (JTE) to quantify how environmental variables, including surface meteorology, radiation, tur- bulent fluxes, and ERA5 reanalysis products, transfer information …

Tissue-Specific Heavy Metal Accumulation And Sediment–Mangrove Dynamics In Port Everglades, Florida, Dimitrios Giarikos, Amy Hirons, Jason Gershman, Sophie Welch

SECLER Data

Coastal wetlands near industrialized waterways face increasing heavy metal contamination, yet the role of mangroves as biogeochemical buffers remains poorly understood. This study quantified 16 heavy metals in sediments and red mangrove (Rhizophora mangle) tissues (roots, branches, and leaves) across four sites near Port Everglades, Florida, examining tissue-specific partitioning, contamination patterns, and sediment-to-plant transfer. The South Turning Basin (STB) was the principal contamination hotspot, with geometric mean (GM) concentrations of arsenic (As; 27.8 µg/g) and zinc (Zn; 203 µg/g) exceeding threshold effect levels, while Cu exceeded its probable effect level (PEL; 193 µg/g). Mercury (Hg) exceeded its PEL …

Chemometric Analysis Of Dissolved Organic Matter Using Fluorescence, Dani Fellner, Ken Overway

Honors Projects

Univariate spectroscopic techniques have been utilized to measure dissolved organic matter (DOM), but challenges arise in the separation and characterization due to similarities in chemical structures and spectral overlap. Multivariate techniques utilize a combination of known analytes with their unique excitation and emission spectra from fluorescence measurements to quantify amount of each analyte present in the mixture using parallel factor analysis. Tryptophan, tyrosine, and phenylalanine are common amino acids found in environmental samples and can be quantified due to their intrinsic fluorescence qualities. These amino acids can be utilized to estimate the amount of DOM in a sample since proteins …

High Throughput Phenomics Pipeline For Pulse Crop Nutritional Breeding, Amod Udayanga Madurapperumage

All Dissertations

Dry pea (Pisum sativum L.), lentil (Lens culinaris Medik.), and chickpea (Cicer arietinum L.) are major pulse crops valued for their high nutritional composition and importance to global food systems. Pulses are rich in carbohydrates, protein, and essential minerals, making them ideal whole foods and critical contributors to food and nutrition security. Due to these advantages, pulse breeding programs are increasingly focusing on enhancing nutritional traits, such as protein quality, amino acid balance, and micronutrient density, through the process of biofortification. However, improvement of agronomic traits remains equally essential. Characteristics such as plant height, standability, stress tolerance, …

Radicals Transforming Organic Matter: Implications For Non-Pyrogenic Black Carbon And Nitrogen Formation, Molecular Dynamics In Tropical Soils, And Lignin Valorization, João Vitor Dos Santos

Chemistry & Biochemistry Theses & Dissertations

Radicals drive the transformation of organic matter in natural and engineered systems, altering its structure, reactivity, and stability. Condensed aromatic carbon (ConAC) and condensed aromatic nitrogen (ConAN) are among the most persistent forms of organic matter in soils and are traditionally interpreted as products of biomass burning. This dissertation challenges the long-standing assumption that these materials are exclusively pyrogenic, showing that iron-mediated radical chemistry can generate condensed aromatic structures under ambient conditions.

Chapters II and III show that Fenton-like radical oxidation of lignin-rich biomass produces condensed aromatic structures compositionally similar to pyrogenic black carbon and black nitrogen when assessed with …

Peruvian Pinniped Teeth Trace Element Data-Tracking Ecosystem Variabilites Through Trace Element Record Found In Peruvian Pinniped Dentin, Dimitrios Giarikos, Amy Hirons, Ally E. Sheehan, Radleigh Santos

SECLER Data

The South American sea lion (Otaria byronia; SASL) and the Peruvian fur seal (Arctocephalus australis; PFS) are apex predators within the Humboldt Current ecosystem, where population dynamics respond to both natural variability and anthropogenic pressures, including El Niño–Southern Oscillation (ENSO) events and coastal mining. This study quantified 18 trace elements (TEs) in canine dentin from both species collected at Punta San Juan, Peru using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to evaluate long-term environmental exposure. Because dentin is deposited incrementally, it preserves a chronological chemical archive reflecting ontogenetic shifts in diet and habitat use. Overall, TE concentrations were broadly similar …

Lc-Ms/Ms Method Development For The Analysis Of Cannabinoids In Wastewater, Abigail M. Castellanos, Ava La Lande

