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Dissertations / Theses on the topic 'High performance liquid chromotography'

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Published: 4 June 2021

Last updated: 10 February 2022

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1

Li, Zhiguo. "High-performance liquid chromotography analysis of fatty acids and mathematical modeling of liquid chromotography." Ohio University / OhioLINK, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1179157379.

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2

Ghugare, Tushar. "Exploring Zirconia as a Column Packing Material." TopSCHOLAR®, 2010. http://digitalcommons.wku.edu/theses/194.

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Zirconia is one of the most promising column packing materials for High Performance Liquid Chromatography (HPLC). The perfect HPLC support material should be energetically homogenous, have a high surface area on which different chemical species can reversibly attach and be physically and chemically stable over a wide range of pH, temperature and solvent conditions. Most existing supports do not have all of these properties. This project is also focused on a proteomics study. Zirconia, hafnium oxide and titanium oxide which are some of the more promising materials currently available, can be used for the separation and analysis of phosphorylated proteins. Adenosine triphosphate, Adenosine diphosphate and Adenosine monophosphate were used as prototypes for phosphorylated proteins. Separation, absorption, fluorescence and SEM studies were performed to determine the adsorption of Adenosine phosphates species at a particular pH on Zirconia. Zirconia was also used for the purification of Fibrinogen Growth Factor (FGF) protein, which are a family of growth factors involved in angiogenesis, wound healing, and embryonic development. The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) technique was used to analyze the off-column purification and separation of this protein. This research suggests that, at acidic conditions, adenosine monophosphate has more favorable absorption on the Zirconia surface. On the other hand, the separation study suggests that basic conditions are more favorable for the absorption of ATP, ADP and AMP when mixed together on Zirconia 500. Furthermore, it was found that Zirconia is a very promising material for the purification of FGF protein.

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3

Carpenter, Sarah Elizabeth. "Enzyme linked spectroscopic assays for Glyoxylate the use of Peptidylglycine alpha-Amidating Monoxygenase for the discovery of Novel alpha-Amidated hormones /." [Tampa, Fla] : University of South Florida, 2006. http://purl.fcla.edu/usf/dc/et/SFE0001415.

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4

Lovell, Christopher Stewart. "High performance bioresorbable liquid crystalline polymers." Thesis, University of Leeds, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.511134.

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5

Abid, F. M. "High performance liquid chromatography : theory and applications." Thesis, Swansea University, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.635837.

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A detailed study was undertaken of both the individual and combined effects of pH, temperature and flow rate on the retention volumes of underivatised amino acids. The relative merits of 3-dimensional S-window diagrams to locate the optimum conditions for the separation of amino acids on a stationary phase comprising 5μ ODS has been successfully performed. The enthalpies of retention of transfer from stationary phase to mobile phase for the amino acids have been measured from the chromatographic data. An isocratic study of the separation of phenylthiohyddation (PTH) amino acids using a 3μ MOS Hypersil reverse phase column was performed by the pre-column derivatisation method. Subsequently, a more detailed investigation was made of the various factors which control the separation, viz. pH, temperature and eluent composition. The conditions for optimum separation were located by constructing, with the aid of a computer, a 3-dimensional S-window diagram. The enthalpy of transfer from stationary phase to mobile phase and the entropy of the process were evaluated from the chromatographic data. A new pre-column derivatisation method for the separation of amino acids by gradient elution was established using an ODS column; this was applied to the analysis of amino acids extracted from mammalian tissue. The retention behaviour of PTH-amino acids was studied on a mixed stationary phase comprising silica bonded to alkylcynanide and octyl silica in the ratio of 60:40, w/w. This factor has an important bearing on the solute retention selectivity of the column. It was found that the selectivity of the acidic and basic PTH-amino acids could be precisely controlled by adjusting the packing percentage and mobile phase composition, suggesting that the mixed phase technique could be profitably exploited for analytical purposes. HPLC group type analyses of oil samples, normally requiring more sophisticated and time consuming methods of analysis, were performed using normal and reverse phase columns of different materials. The separated fraction has been identified by mass spectrometry, and the results obtained have been of some assistance in an investigation relating to poorly combustable oil. Finally, an extended and modified LC theory has been proposed, and a new modified approach which relates the inverse corrected retention volume (1/V<SUB>R</SUB>) and volume fraction composition of polar solvent component (φB) has been established for a polar component variation of 0 to 100% . The results indicate good agreement between the theoretical and experimental values for all systems displaying a non-linear relationship between 1/V<SUB>R</SUB> and φB.

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6

Norcio, Lawrence P. "Stability studies of coal liquid products using high performance liquid chromatography." Morgantown, W. Va. : [West Virginia University Libraries], 1999. http://etd.wvu.edu/templates/showETD.cfm?recnum=984.

