by Tsoi Yeung-pang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 105-106). / Chapter I. --- Acknowledgements --- p.i / Chapter II. --- Abstract --- p.ii / Chapter III. --- Table of contents --- p.iv / Chapter IV. --- List of Tables and Figures --- p.v / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- Modes of chromatography / Chapter 1.2 --- Objective of the present study / References / Chapter Chapter 2. --- Instrumentation and theory --- p.8 / Chapter 2.1 --- Instrumentation of HPLC / Chapter 2.2 --- Theory of liquid chromatography / References / Chapter Chapter 3. --- Determination of citrate in pharmaceutical preparations by HPLC using indirect photometric detection --- p.21 / Chapter 3.1 --- Introduction / Chapter 3.2 --- Review of the analytical methods / Chapter 3.3 --- Theory of detection / Chapter 3.4 --- Experimental / Chapter 3.5 --- Results and discussion / Chapter 3.6 --- Conclusion / References / Chapter Chapter 4. --- Determination of camphor and menthol by HPLC using indirect conductometric detection --- p.74 / Chapter 4.1 --- Introduction / Chapter 4.2 --- Review of the analytical methods / Chapter 4.3 --- Theory of detection / Chapter 4.4 --- Experimental / Chapter 4.5 --- Results and discussion / Chapter 4.6 --- Conclusion / References

Siu Yuen Yu. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 122-139). / Abstracts in English and Chinese. / Abstract (English) --- p.i / Abstract (Chinese) --- p.iii / Acknowledgments --- p.v / Table of Contents --- p.vi / List of Figures --- p.x / List of Tables --- p.xvi / Chapter CHAPTER 1 --- INTRODUCTION --- p.1 / Chapter CHAPTER 2 --- LITERATURE REVIEW --- p.7 / Chapter 2.1 --- Traditional methods for studying zooplankton feeding selectivity --- p.7 / Chapter 2.1.1 --- Cell counting after laboratory feeding experiments --- p.7 / Chapter 2.1.2 --- Direct examination of gut contents --- p.8 / Chapter 2.1.3 --- Use of radioactive tracers --- p.9 / Chapter 2.1.4 --- Gut fluorescence method --- p.9 / Chapter 2.2 --- High Performance Liquid Chromatography analysis of phytoplankton pigments --- p.11 / Chapter 2.2.1 --- Principle --- p.11 / Chapter 2.2.2 --- Pigments as signature markers of phytoplankton --- p.11 / Chapter 2.2.3 --- Development of HPLC analysis of phytoplankton pigments --- p.16 / Chapter 2.2.4 --- Advantages of HPLC analysis of phytoplankton pigments --- p.17 / Chapter 2.2.5 --- Limitation of HPLC analysis of phytoplankton pigments --- p.18 / Chapter 2.3 --- Zooplankton feeding selectivity --- p.19 / Chapter 2.3.1 --- Ecological importance of zooplankton feeding selectivity --- p.19 / Chapter 2.3.2 --- Factors affecting zooplankton feeding selectivity --- p.19 / Chapter 2.3.3 --- Feeding selectivity of zooplankton studied in this study --- p.21 / Chapter 2.3.3.1 --- p. avirostirs --- p.21 / Chapter 2.3.3.2 --- Paracalanus spp --- p.22 / Chapter 2.3.3.3 --- Pseudevadne tergestina --- p.23 / Chapter 2.4 --- Pigment degradation in guts of zooplankton --- p.24 / Chapter 2.4.1 --- Experimental design --- p.24 / Chapter 2.4.2 --- Pigment degradation --- p.24 / Chapter 2.5 --- "Tolo Harbour, Hong Kong" --- p.26 / Chapter 2.5.1 --- Site description --- p.26 / Chapter 2.5.2 --- Phytoplankton and zooplankton in Tolo Harbour --- p.27 / Chapter CHAPTER 3 --- MATERIALS AND METHODS --- p.28 / Chapter 3.1 --- Field sampling --- p.28 / Chapter 3.1.1 --- Study of seasonal patterns in zooplankton feeding selectivity --- p.28 / Chapter 3.1.1.1 --- Collection of phytoplankton and zooplankton for pigment analysis --- p.28 / Chapter 3.1.1.2 --- Collection of phytoplankton and zooplankton for plankton enumeration --- p.30 / Chapter 3.1.2 --- Collection of phytoplankton and zooplankton for laboratory feeding experiments --- p.32 / Chapter 3.2 --- Laboratory experiments and data analysis --- p.33 / Chapter 3.2.1 --- Study of seasonal patterns in zooplankton feeding selectivity --- p.33 / Chapter 3.2.1.1 --- HPLC of phytoplankton pigments --- p.33 / Chapter 3.2.1.2 --- Fluorometric measurement of chlorophyll-α --- p.35 / Chapter 3.2.1.3 --- Plankton identification and enumeration --- p.36 / Chapter 3.2.2 --- Laboratory feeding experiments for investigation of pigment degradation in zooplankton gut --- p.37 / Chapter CHAPTER 4 --- RESULTS --- p.41 / Chapter 4.1 --- Information on Tolo Harbour --- p.41 / Chapter 4.1.1 --- Temperature and salinity in Tolo Harbour --- p.41 / Chapter 4.1.2 --- Plankton composition and community in Tolo Harbour --- p.43 / Chapter 4.1.2.1 --- Phytoplankton --- p.43 / Chapter 4.1.2.2 --- Zooplankton --- p.50 / Chapter 4.2 --- Seasonal zooplankton feeding selectivity investigated by HPLC phytoplankton pigment analysis --- p.53 / Chapter 4.2.1 --- Verification of HPLC pigment analysis by fluorometric analysis --- p.53 / Chapter 4.2.2 --- Correlations between phytoplankton cell densities and pigment concentrations in water samples --- p.55 / Chapter 4.2.3 --- Feeding selectivity of zooplankton on different phytoplankton groups --- p.73 / Chapter 4.2.4 --- Feeding selectivity of zooplankton on dinoflagellates --- p.87 / Chapter 4.2.5 --- Feeding selectivity of zooplankton on diatoms --- p.87 / Chapter 4.3 --- Feeding selectivity on phytoplankton by other cladoceran - Pseudevadne tergestina --- p.89 / Chapter 4.4 --- Pigment degradation in zooplankton guts after ingestion of phytoplankton --- p.90 / Chapter 4.5 --- Clearance rates of P. avirostris and Paracalanus spp. in feeding experiments --- p.101 / Chapter CHAPTER 5 --- DISCUSSIONS --- p.105 / Chapter 5.1 --- Experiment design --- p.105 / Chapter 5.2 --- Seasonal zooplankton feeding selectivity investigated by HPLC phytoplankton pigment analysis --- p.108 / Chapter 5.2.1 --- Correlations between phytoplankton cell densities and pigment concentrations in water samples --- p.108 / Chapter 5.2.2 --- Feeding selectivity of zooplankton on different phytoplankton groups --- p.108 / Chapter 5.2.3 --- Feeding selectivity of Pseudevadne tergestina --- p.111 / Chapter 5.3 --- Feeding experiments for investigating pigment degradation in guts of zooplankton --- p.112 / Chapter 5.3.1 --- Principle --- p.112 / Chapter 5.3.2 --- Degradation for different pigments in guts of P. avirostris and Paracalanus spp. --- p.112 / Chapter 5.4 --- Clearance rates of P. avirostris and Paracalanus spp. --- p.114 / Chapter 5.4.1 --- p. avirostris --- p.114 / Chapter 5.4.2 --- Paracalanus spp. --- p.115 / Chapter 5.5 --- Limitations of HPLC analysis of phytoplankton pigments --- p.116 / Chapter 5.6 --- Environmental events related to feeding selectivity of zooplankton in Tolo Harbour --- p.118 / Chapter 5.6.1 --- Energy transfer in trophic level --- p.118 / Chapter 5.6.2 --- Abilities of p. avirostris and Paracalanus spp. to control red tides in Tolo Harbour --- p.118 / Chapter CHAPTER 6 --- CONCLUSION --- p.120 / REFERENCES --- p.122 / APPENDIX

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Over the last decade, the miniaturization of analytical systems has become an increasingly important and interesting research area. Miniaturized systems offer many advantages, including reduced reagent and sample consumption, shorter analysis times, portability and disposability. This dissertation describes novel approaches in this direction, focusing on two areas: the miniaturization of existing column chromatographic systems and the development of microfluidic systems in which the separation is performed in a channel on a microchip. A new type of methacrylate-based monolithic capillary columns for liquid chromatography and capillary electrochromatography were prepared within the confines of fused-silica tubing using Starburst dendrimers to affect porosity. The polyamidoamine (PAMAM) dendrimers were incorporated into a solution of functionalized monomer, cross-linker, solvents, and polymerization