The Kean Review: Journal in Student Research

The goal of this research was to establish a reliable method to detect the presence of cannabinoids in wastewater and increase the sensitivity of detection. Since the legalization of cannabis in many states, toxicology research has expanded on methods of detection in hopes of identifying usage patterns. At the Joint Meeting of Essex and Union Counties, it was established that cannabinoids are not thoroughly accounted for in the process of filtering wastewater in addition to our limited understanding of consumption trends. This stands true for many wastewater facilities, especially as the intake of cannabis remains prevalent for various populations across …

Application Of Organic Geochemistry To The Characterization Of Hydrochar And Biochar: Insights Into Composition And Optimization, Michael A. Kruge, Teresa A. Centeno, Alvaro Amado-Fierro, José Manuel González-Lafuente, Rubén Forján, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Hydrothermal carbonization has garnered significant attention in recent studies due to potential applications of the hydrochar produced, which overlap with those of torrefied biochar, including soil improvement, carbon sequestration, and energy production. However, unlike the relatively uniform properties of biochar, hydrochar characteristics can vary greatly depending on the feedstock used. Advanced characterization techniques are essential to better understand these materials and enhance their practical applications. Research on hydrochar requires a multi-faceted approach, including molecular-level studies, to optimize production processes and identify specific applications.

In this regard, analytical methods commonly used in organic geochemistry could play a crucial role in deepening …

Novel Methods For Environmental Fluoride Measurement, Cable Warren

Chemistry & Biochemistry Dissertations

Fluoride analysis has been an important focus of analytical analysis for many years and will continue to be so going forward. Today, fluorinated compounds, specifically per/polyfluoroalkyl substances (PFAS), better known as “forever chemicals” have captured the moment and are the subject of vast research and regulation. Under this context, I have researched new methods of fluoride separation and concentration in complex media as well as a novel method of PFAS destruction and total organic fluorine analysis for screening of PFAS in aqueous samples. Through research and work on micro-scale detection methods, an understanding of the state of the art and …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Nanostructured Cathode Catalysts For Aem Electrolysis: From Catalyst Design To Degradation And Hydrogen Dynamics, Yamini Kumaran

Electronic Theses & Dissertations (2024 - present)

Anion exchange membrane water electrolysis (AEMWE) presents a promising pathway toward cost-effective and sustainable hydrogen production by integrating the chemical robustness of alkaline systems with the compact, zero-gap design of proton exchange membrane electrolyzers. However, the widespread implementation of AEMWE is limited by the availability of highly active and durable platinum-group-metal (PGM)-free catalysts and by an incomplete understanding of their degradation behavior under realistic operating conditions.

This dissertation focuses on the development, characterization, and mechanistic investigation of nanostructured MoNi₄–MoO₂-based electrodes for efficient and stable hydrogen generation under alkaline and membrane-integrated environments. MoNi₄–MoO₂ nanorods …

Suitability Of Mobile Phase Recycling For Methylxanthine Quantification In Coffee Samples Using Hplc, Kaitlin O’Keeffe, Marcos Mariano, Brian Murphy

SURE Journal: Science Undergraduate Research Experience Journal

Caffeine, theobromine and theophylline fall under a drug class known as methylxanthines. These three compounds are of major interest in the food industry due to their presence in popular foods and beverages such as tea, coffee, and chocolate. As these compounds can cause physical and mental stress at high dosages, their quantification is essential to ensure product safety and quality. Here, we describe an eco-friendly HPLC method developed to quantify the amount of these analytes in coffee samples sourced across the SETU Waterford, Cork Road campus. Using an isocratic mixture of water and methanol, a mobile phase recycling approach was …

Molecular Design And Engineering Of Luminophores For Aggregation Induced Electrogenerated Chemiluminescence, Jesy Alka Motchaalangaram

Dissertations

Most conventional luminophores produce intense emissions in solutions but suffer from weak emissions or quenching when aggregated in poor solvents due to intermolecular interactions, such as π-π stacking. This phenomenon is known as aggregation caused by quenching (ACQ), limits their applications in their solid state. In contrast, aggregation induced emission (AIE) is a phenomenon in which luminophores are weak- or non-emissive in solution but emit intensively in their aggregated or solid states. AIE has enabled significant advancements in various real-world applications and has inspired new areas of research. The combination of AIE with electrogenerated chemiluminescence (ECL) has resulted in a …