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Thesis (Ph. D.)--West Virginia University, 1999.<br>Title from document title page. Document formatted into pages; contains xi, 152 p. : ill. (some col.) Vita. Includes abstract. Includes bibliographical references (p. 127-133).

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7

Edwardson, P. A. D. "High Performance Liquid Chromatography of polynucleotides and proteins." Thesis, London School of Hygiene and Tropical Medicine (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.376534.

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8

Aggarwal, Pankaj. "High-Performance Polymer Monoliths for Capillary Liquid Chromatography." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/4236.

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This dissertation focuses on improving the chromatographic efficiency of polymeric organic monoliths by characterizing and optimizing the bed morphology. In-situ characterization techniques such as capillary flow porometry (CFP), 3-dimensional scanning electron microscopy (3D SEM) and conductivity measurements were developed and implemented to quantitatively characterize the morphology of poly(ethylene glycol) diacrylate (PEGDA) monoliths. The CFP measurements for monoliths prepared by the same procedure in capillaries with different diameters (i.e., 75, 150, and 250 μm) clearly showed a change in average through-pore size with capillary diameter, thus, certifying the need for in-situ measurement techniques. Serial sectioning and imaging of PEGDA monoliths using 3D SEM gave quantitative information about the average pore size, porosity, radial heterogeneity and tortuosity of the monolith. Chromatographic efficiency was better for a monolith with smaller average pore size (i.e., 5.23 μm), porosity (i.e., 0.49), radial heterogeneity (i.e., 0.20) and tortuosity (i.e., 1.50) compared to another monolith with values of 5.90 μm, 0.59, 0.50 and 2.34, respectively. Other than providing information about monolith morphology, these techniques also aided in identifying factors governing morphological changes, such as capillary diameter, polymerization method, physical/chemical properties of the pre-polymer constituents and weight proportion of the same. A statistical model was developed for optimizing the weight proportion of pre-polymer constituents from their physical/chemical properties for improved chromatographic efficiency. Fabricated PEGDA columns were used for liquid chromatography of small molecules such as phenols, hydroxyl benzoic acids, and alkyl parabens. The chromatographic retention mechanism was determined to be principally reversed-phase (RP) with additional hydrogen bonding between the polar groups of the analytes and the ethylene oxide groups embedded in the monolith structure. The chromatographic efficiency measured for a non-retained compound (uracil) was 186,000 plates/m when corrected for injector dead volume. High resolution gradient separations of selected pharmaceutical compounds and phenylurea herbicides were achieved in less than 18 min. Column preparation was highly reproducible, with relative standard deviation (RSD) values less than 2.1%, based on retention times of the phenol standards (3 different columns). A further improvement in chromatographic performance was achieved for monoliths fabricated using a different polymerization method, i.e., living free-radical polymerization (LFRP). The columns gave an unprecedented column performance of 238, 000 plates/m for a non-retained compound under RP conditions.

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9

Benson, Andrew James. "High-performance liquid chromatography (HPLC) and high-performance liquid chromatography mass spectrometry (HPLC/MS) for the analysis of date rape drugs." FIU Digital Commons, 2002. http://digitalcommons.fiu.edu/etd/1602.

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The drugs studied in this work have been reportedly used to commit drug-facilitated sexual assault (DFSA), commonly known as "date rape". Detection of the drugs was performed using high-performance liquid chromatography with ultraviolet detection (HPLC/UV) and identified with high performance-liquid chromatography mass spectrometry (HPLC/MS) using selected ion monitoring (SIM). The objective of this study was to develop a single HPLC method for the simultaneous detection, identification and quantitation of these drugs. The following drugs were simultaneously analyzed: Gamma-hydroxybutyrate (GHB), scopolamine, lysergic acid diethylamide, ketamine, flunitrazepam, and diphenhydramine. The results showed increased sensitivity with electrospray (ES) ionization versus atmospheric pressure chemical ionization (APCI) using HPLC/MS. HPLC/ES/MS was approximately six times more sensitive than HPLC/APCI/MS and about fifty times more sensitive than HPLC/UV. A limit of detection (LOD) of 100 ppb was achieved for drug analysis using this method. The average linear regression coefficient of correlation squared (r2) was 0.933 for HPLC/UV and 0.998 for HPLC/ES/MS. The detection limits achieved by this method allowed for the detection of drug dosages used in beverage tampering. This method can be used to screen beverages suspected of drug tampering. The results of this study demonstrated that solid phase microextraction (SPME) did not improve sensitivity as an extraction technique when compared to direct injections of the drug standards.

