Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 61 for “"Solid phase extraction (SPE)"”.
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Development of a liquid-liquid, solid-phase extraction (SPE), LC-MS/MS analytical method for qualitative and quantitative drug residue analysis in white-tailed deer
… chromatography (LC) coupled to tandem mass spectrometry (MS/MS). In this dissertation, a brief synopsis of the methodology, instrumentation, sample preparation methods and critical parameters for an analytical method validation will be discussed, as well as, the work flow of liquid …
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APPLICATION OF LAYERED DOUBLE HYDROXIDES IN SOLID-PHASE EXTRACTION
In various sample preparation methods, solid-phase extraction (SPE) is one of the most popular techniques. It has been in use for many decades and yet is able to meet new challenges, such as minimization solvent and sorbent specifically and improvement in the work flow of laborious operations. …
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Evaluation of SPEC®•Microcolumns for the extraction of ranitidine from urine
Solid phase extraction (SPE) has become a popular sample preparation method for the extraction of analytes from complex matrices. Solid phase extraction overcomes such disadvantages as large solvent usage and waste, large amounts of time spent in sample preparation and labor intensive methods with …
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Detection of per- and polyfluoroalkyl substances in biosolids from wastewater treatment plants
… substances (PFASs), with unique and special surfactant activities and chemical properties, are widely used in a variety of industrial and consumer products. The worldwide distribution and ubiquitous presence of these substances has aroused research interests and concerns all over the …
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The characterization of silica-based sorbents in reversed phase liquid chromatography with application to method development in solid-phase extraction
Despite the wide application of solid-phase extraction (SPE) in the environmental, clinical and pharmaceutical fields, method development for this technique has remained largely an empirical process of trial and error. In an effort to provide a systematic approach to method development, the kinetic …
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The Analysis of Flavor Compounds in Green Tea Using Ice Concentration Linked with Extractive Stirrer (Icecles)
… difficult steps in this type of analysis. Many extraction techniques have been used for this purpose, such as liquid-liquid extraction (LLE), accelerated solvent extraction (ASE), microwave-assisted extraction (MAE), solid-phase extraction (SPE), solid-phase microextraction (SPME), and stir bar …
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Photochemistry of Polycyclic Aromatic Hydrocarbons with Environmentally Relevant Metals
… persistent aromatic compounds and varying species of metals with an emphasis on iron. Bulk water suspensions of a standard soil and polycyclic aromatic hydrocarbons (PAH) were analyzed for soluble iron by inductively-coupled plasma mass spectroscopy (ICP-MS) following a 16 hour reaction …
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Analysis of disinfection by products in drinking water by solid phase extraction
… of this research were to develop a broad spectrum method for the extraction, concentration, and analysis of drinking water disinfection by products using solid phase extraction (SPE), and to determine if this method had lower detection limits and less variability than the proposed …
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Silica Based Solid Phase Extraction Sorbent with a Removable Alkyltrimethylammonium Surfactant Phase
Presented is a solid phase extraction (SPE) sorbent having a removable "stationary phase." This removable phase that consists of alkyltrimethylammonium surfactant is initially immobilized onto hydrophilic strong cation exchange resin. The surfactant chain through hydrophobic interactions extracts …
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Paper Spray - Mass Spectrometry: Investigation of Sampling Devices for Illicit Drug Detection and Quantification
Paper spray - mass spectrometry (PS-MS) has been developed as a rapid and direct ionization method for qualitative and quantitative analysis of complex samples at trace levels. In this work, different sampling devices for PS-MS were investigated to improve the assay’s simplicity and sensitivity …
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Extraction and analysis of pharmaceutical residues in environmental samples using SPE with LC-MS/MS
… of residual PPCP contamination based upon solid phase extraction (SPE) and liquid chromatography mass spectrometry (LC-MS). Monolithic silica based stationary phases were used for the development of high performance liquid phase separations of common pharmaceuticals, the antifouling and …
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Characterization of A-type Proanthocyanidins in Peanut Skins Using MALDI-TOF MS
… laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Many similarities were found in the proanthocyanidin composition of cranberries and peanut skins. New oligomeric and polymeric proanthocyanidins in peanut skins, including heteroproanthocyanidins and proanthocyanidins …
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Electrochemical techniques for detection of Tnt and other explosives using disposable screen-printed carbon electrodes
… be significantly improved by coupling it with a solid phase extraction (SPE) protocol using Empore SDB-RPS membranes. The simple, rapid, cost-effective, and sensitive characteristics of this assay make it an excellent candidate for development as a field analytical method for onsite explosives …
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Pesticide distribution in water, sediment, and fish of the Occoquan Watershed
… in 1993, new SOC screening methods consisting of solid-phase extraction (SPE) followed by gas chromatography with mass spectrometric detection (GC/MS) were developed for water and sediment samples. A similar method for fish tissue was developed in this study using methanol extraction with C-18 and …
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HPLC method development for the evaluation of pheromones from the dwarf African clawed frog Hymenochirus
… concentrate the samples: sample lyophilization,..solid phase extraction (SPE), and direct sample loading. Different parameters such as the type and concentration of the phase modifier, wavelength for UV-detection, composition of the mobile phase, flow rate, and gradient elution were studied to …
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Development of chemosensors for endocrine disrupting chemicals (EDCs): synthesis and evaluation of solid-phase bound receptors
… step before the actual analysis. In general, solid-phase extraction (SPE) of aqueous samples is a widly applied technique to enrich pollutants. With the current SPE cartridges, the extraction efficiency of the pollutants depends on their polarity. Thus polar compounds stay in the water sample …
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Monitoring pesticides in the soil, groundwater, and submarine groundwater discharge of the Chesapeake Bay Area
… water was carried out by immunoassay and by solid phase extraction (SPE) with octadecyl bonded extraction disks followed by GC/ECD. Fifty-five soil and sediment samples were Soxhlet extracted followed by gas chromatography/mass spectrometry (GC/MS). Pesticides were detected in 13.4% …
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The characterisation of crude oils and the analysis of by-products produced in petrochemical plants
The use of solid phase extraction (SPE) in conjunction with gas chromatography combined with mass spectrometry (GC/MS) has been evaluated for identifying aromatic compounds in crude oils. A standard hexane solution of polyaromatic hydrocarbons (PAHs) was used for SPE method development using a …
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Biofilm-related Materials as Total N-nitrosamine (TONO) Precursors and Hydroxylamine-based Interferences in TONO and N-nitrosodimethylamine (NDMA) Measurements
… (TONO) assay was adapted to include a solid-phase extraction (SPE) step to assess the role of biologically derived materials as N-nitrosamine precursors. Methanol was determined to be a suitable solvent for the SPE-TONO assay, with N-nitrosodimethylamine (NDMA) losses estimated to be …
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Determination of pesticides and chloroanisoles in water samples using gas chromatography-mass spectrometry.
… were made to optimise both the resolution and speed of analysis for mixtures of carbaryl (a carbamate), lindane (an organochlorine), chlorpyrifos and chlorpyrifos-methyl (both organophosphorus compounds) and simazine (a triazine herbicide). These methods were then applied to the determination …
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