Day-Night Shifts In Water-Soluble Ions Of Size-Resolved Aerosols Before And After The Covid-19 Lockdown In A Coastal Megacity: Metro Manila, Philippines, Grace Betito, Paola Angela Bañaga, Rachel A. Braun, Maria Obiminda Cambaliza, Melliza Templonuevo Cruz, Alexander B. Macdonald, James Bernard Simpas, Connor Stahl, Armin Sooroshian

SOSE Affiliate: Manila Observatory

The COVID-19 pandemic-driven lockdowns offer a unique opportunity to examine how reductions in anthropogenic emissions impacted atmospheric aerosol composition in urban environments. This study investigates the day-night variability of size-resolved water-soluble ions in ambient particulate matter (PM) collected in Metro Manila before (November 2019–February 2020) and after (November 2020–February 2021) lockdown implementation. Using tandem Micro-Orifice Uniform Deposit Impactors (MOUDIs), aerosol samples were collected during daytime (06:00–18:00) and nighttime (18:00–06:00) periods and analyzed for key ionic species (sulfate, ammonium, nitrate, oxalate, sodium, chloride, calcium, and magnesium) via ion chromatography. Submicrometer water-soluble mass declined post-lockdown, particularly during daytime, reflecting suppressed secondary formation …

Highly Contaminated Sediments From The Gowanus Canal (New York) Superfund Site: An Environmental Forensic Approach, Michael A. Kruge, Kevin K. Olsen, Eric A Stern, Maria Mastalerz, Albert Permanyer

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The 2.5 km long Gowanus Canal (Brooklyn, NY, USA) is a severely contaminated urban waterway dating from the mid-19th century, listed as a US Environmental Protection Agency (USEPA) Superfund site since 2010. Applying an environmental forensics approach to the extensive USEPA data set, we detect systematic variations in parent PAH ring number distributions in the canal sediments, as well as an extraordinary enrichment in organic carbon. We subjected a supplemental sample set to a more detailed analysis by quantitative pyrolysis-GC-MS, Rock-Eval pyrolysis, and organic petrology. With these sensitive methods, we can confirm the alkyl-PAH fingerprint of coal tar (a legacy …

Electrochemistry Behind Pfas: Mechanistic And Analytical Approach For Sensing And Degradation Strategies, Jonathan Josue Calvillo Solis

Open Access Theses & Dissertations

Understanding the fundamental electrochemistry of perfluoroalkyl substances (PFAS) is key to developing effective water remediation and sensing strategies. This work explores the thermodynamics and kinetics of perfluorooctanoic acid (PFOA) electroreduction, focusing on C-F bond cleavage. These insights were applied to design a highly sensitive electrochemical sensor for detecting trace levels of PFOA in water. This dissertation focuses on the electrochemical investigation of the reduction reaction of PFOA in aqueous and organic media employing different electrode materials. This exploration allows to understand the defluorination reaction of PFAS to further propose potential strategies for water treatment and PFOA electrosensing. Through electrochemical, spectroscopical …

Trade-Off Between Limonene & Geraniol-Based Reprocessable And Non-Reprocessable Epoxy Thermosets: Role Of Aliphatic Diamines In Polymer Networks Design, Priyankkumar Kanubhai Patel

Electronic Theses & Dissertations

The growing demand for sustainable materials, driven by environmental concerns and the rapid depletion of fossil fuels, has garnered significant attention in the fabrication of bio-based epoxy thermosets as renewable alternatives to petroleum-derived thermosetting polymers. The present study focuses on the synthesis and characterization of epoxy prepolymer resins derived from limonene and geraniol via a two-step process, followed by the fabrication of thermally cross-linked flexible epoxy thermoset films using various traditional aliphatic diamine curing agents, namely 1,2-ethylenediamine (EDA), 1,4-butylenediamine (BDA), and 1,6-hexamethylenediamine (HDA). Additionally, the incorporation of cystamine, a disulfide-containing diamine, enabled the formation of a covalent adaptable network through …

Salmon As An Ecological Pathway Of Contaminants Into Alaskan Food Webs, Miranda Brohman, Gretchen Roffler, Dimitri G. Giarikos, David Kerstetter, Amy C. Hirons

SECLER Data

Salmon are important fish taxa for humans and animals in hemiboreal and subarctic ecosystems. Trace elements and their marine food web bioaccumulation raises biomagnification and potential human health risk concerns. Sixteen trace element concentrations and their health risk assessments were determined in seven different tissues of two Southeast Alaska salmon species (chum, Oncorhynchus keta and pink, Oncorhynchus gorbuscha). Chum tissues had overall higher trace element concentrations compared to pink, which may be attributed to a difference of diets, generally longer-lived and spending more time in the open ocean. All kidney and liver samples exceeded the tolerable daily intake for …