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10

Anyakoha, Ngozi G. "Fatty acid and lipid profiles in models of neuroinflammation and mood disorders. Application of high field NMR, gas chromotography and liquid chromotography-tandem mass spectrometry to investigate the effects of atorvaststin in brain and liver lipids and explore brain lipid changes in the FSL model of depression." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4328.

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Lipids are important for the structural and physiological functions of neuronal cell membranes. Alterations in their lipid composition may result in membrane dysfunction and subsequent neuronal deficits that characterise various disorders. This study focused on profiling lipids of aged and LPS-treated rat brain and liver tissue with a view to explore the effect of atorvastatin in neuroinflammation, and examining lipid changes in different areas of rat brain of the Flinders Sensitive Line (FSL) rats, a genetic model of depression. Lipids and other analytes extracted from tissue samples were analysed with proton nuclear magnetic resonance spectroscopy (1H-NMR), gas chromatography (GC) and liquid chromatography-tandem mass spectroscopy (LC/ESI-MS/MS). Changes in the lipid profiles suggested that brain and liver responded differently to ageing and LPS-induced neuroinflammation. In the aged animals, n-3 PUFA were reduced in the brain but were increased in the liver. However, following treatment with LPS, these effects were not observed. Nevertheless, in both models, brain concentration of monounsaturated fatty acids was increased while the liver was able to maintain its monounsaturated fatty acid concentration. Atorvastatin reversed the reduction in n-3 PUFA in the aged brain without reducing brain and liver concentration of cholesterol. These findings further highlight alterations in lipid metabolism in agerelated neuroinflammation and show that the anti-inflammatory actions of atorvastatin may include a modulation of fatty acid metabolism. When studying the FSL model, there were differences in the lipid profile of different brain areas of FSL rats compared to Sprague-Dawley controls. In all brain areas, arachidonic acid was increased in the FSL rats. Docosahexaenoic acid and ether lipids were reduced, while cholesterol and sphingolipids were increased in the hypothalamus of the FSL rats. Furthermore, total diacylglycerophospholipids were reduced in the prefrontal cortex and hypothalamus of the FSL rats. These results show differences in the lipid metabolism of the FSL rat brain and may be suggestive of changes occurring in the brain tissue in depression.

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11

Anyakoha, Ngozi Gloria. "Fatty acid and lipid profiles in models of neuroinflammation and mood disorders : application of high field NMR, gas chromotography and liquid chromotography-tandem mass spectrometry to investigate the effects of atorvaststin in brain and liver lipids and explore brain lipid changes in the FSL model of depression." Thesis, University of Bradford, 2009. http://hdl.handle.net/10454/4328.

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Lipids are important for the structural and physiological functions of neuronal cell membranes. Alterations in their lipid composition may result in membrane dysfunction and subsequent neuronal deficits that characterise various disorders. This study focused on profiling lipids of aged and LPS-treated rat brain and liver tissue with a view to explore the effect of atorvastatin in neuroinflammation, and examining lipid changes in different areas of rat brain of the Flinders Sensitive Line (FSL) rats, a genetic model of depression. Lipids and other analytes extracted from tissue samples were analysed with proton nuclear magnetic resonance spectroscopy (1H-NMR), gas chromatography (GC) and liquid chromatography-tandem mass spectroscopy (LC/ESI-MS/MS). Changes in the lipid profiles suggested that brain and liver responded differently to ageing and LPS-induced neuroinflammation. In the aged animals, n-3 PUFA were reduced in the brain but were increased in the liver. However, following treatment with LPS, these effects were not observed. Nevertheless, in both models, brain concentration of monounsaturated fatty acids was increased while the liver was able to maintain its monounsaturated fatty acid concentration. Atorvastatin reversed the reduction in n-3 PUFA in the aged brain without reducing brain and liver concentration of cholesterol. These findings further highlight alterations in lipid metabolism in agerelated neuroinflammation and show that the anti-inflammatory actions of atorvastatin may include a modulation of fatty acid metabolism. When studying the FSL model, there were differences in the lipid profile of different brain areas of FSL rats compared to Sprague-Dawley controls. In all brain areas, arachidonic acid was increased in the FSL rats. Docosahexaenoic acid and ether lipids were reduced, while cholesterol and sphingolipids were increased in the hypothalamus of the FSL rats. Furthermore, total diacylglycerophospholipids were reduced in the prefrontal cortex and hypothalamus of the FSL rats. These results show differences in the lipid metabolism of the FSL rat brain and may be suggestive of changes occurring in the brain tissue in depression.

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12

Nordman, Tomas. "In vitro studies on the biosynthesis and reduction of ubiquinone /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-475-5/.

