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Crampton, Mary Catherine. "Factors affecting selectivity of covalent chromatography." Diss., The University of Arizona, 1988. http://hdl.handle.net/10150/184356.
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Of the interactions utilized in the separation of chemical species, the reversible covalent bond is the strongest and most selective. In order to exploit the selectivity of this interaction, an understanding of the effects of several factors on the formation of the covalent bond have been studied. Covalent chromatography is most useful in solid phase extraction. The strength of the covalent bond will allow for high distribution coefficients needed to quantitatively retain chemical species. The selectivity of the covalent interaction allows for the retention of a specific compound or class of compounds. Under conditions where the covalent bond is no longer formed or will break, a low distribution coefficient is possible, and the compounds may be eluted from the sorbent in a small volume allowing for preconcentration. The sorbent consists of three parts, the active functionality capable of forming reversible covalent bonds, the solid support and the spacer arm that tethers the active functionality to the support. Silica supports demonstrate several advantages over organic supports. However, silica supports have been limited by the activity of the residual silanols and the use of hydrophobic spacer arms. This research describes the preparation and characterization of a modification method for silica with a hydrophilic spacer arm that restricts the sample from the residual silanols. Immobilized phenylboronic acid (PBA) interacts with compounds containing polar functionalities in the correct configuration, but this interaction is dependent on the local environment. Controlling the local environment allows for the control of the interaction provided the effects are understood. Diagnostic chromatography was used to determine the effects of the solvent strength, ionic strength, pH and composition of the mobile phase and the effects of the spacer arm on the interactions of PBA with several compounds. Three phases selective for thiols were also characterized. Thiopyridone attached to mercaptopropyl bonded silica through a disulfide linkage, is used for isolation and detection. Immobilized phenylmercury was utilized for the extraction of thiol containing species while immobilized phenylarsonous acid selectively extracts dithiol compounds. A unique and powerful means of separation of monothiol from dithiol compounds has been demonstrated.
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Tam, Wai-ming. "Development of methodology for high performance liquid chromatographic separation of inorganic ions /." [Hong Kong : University of Hong Kong], 1990. http://sunzi.lib.hku.hk/hkuto/record.jsp?B12922869.
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Chen, Xiao Jia. "Development of microscale separation techniques for quality control of Chinese medicines." Thesis, University of Macau, 2012. http://umaclib3.umac.mo/record=b2590374.
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Tuan, Chik Syed Mohd Saufi. "Mixed Matrix Membrane Chromatography for Bovine Whey Protein Fractionation." Thesis, University of Canterbury. Chemical and Process Engineering, 2010. http://hdl.handle.net/10092/3647.
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Whey protein fractionation is an important industrial process that requires effective large-scale processes. Although packed bed chromatography has been used extensively, it suffers from low processing rates due to high back-pressures generated at high flow rates. Batch chromatography has been applied but generally has a low efficiency. More recently, adsorptive membranes have shown great promise for large-scale protein purification, particularly from large-volume dilute feedstocks. A new method for producing versatile adsorptive membranes by combining membrane and chromatographic resin matrices has been developed but not previously applied to whey protein fractionation. In this work, a series of mixed matrix membranes (MMMs) were developed for membrane chromatography using ethylene vinyl alcohol (EVAL) based membranes and various types of adsorbent resin. The feasibility of MMM was tested in bovine whey protein fractionation processes.
Flat sheet anion exchange MMMs were cast using EVAL and crushed Lewatit® MP500 (Lanxess, Leverkusen, Germany) anion resin, expected to bind the acidic whey proteins β-lactoglobulin (β-Lac), α-lactalbumin (α-Lac) and bovine serum albumin (BSA). The MMM showed a static binding capacity of 120 mg β-Lac g⁻¹ membrane (36 mg β-Lac mL⁻¹ membrane) and 90 mg α-Lac g⁻¹ membrane (27 mg α-Lac mL⁻¹ membrane). It had a selective binding towards β-Lac in whey with a binding preference order of β-Lac > BSA > α-Lac. In batch whey fractionation, average binding capacities of 75.6 mg β-Lac g⁻¹ membrane, 3.5 mg α-Lac g⁻¹ membrane and 0.5 mg BSA g⁻¹ membrane were achieved with a β-Lac elution recovery of around 80%.
Crushed SP Sepharose™ Fast Flow (GE Healthcare Technologies, Uppsala, Sweden) resin was used as an adsorbent particle in preparing cation exchange MMMs for lactoferrin (LF) recovery from whey. The static binding capacity of the cationic MMM was 384 mg LF g⁻¹membrane or 155 mg LF mL⁻¹ membrane, exceeding the capacity of several commercial adsorptive membranes. Adsorption of lysozyme onto the embedded ion exchange resin was visualized by confocal laser scanning microscopy. In LF isolation from whey, cross-flow operation was used to minimize membrane fouling and to enhance the protein binding capacity. LF recovery as high as of 91% with a high purity (as judged by the presence of a single band in gel electrophoresis) was achieved from 150 mL feed whey.
The MMM preparation concept was extended, for the first time, to produce a hydrophobic interaction membrane using crushed Phenyl Sepharose™ (GE Healthcare Technologies, Uppsala, Sweden) resin and tested for the feasibility in whey protein fractionation. Phenyl Sepharose MMM showed binding capacities of 20.54 mg mL⁻¹ of β-Lac, 45.58 mg mL⁻¹ of α-Lac, 38.65 mg mL⁻¹ of BSA and 42.05 mg mL⁻¹ of LF for a pure protein solution (binding capacity values given on a membrane volume basis). In flow through whey fractionation, the adsorption performance of the Phenyl Sepharose MMM was similar to the HiTrap™ Phenyl hydrophobic interaction chromatography column. However, in terms of processing speed and low pressure drop across the column, the benefits of using MMM over a packed bed column were clear.
A novel mixed mode interaction membrane was synthesized in a single membrane by incorporating a certain ratio of SP Sepharose cation resin and Lewatit MP500 anion resin into an EVAL base polymer solution. The mixed mode cation and anion membrane chromatography developed was able to bind basic and acidic proteins simultaneously from a solution. Furthermore, the ratio of the different types of adsorptive resin incorporated into the membrane matrix could be customised for protein recovery from a specific feedstream. The customized mixed mode MMM consisting of 42.5 wt% of MP500 anionic resin and 7.5 wt% SP Sepharose cationic resin showed a binding capacity of 7.16 mg α-Lac g⁻¹ membrane, 11.40 mg LF g⁻¹ membrane, 59.21 mg β-Lac g⁻¹ membrane and 6.79 mg IgG g⁻¹ membrane from batch fractionation of 1 mL LF-spiked whey. A tangential flow process using this membrane was predicted to be able to produce 125 g total whey protein per L membrane per h.
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Grosfils, Valérie. "Modelling and parametric estimation of simulated moving bed chromatographic processes (SMB)." Doctoral thesis, Universite Libre de Bruxelles, 2009. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210313.
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La chromatographie à lit mobile simulé (procédé SMB) est une technique de séparation bien maîtrisée dans certains secteurs traditionnels tels que la séparation de sucres et d’hydrocarbures. Cependant, son application à la séparation de composés à haute valeur ajoutée dans l’industrie pharmaceutique pose de nouveaux problèmes liés à la nature des produits à séparer ainsi qu'aux exigences plus strictes en matière de pureté et de quantités produites. Les principaux problèmes ouverts sont notamment la détermination des conditions de fonctionnement optimales, la conception de structures robustes de régulation, et le développement d’un système de supervision permettant la détection et la localisation de dégradations de fonctionnement. Ces tâches requièrent l’usage d’un modèle mathématique du procédé ainsi qu’une méthodologie d’estimation paramétrique. L’étude et le développement des modèles mathématiques pour ce type d’installation ainsi que l’estimation des paramètres des modèles sur base de mesures expérimentales constituent précisément l’objet de nos travaux de doctorat.Les modèles mathématiques décrivant les procédés SMB consistent en les bilans massiques des composés à séparer. Ce sont des modèles à paramètres distribués (décrit par des équations aux dérivées partielles). Certains ont un comportement dynamique de type hybride (c'est-à-dire faisant intervenir des dynamiques à temps continu et des événements discrets). Quelques modèles ont été développés dans la littérature. Il s’agit de sélectionner ceux qui paraissent les plus intéressants au niveau de leur temps de calcul, de leur efficacité et du nombre de paramètres à déterminer. En outre, de nouvelles structures de modèles sont également proposées afin d’améliorer le compromis précision / temps de calcul.
