Analytical Chemistry Commons^™

Molecular Characterization Of Humic And Fulvic Acids On Watterlogged And Well-Drained Amazonian Podzols, Amanda M. Tadini, Aleksandar I. Goranov, Stéphane Mounier, Débora M.B.P. Milori, Célia R. Montes, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

The Amazon rainforest is the largest tropical rainforest in the world. Amazonian Podzol soils, characteristic of this region, are known to store substantial amounts of organic carbon in both their surface and deep horizons. Despite decades of research, the molecular-level composition of these soils remains uncharacterized. This study addresses this knowledge gap by employing ultrahigh resolution mass spectrometry, namely, Fourier transform–ion cyclotron resonance–mass spectrometry (FT-ICR-MS), to determine the molecular composition of humic acid (HA) and fulvic acid (FA) fractions from two Amazonian Podzol profiles of varying levels of groundwater exposure (waterlogged vs well-drained). In the waterlogged soil compounds containing nitrogen, …

Near-Infrared Fluorescent Cyanine Probes For Monitoring Nad(P)H Dynamics In Living Cells And Drosophila Larvae, May Waters

Dissertations, Master's Theses and Master's Reports

Nicotinamide adenine dinucleotide (NAD+/NADH) plays a critical role in cellular metabolism, with abnormally elevated NADH levels linked to disrupted metabolic processes and cancer. In this study, we developed near-infrared fluorescent probes to selectively measure NADH concentrations. We present five cyanine-based probes, which were optimized by modifying the connection bridges to fine tune electronics. Two NAD(P)H-biosensing probes consisting of 1,3,3-trimethyl-3H-indolium and 3-quinolinium acceptors, linked by thiophene, A, and 3,4-ethylenedioxythiophene, B, bridges are detailed. They exhibit near-infrared fluorescence at 742.1 nm and 727.2 nm for probes A and B, respectively, and generate absorbance signals at 690.6 nm and 685.9 nm. Probe A …

Development Of Fast And Comprehensive Approaches For Gunshot Residue Interpretation Using Ambient Ionization, Mass Spectrometry, And Microparticle Sampling Studies, Thomas Dimmey Ledergerber

Graduate Theses, Dissertations, and Problem Reports (ETD)

The information derived from the forensic examination of gunshot residue (GSR) can be critical during the investigative and trial stages in the criminal justice system. However, the complexity of the GSR deposition, transfer, and persistence mechanisms calls for meticulous handling and identification processes. Novel advances in evidence interpretation and analysis via instrumental methods are current areas of growing interest that must be pushed along the chain from research to practice in a timely manner. Therefore, this research focuses on developing both rapid and comprehensive methods for detecting gunshot residue evidence and effectively communicating its significance to the investigators or trier …

Unraveling The Reactivity Of Nitrate Ester Explosives: Insights From Femtosecond Time-Resolved Mass Spectrometry And Computational Chemistry, Erica Britt

Theses and Dissertations

This dissertation uncovers the ultrafast molecular mechanisms underlying the decomposition of nitrate ester explosives—nitroglycerin (NG), ethylene glycol dinitrate (EGDN), and amyl nitrate—through the integration of femtosecond time-resolved mass spectrometry and advanced computational chemistry. Although these compounds play fundamental roles in both military and civilian contexts, the precise molecular dynamics governing their pronounced reactivity and impact sensitivity have remained inadequately characterized. Our research establishes that low O–NO2 bond dissociation energies are the primary driver of ultrafast fragmentation and high reactivity in all three esters. The distinctive molecular architectures of these esters dictate their explosive properties: NG’s tri-nitrate configuration leads to exceptional …

Chromatographic And Electrophoretic Analysis Of Lignin-Derived Monomers And Dimers: Extraction Method Development And Evaluation Of Cyclodextrins For Recovery, Anjam Sadik

Theses and Dissertations--Chemistry

Biorefineries play a vital role in reducing dependence on fossil fuels and addressing global warming concerns. Unfortunately, investment in biorefineries remains limited due to economic sustainability concerns. One approach to enhance the economic viability of biorefineries is by fully utilizing the potential of feedstocks, particularly lignocellulosic biomass, which is commonly used in these processes. Traditional processing methods often alter the lignin portion of biomass, making it unsuitable for further utilization. However, when retained in its native form, lignin can serve as a valuable source of chemicals that contribute to the economic sustainability of biorefineries.