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13

Hider, Gregg C. "High-performance liquid chromatographic analysis of commonly used drugs /." Online version of thesis, 1988. http://hdl.handle.net/1850/10693.

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Thesis (M.S.)--Rochester Institute of Technology, 1988.<br>Includes Addendum: High-performance liquid chromatographic analysis of commonly used drugs: Six laboratory experiments for clinical chemistry students. Includes bibliographical references (leaves 48-52).

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14

Young, Erepamowei. "Nebulized flame ionization detection in high performance liquid chromatography." Thesis, Loughborough University, 2008. https://dspace.lboro.ac.uk/2134/15141.

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A nebulized flame ionization detector interfaced with LC was examined and found to be more versatile in applications than common LC detectors, such as UV, RID, ELSD and CAD. The technique can be used for both volatile and non-volatile analytes. It is compatible with gradient elution and can be used for the analysis of non chromophore-possessing analytes. The calibration plots of non-volatile analytes were linear in contrast to other aerosol-based detectors, such as ELSD and CAD. The technique was examined in three consecutive stages; optimization of the FID, testing the response patterns of analytes (volatile and non-volatile) and applications to the analysis of compounds of diverse functional groups. The optimum conditions for the operation of the FID were: hydrogen, 157 ml/min; nitrogen, 250 ml/min; air, 654 ml/min; spray chamber internal diameter, 40 mm, collector internal diameter, 4mm and eluent (water), 1 ml/min. The calibration plots of all volatile analytes were linear while those of the non-volatile analytes were linear only when anions (in the form of sulfuric acid, nitric acid, hydrochloric acid, orthophosphoric acid, sodium sulphate and ammonium sulphate) were added to the eluent The separations of diverse analytes (alcohols, aldehydes, ketones, amines, amino acids, carboxylic acids and sugars) gave detection limits in the low μg range.

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15

Meeson, Stephen Russell. "The separation of enantiomers by high performance liquid chromatography." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278414.

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16

Sabharwal, Arvind. "Preparative reversed-phase high performance liquid chromatography of proteins." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.361678.

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17

Mohd, Noor Laili Rusman. "Determination of transition metals by high performance liquid chromatography." Thesis, Sheffield Hallam University, 1990. http://shura.shu.ac.uk/20176/.

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A simple chromatographic analysis system was developed based on dynamic ion pairing using long chain anionic modifiers with a silica reversed phase based column. The aim was to carry out simultaneous multielement quantitative as well as qualitative analysis of samples containing mixtures of transition metal ions. Among the problems encountered and solved were: metalcontamination of the eluent,finding a suitable pump for the system, minimising the noise and reducing the elution times. Detection of the separated metal ions was enabled by post-column derivatisation prior to introduction to thespectrophotometric detector. This introduced many problems as the eluent and post-column reagent stream must beproperly mixed and reacted to ensure successful detection. The design and orientation of the device used for this purpose is also critical and this was studied in detail. The role played by the various constituents of the eluent in the chromatographic separation was investigated thoroughly to enable modifications to it to be made so that thechromatographic analysis could be optimised. It wasdiscovered that retention times were greatly affected byvariations in concentration and type of anionic modifier, concentration and composition of the complexing agent in the eluent and variations in the pH of the eluent. This enabled better understanding of the retention mechanism and a retention mechanism model for a dynamically coated column was proposed. Separation of copper, lead, zinc, nickel, cobalt, cadmiumand manganese in seven minutes was achieved using a mobile phase containing sodium hexanesulphate as anionic modifier, hydrogen tartrate as complexing agent at pH 3.1, with 4-(2-pyridylazo)resorcinol (PAR) detection monitored at 510 nm. Under these conditions, limits of detection in the range of 2 - 20 p.p.b. were achieved for 20 muL injections.

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18

Sun, Yaqin. "Exploration in Analytical Separations Using High Performance Liquid Chromatography." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1148586934.

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19

Li, Zhiguo. "High-performance liquid chromatography analysis of fatty acids and mathematical modeling of liquid chromatography." Ohio : Ohio University, 2001. http://www.ohiolink.edu/etd/view.cgi?ohiou1179157379.

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20

Lei, Tian. "Selenium speciation by high performance liquid chromatography -atomic absorption spectrometry." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=55507.

