Analytical Chemistry Commons^™

Advances In Structure Elucidation Of Small Molecules And Peptides By Nuclear Magnetic Resonance Spectroscopy And Mass Spectrometry, Ryan D. Cohen

Seton Hall University Dissertations and Theses (ETDs)

This dissertation reports on improvements in nuclear magnetic resonance (NMR) and mass spectrometry (MS) structure determination methods of organic compounds, with particular focus on challenging cyclic peptides. A recent and important innovation in NMR spectroscopy is the combination of theoretical property predictions, such as chemical shifts, using density functional theory (DFT) to aid in challenging NMR structure assignments, such as determination of regio- and stereo-configurations. In the first part of this thesis, a comprehensive benchmark study of DFT chemical shift prediction methods was performed using experimental NMR data collected from 50 well curated compounds, which was referred to as the …

Surface Characterization Of Mixed-Mode Adsorbents Using Bet C-Constant Energy Scale, Dinah C. Lee

Seton Hall University Dissertations and Theses (ETDs)

Mixed-mode chromatography is a chromatographic method in which solutes interact with stationary phase through more than one interaction mode or mechanism. It is because of these multiple complex interactions, which makes it difficult to predict chromatographic behavior of analytes on Mixed-mode columns. In order to fully understand the retention mechanisms on Mixed-mode columns, the packing material properties must be well characterized since each characteristic may contribute to the overall chromatographic performance of the column. Many non-chromatographic and chromatographic techniques are available to characterize and compare Mixed-mode columns in terms of their interaction abilities, retentivity, surface chemistry, chemical properties and geometry. …

Extending The Application Of Polyol-Induced Extraction For The Analysis Of Glucocorticoids And Nsaids In Water Using Uhplc-Ms/Ms, Shipra Patel

Seton Hall University Dissertations and Theses (ETDs)

Polyol induced extraction (PIE) is an extraction technique developed and patented by Sowa Jr., Murphy, and Deshpande at Seton Hall University as a method of removal of water from acetonitrile. PIE is a technique that separates water from a mixture containing an organic liquid and water by adding a polyol to the mixture that leads to phase separation of aqueous and organic phase. The goal of this work was to extend the application of PIE and to demonstrate that PIE can be an alternative method for extraction of glucocorticoids and non-steroidal anti-inflammatory drugs (NSAIDS) which then can be analyzed using …

Using Thermodynamics To Evaluate Stationary Phase Polarity In Gas Chromatography- A New Look, Hetal R. Rana

Seton Hall University Dissertations and Theses (ETDs)

Abstract

Gas chromatography is a separation method in which the components of a sample partition between a gaseous mobile phase (carrier gas) and a solid or liquid stationary phase. The stationary phase is usually a polymer coated or chemically bonded to a solid support on the column wall and its function is to separate different components, based on their relative vapor pressure and their intermolecular interactions with the stationary phase. If the analyte polarity is similar to the stationary phase polarity, then the retention time increases because the intermolecular interactions are stronger and if the polarities are different then the …

Surface Chemistry And Surface Properties Of Energetic Nitrocellulose (Nc), Henry Grau

Seton Hall University Dissertations and Theses (ETDs)

This research describes an investigation into the wettability of nitrocellulose (NC), most importantly to nitroglycerin (NG), which are key components of formulations used to propel military ammunition. NG demonstrates complete wetting of NC and, overtime, NG sweats on the NC surface and leaks out. The leaking out of NG from the solid formulation is a known cause of fires and explosions resulting from storage. The origin of this research is inspired by the need to engineer a solution to leakage problems of energetic plasticizer in NC based propellant. While searching for a viable material for a specific application, we journeyed …

Performance Of Nitrogen As A Carrier Gas In Capillary Gas Chromatography Using A Thin Film Column, Brittany A. Handzo

Seton Hall University Dissertations and Theses (ETDs)

Gas chromatography (GC) is one of the most widely used analytical techniques for the separation and analysis of volatile compounds. Solids, liquids, and gases, organic and inorganic materials, and large molecular weight compounds can all be analyzed via this technique. Gas chromatographic separations are fast, accurate, and reliable. One of the reasons why these separations are so efficient is because of the carrier gas. The purpose of the carrier gas is to carry the injected sample through the column. It is known as the mobile phase and does not interact chemically with the sample. Common carrier gases include helium, hydrogen, …

Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji

Seton Hall University Dissertations and Theses (ETDs)

Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …

Determination Of Polar Solvents By Static Headspace Extraction – Gas Chromatography (She-Gc), Michael Sithersingh

Seton Hall University Dissertations and Theses (ETDs)

ABSTRACT

The term “headspace” is defined as the vapor that forms above or around a liquid or solid sample in a closed container. Usually, the vapor is above the liquid or solid at the top of the container, hence the term headspace. Headspace sampling is a method for separating volatile materials that may be extracted from a more solid sample matrix and then analyzed using gas chromatography. Headspace extraction refers to the collection and analysis of the vapor phase in the container. The Static Headspace Extraction – Gas Chromatography (SHE-GC) technique has been used since the early days of Gas …

The Effects Of Cold Plasma Treatment On Sweet Basil (Ocimum Basilicum), Sauvelson Auguste

Seton Hall University Dissertations and Theses (ETDs)

The study discussed herein looks both to continue and to expand upon previous work conducted here at Seton Hall University, which investigated the effect of cold plasma processing on sweet basil and their essential oils. It was found that the application of cold plasma treatment increases plant growth and eugenol concentration, which is an essential oil component and one of the potential natural antioxidants used in food preservation. In this study, we considered methods for increasing the production and harvesting of plants that produce essential oils such as sweet basil (Ocimum basilicum). The study also incorporated more controls …

Assessment Of The Viability Of Microwell Plates As Sample Holders For Analytical Excitation-Emission Spectroscopy Of Polyaromatic Hydrocarbons In 75% Ethanol, Lauren M. Ridley-Hoffman

Seton Hall University Dissertations and Theses (ETDs)

Polyaromatic hydrocarbons (PAHs) in the environment are a significant concern as many compounds in this class are potential carcinogens. PAHs resulting from petroleum spills can contaminate natural waters and the products obtain from them (fish and fish products in particular). Previous studies by Pena, et. al. on ethanolic extracts of organs from menhaden captured in the vicinity of the Deepwater Horizon (Macondo oil well) spill have shown that fluorescence excitation spectroscopy is a useful technique for detecting the presence of PAH metabolites and fluorescent vitamins. The study has also concluded that previous methods for analyzing PAHs using fluorescence spectroscopy used …

Assessment Of Energetic Heterogeneity Of Reversed-Phase Surfaces Using Excess Adsorption Isotherms For Hplc Column Characterization, Leih-Shan Yeung

Seton Hall University Dissertations and Theses (ETDs)

This research is to explore a more general column categorization method using the test attributes in alignment with the common mobile phase components. As we know, the primary driving force for solute retention on a reversed-phase surface is hydrophobic interaction, thus hydrophobicity of the column will directly affect the analyte retention. This research describes a method to determine the column hydrophobicity by the ratio of adsorbed acetonitrile and methanol to water on the column surface using excess adsorption isotherm estimation. An excess adsorption isotherm for a binary mobile phase system represents a competitive interaction of both solvent components with the …

Apparent Retention Volume Variation With Flow Rate Change In High Performance Liquid Chromatography, Susanne Buntz Erz

Seton Hall University Dissertations and Theses (ETDs)

Recent studies have demonstrated noticeable flow rate dependency of the chromatographic zone retention volume with respect to migration within the empty capillary. This appears to be the result of superposition of asymmetric lateral diffusion and of the laminar flow profile. Although these effects have been studied on empty capillaries, in the presence of the packed column, the retention shift may be insignificant relative to the adsorption-based retention of the analytes. In the case of fast and ultrafast HPLC with short capillary columns, the effect of extra-column caused variation in the analyte retention may constitute an increase of up to 120 …

Study Of Selectivity In Extraction, Separation, And Detection On Drugs Using Gas Chromatography, Anumeha P. Muthal

Seton Hall University Dissertations and Theses (ETDs)

The selectivity of a method is defined by its ability to determine a particular analyte without interference in a complex mixture. Selectivity in gas chromatography (GC) can be obtained at different points in the analysis including the sample preparation, sample introduction, separation on column and detection. In GC, the first dimension of selectivity can be obtained in sample preparation; the second dimension in chromatographic separation and the third dimension in detection. This research focuses on the relationships between selectivity in these different dimensions, studied using some non-steroidal anti-inflammatory drugs, glucocorticoids, fatty acid methyl esters and polycyclic aromatic hydrocarbons. Recent methodologies …