Ces modèles comportent généralement certains paramètres inconnus. Ils consistent soit, en des grandeurs physiques mal définies au départ des données de base, soit, en des paramètres fictifs, introduits à la suite d'hypothèses simplificatrices et englobant à eux seuls un ensemble de phénomènes. Il s’agit de mettre au point une procédure systématique d’estimation de ces paramètres requérant le moins d’expériences possible et un faible temps de calcul. La valeur des paramètres est estimée, au départ de mesures réelles, à l'aide d'une procédure de minimisation d'une fonction de coût qui indique l’écart entre les grandeurs estimées par le modèle et les mesures. La sensibilité du modèle aux écarts sur les paramètres, ainsi que l’identifiabilité du modèle (possibilité de déterminer de manière univoque les paramètres du modèle) sur la base de mesures en fonctionnement normal sont étudiées. Ceci fournit un critère de comparaison supplémentaire entre les différents modèles et permet en outre de déterminer les conditions expérimentales optimales (choix du type d’expérience, choix des signaux d’entrée, choix du nombre et de la position des points de mesures…) dans lesquelles les mesures utilisées lors de l’estimation paramétrique doivent être relevées. De plus, les erreurs d’estimation sur les paramètres et les erreurs de simulation sont estimées. La procédure choisie est ensuite validée sur des données expérimentales recueillies sur un procédé pilote existant au Max-Planck-Institut für Dynamik komplexer technischer systeme (Magdebourg, Allemagne).
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
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Bentley, Jason A. "Systematic process development by simultaneous modeling and optimization of simulated moving bed chromatography." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47531.
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Adsorption separation processes are extremely important to the chemical industry, especially in the manufacturing of food, pharmaceutical, and fine chemical products. This work addresses three main topics: first, systematic decision-making between rival gas phase adsorption processes for the same separation problem; second, process development for liquid phase simulated moving bed chromatography (SMB); third, accelerated startup for SMB units. All of the work in this thesis uses model-based optimization to answer complicated questions about process selection, process development, and control of transient operation.
It is shown in this thesis that there is a trade-off between productivity and product recovery in the gaseous separation of enantiomers using SMB and pressure swing adsorption (PSA). These processes are considered as rivals for the same separation problem and it is found that each process has a particular advantage that may be exploited depending on the production goals and economics. The processes are compared on a fair basis of equal capitol investment and the same multi-objective optimization problem is solved with equal constraints on the operating parameters.
Secondly, this thesis demonstrates by experiment a systematic algorithm for SMB process development that utilizes dynamic optimization, transient experimental data, and parameter estimation to arrive at optimal operating conditions for a new separation problem in a matter of hours. Comparatively, the conventional process development for SMB relies on careful system characterization using single-column experiments, and manual tuning of operating parameters, that may take days and weeks. The optimal operating conditions that are found by this new method ensure both high purity constraints and optimal productivity are satisfied. The proposed algorithm proceeds until the SMB process is optimized without manual tuning. In some case studies, it is shown with both linear and nonlinear isotherm systems that the optimal performance can be reached in only two changes of operating conditions following the proposed algorithm.
Finally, it is shown experimentally that the startup time for a real SMB unit is significantly reduced by solving model-based startup optimization problems using the SMB model developed from the proposed algorithm. The startup acceleration with purity constraints is shown to be successful at reducing the startup time by about 44%, and it is confirmed that the product purities are maintained during the operation. Significant cost savings in terms of decreased processing time and increased average product concentration can be attained using a relatively simple startup acceleration strategy.
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Van, der Westhuizen Rina. "The use of multidimensional GC techniques for the analysis of complex petrochemical products." Thesis, Stellenbosch: University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/4639.
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90 leaves on CD format, preliminary i-ix pages and numbered pages 1-81. Includes bibliography, list of figures in color to pdf format (OCR).Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: The composition of petrochemical products obtained from Fischer Tropsch (FT) technologies is of the highest complexity possible and may contain thousands of components. Chemicals produced from FT feedstocks often contain trace level contaminants that can poison catalysts or that affect product performance in down-line processes. Single dimension GC analysis of these mixtures provides incomplete information because of lack of separation power. This study evaluates the separation power of heart-cut GC-GC, comprehensive GCxGC and sequential GC-GC for three selected challenging petrochemical applications. The fundamental theoretical aspects of the techniques are discussed. Oxygenates are removed as far as possible in C10 – C13 alkylation feedstocks, used in the production of linear alkyl benzenes, because the oxygenates may have deactivating effects on some expensive alkylation catalysts. Residual oxygenates may still be present and can consist of hundreds of components. Detection of individual components at ng/g levels is required. Heart-cut GC-GC is used to illustrate the separation and enrichment power for oxygenates in an alkylation feedstock. The stationary phase in the first dimension column was selected to provide separation of the oxygenates from the hydrocarbons in a relatively narrow window. The oxygenate fraction is then enriched by repeated injections and collection on the cryotrap. After sufficient enrichment, the trap is heated and the oxygenates are analysed on the second dimension column. Comprehensive GCxGC and Sequential GC-GC are compared for the separation and analysis of the oxygenated chemical component classes in the alkylation feedstock, before removal of oxygenates. Cyclic alcohols can occur in detergent alcohols produced from FT feedstocks. These cyclics are regarded as impurities because they affect the physical properties of the detergents. The cyclic and noncyclic alcohols in a narrow C12 – C13 detergent alcohol distillation cut have similar boiling points and polarities, and separation of individual components is thus difficult to achieve. Comprehensive GCxGC and sequential GC-GC are evaluated for the separation of the alcohol component classes. The study shows that both approaches provide component class separation but the high resolving power of the second column and the optimal chromatographic operating conditions of sequential GC-GC provide better separation of the individual components. The study illustrates the immense power of the three multidimensional GC techniques namely heart-cut GC-GC, comprehensive GCxGC and sequential GC-GC. The three multidimensional GC techniques each have their own advantages, disadvantages and unique applications and should be used as complementary rather than as competitive analytical tools.
AFRIKAANSE OPSOMMING: Fischer Tropsch (FT) petrochemiese produkte is van baie hoë kompleksiteit en kan uit duisende komponente bestaan. Chemikalië afkomstig van dié voerstrome bevat soms spoorhoeveelhede onsuiwerhede wat deaktiverend op kataliste kan inwerk of wat die werkverrrigting van finale produkte kan beïnvloed. Enkeldimensie GC analises van die komplekse mengsels is meesal onakkuraat as gevolg van geweldige piekoorvleueling. Die studie evalueer die skeidingsvermoë van drie multidimensionele tegnieke, Heart-cut GC-GC, Comprehensive GCxGC en Sequential GC-GC vir geselekteerde petrochemiese toepassings. Die fundamentele teoretiese aspekte van die tegnieke word bespreek en drie analitiese toepassings word beskryf. Oksigenate word so ver moontlik verwyder uit C10 – C13 paraffien-voerstrome, wat gebruik word in die vervaardiging van liniêre alkielbenzene, aangesien dit deaktiverend kan inwerk op alkileringskataliste. Die oorblywende oksigenate kan uit honderde komponente bestaan sodat analise van individuele komponente tot op lae ng/g vlakke nodig is. Heart-cut GC-GC word gebruik om die skeiding en verryking van die oksigenate in die alkileringsvoerstroom te illustreer. Die stationêre fase in die eerste-dimensie kolom is so gekies dat skeiding tussen oksigenate en koolwaterstowwe verkry word. Met herhaalde inspuitings verhoog die oksigenaat-konsentrasie op die cryo val en - na voldoende verryking - word die val verhit en die oksigenate geanaliseer op die tweede dimensie kolom. Die skeiding en analises verkry met Comprehensive GCxGC en Sequential GC-GC word vergelyk vir die chemiese klasse-skeiding van die alkileringsvoer (voor verwydering van oksigenate). Sikliese alkohole kan voorkom in detergent-alkohole vervaardig vanaf FT voerstrome. Dit word as onsuiwerhede beskou aangesien dit die fisiese eienskappe van die finale produkte beïnvloed. Die sikliese en nie-sikliese alkohole se kookpunte en polariteite is baie naby aanmekaar sodat skeiding van individuele komponente moeilik verkry word. Comprehensive GCxGC en Sequential GC-GC word evalueer vir die skeiding van die alkohol. Die studie toon aan dat albei die tegnieke skeiding gee van die chemiese komponent-klasse maar dat die hoë-resolusie tweede-dimensie kolom en die optimisering van die experimentele kondisies van die Sequential GC-GC sisteem beter skeiding van individuele komponente gee. Die uitsonderlike skeidingsvermoë van die drie multidimensionele tegnieke, Heart-cut GC-GC, Comprehensive GCxGC en Sequential GC-GC word geïllustreer in die studie. Elke tegniek het sy eie voordele, nadele en unieke toepassings en die drie tegnieke behoort as komplementêre eerder as kompeterende tegnieke gebruik te word.
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De, Villiers A. J. (Andre Joubert). "Evaluation of pressure- and electrodriven separation techniques for the determination of phenolic compounds in wine." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51753.