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Selenium has been shown to have multiple biochemical effects ranging from nutrient deficiency at low levels to toxicity at high levels. This duality of concern has led to a demand for increased numbers of highly accurate and precise determinations of selenium in biological materials. A convenient procedure was developed for determining selenoamino acids by HPLC-THG-AAS, based on the derivatization of these analytes with Sanger's reagent. Selenomethionine, selenocystine and selenocysteine (after blocking the free selenol group with phenylmercurio cation) were converted to their N-2,4-dinitrophenyl derivatives, and separated on a Nucleosil 5-NO$ sb2$ column with methanolic mobile phase containing acetic acid and triethylamine. Furthermore, an improved HPLC-AAS interface design was modified and optimized for the detection of selenium in HPLC column eluate. The new design was (i) compatible with aqueous mobile phases containing volatile buffers and (ii) provided equivalent molar response to analytes containing Se($-$II), Se(+IV) and Se(+VI). A method for simultaneously determination of selenate, selenite, selenocystine, selenomethionine and selenoethionine was developed by using the HPLC-AAS system with aqueous acetic acid containing ammonium acetate as eluate solution on the cyanopropyl column. The equivalent low ng limits of detection (1-2 ng as Se) for different oxidation states of selenium analytes were obtained using several different mobile phases and/or columns. A phenol extraction procedure for selenate, selenite, selenocystine, selenomethionine and selenoethionine was evaluated for the determination of these selenium analytes in natural waters and wheat samples. The current HPLC-AAS system provides an inexpensive alternative to conventional techniques for the determination of selenium analytes in environmental samples.

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21

Zhong, Qiqing. "Chemical separations by distillation and chiral high performance liquid chromatography." [Ames, Iowa : Iowa State University], 2006.

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22

Plant, Stephen Paul. "Novel bonded polymeric stationary phases in high performance liquid chromatography." Thesis, Cardiff University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278702.

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23

Hamzah, Mohd Suhaimi. "Separation and determination of lanthanides by high performance liquid chromatography." Thesis, University of Salford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308131.

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24

Teoh, Hooi Kim. "Optimal design and operation of high performance liquid chromatographic process." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270532.

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25

Sexton, Danessa Leann. "Determination of lactose by reversed-phase high performance liquid chromatography." [Johnson City, Tenn. : East Tennessee State University], 2004. http://etd-submit.etsu.edu/etd/theses/available/etd-0328104-212023/unrestricted/SextonD041504f.pdf.

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Thesis (M.S.)--East Tennessee State University, 2004.<br>Title from electronic submission form. ETSU ETD database URN: etd-0328104-212023. Includes bibliographical references. Also available via Internet at the UMI web site.

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26

Sidwell, Rachel. "Analysis of Glyoxalase II Activity by High Performance Liquid Chromatography." Miami University Honors Theses / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=muhonors1111089246.

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27

Fong, Yuen Ting. "Quantitative structure retention relationships on using high-performance liquid chromatography." HKBU Institutional Repository, 2003. http://repository.hkbu.edu.hk/etd_ra/426.

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28

Scherzinger, Sabine Hilda. "Phenylpropanolamine : analytical and pharmacokinetic studies using high-performance liquid chromatography." Thesis, Rhodes University, 1988. http://hdl.handle.net/10962/d1004528.

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Phenylpropanolamine (PPA), a synthetic sympathomimetic amine structurally related to ephedrine has been widely used over t he past 40 years as a nasal decongestant and appetite suppressant. It has been the focus of much controversy concerning the efficacy of the drug in its use as an anorectic agent, and due to the side effects caused by the higher doses of PPA required for appetite suppression. Although extensively used, there is little information concerning the determination of PPA in biological fluids and on the pharmacokinetics of this drug. An adaptation of a published high-performance liquid chromatographic (HPLC) assay for PPA in serum and urine using U.V. detection at 210 nm is presented. PPA was separated in the reversed phase mode. The method has a limit of sensitivity of 5.0 ng/mL and 10.0 ng/mL in serum and urine respectively. Serum concentration data following a single 25 mg dose of phenylpropanolamine in human volunteers demonstrate the application of the analytical method for bioavailability and pharmacokinetic studies. After the administration of 25 mg, 50 mg or 100 mg PPA.HCl solutions to 5 human volunteers, a dose proportionality study demonstrated that PPA appears to exhibit linear kinetics. Linear one body compartment kinetics were assumed and the wagner-Nelson method used to transform in vivo serum data to absorption plots. The serum data were fitted to a model using nonlinear regression techniques to characterize the pharmacokinetic processes of PPA. The absorption of phenylpropanolamine appears to be discontinuous and the drug seems to favour a two body compartment model. The pharmacokinetic parameters obtained from a steady state study using multiple dosing of PPA.HCl solutions compared with those found from previous studies after the administration of sustained-release formulations. A plasma protein binding study using equilibrium dialysis demonstrated that PPA is not highly protein bound in the blood.