The lignin-first approach, which removes lignin …

Insights Into Factors Influencing Radical Coupling Chemistry Of Monolignols During Lignification And Induced Changes In Plant Secondary Metabolism, Rachel Poornima Sutherland

Theses and Dissertations--Chemistry

Lignin is a complex aromatic biopolymer and an important constituent in plant cell walls. The process of lignin biosynthesis, known as lignification, is poorly understood and challenging to study but has important implications in a variety of fields including sustainable energy, bioengineering, and materials science and is therefore of interest to pursue. In the final stage of lignification, H-, G-, and S-monolignols are oxidized by laccase and peroxidase enzymes to generate radical species that couple to form dimers and further oligomeric species to ultimately produce the lignin polymer. Biomimetic lignin model systems utilize in vitro oxidative coupling reactions as an …

Targeted Mitigation Strategies To Reduce Secondary Emissions In Co2 Capture Systems, Keemia Abad

Theses and Dissertations--Chemistry

Global CO₂ emissions from industrial, power generation and transportation sources has led to the call for increased implementation of carbon capture strategies. The most developed of these is point source carbon capture, which refers to the process of capturing CO₂ directly from large (point) source emitters, before the CO₂ is released into the atmosphere. The challenge becomes separating CO₂ from the other components of the emitted gas, mainly nitrogen. These CO₂ capture processes typically involve the use of aqueous solutions of amines to absorb (capture) CO₂ from the gas stream, where the CO₂ and the …

Design, Synthesis, And Evaluation Of Di-Peptide Probes For Stoichiometric Quantitative Analysis Of Antibodies, Taylor Gladson

Graduate Research Theses & Dissertations

Quantitative information on biomarkers is a decisive factor in a wide range of situations concerning individual and public well-being. Under certain circumstances, the availability of accurate quantitative information can even become a matter of life or death. Therefore, the ability to make quantitative measurements in point-of-care (POC), do-it-yourself (DIY), and limited resource settings (LRS) is crucial for diagnostics, disease management, food safety, biomedical research, forensics, and other areas.In the work, we develop a POC/DIY/LRS-compatible platform for unambiguous (yes/no type) quantitative analysis of antibodies. The heart of the approach is negative cooperativity-based target – probe binding. The binding modality yields a …

Gas–Phase Studies Of C–H Activation And Dehydrogenation Of Liquid Organic Hydrogen Carrier Model Compounds, Robert S. King

Graduate Research Theses & Dissertations

In the transport of hydrogen, cryogenic methods are often utilized; however, this method is high in energy cost and not sufficiently safe in terms of release prevention. Liquid organic hydrogen carriers (LOHCs) are one of the many methods being developed for a robust and safe hydrogen energy infrastructure. One aspect of LOHCs with a rich research field as of late is dehydrogenation techniques to liberate stored hydrogen gas for energy consumption. This process currently requires excessive cost (environmental and monetary), specialty catalysts using expensive metals like palladium for the selective dehydrogenation without coking of the catalyst surface. In search for …

Catalytic Innovation For Sustainable Styrene Production: Green Chemistry Strategies Utilizing Octahedral Ruthenium (Ii) Complexes Supported By A Single Bipyridine Ligand, Kennedy G. Musso, Brandon Quillian, Clifford Padgett, Jose Jimenez