Refining Chlorosulfonation Methods For The Synthesis Of A Perfluoroalkyl Arylsulfonimide (Pfsi) Monomer, Ainsley P. Foster, Ben Varney, Hua Mei

SPARK Symposium Presentations

Proton-exchange membrane (PEM) fuel cells are sources of energy that are clean, quiet, and highly responsive to changes in power needs, making them promising for use in automobiles and other portable power devices. The electrolyte of a PEM cell–the layer responsible for conductivity–is a polymer membrane, commonly consisting of perfluoroalkyl sulfonic acid (PFSA) polymers. In place of the PFSA polymers, perfluoroalkyl arylsulfonimide (PFSI) polymers are expected to improve the efficiency of PEM fuel cells with better stability and proton conductivity. The trifluovinylether (TFVE) aryl perfluorosulfonamide monomer is a new PFSI monomer proposed to fulfill these benefits once polymerized. The previous …

Geochemical Assessment Of Sediment Flux In A Sediment Core From A Tidal Flat In A Tropical Estuary, Olumide Ajulo

Master's Theses or Doctor of Nursing Practice

Sediment flux in estuaries is influenced by both natural processes and anthropogenic activities. Understanding the historical and current trends in sediment flux inputs and geochemical composition are essential for evaluating the estuary’s response to natural and human-induced changes and for developing effective environmental management strategies. The tropical Wouri Estuary in Cameroon receives water and sediment inputs from three main rivers draining urban, industrial, and agricultural areas, as well as different rock terrains. The complex inputs into the estuary can significantly affect sediment flux, consequently impacting the ecosystem. Thereby making an understanding of the temporal variations in sediment inputs in the …

Rwanda's Natural Remedies: A Fresh Look At The Fight Against Malaria, Leandre Nsabimana Ndisanze

Pomona Senior Theses

Malaria remains one of the most devastating parasitic diseases globally, disproportionately affecting sub-Saharan Africa, where Rwanda continues to face high transmission rates and rising resistance to conventional interventions. Despite decades of control efforts, the emergence of drug-resistant Plasmodium falciparum and insecticide-resistant Anopheles mosquitoes threatens to reverse recent gains. This research responds to the urgent need for sustainable and culturally relevant alternatives by exploring the therapeutic potential of Rwandan traditional medicinal plants. These indigenous remedies, long used by local healers, offer an underexplored reservoir of bioactive compounds that may provide the basis for novel antimalarial drugs.

The central hypothesis of this …

Developing A Method To Identify Tyre Particles By Detecting Benzothiazole Via Gc-Ms, Emma Paull

The Plymouth Student Scientist

Tyre particles are a dominant source of microplastic pollution in our environment. However, their chemical and physical properties are poorly understood and no standardised methods for identifying and quantifying them exist. This study looked to develop a method to identify tyre particles using two tyre samples of differing particle sizes, fine (62 - 125 µm) and coarse (250 – 500 µm). Both samples underwent ultrasound-assisted extraction before being analysed via gas chromatography-mass spectrometry (GC-MS) in both full scan and SIM mode, using benzothiazole as a marker. Both samples were also analysed via particle size analysis, scanning electron microscopy (SEM) and …

Northern Fur Ssal Vibrissae Organochlorine Contaminant Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …

Northern Fur Seal Vibrissae Polybrominateddiphenylether Concentrations, Dimitri Giarikos, Amy Hirons, Courtney White

SECLER Data

The eastern Pacific stock of northern fur seals (Callorhinus ursinus) on the Pribilof Islands has experienced population declines since 1980. The decline may be due to anthropogenic persistent organic pollutants (POPs) which bioaccumulate, are toxic, and persistent. This study conducted a comparison of 21 organochlorine (OC) and 39 polybrominated diphenyl ether (PBDE) analyte concentrations utilizing archived vibrissae (whiskers) from individual fur seals sampled in 1993 (n=30) and 2013 (n=41). The PBDEs had values five times greater than the legacy status OCs. There were no significant mean concentration differences between 1993 and 2013 for total organochlorines (ΣOCs), or total …

Development Of A Flow Cytometry Method For The Identification And Enumeration Of Enterococcus Faecalis, Riza Magbitang