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Thesis (MSc)--Stellenbosch University, 2000.ENGLISH ABSTRACT: The phenolic content of wine is responsible for determining characteristics such as the organoleptic qualities, colour stability, ageing properties and health-beneficial effects associated with wine. The aim ofthis study was to investigate the possibilities offered by capillary electrophoresis (CE) as an alternative separation technique to high performance liquid chromatography (HPLC) for the analysis of polyphenols in wine. The complexity of wine samples was the cause that neither technique was capable of a satisfactory singlestep analysis of wine. Suitable sample preparation techniques such as Sephadex- and Sep- Pak fractionation and ether extraction of wine polyphenols were investigated. These techniques did not, however, prove to be universal. A novel form of sample preparation namely a process analogous to lyophylization used to separate wine volatiles from nonvolatiles was introduced. The versatility of CE was further investigated in an attempt to eliminate the need for sample preparation. The use of polyvinylalcohol (PVA) coated capillaries, micellar electrokinetic chromatography (MEKC) and capillary gel electrophoresis (CGE) were investigated in this regard. Although none of these techniques could offer conclusive results, useful applications were forthcoming and routes for further investigation were outlined. Liquid chromatography coupled to electro spray ionisation mass spectroscopy (LC-ESI-MS) and capillary electrophoresis coupled to electro spray ionisation mass spectroscopy (CE-ESI-MS) were compared for the analysis of polyphenols in wine. While the latter technique could not produce sufficient separation compared to the former, future development ofCE-ESI-MS should make it a powerful technique for these analyses.
AFRIKAANSE OPSOMMING: Die fenoliese komponente in wyn speel 'n bepalende rol by eienskappe soos die organoleptiese karakter, kleur stabiliteit, verouderingspotensiaal en gesondheids-voordele wat met wyn geassosieër word. Die doel van hierdie projek was om ondersoek in te stel na die potensiaal wat kapillêre elektroforese (CE, "capillary electrophoresis") as 'n alternatiewe skeidingstegniek teenoor hoë druk vloeistof chromatografie (HDVC) vir die analise van die polifenole in wyn bied. Die kompleksiteit van wyn monsters is van so 'n aard dat 'n bevredigend enkelstap analise met geeneen van die tegnieke moontlik is nie. Gepaste monster-voorbereidingstappe soos Sephadex- en Sep-Pak fraksionering asook eter ekstraksie van die polifenole in wyn is ondersoek. Geeneen van die tegnieke was egter universeel toepaslik nie. 'n Nuwe metode van monster-voorbereiding, naamlik 'n proses analoog aan liofilisasie wat gebruik word om die wyn te skei in vlugtige en nievlugtige komponente is gedemonstreer. Die veelsydigheid van CE was gevolglik ondersoek in 'n poging om monstervoorbereiding uit te skakel. Die gebruik van polyvinielalkohol-(pVA) bedekte kapillêre, missellêre elektrokinetiese chromatografie (MEKC) en kapillêre gel elektroforese (CGE, "capillary gel electrophoresis) is in hierdie verband ondersoek. Alhoewel geeneen van hierdie tegnieke onweerlegbare resultate gelewer het nie, het bruikbare toepassings hieruit voortgespruit en is die grondslag vir verdere navorsing gelê. Vloeistof chromatografie gekoppel aan eIektrosproei ionisasie massaspektroskopie (LCESI- MS) en kapillêre elektroforese gekoppel aan elektrosproei ionisasie massaspektroskopie (CE-ESI-MS) is vergelyk vir die analise van polifenole in wyn. Alhoewel laasgenoemde tegniek onvoldoende skeiding lewer vergeleke met eersgenoemde, behoort toekomstige ontwikkelinge op die gebied van CE-ESI-MS dit 'n kragtige tegniek vir die analise van hierdie monsters te maak.
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Kaplan, Muammer. "Infrared spectroscopy in supercritical fluid analysis." Thesis, University of Nottingham, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385210.
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Wong, Victor, University of Western Sydney, of Science Technology and Environment College, and of Science Food and Horticulture School. "A fundamental study towards improving the performance of liquid chromatographic separation." THESIS_CSTE_SFH_Wong_V.xml, 2003. http://handle.uws.edu.au:8081/1959.7/467.
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The three factors of the resolution (Rs)equation(see Equation 1.1)were explored in this thesis. During the course of the research project, an important aim was to explore separation processes that would lead to an increase in productivity without sacrificing Rs. To that end, an increase in the retention factor (k)to enhance Rs was deemed detrimental to the cycle time, hence the production rate, particularly when preparative separations are involved. Consequently the primary objectives were to (i)prepare more efficient columns and (ii)investigate new strategies in manipulating selectivity. The significance of the work contained in this thesis is highlighted in 27th International Symposium on High Performance Liquid Phase Separations and Related Techniques (HPLC 2003)held in Nice, France between 15-19 June, 2003. Many of the papers presented significantly compared to chapters contained in this researchDoctor of Philosophy (PhD)
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Cao, Liming. "Protein Separation with Ion-exchange Membrane Chromatography." Link to electronic thesis, 2005. http://www.wpi.edu/Pubs/ETD/Available/etd-050405-174109/.
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Wong, Victor. "A Fundamental study towards improving the performance of liquid chromatographic separation /." View thesis, 2003. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20060428.124908/index.html.
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Thesis (Ph.D.) -- University of Western Sydney, 2003."A thesis submitted for the degree of Doctor of Philosophy (Science), School of Science, Food and Horticulture, University of Western Sydney, Richmond, New South Wales, Australia. December 2003". CD "attached to back cover of thesis is in Super Video-CD (SVCD) format showing the development of viscous fingering in realtime." Bibliography : leaves 135 - 147.
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Kang, Jasjit. "The chromatographic and spectrochemical analysis of foodstuffs." Thesis, University of Surrey, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335390.
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Yeung, Kai Tai. "Molecular simulations of the enantioseparating mechanism of polysaccharide-based chiral stationary phase and enzymatic acylation of N-benzoyl-L-arginine ethyl ester in binary aquo-organic solvent mixtures." HKBU Institutional Repository, 2007. http://repository.hkbu.edu.hk/etd_ra/819.
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Layton, Sherry E. "Comparison of various chiral stationary phases for the chromatographic separation of chiral pharmaceuticals /." Electronic version (PDF), 2005. http://dl.uncw.edu/etd/2005/laytons/sherrylayton.pdf.
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Matoetoe, Mangaka Clara. "Synthesis, characterization and potential chromatographic separation of palladium and platinum complexes of N,N-Dialkyl-N'-Benzoylthioureas." Master's thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/22280.
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Bibliography: pages 117-120.A series of para-phenyl substituted N,N-dialkyl-N'-benzoylthioureas where para-phenyl substituents are H, Cl, Br, I, NO₂ and OCH₃ and alkyl chains are -CH₂CH₃, -(CH₂)₃CH₃ and and -CH₂C₆H₅ as well as their corresponding neutral bis complexes of type cis [ML₂] where M = Pd(II) and Pt(II) have been prepared and characterized. The structures of these compounds has been studied using high resolution nuclear magnetic resonance technique. Studies were also carried out to investigate possible use of these N,N-dialkyl-N-benzoylthioureas as ligands suitable for the chromatographic separation of Pt(II), Pd(II), Ni(II) and Cu(II). To this end the possible selective extraction of these complexes from acidic aqueous phases was examined. This layer normal phase chromatography has been mainly used, using a variety of organic phases as eluent. A preliminary investigation of the suitability of using normal phase HPLC for the separation of the platinum and palladium complexes was undertaken.
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譚偉明 and Wai-ming Tam. "Development of methodology for high performance liquid chromatographicseparation of inorganic ions." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1990. http://hub.hku.hk/bib/B31232401.
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Reilly, John. "A comparison of electrophoretic and chromatographic separation techniques for the determination of chiral and achiral impurities." Thesis, Imperial College London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270880.
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Van, Kralingen Leon. "Ligand modification of Pluronic F108 for use in immobilized metal affinity separation of bio-macromolecules." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52918.