College of Graduate Studies: Theses & Dissertations

This study investigates: 1) the synthesis and reactivity of the mono- substituted systems, [κ²-(t-bipy)Ru(NCMe)2(Ph)(PR3)][BArF'] supported by different ancillary ligands PR3 = (P(OCH3)3 and P(CH3)3) and a single bidentate ligand, 4,4′-di-tert-butyl-2,2′-bipyridine (t-bipy), and 2) UV/heat formation of di-PR3 and tri-PR3 systems supported by a single bidentate ligand to better understand the mechanism of styrene production. Utilizing [(η6-p-cymene)RuI(µ-I)]2 (1), the complexes (η6-p-cymene)RuI2(P(OCH3)3) (2) and (η6-p-cymene)RuI2(P(CH3)3) (3) were synthesized and phenylated to produce (η6-p-cymene)RuI(Ph)(PR3) (6; PR3 = P(OCH3)3 and 7; PR3 = P(CH3)3). Complex 4, (η6-p-cymene)RuCl2(P(CH3)3), was also synthesized and phenylated to produce (η6-p-cymene)RuClPh(P(CH3)3) (5) to understand the impact of chloride versus iodine …

Identification Of Fentanyl And Fentanyl Analogs Found In Human Urine Using Gas Chromatography-Mass Spectrometry, Adam M. Fisher

Electronic Theses & Dissertations (2024 - present)

Identification of fentanyl and its analogs in unknown samples is a frequent practice completed in forensic crime labs, as the fentanyl epidemic continues. With the continued increase in illicit drug use, crime labs are not able to keep up with the flooding of new fentanyl analogs being developed, resulting in new analogs slipping past the crime labs’ authority. This research is to start to develop a database of commonly found fentanyl analogs in New York State. Gas Chromatography-Mass Spectrometry (GC-MS) is a widely used method for the detection and identification of illicit drugs in forensic crime labs. A database that …

3d Printed Microfluidic Platforms For Elisa-Based Diagnostics: Advancing Toward Point Of Care, Brandi Marie Binkley

Graduate Theses, Dissertations, and Problem Reports (ETD)

Protein biomarker detection is a critical analytical method for quantifying proteins in biological samples. It is relevant not only in medical diagnostics and research but also numerous other fields such as environmental monitoring, pharmacology, food safety, and biotechnology. Sensitive detection at picogram-per-milliliter (pg/mL) levels is essential for diagnosing diseases, monitoring progression, and tailoring treatments, especially for low-abundance biomarkers like troponin, interleukin 6, carcinoembryonic antigen (CEA), activin A, and vascular endothelial growth factor (VEGF). Immunoassays, particularly enzyme-linked immunosorbent assays (ELISAs), are the gold standard for protein biomarker detection due to their high specificity and sensitivity. The development of point-of-care (POC) diagnostic …

Expanding The Vibrating Sharp-Edge Spray Ionization Toolkit For Oligonucleotide Characterization, Sultan Mahmud

Graduate Theses, Dissertations, and Problem Reports (ETD)

A gentle or soft Ionization process is a critical component in native mass spectrometry (MS) to lift the biomolecules from the bulk solution into the gas phase environment of the mass spectrometer preserving their shape, topology and non-covalent interactions. Electrospray ionization (ESI) facilitates structural preservation of proteins, nucleic acids and their complexes and as a result it has been extensively used in native MS. However, in negative ion mode, ESI is somewhat limited in sensitivity due to corona discharge effect resulting from the requirement of a high amount of voltage. This often disrupts the ESI process and may not preserve …

Development And Applications Of Capillary Vibrating Sharp-Edge Spray Ionization Coupled With Atmospheric Pressure Chemical Ionization (Cvssi-Apci), Madison Elizabeth Pursell

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mass spectrometry (MS) is a technique that is used in fields in which both complex and non-complex mixtures are analyzed. The state-of-the-art ion sources that are utilized for MS are being demonstrated to be functional for direct infusion of samples as well as for use with online separations. However, ion sources, such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) can encounter problems such as ion suppression and an inability to ionize based on size and/or polarity, respectively. Further these sources are bulky and require gas flow, heat sources, and additional high voltage power supplies for optimal performance. …

Towards Developing Glut2 Specific Probes For Biochemical And Biomedical Applications, Abdelrahman Ismail