Master's Theses

A multi-color flow cytometry method coupled with fluorescent staining was developed to detect and quantify E. faecalis concentrations in coastal waters as an alternative to the traditional membrane filtration method. The developed method was used to characterize E. faecalis during batch growth and yielded consistent results across the various physiological states of the cells. Additionally, the application of propidium iodide (i.e., a viability stain), afforded the method the ability to differentiate between cells with intact and compromised cell membranes, which raises the potential of quantifying cells that are in viable-but-non-culturable (VBNC) state. Initial field test using natural seawater samples spiked …

Assessing The Reactivity Of Amino Acids To Chlorination Using Capillary Electrophoresis, Pedro De Allende

Electronic Theses, Projects, and Dissertations

Amino acids (AA) are ubiquitous in wastewater systems. One of the most popular wastewater treatments is chlorination which is effective at eradicating bacteria and overall treating the wastewater, but it can also produce disinfection by-products (DBPs). Certain DBPs have been classified as Class B Carcinogens to humans and are therefore highly regulated and monitored. Past studies have shown that natural organic matter (NOM), specifically amino acids, can be precursors to DBPs if chlorinated to the correct dose. This thesis project explored AA chlorination's mechanism(s) to understand further which products arise. In particular, the investigation detailed which steps of the mechanism …

Heavy Metals Implications To Sediment Microbiome And Coral Response To Arsenic Dosing, Dimitrios G. Giarikos, Amy Hirons, Jose V. Lopez, Abigail Renegar, Jason Gershman

SECLER Data

No abstract provided.

Modification, Transport, And Sources Of Hydrocarbon Oxidation Products From Groundwater At Crude Oil And Diesel Spill Sites In Minnesota: Unveiling Common “Theems” Via Spectroscopy & Chromatography, Eduardo E. Turcios Valle

LSU New Orleans Theses and Dissertations

In this thesis, petroleum-contaminated groundwater from three spill-affected Minnesota sites—two contaminated with crude oil; one with diesel—is investigated to elucidate whether differences in degradation products from different parent oils exist. After spill events, parent molecules from the leaked oil seep underground and undergo microbial degradation over time, transforming into hydrocarbon oxidation products (HOPs), water-soluble contaminants that infiltrate groundwater aquifers, flowing into nearby environments and towns while exhibiting environmental persistence, toxicity to aquatic biota, and potential risks to humans that become exposed. Spectroscopic and chromatographic study of the structural themes and spatial distributions of HOPs reveals preferential degradation of aliphatic (biolabile) …

Chemical Composition, Fate, And Toxicity Of Dissolved Hydrocarbon Oxidation Products In High Latitude Aquatic Environments, Maxwell Louis Harsha

LSU New Orleans Theses and Dissertations

Oil spilled in aquatic environments undergoes abiotic and biotic oxidation processes that produce hydrocarbon oxidation products (HOPs). HOPs rapidly diffuse in the water column, persisting and readily bioavailable to aquatic organisms. Characterizing HOPs is challenging because most of the mixture resides in the unresolved complex mixture (UCM). Understanding of the formation, fate, and toxicity of HOPs in high latitude environments remains limited. This research addresses these gaps through a comprehensive experimental approach, utilizing various analytical techniques including nonvolatile dissolved organic carbon (NVDOC) analysis, ultrahigh-resolution mass spectrometry, tandem mass spectrometry, inductively coupled plasma mass spectrometry, and fluorescence excitation-emission matrix spectroscopy. Additionally, …

The Surface Chemistry And Binding Interactions Of Lignin With Polymer-Encapsulated Gold Nanoparticles Acting As Model Microplastics, Oluwaseun Ayodeji Akinsola

All Master's Theses

This study investigates the surface chemistry and molecular-level interactions between lignin, a special type of natural organic matter, and polymer-capped gold nanoparticles, shedding light on the strength of adsorption between lignin and nanoscale polymer surfaces. Specifically, the study presents a variety of nanoscale polymer surfaces displaying different charged functional groups, using layer-by-layer assembly of three polyelectrolytes (polyallylamine hydrochloride (PAH)), polyacrylic acid (PAA), and poly(diallyldimethylammonium chloride (PDADMAC)) on 90 nm citrate-stabilized gold nanoparticles (AuNPs). This approach provides a library of polymer-encapsulated AuNPs for investigating the binding interactions of lignin to nanoscale polymers via spectroscopic techniques. ζ-potential, dynamic light scattering (DLS), …