Polyol Induced Partitioning Of Essential Oils In Aqueous Organic Solvent Mixtures, Thomas Delmastro

Seton Hall University Dissertations and Theses (ETDs)

Polyol Induced Extraction (PIE) was developed and patented at Seton Hall University by Drs. John R. Sowa Jr., Wyatt R. Murphy, and Mithilesh Deshpande. It was originally discovered and implemented as a method to recycle and reuse waste acetonitrile during the production shortage in 2008. Through the use of PIE, a solvent mixture containing acetonitrile and water can be separated by employing a polyol mass separating agent, which induces a phase separation. The system is separated into its corresponding aqueous and organic phases, with the organic phase being a highly purified organic liquid. Based on the successful experimental results that …

Application Of An Ionic Liquid Column To The Analysis Of Flavor And Fragrance Ingredients, Nicole L. Curto

Seton Hall University Dissertations and Theses (ETDs)

Traditional, polar (polyethylene glycol/wax) stationary phase gas chromatography columns pose challenges for flavor and fragrance analysis particularly in regards to thermal instability at high temperatures, degradation when exposed to water, unchanging selectivity, and relatively short shelf lives. Recently, capillary columns using ionic liquids as stationary phases have become available. Ionic liquid columns offer a potential combination of high polarity and high temperature stability with unique selectivity. An in depth discussion about the history and development of column phase characterization, with specific emphasis on selectivity and polarity, will allow for a critical look at the polarity scale currently employed to characterize …

Fluorinated Metallo Phthalocyanines For Chemical And Biological Catalysis, Hemantbhai H. Patel

Seton Hall University Dissertations and Theses (ETDs)

The rational design of robust oxidation catalysts based on organic molecules is hindered by the presence of labile C-H bonds. We have shown recently that replacing all C-H bonds by a combination of fluoro- and perfluoro-groups in a bioinspired Cytochrome P450 model based on a phthalocyanine, Pc, scaffold results in a stable yet reactive oxidation catalyst. The Pc cobalt complex catalyzes, for example, the aerobic oxidation of thiols to disulfides, a reaction of both biological significance and industrial importance.

The presence of robust C-F bonds, however, renders the catalyst unsuitable for attachment to solid-state supports, except via van der Waals …

Applications Of Green Chemistry In Asymmetric Transfer Hydrogenation And Chiral Separations, Ruoqiu Wu

Seton Hall University Dissertations and Theses (ETDs)

Green chemistry has been applied to all aspects of the life cycle of chemically related products, including design, usage, manufacturing, analysis, and disposal. In this thesis, I focus on the green chemistry applications in organic synthesis and analytical chemistry. More specifically, allylic and chiral alcohols are abundant in natural sources such as in essential oils, and widely utilized as starting materials. They are also major components in food, fragrance, biocides and the pharmaceutical compounds. In this thesis, I report the first Ru-catalysed asymmetric transfer hydrogenation (ATH) of prochiral allylic alcohols. This reaction provides chiral secondary alcohols in excellent enantioselectivities and …

Quechers (Quick, Easy, Cheap, Effective, Rugged, And Safe) Extraction – Gas Chromatography For The Analysis Of Drugs, Michelle L. Schmidt

Seton Hall University Dissertations and Theses (ETDs)

QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) is an extraction technique developed by Anastassiades and co-workers initially for the extraction of veterinary drugs from animal tissue. Since its inception, it was discovered that this method is particularly adept for the extraction of polar and basic compounds, thus the majority of research previously performed using QuEChERS involves the extraction of pesticides from various matrices, especially fruits, vegetables, and other food products. Combining a liquid-liquid extraction (LLE) and a dispersive solid phase extraction (d-SPE) clean up, QuEChERS provides a clean sample for analysis by gas chromatography (GC) or liquid chromatography (LC) …

Monitoring Dissolution Of Nonsteroidal Anti-Inflammatory Drugs Using Infrared Spectroscopy, Julianne Berger

Seton Hall University Dissertations and Theses (ETDs)