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Thesis (MSc)--Stellenbosch University, 2002.ENGLISH ABSTRACT: Inthis work we aim to put into place a system to separate or immobilise biomacromolecules by means ofimmobilised transition metal ions like nickel(II) or copper(II). Although the concept of immobilised metal affmity chromatography (IMAC) has been around since the early 1960's, the metal ions were always immobilised by covalent modification of the support matrix. Recently the concept of IMAC was applied to membranes, and again the metal ion was immobilised by covalent modification of the membrane surface. Inthis study we covalently modified the support matrix by attaching a linear, EDTA type ligand to the hydroxy end groups of a tri-block copolymer (polyethylene oxide (PEO)m = 129 - polypropylene oxide (PPO)n = 56 - polyethylene oxide (PEO)m= 129), Pluronic® F108. The middle block of this polymer, which is hydrophobic, will non-covalently adsorb onto the membrane surface through hydrophobic interaction. The hydrophilic outer blocks, with the ligand modified end groups, will associate with the aqueous substrate exposing the chelated metal ion for interaction with the bio-macromolecules. This affords a system which is recyclable, without replacing the membranes, simply by stripping the expired ligand modified-polymer and adsorbing fresh polymer. A series of model ligands and their complexes were synthesised and characterised, to study the coordination of the ligand around the metal ions. The model compounds were also essential in characterising the final product - the ligand modified Pluronic. Finally the ligand modified Pluronic was tested for its metal binding capabilities. This was done in aqueous solution by qualitatively comparing the UV-VIS spectra of the modified Pluronic with that of the model ligands and complexes. The spectra indicate that metal coordination does take place.
AFRIKAANSE OPSOMMING: In die studie het ons beoog om 'n sisteem daar te stel vir die skei en immobilisering van bio-makromolekules deur middel van oorgangsmetale soos nikkel(II) en koper(II). Alhoewel die beginsel van geïmmobiliseerde Metaal-ioon Affmiteits Chromatografie (IMAC) reeds sedert die vroeë 1960's bekend is, is die metaal ione geïmmobiliseer deur kovalente modifikasie van die draermaterial. Onlangs is die beginsel van IMAC uitgebrei na membrane en ook hierin is die metaalione geïmmobiliseer deur kovalente modifikasie van die membraanoppervlaktes. In die projek het ons die draermateriaal kovalent gemodifiseer deur 'n lineêre EDT A-tipe ligand te koppel aan die hidroksie eindgroepe van 'n tri-blok ko-polimeer (poli-etileen oksied (PEO)m = 129 - poli-propileen oksied (PPO)n = 56 - poli-etileen oksied (PEO)m = 129), Pluronic® FI08. Die middelste blok van die polimeer, wat hidrofobies is, sal nie-kovalent aan die membraan oppervlakte adsorbeer d.m. v hidrofobiese interaksie. Die hidrofiliese buite blokke, met die ligand-gemodifiseerde eindgroepe, sal assosieer met die waterige substraat en die metal ioon blootstel vir interaksie met die biomakromolekules. Dit stel dus 'n sisteem in plek wat herbenut kan word, sonder om die membrane te vervang, deur eenvoudig die ligand-gemodifiseerde polimeer wat verval het te stroop en te vervang met nuwe polimeer. 'n Reeks modelligande en hul komplekse was gesintetiseer en gekarakteriseer om die koördinasie van die ligande rondom die metaal ione te bestudeer. Dié model verbindings was van groot belang in die karakterisering van die finale produk - die ligand-gemodifiseerde Pluronic. Laastens is die ligand-gemodifiseerde Pluronic getoets vir sy metaal bindings vermoeë. Dit is gedoen deur die UV-VIS spectra van die gemodifiseerde Pluronic kwalitatiefte vergelyk met die spectra van die modelligande en komplekse, in waterige oplossings. Die spectra dui aan dat metaalbinding wel plaasvind.
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Barks, Hannah Lynn. "Separation and identification of complex mixtures using chromatography mass spectrometry." Thesis, Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/33953.
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Here, for the first time, the formation of adenine, hypoxanthine, and guanine from formamide solutions with heating only to 130 degrees C and UV-irradiation in the absence of minerals or inorganic salts is shown using LC-MS/MS as the analysis technique. The thesis goes on to demonstrate that the product distributions change drastically when the temperature is increased to 160 degrees C from 130 degrees C, specifically that the amount of hypoxanthine increases with the addition of UV light, and the amount of adenine increases with an increase in temperature. Along with showing the formation of purines in these reactions, the identification of pyrimidines was also achieved by GCxGC-MS. GCxGC-MS was also used to study additional samples, specifically bio-oils, where the type of compounds in the samples were easily identifiable, which allowed for a direct comparison between different types of bio-oils (e.g. Douglas-fir bark, Southern pine bark, and a Southern pine bark-wood mixture).
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Allegood, Jeremy Chadwick. "Application of liquid chromatography tandem mass spectrometry for the separation and quantitative analysis of sphingolipids." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42691.
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Sphingolipids are a highly diverse category of compounds that serve not only as components of biologic structures but also as regulators of numerous cell functions. Because so many of the structural features of sphingolipids influence their biological activity, there is a need for comprehensive methods for quantitation of as many individual subspecies as possible. This dissertation describes methods that have been developed and validated for the extraction, liquid chromatographic separation, identification and quantitation of sphingolipids by electrospray ionization (ESI), tandem mass spectrometry (MS/MS) using an internal standard cocktail developed by the LIPID MAPS Consortium. The compounds that can be readily analyzed are sphingoid bases and sphingoid base 1-phosphates, as well as more complex species such as ceramides, ceramide 1-phosphates, sphingomyelins, and mono- and di-hexosylceramides. For broader utility, the methods have been optimized for two categories of tandem mass spectrometers. With minor modifications, these methods can be applied to the analysis of isomers such as glucosylceramide and galactosylceramide, and with the availability of additional internal standards, more complex species such as sulfatides can also be quantified. Using these methods 46 species of these compounds have been quantified in RAW264.7 cells, a macrophage cell line. Quantitation of individual sphingolipid metabolites is possible using liquid chromatography, tandem mass spectrometry, and stable isotope labeling with [13C]palmitic acid can be used to differentiate between metabolites produced by de novo synthesis versus turnover. This approach is more accurate when one knows the isotope enrichment of the precursor pool (in this case, [13C]-palmitoyl-CoA); therefore this dissertation describes methods to analyze both the various isotopic forms of palmitoyl-CoA and sphingolipids through sphingomyelins and monohexosylceramides using two cell models, HEK293 cells and RAW264.7 cells treated with Kdo2-Lipid A. The sphingolipid analysis was simplified by the fragmentation of most of the metabolites to backbone product ions. For example the presence of the isotopic label in the long chain base, N-acyl linked fatty acid, or both was determined via, m/z 264 for [12C]sphingosine (d18:1) and m/z 280 for [13C]sphingosine (m+16, d18:1), versus the m/z of the isotopically labeled precursor, (m+16 versus m+32).
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Welbeck, Edward William. "Separation, identification and standardisation of plant metabolites in traditional Chinese Medicines by chromatographic spectroscopic and multivariate analysis processess." Thesis, London Metropolitan University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.517140.
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Trujillo, Rebollo Andres. "ROLE OF BRILLIANT GREEN ON THE DETECTION AND SEPARATION OF NON-CHROMOPHORIC ANALYTES BY REVERSED-PHASE LIQUID CHROMATOGRAPHY (DIMERIZATION)." Thesis, The University of Arizona, 1985. http://hdl.handle.net/10150/275434.
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Davis, Kellie M. "Open tubular capillary electrochromatography-laser induced fluorescence for the separation and detection of proteins and amino acids." Greensboro, N.C. : University of North Carolina at Greensboro, 2007. http://libres.uncg.edu/edocs/etd/1513Davis/umi-uncg-1513.pdf.
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Thesis (M.S.)--University of North Carolina at Greensboro, 2007.Title from PDF t.p. (viewed Mar. 11, 2008). Directed by G. Brent Dawson; submitted to the Dept. of Chemistry. Includes bibliographical references (p. 67-69).
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SADI, BAKI BILLAH MOHAMMED. "HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC SEPARATION COUPLED TO INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY FOR ELEMENTAL SPECIATION IN ENVIRONMENTAL SAMPLES." University of Cincinnati / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1130263794.
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Montecchia, Matteo. "Experimental analysis of a separation control device based on plasma technology." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4744/.
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In this thesis effects of plasma actuators based on Dielectric Barrier Discharge (DBD) technology over a NACA 0015 bidimensional airfoil have been analyzed in an experimental way, at low Reynolds number.
Work developed on thesis has been carried on in partnership with the Department of Electrical Engineering of Università di Bologna, inside Wind Tunnel of the Applied Aerodynamic Laboratory of Aerospace Engineering faculty.
In order to verify the effectiveness of these active control devices, the analysis has shown how actuators succeed in prevent boundary layer separation only in certain
conditions af angle of attack and Reynolds numbers.
Moreover, in this thesis actuators’ chordwise position effect has been also analyzed, together with the influence of steady and unsteady operations.
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Dabat, Duval Marilyne. "Etude des différences de structure entre des héparines d'origines animales diverses par électrophorèse capillaire et chromatographie d'échange d'ions." Rouen, 1995. http://www.theses.fr/1995ROUES007.
