Analytical Chemistry Commons^™

Analysis Of Terpenes In Cannabis Flowers Using Gas Chromatography Via Headspace-Solid Phase Microextraction (Hs-Spme), Hannah I. Bergner

Forensic Science Master's Projects

As cannabis commercialization grows, rigorous profiling of cannabinoids, terpenes, and chemical contaminants is legally required for industry standardization and consumer safety. Terpenes are highly volatile components that dictate the unique aromatic profiles and therapeutic properties of cannabis via receptor pathways. This project focused on a gas chromatography-flame ionization detector/mass selective detector (GC-FID/MSD) combined with headspace-solid phase microextraction (HS-SPME) sampling to analyze terpenes present in four cannabis samples. Cannabis samples were tightly sealed in vials (10 mL) and heated to vaporize terpenes in the headspace above the samples, followed by the extraction of the vaporized terpenes using a polydimethylsiloxane (PDMS)-coated SPME …

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 …

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 …

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 …

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. …

Impaired Waters: New Treatments And Improved Methods For Pfas And Algae Toxins, Alexandria Forster

Theses and Dissertations

Per- and polyfluoroalkyl substances (PFAS) are high-profile environmental contaminants, many having long persistence in the environment and widespread presence in humans and wildlife. Following phase-out of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in North America and restrictions in Europe, PFAS replacements are now widely found in the environment. While liquid chromatography (LC)-mass spectrometry (MS) is typically used for measurement, much of the PFAS is missed. To more comprehensively capture organic fluorine, we developed sensitive and robust methods using activated carbon adsorption, solid phase extraction, and combustion ion chromatography (CIC) to measure total organic fluorine (TOF) in industrial wastewaters, river …

Making And Breaking Bonds: Studying Intrinsic Chemistry In The Gas-Phase, Luke Metzler

Electronic Theses and Dissertations

The nature of chemical interactions can be difficult to ascertain in the condensed phase; chemistry can be observed, but with the plethora of variables such as solvation, mixes of counter-ions, and complex equilibria, the true intrinsic chemical properties of a given chemical species may be obfuscated. By conducting research in the gas-phase, many of these variables can be reduced, if not eliminated entirely, which can allow for the careful observation of the true physical phenomena driving chemical reactivity.

The research presented herein focuses on the use of ion-trapping (specifically in a linear ion trap) as a method for unveiling the …

Investigation Of The Prevalence Of Fentanyl Analogs In A Drug Testing Population Using Liquid Chromatography Tandem Mass Spectrometry (Lc-Ms-Ms), Ivan Cordova

Student Theses

This study serves to determine the prevalence of novel fentanyl analogs that are present within a drug testing population in New York State. Samples were analyzed using liquid chromatography tandem mass spectrometry (LC-MS/MS) to qualitatively determine the presence of various possible fentanyl analogs. The sample preparation of this assay consisted of a simple dilute and shoot. This method of sample preparation can be quicker, eliminating sample preparation times as well as being less financially strenuous to clinical laboratories as it eliminates the need for various solvents and solid/liquid phase cartridges. The assay was aimed to see if analytes can be …

Investigating The Ultrafast Dissociation Dynamics Of Energetic Materials Using Femtosecond Time-Resolved Mass Spectrometry, Jacob M. Shusterman

Theses and Dissertations

Shock initiation of energetic materials produces cations and anions that can contribute to initial endothermic chemical reactions which lead to detonation. Hence, knowledge of the initial dissociation pathways of ionized energetic molecules is important for advancing the understanding of initiation mechanisms and meeting longstanding goals of the Department of Defense. Despite their potential importance, these transient charged species are difficult to detect in detonation experiments and are often ignored in molecular dynamics modeling of shocked energetic materials. However, the technique of pump-probe femtosecond time-resolved mass spectrometry (FTRMS) paired with complementary theoretical calculations can be used to elucidate initial unimolecular dissociation …

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 …

Studies Toward Provenance Determination For Indigo Dyes, Erin Kibby

Undergraduate Honors Thesis Projects

Species of indigo-producing plants have been used to color textiles for thousands of years all over the globe. Natural indigo-producing species have historically been harvested in regions of Asia, North Africa, and North and South America. This study is an exploration of methods that can be used to determine the provenance (origin) of the indigo dye in a textile through the extraction and isolation of indigoids, flavonoids, and other compounds from the natural dyestuff. There is no accepted method of extracting flavonoids from indigo-dyed textiles specifically, and there is little investigation of the regionally different species. If a method is …

Extending Plasma Proteome Coverage To Enable Biomarker Discovery, Jordan Bruce Burton