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29

Ritchie, Harald John. "Development of new packing materials for high performance liquid chromatography." Thesis, University of Edinburgh, 1987. http://hdl.handle.net/1842/14283.

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30

Van, Meter David S. III. "Synthesis and Characterization of Surface-Confined Ionic Liquid Stationary Phases for High Performance Liquid Chromatography." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1227275073.

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31

Murphy, Kellyann M. "Analysis of Biodiesel Quality Using Reversed Phase High-Performance Liquid Chromatography." Scholarship @ Claremont, 2012. http://scholarship.claremont.edu/pomona_theses/45.

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The alternative fuel biodiesel is produced from the transesterification of vegetable oils or animal fat to fatty acid methyl esters. Pomona has a reactor on campus that can be used to run this reaction and produce biodiesel. The use of biodiesel has been found to lower air pollutant and greenhouse gas emissions, but can be potentially harmful to the engines if it contains impurities. This paper proposes a method using high-performance liquid chromatography to test the quality of biodiesel. This method utilizes instrumentation and materials that are available in Pomona College's Chemistry Department, requires very little sample preparation, and is relatively safe, as long as general lab safety practices are followed. This method can also be used to optimize the procedure used to make the biodiesel. An optimized production procedure and a test method to assess the final product will ensure high quality fuel that can be used with confidence in diesel engines. This will likely add strength to proposals to increase the use of the on-campus reactor and produce biodiesel for campus grounds equipment from waste vegetable oil.

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32

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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33

Kaur, Bulvinder. "Porous graphitic carbon : a new material for high performance liquid chromatography." Thesis, University of Edinburgh, 1986. http://hdl.handle.net/1842/12218.

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This thesis is divided into four parts. In the first part, the history of chromatography is described. Different modes of chromatography are briefly discussed and a survey of stationary phases being used in High Performance Liquid Chromatography (HPLC) is made. The need for a non-polar reversed-phase stationary phase is highlighted. A brief survey of the use of carbon by other workers in liquid chromatography is also made. The second part of the thesis deals with the production and structural study of porous graphitic carbon (PGC). the different stages of production of PGC are discussed. Pore volume and surface area studies on PGC have also been made. A detailed structural study of PGC has been presented. The third part of the thesis deals with the literature survey of the formation of surface complexes on carbon and the gas reactions of carbon, an understanding of which was necessary for the production and control of the final quality of PGC. The fourth part of the thesis deals with the use of PGC in HPLC. A packing method for PGC has been investigated. Different batches of PGC's produced have been tested with standard test solutes. A separation of a wide variety of solutes, including polymethylphenols, polymethylbenzenes, alkylbenzenes, bases, acids, polyaromatic hydrocarbons, pheynl ketones and phthalates on PGC have been achieved. Analgesics can also be separated. Solvent strengths on PGC have been investigated using different solvents and different solutes.

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34

Wu, Zhiwei. "The study of cell surface phenotypes by high performance liquid chromatography." Thesis, University of Edinburgh, 1990. http://hdl.handle.net/1842/11961.

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Size-exclusion high performance liquid chromatography was developed to study surface membrane proteins of malignant lymphocytes. The membrane proteins were separated in accordance to their molecular sizes or complexed sizes and displayed, in conjunction with SDS-PAGE, as two-dimensional matrices on which the location of proteins is determined by both retardation in the HPLC column and the mobility on the SDS-PAGE gels. Any association or induced-interaction between proteins are reflected by predictable changes of the retention times, thus by the location on the two-dimensional matrix. Individual membrane proteins in the mixture were identified or separated by the changes in their retardation in the column when mAb-Ag complexes formed by applying specific monoclonal antibodies to the extracts of vectorially labelled cells. A number of surface markers have been identified and several new components are characterized. This study has demonstrated that (1) SE-HPLC is a potent method for analysis of complicated mixtures, particularly when a complete separation is not necessary (2) the technique has advantages for the study of non-covalentinteractions between proteins, particularly valuable for antibodies of low affinity (3) the method is powerful for compositional study and initiative investigation of the complexity of mixtures. By using this technique in conjunction with SDS-PAGE, B-CLLs were found to have heterogeneous surface phenotypic presentations with respect to both quantity and quality. The HPLC-SDS PAGE study revealed that the expression levels of individual surface components in B-CLL patients were at a correlated fashion and, across the patient panel, present a continuous spectrum of such relationships, confirmed the earlier reports of immunological studies by Maddy et.al. that individual B-CLL patients can be ranked in a sequence according to their expression level of CD45 isoforms and that this sequential variation of CD45 is in correlation with levels of sIg and CD21. In addition, this study discovered a group of uncharacterized proteins, band 4.1 (160KD), band 4.3 (135KD) and band 2 (300KD) which are also correlated with CD45RA, CD21 and sIg. A comprehensive repertoire of B-CLL phenotypes has been established with respect to the membrane protein expression.