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L'objectif de cette étude est d'établir une méthode de différenciation des héparines en fonction de leur origine animale (le plus souvent porcine mais parfois bovine) et de leur origine tissulaire (mucus d'intestin ou poumon). En effet, la détermination de l'origine des héparines entrant dans la fabrication du principe actif d'un médicament est un facteur déterminant de la qualité de celui-ci. De nos jours, les autorités de la santé publique sont particulièrement vigilantes et attentives aux cas des médicaments dont le principe actif est extrait à partir d'organes animaux. L'accent est plus particulièrement mis sur les produits d'origine bovine en raison de l'occurence d'une maladie qui touche essentiellement les bovins: l'encéphalite spongiforme. Bien que toutes les héparines commercialisées devraient dorénavant être d'origine porcine, il est de l'interêt général de disposer d'une méthode d'analyse permettant de vérifier l'origine animale des héparines et d'être capable de quantifier par un pourcentage la présence éventuelle d'héparine d'intestin de boeuf dans un lot d'héparine d'intestin de porc. Dans le cadre de cette étude, nous nous sommes intéressés à la différenciation de l'origine animale des héparines, par l'analyse de leur produit de dépolymérisation. Les héparines ont été successivement depolymérisées chimiquement (par l'acide nitreux) ou enzymatiquement (par les héparinases I et II). L'analyse des produits de dépolymérisation est effectuée en HPLC d'échange d'ions et en électrophorèse capillaire pour la réalisation de cartographies des différentes héparines. En conclusion, la digestion des héparines par l'héparinase II produit un mélange de disaccharides dont l'analyse quantitative en HPLC d'échange d'ions et en électrophorèse capillaire, permet la détection de 5 a 10% d'héparine bovine dans un lot d'héparine porcine
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Wanekaya, Adam. "Novel hyphenated technologies for sensing, separation and sample treatment." Diss., Online access via UMI:, 2005. http://wwwlib.umi.com/cr/binghamton/main/.
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Sun, Hongyan. "Circuit analysis tools for evaluating separation efficiency of dense medium separators." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4385.
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Thesis (M.S.)--West Virginia University, 2005.Title from document title page. Document formatted into pages; contains ix, 95 p. : ill. Includes abstract. Includes bibliographical references (p. 86-88).
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Dao, Kwok-leung. "Development of sample decomposition methods, preconcentration techniques and separation methods for high performance liquid chromatographic analysis of environmental pollutants and industrial wastes /." [Hong Kong : University of Hong Kong], 1994. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13793871.
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Sun, Chen. "Microfluidic technology for cellular analysis and molecular biotechnology." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/78742.
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Microfluidics, the manipulation of fluids at nanoliter scale, has emerged to offer an ideal platform for biological analysis of a low number of cells. The technological advances in microfluidics have allowed both forming of valves, mixers and pumps and integrating of optic and electronic components into microfluidic devices to construct complete and functional systems. In this dissertation, I present novel microfluidic techniques and their applications in cellular probes delivery, cell separation and epigenetic study. In the first part of the dissertation, electroporation is implemented on microfluidic platform to generate uniform delivery of "exposed" nanoparticle or protein into cells. In contrast to endocytosis, electroporation is a physical method to breach cell membrane and does not involve vesicle encapsulation of delivered probes, which means these probes have exposed surface in the cytosol. Such trait enables the use of delivered nanoparticle and protein for intracellular targeting of native biomolecules. Laser-induced fluorescent microscopy was used for single particle illuminating to track single molecules in cells. Microfluidic device provide integrated platform for conducting electroporation, cell culture and imaging. In the second part, microfluidic immunomagnetic cell separation is introduced. I showed two new approaches to enhance immunomagnetic cell separation based on (1) uniquely microfabricated paramagnetic patterns inside separation channels; and (2) using combination of nonmagnetic beads and magnetic beads for selection of tumor initiating cells based on two markers of opposite preference in one step. Enhancement in cell isolation (high capture efficiency or high selection purity) is experimentally observed and the former is explained by computational model. In the final part of the dissertation, microfluidic device incorporating valves and mixers for sensitive study of chromosome conformation is presented. This device has small reaction chamber minimizing sample requirement, and allows multiple steps of biological analysis in a single chip avoiding sample loss during sample transfer. Several orders of magnitude improved detection sensitivity is achieved with our microfluidics based method. I envision all novel techniques discussed in this dissertation have great potential in application of disease prognosis, diagnosis and treatment.Ph. D.
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Link, Jeanne Meyers. "Mixed-mode chromatographic separation and whole column radiation detection to improve sensitivity in radiometabolite analysis : application to (Carbon-11)-meta-hydroxyephedrine in plasma /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/8578.
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Mainwaring, David, and Jonathan Österberg. "Sound Pattern Recognition : Evaluation of Independent Component Analysis Algorithms for Separation of Voices." Thesis, KTH, Skolan för teknikvetenskap (SCI), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-230746.
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With computers being used for more applications where commands can be spoken it is useful to findalgorithms which can separate voices from each other so that software can turn spoken words intocommands. In this paper our goal is to describe how Independent Component Analysis (ICA) can beused for separation of voices in cases where we have at least the same number of microphones, atdifferent distances from the speakers, as speakers whose voices we wish to separate, the so called``cocktail party problem". This is done by implementing an ICA algorithm on voice recordingscontaining multiple persons and examining the results. The use of both ICA algorithms result in aclear separation of voices, the advantage of fastICA is that the computations take a fraction of thetime needed for the ML-ICA. Both algorithms can also successfully separate voices when recordingsare made by more microphones than speakers. The algorithms were also able to separate some ofthe voices when there were fewer microphones than speakers which was surprising as thealgorithms have no theoretical guarantee for this.I detta arbete har vi undersökt hur oberoende komponentanalys algoritmer (ICA) kan användas förseparation av röster där vi har ett varierande antal röster och mikrofoner utplacerade på olikapositioner i ett rum, mer känt som ”cocktailparty problemet”. Detta görs genom att resultatet frånICA-algoritmer appliceras på ljudinspelningar där flera personer talar i mun på varandra. Vi testar ICAalgoritmerna Maximum Likelihood-ICA (ML-ICA) och fastICA. Båda algoritmerna ger goda resultat närdet är minst lika många mikrofoner som talare. Fördelen med fastICA mot ML-ICA är att körtiden ärmycket kortare. Överraskande resultat från båda algoritmerna är att de klarade att separera ut minsten av rösterna när det var fler talare än mikrofoner då detta inte var ett förväntat resultat.
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Jacobson, Barry David. "Combined-channel instantaneous frequency analysis for audio source separation based on comodulation." Thesis, Massachusetts Institute of Technology, 2008. http://hdl.handle.net/1721.1/45911.
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Thesis (Ph. D.)--Harvard-MIT Division of Health Sciences and Technology, 2008.Includes bibliographical references (p. 295-303).
Normal human listeners have a remarkable ability to focus on a single sound or speaker of interest and to block out competing sound sources. Individuals with hearing impairments, on the other hand, often experience great difficulty in noisy environments. The goal of our research is to develop novel signal processing methods inspired by neural auditory processing that can improve current speech separation systems. These could potentially be of use as assistive devices for the hearing impaired, and in many other communications applications. Our focus is the monaural case where spatial information is not available. Much perceptual evidence indicates that detecting common amplitude and frequency variation in acoustic signals plays an important role in the separation process. The physical mechanisms of sound generation in many sources cause common onsets/offsets and correlated increases/decreases in both amplitude and frequency among the spectral components of an individual source, which can potentially serve as a distinct signature. However, harnessing these common modulation patterns is difficult because when spectral components of competing sources overlap within the bandwidth of a single auditory filter, the modulation envelope of the resultant waveform resembles that of neither source. To overcome this, for the coherent, constant-frequency AM case, we derive a set of matrix equations which describes the mixture, and we prove that there exists a unique factorization under certain constraints. These constraints provide insight into the importance of onset cues in source separation. We develop algorithms for solving the system in those cases in which a unique solution exists. This work has direct bearing on the general theory of non-negative matrix factorization which has recently been applied to various problems in biology and learning. For the general, incoherent, AM and FM case, the situation is far more complex because constructive and destructive interference between sources causes amplitude fluctuations within channels that obscures the modulation patterns of individual sources.
(cont.) Motivated by the importance of temporal processing in the auditory system, and specifically, the use of extrema, we explore novel methods for estimating instantaneous amplitude, frequency, and phase of mixtures of sinusoids by comparing the location of local maxima of waveforms from various frequency channels. By using an overlapping exponential filter bank model with properties resembling the cochlea, and combining information from multiple frequency bands, we are able to achieve extremely high frequency and time resolution. This allows us to isolate and track the behavior of individual spectral components which can be compared and grouped with others of like type. Our work includes both computational and analytic approaches to the general problem. Two suites of tests were performed. The first were comparative evaluations of three filter-bank-based algorithms on sets of harmonic-like signals with constant frequencies. One of these algorithms was selected for further performance tests on more complex waveforms, including AM and FM signals of various types, harmonic sets in noise, and actual recordings of male and female speakers, both individual and mixed. For the frequency-varying case, initial results of signal analysis with our methods appear to resolve individual sidebands of single harmonics on short time scales, and raise interesting conceptual questions on how to define, use and interpret the concept of instantaneous frequency. Based on our results, we revisit a number of questions in current auditory research, including the need for both rate and place coding, the asymmetrical shapes of auditory filters, and a possible explanation for the deficit of the hearing impaired in noise.
by Barry David Jacobson.