Wayne State University Dissertations

Two features make plasma a valued source of health information: First, plasma contains secreted proteins from all tissues in the body and can, therefore, provide information about the health status of all tissues. Second, plasma is available in large quantity using a minimally invasive procedure that is well tolerated. The status of plasma as a valued source of health information is matched by the difficulty in extracting proteome information from the samples. Using state of the art instrumentation a standard analysis of plasma yields quantitative information on approximately 300 proteins. Extreme fractionation strategies coupled with increased mass spectrometry time extends …

Mass Spectrometric Analysis Of Lignin Model Compounds: Fundamental Investigations Of Ionization And Supramolecular Interactions For Lignocellulosic Biomass Applications, Kimberly Dean

Theses and Dissertations--Chemistry

Lignocellulosic biomass is pivotal for the development of renewable energy sources and materials essential to mitigate the exploitation of fossil fuels causing climate change and environmental pollution issues. The conversion of biomass into fuel requires the hydrolysis of cellulose and a biproduct of this process is the isolation of millions of tons of lignin as biorefinery waste. Lignin is a complex high molecular weight polymer whose structure remains undefined and critically limits potential industrial applications of lignocellulosic biomass. The advancement of analytical methods for structural elucidation of lignin and its ensemble of phenolic compounds is therefore essential to advance this …

Application Of Mass Spectrometry For Characterization Of Plant-Based Phenolics And Alkaloids, Masoumeh Dorrani

Theses and Dissertations--Chemistry

Plant-derived compounds have the potential to produce value-added compounds with a variety of applications. For example, the lignin part of the lignocellulosic biomass, produced in large quantities as waste from the paper and pulp industries, is a rich source of phenolics with potential applications in the renewable energy sector, pharmaceutical, and chemical industries. On the other hand, plant alkaloids are the primary source for developing plant-derived therapeutics. Unfortunately, the recalcitrant nature of plant cell walls, low extraction yields of small secondary metabolites, and the lack of effective analytical methods for a rapid and accurate identification of plant-based compounds and plant’s …

Rapid Quantitative Analysis Of Toxic Norditerpenoid Alkaloids In Larkspur (Delphinium Spp.) By Flow Injection - Electrospray Ionization – Mass Spectrometry, Dale R. Gardner, Stephen T. Lee, Daniel Cook

Poisonous Plant Research (PPR)

A rapid flow injection - electrospray ionization – mass spectrometry (FI-ESI-MS) method for the quantitative and qualitative analysis of norditerpenoid alkaloids in larkspur plants was developed. The FI-ESI-MS method was calibrated for alkaloid concentrations with larkspur plant samples against an existing Fourier transform infrared spectroscopy FTIR method. There was a strong correlation (r = 0.9926, r = 0.9891) between the FTIR and FI-ESI-MS methods. The relative standard deviation (RSD) for all measurements were ≤ 6.2 % except for the sample with the lowest concentration which was 19%. The sample throughput of the FI-ESI-MS method is much higher than the FTIR …

Comparison Of Supported Liquid Extraction And Solid Phase Extraction Of Methamphetamine From Urine And Method Validation By Gas Chromatography-Mass Spectrometry, Taylor Hood

Master's Theses

Applications of SLE (supported liquid extraction) is a relatively new extraction technique that is not widely used in forensic toxicology. SLE is also easier and less time consuming than traditional LLE (liquid-liquid extraction) and SPE (Solid phase extraction). This work will compare the extraction efficiencies between SLE and SPE for methamphetamine from urine with detection and quantitation using GC-MS (gas chromatography- mass spectrometry). The SLE cartridges provide better analyte recoveries, eliminate emulsion formation, and allow for shorter processing time than other extraction techniques. The SPE cartridges used have a mixed-mode non-polar/strong cation exchange retention mechanism to extract basic analytes like …

Determination Of Molecular Markers Of Vaccinium Berry Standard Reference Materials Through Differential Analysis With Ultrahigh Resolution Lc/Ms, Abby Mikolitis

Dissertations, Master's Theses and Master's Reports

Blueberries and cranberries have vastly different flavor profiles despite both being a part of the Vaccinium genus. Their high content of phenolics makes them subjects of interest in preventative medicine, especially research in illnesses such as heart disease and cancer. Analysis has primarily focused on the identification and characterization of polyphenols, primarily anthocyanins which are a subclass of polyphenols, with ultra-high performance liquid chromatography coupled with electrospray ionization high resolution mass spectrometry (UHPLC-ES/HRMS). This study aims to develop a novel method of non-targeted UHPLC-ES/MS analysis with post processing and formula assignment performed with MZmine 2.53 and MFAssignR software tools. Pairing …