A comparison study was conducted to look at the formulation of three brands of naproxen sodium. These brands included Bayer Aleve ®, CVS All Day Pain Relief and Walgreens All Day Pain Relief. The active and inactive ingredients were the same yet the size and shape of the tablets differ among the three brands. S-naproxen was extracted from the tablets and evaluated by GC-MS to determine the purity of naproxen in the tablets. Dissolution was monitored by an IR probe for eight hours while using 0.1M phosphate buffer pH 7.4, 0.05M phosphate buffer pH 4.5 and simulated gastric fluid pH …

Polycyclic Aromatic Hydrocarbon Determination In Liver Of Menhaden Exposed To The Deep Water Horizon Oil Spill, Rebecca Hawke

Seton Hall University Dissertations and Theses (ETDs)

The April 2010 BP® oil spill has caused great concern for ecological impacts in the Gulf of Mexico. Crude oil contains polycyclic aromatic hydrocarbon (PAHs) and oil spills increase the exposure of aquatic organisms to this class of chemicals. The overall detrimental health effects associated with PAH exposure depend on the exposure period, the concentration of PAHs, and the toxicity of the PAHs in the mixture. Brevoortia tyrannus and Brevoortia patronus are filter feeding fish commonly known as menhaden and account for over 40% of the commercial industry fisheries catch. As primary consumers, they are a major link in the …

Extending The Limits Of Solid Phase Microextraction, Shilpi Chopra

Seton Hall University Dissertations and Theses (ETDs)

Solid phase microextraction (SPME) is a solventless extraction technique that combines sample preparation and sample introduction into a gas chromatograph into a single step. For the past 20 years, solid-phase micro-extraction (SPME) has been used in numerous fields such as: food analysis, including juices, alcohols fruits and vegetables for volatiles, aroma, caffeine, fatty esters, environmental applications including volatile organic contaminants, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenols, pesticides, steroids, herbicides, acid/neutral/base compounds, and organometallic compounds from water, air, soil, sludge, and sediment samples and in biomedical analysis.

This work demonstrates the extension of the limitations of SPME with respect to extraction …

Ionic Liquids In Micro Extractions And Gas Chromatographic Stationary Phases, Ramkumar Dhandapani

Seton Hall University Dissertations and Theses (ETDs)

Ionic liquids are salts that exist entirely as ionic species. They are composed of cation, anion and side chain or linkage group. Due to the different combination of the these groups, the ionic liquid exhibits unique selectivity. Their applications are enormous in the field of analytical chemistry.

The interest of using ionic liquids as gas chromatographic stationary phase has increased in recent years. The low volatility, tailorable physico-chemical property and high thermal stability of ionic liquids make them an ideal choice for gas chromatographic stationary phase. For the present research, commercially available ionic liquid capillary columns were investigate for thermodynamics …

Polymers For Dna Binding, Sue Yuan Li

Seton Hall University Dissertations and Theses (ETDs)

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Chemical Analysis Of Ophthalmic Solutions, Pagagiotis Tavlarakis

Seton Hall University Dissertations and Theses (ETDs)

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Synthesis, Modification, And Characterization Of Spherical Sba-15 Ordered Mesoporous Silica And Evaluation In High Performance Liquid Chromatography, Alexander P. Giaquinto

Seton Hall University Dissertations and Theses (ETDs)

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Analysis Of Street Drugs Using Comprehensive Two Dimensional Gas Chromatography Coupled With Time Of Flight Mass-Spectrometry, Brian B. Barnes

Seton Hall University Dissertations and Theses (ETDs)

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Influence Of Ionic Mobile Phase Additives With Low Charge Delocation On The Retention Of Ionic Analytes In Reversed Phase Hplc, Cesar Florez

Seton Hall University Dissertations and Theses (ETDs)

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Adsorbents With Chemically Bonded Saccharide Surfaces: Synthesis And Application For Stereoisomer Separation And The Synthesis Of Chiral Porous Silicas Using Templates Chiral Surfactant, Edwin Vega

Seton Hall University Dissertations and Theses (ETDs)

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The Effect Of Adsorbent Geometry And Surface Chemistry On Hplc Retention, Zhaoxia Liu

Seton Hall University Dissertations and Theses (ETDs)

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The Biophysical Analysis Of The Human Telomeric Repeat (Ttaggg)4 And Characterization Of Porphyrin Binding In Potassium Solutions, Cosimo Antonacci

Seton Hall University Dissertations and Theses (ETDs)

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