Ph.D.
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Thakker, Alpesh. "Development of mass spectrometry protocols for analysis of oxidised lipidome in inflammatory disease models : using semi-targeted mass spectrometry based approach & optimized chromatographic separation." Thesis, Aston University, 2017. http://publications.aston.ac.uk/33353/.
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Phospholipid oxidation generates a wide variety of products with potentially novel biological activities that may be associated with disease pathogenesis. To understand their role in disease requires precise information about their abundance in biological samples. Liquid chromatography-mass spectrometry (LCMS) is a sensitive technique that can provide detailed information about the oxidative lipidome, but challenges still remain. The work in this thesis developed improved methods for detection of OxPLs by improvement of chromatographic separation through the comparison and optimisation of several HPLC columns such as C8, C18 and C30 reverse phase, polystyrene-divinylbenzene based monolithic, and mixed-mode hydrophilic interaction (HILIC) columns & solvent systems, with use of semi-targeted mass spectrometry approaches. The results suggests that the monolithic column was the most robust method for separating short chain oxPLs from long chain oxidised and native PLs. In addition, several approaches for method validation were explored such as testing of reproducibility and repeatability of the methods, together with the reanalysis of samples on a high resolution QToF mass spectrometer with automated quantitative data analysis using the Progenesis QI software to validate the identification. The combination of the developed methods allowed the identification of several oxPLs in biological samples. These were: i) ascites fluid of lean and obese rat model of acute pancreatitis; ii) isolated components of red blood cells (RBCs) infected with the malarial parasite Plasmodium falciparum; and iii) plasma samples of healthy and diabetic patients. In addition, an evaluation of post-acquisition data handling to minimise inherent biological variation was performed. Quantitative differences in oxPLs were observed in isolated malarial components as well as other studied disease models. Overall, several protocols were developed that provide improved performance for the identification of OxPL in biological samples that can be used as a reference method by research laboratories interested in oxidative lipidomics work.
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TAKEDA, Kazuya, Takanori NISHINO, and Kenta NIWA. "Selective Listening Point Audio Based on Blind Signal Separation and Stereophonic Technology." Institute of Electronics, Information and Communication Engineers, 2009. http://hdl.handle.net/2237/15055.
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Makan, Ashwell Craig. "Asymmetric flow field flow fractionation (AF4) of polymers with focus on polybutadienes and polyrotaxanes." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/19997.
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Thesis (MSc)-- Stellenbosch University, 2012.ENGLISH ABSTRACT: Over the past two decades, field flow fractionation (FFF), as a polymer characterization technique, has become cutting edge technology. The demand for molar mass and size characterisation of complex polymer systems has increased, especially in cases where classical calibration techniques such as size exclusion chromatography (SEC) has shown several shortcomings. FFF is a technique resembling chromatography. It has several significant advantages over SEC, especially for the characterisation of ultrahigh molar mass (UHMM), branched and gel-containing polymers. In this study, polybutadienes, which often contain the abovementioned species, were analysed by SEC and asymmetric flow field flow fractionation (AF4). Both separation techniques were coupled to refractive index and multi-angle laser light scattering detection. Similarly, polyrotaxanes, which are polymers with complex and unique molecular architectures, were also investigated. Results showed that AF4 can explicitly be used as a superior tool over SEC. In the case of UHMM polybutadienes, much higher molar masses could be detected by AF4, due to the absence of shear degradation which is often encountered in SEC. Gel-containing species could be detected by AF4 as no filtering is required prior to injection. Abnormal retention behaviour, a phenomenon often encountered in UHMM branched polymers, was observed in SEC analysis of the polyrotaxanes materials. AF4 provided sufficient separation from low to high molar masses, without out any irregularities.
AFRIKAANSE OPSOMMING: Gedurende die afgelope twee dekades het veldvloeifraksionering (FFF) as ‘n polimeerkarakteriseringstegniek groot veld gewen. Die aanvraag na molekulêre massa en groottekarakterisering van komplekse polimeersisteme het toegeneem, veral in die gevalle waar klassieke kalibrasietegnieke soos grootte-uitsluitingschromatografie (SEC) etlike tekortkominge getoon het. FFF is ‘n tegniek soortgelyk aan chromatografie, en het voorheen bewys dat dit oor ‘n redelike aantal voordele bo SEC beskik, veral in die geval van ultrahoë molekulêre massa- (UHMM-), vertakte- en jelbevattende spesies. In die huidige studie is polibutadieenpolimere, wat dikwels bogenoemde spesies bevat, geanaliseer met behulp van SEC en onsimmetriese vloei-veldvloeifraksionering (AF4). Beide skeidingstegnieke is gekoppel aan ‘n brekingsindeks en multihoek-laserligverstrooiingsdetektors. Op dieselfde wyse is polirotaksane (polyrotaxanes) met komplekse molekulêre argitektuur bestudeer. Daar is bewys dat AF4 uitsluitlik gebruik kan word as ‘n meer geskikte tegniek bo SEC. Baie hoër molekulêre massas kon deur middel van AF4 vir UHMM polibutadieenpolimere raakgesien word as gevolg van die verminderde afbrekende degradasie wat dikwels voorkom met SEC. Jel-bevattende spesies is suksesvol geïdentifiseer met behulp van AF4 waartydens geen filtrering vir analise nodig was nie. Abnormale retensie was sigbaar tydens SEC analise van monsters van polirotaksane, wat dikwels voorkom in vertakte polimere. In teenstelling het AF4 bewys dat ‘n bevredigende skeiding van klein na groot molekulêre massas, sonder enige tekortkominge, moontlik is.
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Ide, Alessandra Honjo. "Produtos farmacêuticos e de higiene pessoal no rio Iguaçu e seus afluentes." Universidade Tecnológica Federal do Paraná, 2014. http://repositorio.utfpr.edu.br/jspui/handle/1/992.
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CAPES; CNPq; Fundação AraucáriaA qualidade das águas é atualmente um assunto que tem atraído a atenção de pessoas de todas as áreas, especialmente quanto à contaminação dos ambientes aquáticos pelos chamados poluentes emergentes. Esses contaminantes constituem compostos orgânicos ou inorgânicos, sintéticos ou naturais, contidos nos bens de consumo utilizados por toda população e que tem como destino final os corpos aquáticos. O objetivo deste trabalho foi verificar a presença de produtos farmacêuticos e de higiene pessoal (cafeína, ácido acetilsalicílico, ácido salicílico, cetoprofeno, naproxeno, genfibrozila, fenofibrato, estradiol, etinilestradiol, estrona, 4-metilbenzilideno cânfora, metoxicinamato de octila e octacrileno) no rio Iguaçu, da nascente até sua foz, e em seus principais afluentes na Região Metropolitana de Curitiba. A determinação dos contaminantes emergentes foi realizada utilizando a extração em fase sólida e cromatografia em fase líquida com detector de arranjo de diodos e cromatografia em fase gasosa acoplada a espectrometria de massas. Realizou-se validação da metodologia empregada de acordo com os padrões estabelecidos pela Agência Nacional de Vigilância Sanitária. O método para extração e quantificação dos 13 compostos mostrou-se eficiente para a determinação de 10 desses analitos nas amostras de água. A cafeína foi o composto mais presente nas amostras; o ácido acetilsalicílico foi o produto farmacêutico encontrado em maiores concentrações; o estradiol, o hormônio sexual feminino detectado com maior frequência e o metoxicinamato de octila, o produto de higiene pessoal mais detectado. Os resultados obtidos neste trabalho indicam grande influência antrópica na bacia do Alto Iguaçu, principalmente devido à presença de esgotos domésticos. Observou-se também que as estações de tratamento de esgoto contribuem com a entrada de nutrientes e contaminantes emergentes que não são eficientemente removidos nos tratamentos utilizados. A falta de saneamento básico impacta negativamente na qualidade das águas do rio Iguaçu, que encontra-se altamente degradado devido a influência dos afluentes da Região Metropolitana de Curitiba.