Mass Spectrometry Method Development For The Discovery And Characterization Of Secondary Metabolites, Zachary Kelley

Theses and Dissertations--Chemistry

Secondary metabolites are organic compounds produced by an organism for reasons other than growth and development. In plants, secondary metabolites generally act as defense agents produced to deter predators and inhibit other competitive species. For humans, these compounds can often have a beneficial effect and are pursued and utilized as natural pharmaceuticals. The development of sensitive, high-throughput analytical screening methods for plant derived metabolites is crucial for natural pharmaceutical product discovery and plant metabolomic profiling. Here, metabolomic profiling methods were developed using a microfluidic capillary zone electrophoresis device and evaluated against traditional separation approaches. An alkaloid screening assay was constructed …

Development Of Vibrating Sharp-Edge Spray Ionization (Vssi) Methods For Mass Spectrometry Analysis And Imaging, Nandhini Ranganathan

Graduate Theses, Dissertations, and Problem Reports (ETD)

Mass Spectrometry (MS) is one of the widely used tools for chemical detection down to attomole concentrations for certain proteins. Ionization sources are a critical component for MS analysis. One of the major ionization methods is electrospray ionization (ESI), which remains a gold standard for proteins and peptides. ESI uses voltages up to ~4 kV to produce ions from solubilized molecules. Recently, a novel ionization method termed vibrating sharp-edge spray ionization (VSSI) that nebulizes liquids efficiently at the edge of a vibrating glass slide has been reported. The work in this thesis leverages the capabilities of VSSI for continuous flow-based …

Functionalized Materials From Atom Transfer Radical Processes, Sean Fischer

Electronic Theses and Dissertations

This work is focused on the synthesis, characterization, and application of functionalized materials prepared from atom transfer radical processes. Atom transfer radical processes encompass both atom transfer radical addition (ATRA) and polymerization (ATRP) reactions, both of which are catalyzed by ppm amounts of copper complexes. The synthetic efforts of ATRA include increasing adduct selectivity through optimization of reaction conditions to generate small molecules in high to moderate yields. ATRA provides retention of the halogen moiety, which is an attractive functional group that can be further modified with other transformations. Specifically, the copper-catalyzed azide-alkyne [3+2] cycloaddition (CuAAC) allows for the realization …

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 …

Development Of Methods For The Removal Of Selected Pollutants From Several Matrices And Identification Of Unknown Pollutants Adsorbed Onto Plastics Collected From Freshwater, Kathryn Marie Renyer

Dissertations

Plastic pollution represents one of greatest anthropogenic threats to the environment. Five to ten billion tons of plastic are manufactured every year. Currently, Earth's ecosystem is contaminated with billions of tons of plastic debris, much of which cannot be recycled. Over time, this plastic debris decomposes into small particles. Small plastic particles are known to adsorb toxic compounds in marine environments. My research is concerned with creating novel methods for the detection and quantification of selected persistent organic pollutants from several media. Specifically, I developed methods for the detection and quantification of endosulfan sulfate (ESS) from Lumbricus terrestris tissue and …

Novel Mass Spectrometric Approaches For Deciphering The Epitranscriptomic Code, William D. Mcintyre

Legacy Theses & Dissertations (2009 - 2024)

According to the results of the Human Genome Project, less than 5% of our genome consists of sequences that code for actual proteins. At the same time, however, ~90% of these non-coding sequences are transcribed into a myriad of classes of ribonucleic acids collectively known as ncRNAs, which have been recognized as essential regulatory factors. It has been recently shown that the activity of ncRNAs can be in turn modulated by post-transcriptional modifications (PTMs), covalent marks that can be established/removed by tightly regulated enzymatic pathways. Now, the race is on to understand the new set of controls of cellular functions …

Extreme Molecular Diversity In Biomass Burning Atmospheric Organic Aerosol Observed Through Ultrahigh Resolution Mass Spectrometry, Matthew Brege

Dissertations, Master's Theses and Master's Reports

Ambient atmospheric aerosol is ubiquitous in the atmosphere, originating from a variety of natural and man-made sources. These microscopic particles have profound impacts on the global climate system as well as human health. The organic fraction of atmospheric aerosol is an extremely complex mixture which is not yet fully characterized. These unknown organic aerosol species contribute to the uncertainty in the effect of aerosol on climate and uncertainty in overall ambient aerosol toxicity. Light absorbing organic aerosol can interact with incoming solar radiation and contribute to atmospheric heating; however, the source apportionment and overall fate of these absorbing organic aerosol …