initiator. Thermal polymerization, followed by the removal of solvent and dendrimers, produced a continuous rod of polymer with uniform porosity. Different column porosities were obtained by varying the amount of the dendrimer template. The chromatographic performance of these monolithic columns was evaluated using a peptides mixture obtained by tryptic digestion of chicken egg lysozyme. A distinct advantage of polymer monolithic stationary phases over conventional packed chromatographic beds is the ability to prepare them easily and rapidly via free radical polymerization within the channels of a microfluidic device. In this work, continuous polymeric beds were prepared within a channel of three different microchip substrates: glass, poly(dimethylsiloxane) and polycarbonate. The methacrylate-based monolith was cast in-situ via UV-initiated polymerization. The functionalization of the inner wall of the channel with methacryloyl groups enabled the covalent binding of the monolith to the wall. The morphology of the wall-anchored monolith was studied by SEM of chip sections, and by SEM of an extruded segment of non-anchored monolith from a separate chip. / Graduation date: 2005

The radial heterogeneity of some columns used in high performance liquid chromatography (HPLC) was investigated using an on-column microelectrochemical amperometric detector. Such a detector allowed the recording of the elution profiles at different spatial positions throughout the column exit cross-section. From this, we obtain information about the radial distribution of the mobile phase velocity, column efficiency, and analyte concentration. In all cases, the results obtained show that the spatial distribution of the mobile phase velocity does not follow a piston-flow behavior but exhibits radial heterogeneity with differences not exceeding 5% between the center and wall regions of any column. The efficiency was found to be lower in the wall region of the column than in its core region (the central core with a radius of 1/3 the column inner radius) by up to 40-50% in some columns. The radial distribution of the maximum concentration of the peaks varies throughout the column exit section, partially due to the radial variations of the column efficiency. The technology used in constructing the microelectrochemical detectors was further exploited to fabricate and incorporate an online detector array for a pressurized flat wide column measuring 10x10x0.1 cm in dimensions. Thus, unlike traditional thin layer chromatography, samples in this pressurized flat bed are completely eluted and detected in a time-based mode just like they are in HPLC. Also, a lateral arrangement of the detector array allows for an easy monitoring of the homogeneity of the flat wide column. Also, information on the surface properties of three novel chemically bonded phase packing materials for HPLC was obtained using solid state cross-polarization (CP) magic-angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopic experiments for the 29Si, and 13C nuclei. These packing materials were: Cogent bidentate C18 bonded to type-C silica, hybrid packing materials XTerra MS C18, and XBridge Prep. C18. The spectra obtained using cross-polarization magic angle spinning (CP-MAS) on the Cogent bidentate C18 bonded to type-C silica show the surface to be densely populated with hydride groups (Si-H), with a relative surface coverage exceeding 80%. The hybrid packing materials XTerra and XBridge gave spectra that reveal the silicon atoms to be bonded to alkyl moieties embedded in the molecular structure of these materials with over 90% of the alkyl silicon atoms found within the completely condensed silicon environments.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2005. / Bibliography: leaves 63-67.

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Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 145-148).