Water quality is a currently subject that has attracted the attention of people from all areas, especially the contamination of aquatic environments by so-called emerging pollutants. These contaminants are organic or inorganic, natural or synthetic compounds, contained in products used throughout the population and that reacht water bodies. With this work, we intended to verify the presence of pharmaceuticals and personal care products (caffeine, acetylsalicylic acid, salicylic acid, ketoprofen, naproxen, gemfibrozil, fenofibrate, estradiol, ethinylestradiol, estrone, 4– methylbenzylidencamphor, octylmethoxycinnamate and octacrilene) in Iguaçu River, from source to mouth, and its major tributaries in the Metropolitan Region of Curitiba. The determination of emerging contaminants was done using solid phase extraction and liquid chromatography with diode array detector and gas chromatography tanden mass spectrometry. Validation of the methodology was conducted in accordance with standards established by the Agência Nacional de Vigilância Sanitária. The method for extraction and quantitation of the 13 compounds proved to be efficient for the determination of 10 of these analytes in water samples. Caffeine was the main compound present in the samples; acetylsalicylic acid was the pharmaceutical product founded in the highest concentractions; estradiol, the female sexual hormone more frequently detected and octylmethoxycinnamate, the personal care product longer detected. The results of this study indicate intense anthropogenic influence in the Upper Iguaçu basin, mainly due to the presence of domestic sewage. It was also observed that the wastewater treatment plants contribute to the entry of nutrients and emerging contaminants that are not efficiently removed in the treatments used. The lack of sanitation has a negative impact on water quality of the Iguaçu river, which is highly degraded due to the influence of the tributaries of the Metropolitan Region of Curitiba.
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Wei, Shuting. "Capturing molecules with templated materials analysis and rational design of molecularly imprinted polymers /." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/24817.
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Thesis (Ph.D.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2008.Committee Chair: Boris Mizaikoff; Committee Member: Andrew Lyon; Committee Member: Ching-Hua Huang; Committee Member: David Collard; Committee Member: Facundo M. Fernandez.
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Zapata, Pedro José. "High throughput characterization of cell response to polymer blend phase separation." Thesis, Available online, Georgia Institute of Technology, 2005, 2004. http://etd.gatech.edu/theses/available/etd-07082004-160241/.
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Mohamed, Noha Nahedj Atia. "Pharmaceutical analysis and in-vitro aerodynamic characterisation of inhaled theophylline formulations containing drug particles prepared by supercritical fluid processing : chromatographic, spectroscopic, and thermal analysis of micron-sized theophylline particles prepared by supercritical fluid technology and in-vitro evaluation of their performance as inhaled dry powder formulations." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4297.
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The aim of this work is to study the in-vitro aerodynamic performance of a new inhaled theophylline formulation prepared by supercritical fluids technique. For the analysis of the output from the in-vitro tests (and further in-vivo tests) a new, fast, sensitive high performance liquid chromatographic (HPLC) method was developed and validated for the determination of theophylline and other related derivatives in aqueous and urine samples using new packing materials (monolithic columns). These columns achieve efficient separation under lower backpressure and shorter time comparing to other traditionally or newly introduced C18 columns. Solution enhanced dispersion by supercritical fluid (SEDS) process has been applied for the production of anhydrous theophylline as pure crystals in the range 2-5 μm to be used as new inhaled dry powder formulation for asthma. Fifteen theophylline samples have been prepared under different experimental conditions. The drug produced by this method has been subject to a number of solid-phase analytical procedures designed to establish the crystal structure [X-ray powder diffraction (XRPD)], the structure and conformation [(FTIR), Fourier-transform Raman spectroscopy (FT-Raman)], and the morphology and particle size [scanning electron microscope (SEM)]. While, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) have been used to monitor any phase transition or polymorphic changes after processing. All these analytical techniques gave a satisfactory indication of the solid-state chemistry of the processed particles and assess the development of new inhalation product. The performance of inhaled SEDS theophylline with or without a carrier was evaluated using the developed HPLC method. Three samples having different particle sizes were selected out of the prepared powders by SEDS technique to be tested. The dose sampling unit and the Anderson Cascade Impactor were used to determine the in-vitro emitted dose and the deposition profiles of SEDS samples, respectively. The effect of different inhalation flows was studied using two different flows 28.3, and 60 L min-1 with 4 L inhalation volume. Different DPI devices were investigated in this study; Easyhaler® and Spinhaler®. The particle size has an important effect on the aerodynamic behaviour and deposition profile of inhaled drug, the smaller the particles the greater the total lung deposition. The presence of a carrier improves the respirable fraction for all the tested formulations.
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Mohamed, Noha N. A. "Pharmaceutical analysis and in-vitro aerodynamic characterisation of inhaled theophylline formulations containing drug particles prepared by supercritical fluid processing. Chromatographic, spectroscopic, and thermal analysis of micron-sized theophylline particles prepared by supercritical fluid technology and in-vitro evaluation of their performance as inhaled dry powder formulations." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4297.
Full textAbstract:
The aim of this work is to study the in-vitro aerodynamic performance of a new inhaled theophylline formulation prepared by supercritical fluids technique.
For the analysis of the output from the in-vitro tests (and further in-vivo tests) a new, fast, sensitive high performance liquid chromatographic (HPLC) method was developed and validated for the determination of theophylline and other related derivatives in aqueous and urine samples using new packing materials (monolithic columns). These columns achieve efficient separation under lower backpressure and shorter time comparing to other traditionally or newly introduced C18 columns.
Solution enhanced dispersion by supercritical fluid (SEDS) process has been applied for the production of anhydrous theophylline as pure crystals in the range 2-5 ¿m to be used as new inhaled dry powder formulation for asthma. Fifteen theophylline samples have been prepared under different experimental conditions.
The drug produced by this method has been subject to a number of solid-phase analytical procedures designed to establish the crystal structure [X-ray powder diffraction (XRPD)], the structure and conformation [(FTIR), Fourier-transform Raman spectroscopy (FT-Raman)], and the morphology and particle size [scanning electron microscope (SEM)]. While, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) have been used to monitor any phase transition or polymorphic changes after processing. All these analytical techniques gave a satisfactory indication of the solid-state chemistry of the processed particles and assess the development of new inhalation product.
The performance of inhaled SEDS theophylline with or without a carrier was evaluated using the developed HPLC method. Three samples having different particle sizes were selected out of the prepared powders by SEDS technique to be tested. The dose sampling unit and the Anderson Cascade Impactor were used to determine the in-vitro emitted dose and the deposition profiles of SEDS samples, respectively. The effect of different inhalation flows was studied using two different flows 28.3, and 60 L min-1 with 4 L inhalation volume. Different DPI devices were investigated in this study; Easyhaler® and Spinhaler®. The particle size has an important effect on the aerodynamic behaviour and deposition profile of inhaled drug, the smaller the particles the greater the total lung deposition. The presence of a carrier improves the respirable fraction for all the tested formulations.Egyptian Ministry of Higher Education
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Viljoen, Francois Petrus. "Quantification of 3-methoxy-4-hydroxyphenylglycol in human saliva by an optimised HPLC method with electrochemical detection." Thesis, Bloemfontein : Central University of Technology, Free State, 2011. http://hdl.handle.net/11462/17.
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Friberg, Andrew S. "Standardization of Islet Isolation and Transplantation Variables." Doctoral thesis, Uppsala universitet, Klinisk immunologi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-150247.
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Currently, the transplantation of islets of Langerhans is a viable means to maintain control of blood sugar levels and reduce the risk of hypoglycemia in defined populations with brittle type I diabetes mellitus or those requiring pancreatectomy. However, the process of islet isolation is highly variable and not all isolations result in islet numbers or quality suitable for transplantation. This thesis aimed to improve transplantation success through optimization and standardization of the isolation process and to identify pretransplant variables associated with early islet engraftment. A previously disregarded enzyme activity, tryptic-like activity (TLA), has been identified to influence pancreas digestion efficiency and islet isolation success in both the preclinical and clinical situations. For human pancreases, islet isolation success rates improved from 0% in the lowest TLA group to over 50% in the highest TLA groups without affecting islet quality. These findings should help standardize evaluation of enzymes for clinical islet isolation. A closed, automated, pump-made gradient system was compared to the open, manual method for islet separation. No differences were observed in expected gradient volumes, islet yields or total purities between the two methods. The pump-made gradient system successfully removed manual influences on density gradient production while fulfilling regulatory requirements for closed system processing. Islet quantification was evaluated with computer-assisted digital imaging analysis (DIA) and a semi-closed assessment system. By using the DIA system method, which measures islet purity and pellet volume instead of manual counting methods, variation in islet counts and purity reduced by almost half. By using a transplant outcome measurement of C-peptide adjusted by blood glucose and creatinine, we identified four pretransplant factors that affect early transplant outcome. Of the four factors, one was related to the organ transport time, one to function of the islets, and two to the transplanted tissue volume. When these four factors were put into a predictive model, it accounted for about 40% of the transplant outcome. The work contained in this thesis identifies and optimizes a number of critical elements related to islet isolation and transplantation protocols.