Roaming Transition States And Highly Accurate Thermochemistry: A Pepico Study Of Two Small Combustion Systems, Kyle John Covert

University of the Pacific Theses and Dissertations

Two small combustion systems, methyl hydroperoxide (CH₃OOH) and 2-propanol ((CH₃)₂CHOH), were studied using imaging photoelectron photoion coincidence spectroscopy (iPEPICO), which combines photoelectron spectroscopy and photoionization mass spectrometry to detect coincident photoelectron-photoion pairs. In the photon energy range of 11.4–14.0 eV, energy selected CH₃OOH⁺ ions dissociate into CH₂OOH⁺, HCO⁺, CH₃⁺, and H₃O⁺ ions. The lowest-energy dissociation channel is the formation of the cation of the smallest “QOOH” radical, CH₂OOH⁺. A statistical rate model fitted to the …

Multidimensional Mass Spectrometry Of Chemonic™ Ccg-6 Nonionic Surfactant With Separation By Polarity And Shape, Charles Johnson

Williams Honors College, Honors Research Projects

Chemonic™ CCG-6 surfactant is a water-soluble poly(ethylene glycol) (PEG) conjugated alkyl glyceride emollient. This surfactant exists as a complex mixture of a glycerol cores conjugated with poly(ethylene glycol) branches (PEGylation) that were partially esterified with caprylic (C8) and capric (C10) acids. These may be esterified on one, two, or all three arms of the glyceride. The architecture of the structures in this mixture was studied using multidimensional mass spectrometry (MS). Mass spectrometry was interfaced with ultra-performance liquid chromatography (UPLC) and ion mobility (IM) separation. The mixture was separated by reversed-phase LC, oligomers of the star-branched polymer were separated according to …

Bottom-Up Lignomics: Towards The Development Of Adduct Electrospray Ionization Mass Spectrometric Methods To Characterize And Sequence Lignin Oligomers, Shardrack O. Asare

Theses and Dissertations--Chemistry

Lignin, the second most abundant naturally occurring polymer found in plant cell wall has the potential of becoming an alternative source for the production of chemical synthons for the pharmaceuticals and other chemical industries. While much gain has been made towards the development of degradation methods to break down lignin, effective analytical methods are still required to rapidly and accurately identify the products of lignin breakdown experiments. The goal of this work was to develop mass spectrometric methods for the characterization of lignin oligomers based on the study of model lignin compounds.

Unlike peptides and oligosaccharides, lignin model compounds that …

Investigation Of Thiol-Containing Biomarkers And Their Role In The Exposome, Tracy Gastineau-Stevens

Theses and Dissertations--Chemistry

Exposomics is an emerging area of study that looks at how the environment around a person or persons affects their overall health. Biomarkers have emerged as useful tools to better understand how the exposome affects a person. In this work, we investigate two potential endogenous biomarkers, homocysteine and glutathione that have been previously implicated in a number of diseases that have been linked to environmental causes. We also investigated an environmental exposure, the fungicide Ziram, which epidemiologically has been linked to diseases. In our investigation, we utilized capillary electrophoresis and capillary electrophoresis-mass spectrometry to develop a method for homocysteine and …

Enhanced Analysis Of Lignin Dehydrogenation Oligomers Via Mass Spectrometry, Amber Suzanne Bowman

Theses and Dissertations--Chemistry

Effective analytical techniques need to be developed to characterize the products of lignin degradation experiments to be able to generate renewable products from lignin. Mass spectrometry is an valuable analytical approach for lignin characterizaion, but it is hindered by lignin’s poor ionization efficiency, especially in the positive ion mode. In this work, we attempt to improve lignin’s ionization by utilizing electrospray and laser desorption mass spectrometry coupled with the addition of cations and chemical derivatives. We confronted the ionization problem from both a top-down and bottom-up analytical approach by analyzing synthesized monomers, dimers, and polymers along with natural lignin extracts …

Fatty Acid Biomarker Detection For Breast Cancer Using Differential Mobility Spectrometry With Non-Radioactive Ion Source, James Joseph Alberti

USF Tampa Graduate Theses and Dissertations

Differential Mobility Spectrometry (DMS) using a non-radioactive ion source (NRIS) is investigated as a possible medical diagnostic instrument for near real-time detection of breast cancer biomarkers. In previous clinical studies, concentrations of Linoleic, Palmitic and Stearic fatty acids have been observed at different levels in women with carcinoma breast cancer versus women with benign tumors or healthy women showing no signs of breast cancer. Present diagnostic methods require a biopsy of the suspect tissue and a microscopic lab analysis performed to determine its disease state. This process can take hours or days before the patient and doctor are informed of …