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35

Garba, A. "Reverse-phase high performance liquid chromatography of some Group (III) oxinates." Thesis, University of Salford, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.356196.

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36

Lee, Suk Hean. "Investigation of alcoholic and malolactic fermentation using high performance liquid chromatography." Thesis, Anglia Ruskin University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327472.

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37

Mew, Christopher Derwent. "A prototype multiplexed UV absorbance detector for high performance liquid chromatography." Thesis, King's College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.324979.

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38

Narine, Raymond. "A novel microcomputer-controlled transport detector for high-performance liquid chromatography." Thesis, King's College London (University of London), 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.281718.

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39

Li, F. "Studies of haem biosynthesis and metabolism by high-performance liquid chromatography." Thesis, University of Cambridge, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.378943.

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40

El-Rjoob, Abdul-Wahab. "Dynamic stationary phase modification in reversed-phase high performance liquid chromatography /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9720536.

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41

Liu, Fuyou. "Determination of Hydroquinone in Cosmetic Creams by High Performance Liquid Chromatography." Digital Commons @ East Tennessee State University, 2007. https://dc.etsu.edu/etd/2114.

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Hydroquinone is a most commonly used whitening agent in cosmetics. A high performance liquid chromatography method was developed and validated for the quantitative determination of hydroquinone in creams. Validation parameters such as linearity, precision, accuracy, and limit of detection and limit of quantitation were determined. HPLC was carried by reverses phase technique on a RP-C18 column with a mobile phase of water and methanol (pH 5.0) 70:30. The linearity in the range of 2.0-40.0 μg/mL presents a correlation coefficient of 0.9998. The LOD and LOQ were 0.16 and 0.53 μg/mL, respectively. The precision of the method was found to be satisfactory with a coefficient of variation below 2.2%. The recovery values were in the range of 92.4 to 99.0%. The method is sensitive, fast, and simple. It has been successfully applied to the determination of hydroquinone in cosmetic creams. The results obtained agreed well with the percentages given by the manufacturers.

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42

Stubbs, Christopher. "High performance liquid chromatographic analysis of erythromycin in serum and urine." Thesis, Rhodes University, 1985. http://hdl.handle.net/10962/d1004581.

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Erythromycin, a macrolide antibiotic used mainly against gram-positive bacteria has been in clinical use since 1952 (1). Previous pharmacokinetic data published on this antibiotic have been derived predominantly from microbiological assay techniques. However, these techniques are relatively imprecise as well as being non-specific and extremely tedious to perform. A novel high performance liquid chromatographic analysis of erythromycin in human serum and urine using U.V. detection at 200 nm and/or electrochemical detection using both an amperometric and a coulometric electrochemical detector is presented. The method involves a solid phase extraction procedure followed by a simple phase separation step and chromatography on a reverse phase column. In order to select the optimum U.V. detector for this analysis, five "state of the art" detectors were compared in terms of their signal-to-noise ratios at U.V. wavelengths between 200 and 210 nm. A known metabolite des-N-methylerythromycin is readily detectable using U.V. detection, whilst another metabolite/degradation product anhydroerythromycin is not seen using U.V. detection but is readily observable using an electrochemical detector. The method has a limit of sensitivity of 0.25 μg/mL and 1.00 μg/mL in serum and urine respectively (U.V. detection) and is sufficiently sensitive to monitor serum and urine concentrations of erythromycin in man after administration of a single 500 mg erythromycin stearate tablet.<br>KMBT_363<br>Adobe Acrobat 9.53 Paper Capture Plug-in

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43

DONALD, GREGORY THOMAS. "Model Chiral Ionic Liquids for High Performance Liquid Chromatography Stationary Phases." University of Cincinnati / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1214325450.

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44

Lee, Stephen Thomas. "Evaluation of Enhanced-Fluidity Mobile Phases For High Performance Liquid Chromatography /." The Ohio State University, 1996. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487868114111489.

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45

Mathiba, Kgama. "High pressure liquid chromatographic quantification of nitrile biocatalysis." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1015710.