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Filippe, Tais Cristina. "Cafeína, fármacos, hormônios e produtos de cuidados pessoais no Rio Palmital - PR." Universidade Tecnológica Federal do Paraná, 2018. http://repositorio.utfpr.edu.br/jspui/handle/1/3146.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Uma grande variedade de produtos que estão presentes no cotidiano da população é continuamente lançada nos ecossistemas aquáticos. Esses produtos contêm compostos de diferentes classes, como fármacos, hormônios, produtos de cuidados pessoais, entre outros. O crescente interesse por essas substâncias ocorre principalmente porque elas podem exibir atividade biológica em concentrações muito baixas, da ordem de µg L-1 e ng L-1 . Portanto, neste trabalho, foi avaliada a presença e determinada a concentração de 20 microcontaminantes, pertencentes a diferentes classes (antiinflamatórios, reguladores lipídicos, antimicrobianos, antissépticos, hormônios sexuais e cafeína), no rio Palmital, localizado na Região Metropolitana de Curitiba. Para investigar a presença desses poluentes, foi realizado o monitoramento ao longo de quatro coletas, em sete pontos de amostragem no rio Palmital. As amostras coletadas foram submetidas ao processo de extração em fase sólida e posteriormente os compostos foram determinados utilizando cromatografia em fase líquida com detector de arranjo de diodos e cromatografia em fase gasosa hifenada a espectrometria de massas. A validação da metodologia utilizada baseou-se nos padrões estabelecidos pela Agência Nacional de Vigilância Sanitária e pelo Instituto Nacional de Metrologia. O método de extração e quantificação foi eficiente para a determinação desses analitos em amostras de água. Dentre os contaminantes analisados, a Cafeína foi detectada em quase 100% das amostras e teve a concentração mais elevada (3,58 µg L-1 ). Entre os produtos farmacêuticos investigados, o cetoprofeno esteve presente em 27 das 28 amostras analisadas, porém em concentrações mais baixas (concentração máxima de 0,18 µg L-1 ) que os demais fármacos; o ácido acetilsalicílico teve a maior concentração (2,31 µg L-1 ) seguida do paracetamol (1,28 µg L-1 ). Concentrações significativas de hormônios também foram quantificadas no rio Palmital, assim como os parabenos e triclosan indicando uma possível influência antrópica no ambiente aquático estudado. Observou-se que ocorreram mudanças associadas a variações sazonais, sendo que em período de estiagem (outubro/2016 e julho/2017), as concentrações foram mais elevadas para a maioria dos contaminantes analisados no rio Palmital. Com o tratamento estatístico dos dados foi possível verificar uma relação entre os contaminantes emergentes estudados em conjunto com as concentrações de Namoniacal e ortofosfato. Os resultados indicaram que o rio Palmital apresentou grande influência antrópica, possivelmente aporte de efluentes domésticos provenientes de áreas densamente povoadas, as quais possuem um serviço de coleta e tratamento de esgoto que não atende a todos os domicílios.
A wide variety of products present in the daily life of the population is released into aquatic ecosystems. These products contain compounds of different classes, such as pharmaceuticals, hormones, personal care products, among others. The growing interest in these substances occurs mainly because they may exhibit biological activity at very low concentrations of the order of μg L-1 and ng L-1 . Thus, it was evaluated in the presence and concentration of 20 microcontaminants belonging to different classes (anti-inflammatories, lipid regulators, antimicrobials, antiseptics, sex hormones and caffeine) in the Palmital River, located in the Metropolitan Region of Curitiba. In order to investigate the presence these pollutants, monitoring was carried out over four samplings at seven points on the Palmital River. The collected samples were submitted to extraction in solid phase and analyzed by liquid phase chromatography with diode array detector and gas chromatography tandem mass spectrometry. The validation of the methodology used was based on the standards established by the Agência Nacional de Vigilância Sanitária and the Instituto Nacional de Metrologia. The extraction and quantification method were efficient for the determination of these analytes in water samples. Among the contaminants analyzed, Caffeine was detected in almost 100% of the samples and had the highest concentration (3.58 μg L-1 ). Among the investigated pharmaceutical products, ketoprofen was present in 27 of the 28 analyzed samples, but in lower concentrations (maximum concentration of 0.18 μg L-1 ) than the other drugs; acetylsalicylic acid had the highest concentration (2.31 μg L-1 ) followed by paracetamol (1.28 μg L-1 ). Significant concentrations of hormones were also quantified in the Palmital river, as well as the parabens and triclosan indicating a possible anthropic influence in the aquatic environment studied. It was observed that changes were associated with seasonal variations, and in the drought period (October / 2016 and July / 2017) the concentrations were higher for most of the contaminants analyzed in the Palmital River. With the statistical treatment of the data it was possible to verify the relation between the emerging contaminants studied together with the concentrations of Nammonia and Orthophosphate. The results indicated that the Palmital River presents a great anthropic influence, possibly due to the contribution of domestic effluents from densely populated areas, which have a sewage collection and treatment service that does not serve all households.
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Mileros, Martin D. "A Real-Time Classification approach of a Human Brain-Computer Interface based on Movement Related Electroencephalogram." Thesis, Linköping University, Department of Mechanical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2824.
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A Real-Time Brain-Computer Interface is a technical system classifying increased or decreased brain activity in Real-Time between different body movements, actions performed by a person. Focus in this thesis will be on testing algorithms and settings, finding the initial time interval and how increased activity in the brain can be distinguished and satisfyingly classified. The objective is letting the system give an output somewhere within 250ms of a thought of an action, which will be faster than a persons reaction time.
Algorithms in the preprocessing were Blind Signal Separation and the Fast Fourier Transform. With different frequency and time interval settings the algorithms were tested on an offline Electroencephalographic data file based on the "Ten Twenty" Electrode Application System, classified using an Artificial Neural Network.
A satisfying time interval could be found between 125-250ms, but more research is needed to investigate that specific interval. A reduction in frequency resulted in a lack of samples in the sample window preventing the algorithms from working properly. A high frequency is therefore proposed to help keeping the sample window small in the time domain. Blind Signal Separation together with the Fast Fourier Transform had problems finding appropriate correlation using the Ten-Twenty Electrode Application System. Electrodes should be placed more selectively at the parietal lobe, in case of requiring motor responses.
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Razavilar, Negin. "Chromatographic separation of asphaltenes on silica materials." Master's thesis, 2009. http://hdl.handle.net/10048/708.
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Thesis (M. Sc.)--University of Alberta, 2009.Title from pdf file main screen (viewed on Dec. 11, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Chemicals and Materials Engineering, University of Alberta." Includes bibliographical references.
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Al-Somali, Ali M. "Chromatographic methods for the separation and analysis of gold nanocrystals." Thesis, 2006. http://hdl.handle.net/1911/18868.
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With the ever growing applications of nanomaterials, fast, accurate and cost effective characterization methodologies are needed to ensure high quality materials and practical manufacturing. This problem is a challenging one as nanoparticle shape, size and size distribution are all important features which govern properties as diverse as sample melting point and chemical reactivity. New methods that provide key analytical information, along with a means of improving size and shape distributions would have substantial impact on this growing area. Chromatography is a technique which traditionally has been used to both provide analysis as well as separation of high valued added chemicals. Its applications in nanoscience are to date quite limited, and the objective of this thesis is to demonstrate that chromatographic techniques can be used to measure the dimensions of gold nanocrystals in solution as well as provide methods for physically separating complex distributions of particles.
Recycling size exclusion chromatography (RSEC) has been employed to effect physical, base-line separation of subpopulations of spherical gold nanocrystals. This method can be easily applied on other nanocrystalline systems and is scalable to large production. Anisotropic gold nanocrystals, such as gold nanorods, exhibit spectacular optical properties that can be utilized in medical and biological fields. An analytical method, based on aqueous SEC that determines the dimensions of gold nanorods has been developed. The method couples the hydrodynamic volume obtained from SEC and aspect ratio from absorption spectra to provide a complete assessment of nanorod ensembles directly in liquid phase media. Additionally, a close analysis of the hydrodynamic values reveals that the nanorods are aligned with the flow, which makes the separation responsive to variations in aspect ratio. Finally, conventional chromatography provides a resolution which is not large enough to sharpen the distributions of the most monodisperse nanoparticles now produced directly in solution. The application of super high-resolution methods, such as critical point chromatography, can substantially improve the separation power and its application to polymer stabilized gold nanocrystals has been demonstrated.
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Rios, Albertina Gonçalves. "Chromatographic Separation of Dyes in a Fixed Bed Adsorber." Dissertação, 2017. https://repositorio-aberto.up.pt/handle/10216/106144.
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Rios, Albertina Gonçalves. "Chromatographic Separation of Dyes in a Fixed Bed Adsorber." Master's thesis, 2017. https://repositorio-aberto.up.pt/handle/10216/106144.
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