Dissertations, Master's Theses and Master's Reports

Facilitated Glucose transporters (GLUTs) are membrane proteins responsible for the uptake of simple sugars and other structurally similar metabolites in all mammalian cells. One of the hallmarks of cancer is dysfunctional sugar metabolism, known as the Warburg effect, and one of the manifestations of that effect is abnormal GLUT expression. There are 14 known GLUT proteins with different expression patterns in different tissues, and tumors tend to express certain GLUTs that are not present in surrounding healthy tissue. Therefore, selective targeting of GLUTs presents a potentially powerful tool for diagnostics and treatment of cancer and other diseases. This has been …

Microwave Assisted Syntheses And Characterizations Of Near-Infrared Ratiometric Probes For Mitochondrial Ph Detection And Monitoring, Ronald J. Schwandt

Dissertations, Master's Theses and Master's Reports

Within the field of biochemistry, there has been a significant development of ratiometric fluorescent probes designed for mitochondrial pH detection; however, many of these probes have emissions within the visible spectrum and require long synthesis times with low-yield reactions. However, in recent years, microwave-assisted syntheses of organic molecules have led to significant increases in reaction yields and quicker reaction times. In this work, two common reactions in probe synthesis, Heck coupling, and Knoevenagel condensations are investigated using microwave-assisted synthesis. It was found the low-concentration Heck coupling reactions using palladium (II) acetate led to extremely efficient Heck coupling. Also, a novel …

Development Of Near-Infrared Probe For The Detection Of Nadh And Nad(P)H In Live Cells And D. Melanogaster Larvae, Sophia J. Jaeger

Dissertations, Master's Theses and Master's Reports

A near-infrared fluorescent probe, A, was designed by substituting the carbonyl group of the coumarin dye’s lactone with a 4-cyano-1-methylpyridinium methylene group and then attaching an electron-withdrawing NADH-sensing methylquinolinium acceptor via a vinyl bond linkage to the coumarin dye at the 4-position. The probe exhibits primary absorption maxima at 603, 428, and 361 nm, and fluoresces weakly at 703 nm. The addition of NAD(P)H results in a significant blue shift in the fluorescence peak from 703 to 670 nm, accompanied an increase in fluorescence intensity. This spectral shift is attributed to the transformation of A−π–A−π–D configuration to D−π–A−π–D pyridinium platform …

Contributions To Journal Of Electrochemistry, The Flagship Journal Of Chinese Chemical Society Electrochemical Committee, Will Be Listed As A New Recommendation Policy For China Youth Awards Of Electrochemist, Editorial Office Of J.Electrochem.

Journal of Electrochemistry

No abstract provided.

Intrinsic Gas-Phase Behavior Of Uranium Species: A Comprehensive Reactivity Study Of [O=U≡Ch]+ And [Uh]+, Justin Terhorst

Electronic Theses and Dissertations

The intrinsic chemistry of actinide elements, particularly uranium, remains a key challenge in understanding f-block reactivity due to the complexity introduced by solvent interactions, counter-ions, and complex equilibria in the condensed phase. In this dissertation, a systematic gas-phase study utilizing preparative tandem ion-trap mass spectrometry (PTMSⁿ) is presented, focusing on the reactivity of uranium-centered species, specifically [OUCH]⁺, an oxy uranium methylidyne species, and [UH]⁺ ions. By stripping away solvent effects and isolating the ions, PTMSⁿ provides a powerful platform to probe the fundamental chemical behavior of uranium species in their intrinsic state.

The …

An In-Depth Analysis And Comparison Of Eco And Non-Eco Surfboard Waxes, Markos Kaskaneas - Efthymiou

The Plymouth Student Scientist

Questions regarding the sustainability of petroleum-based surfboard waxes gave rise to the development and marketing of a sustainable alternative called “Eco” surf wax. The chemistry behind surf waxes is generally unknown and there is no published research on the area of surf waxes. In this analysis, the chemical properties of both types of waxes were investigated, to determine the difference between non-eco and eco waxes and between different water temperature rating waxes. 15 surf wax samples (10 non-eco, 5 eco) were extracted into organic and inorganic fractions and analysed by FT-IR, GC-MS, and HTGC-FID/MS. Multivariate statistical analysis was also performed. …