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Nitrile biocatalysts are of use in the chemical and pharmaceutical industries for the synthesis of carboxyamides and carboxylic acids. In particular, the application of biocatalysts in the synthesis of single enantiomer compounds is of increasing interest, but requires novel substrate specific highly stereoselective biocatalysts. Addition to the limited toolbox of known nitrile biocatalysts requires definitive characterisation of the biocatalysts through accurate determination of the substrate profiles and quantification of activity. The accurate quantification of stereoisomers chiral mixtures to determine biocatalyst stereoselectivity remains a significant challenge due to the difficulty in separating stereoisomers by physical methods. The known nitrile metabolising organism, Rhodococcus rhodochrous ATCC BAA-870, was grown in a defined medium and harvested, providing whole cell biocatalyst. Additional biomass was disrupted to provide a cell free enzyme extract, which was put through an enzyme purification protocol to provide a solution with specific activity of 351 U.mg⁻¹. A portion of the enzyme was self immobilised using the SphereZyme™ technique. The nitrile hydratase SphereZymes™ (1.2 U.mg⁻¹ initial activity) that were prepared had pH and temperature optima of 6 and 30°C respectively, and could be recovered by repeated washing. The particles retained activity in the presence of the organic solvents isooctane and n-hexadecane saturated with 50 mM phosphate buffer (pH 7.5). An initial analytical system was devised for quantification of the nitrile hydratase activity using the non-chiral substrate benzonitrile. An improved reversed phase high performance liquid chromatography method was developed to separate and quantify benzamide, benzoic acid and benzonitrile. The mobile phase consisting of 0.1% trifluoroacetic acid in H₂O and acetonitrile (70:30, %v/v), at a flow rate of 0.5 ml.ml⁻¹, 25°C, resolved all three analytes in 3.5 minutes on a Waters X-Terra MS C18 3.5μm column. UV detection was carried out at 210 nm. Analytical methods to determine activity and enantioselectivity of the whole cell biocatalyst were subsequently developed for both β-amino nitriles and β-hydroxy nitrile substrates and hydrolysis products.

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46

Forssén, Patrik. "Adsorption isotherm parameter estimation in nonlinear liquid chromatography /." Uppsala : Acta Universitatis Upsaliensis : Univ.-bibl. [distributör], 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-5971.

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47

Nam, Kiebang. "Rapid Isolation and Purification of Plasmid DNA Using High Performance Liquid Chromatography." Thesis, North Texas State University, 1987. https://digital.library.unt.edu/ark:/67531/metadc504136/.

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High Performance Liquid Chromatography (HPLC) has been employed as an analytical tool for the purification and separation of nucleic acids. A Nucleogen DEAE 4000-10 weak anion exchange column, prepacked with modified silica gels, was used to purify and separate a number of Escherichia coli plasmids. Plasmid DNAs were extracted by the alkaline lysis method. The cleared lysate was injected directly onto the Nucleogen column, and the peaks were collected, desalted and analysed by gel electrophoresis. On the chromatogram, the pBR322 formed a distinctive peak at 27 minutes and partial separation was made for the E. coli V517 plasmids. Plasmid pBR322 showed a clear band without any detectable contamination on agarose gel. This purified plasmid DNA is biologically active for enzymatic reaction commonly used in genetic engineering techniques.

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Ehlert, Steffen [Verfasser], and Ulrich [Akademischer Betreuer] Tallarek. "High-performance liquid chromatography with packed microchips / Steffen Ehlert. Betreuer: Ulrich Tallarek." Marburg : Philipps-Universität Marburg, 2011. http://d-nb.info/1013075382/34.

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49

Ferreira, Diana Santos. "Application of chemometrics to process monitoring with online high performance liquid chromatography." Thesis, University of Bristol, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.544423.

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50

Al, Tannak Naser Faisal. "Applications of high performance liquid chromatography in the analysis of basic compounds." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=18692.

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The development of chromatographic methods for basic drugs can still present problems. Two modes of chromatographic separation were studied in order to assess their performance with regard to the separation of organic bases. Reversed phase chromatography was applied in the assessment of the stability of two extemporaneous formulations of drugs used in hospital for pain relief in palliative care, for which there was no stability information. Three different formulations of the two combinations were assessed. In the case of the diamorphine/clonidine/bupivacaine combination there were no major stability issues apart from the slow hydrolysis of diamorphine to monoacetyl morphine. In a combination containing morphine and levomepromazinemorphine remained stable, but there was a gradual decline in the level of levomepromazine which fell to below 90% of the original concentration after one week. The theme of chromatographic analysis of basic drugs was continued in the second part of the PhD project where silica based alkyl phases were studied with regard to their ability to retain basic drugs under hydrophilic interaction like conditions. It was observed that with mobile phases containing high levels of organic solvent, for example water/acetonitrile (5:95 % v/v) containing 0.025% w/v ammonium acetate, basic compounds were strongly retained. The strength of the retention of the bases depended on the % of water in the mobile phase and the strength of the ammonium acetate. The novel methods developed were applied to drug impurity profiling and fundamental research on mechanisms was carried out using simple basic test probes.

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