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Heparin is a mixture of sulfonated polysaccharides which is negatively charged. Heparin is a substance which is important in organism and fundamentally affects its physiology. Main attribute of heparin is anticoagulation - it prevents the complete blood coagulation. This anticoagulant effect balances the hemocoagulation by influencing the coagulation pathway. In some cases a pharmacological application of heparin is needed so the heparin is administrated as a injection of physiological solution of sodium or calcium heparine salt. Monitoring of level of the heparin in blood is problematic - methods used today are based on the measurement of a time required for blood clot formation. The result evaluation is done by comparing a sample with reference solution. These methods are relatively imprecise, can not be used in "on-line" setting and are highly influenced by general health condition of patient. In this work some principles of affinity capillary electrophoresis were adapted from another work - heparin was determined indirectly by monitoring of decrease of the peak area of protamine. Protamine is medically used antidote of heparin because they create a stable complex together. In this work protamine was replaced by well defined tetraarginine because the most frequent amino acid in protamine is...

Lee Wai Hang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2004. / Includes bibliographical references (leaves 71-76). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Abstract --- p.ii / Table of Contents --- p.v / Abbreviations --- p.viii / List of Figures --- p.ix / List of Tables --- p.xiv / Chapter / Chapter 1. --- Introduction --- p.1 / Chapter 1.1 --- The French Paradox --- p.1 / Chapter 1.2 --- Flavonoids --- p.2 / Chapter 1.3 --- Grape seed extract --- p.4 / Chapter 1.4 --- Instrunmental analysis --- p.7 / Chapter 1.4.1 --- High Performance Liquid Chromatography --- p.7 / Chapter 1.4.2 --- Colorimetry --- p.9 / Chapter 1.5 --- Capillary Electrophoresis --- p.10 / Chapter 1.5.1 --- Instrunmentation --- p.10 / Chapter 1.5.2 --- Electroosmotic Flow --- p.11 / Chapter 1.5.3 --- Electrophoretic mobility --- p.13 / Chapter 1.6 --- Objective of the study --- p.15 / Chapter 2. --- Experimental --- p.18 / Chapter 2.1 --- Reagents and material --- p.18 / Chapter 2.1.1 --- Reagents --- p.18 / Chapter 2.1.2 --- Instrunmentation --- p.18 / Chapter 2.1.3 --- Reference compounds --- p.19 / Chapter 2.1.4 --- Samples --- p.19 / Chapter 2.2 --- Selection of solvent for sample preparation --- p.20 / Chapter 2.3 --- Procedures --- p.21 / Chapter 2.3.1 --- Preparation of running buffer solution --- p.21 / Chapter 2.3.2 --- Preparation of standard solution --- p.21 / Chapter 2.3.3 --- Preparation of sample solution --- p.22 / Chapter 2.3.4 --- Flushing procedures --- p.22 / Chapter 3. --- Results and Discussion --- p.24 / Chapter 3.1 --- Preliminary experiments --- p.24 / Chapter 3.2 --- Effect of pH --- p.27 / Chapter 3.3 --- Addition of surfactant --- p.30 / Chapter 3.4 --- Effect of SDS concentration --- p.35 / Chapter 3.5 --- Addition of cyclodextrins --- p.39 / Chapter 3.6 --- Urea --- p.46 / Chapter 3.7 --- Addition of organic modifier --- p.47 / Chapter 3.8 --- Effect of borate concentration --- p.49 / Chapter 3.9 --- Effect of cyclodextrin concentration --- p.53 / Chapter 3.10 --- Optimized condition --- p.58 / Chapter 3.11 --- Reproducibility of the method --- p.58 / Chapter 3.12 --- Quantitative analysis of reference compounds --- p.60 / Chapter 3.13 --- Application of the CE method in grape seed products --- p.62 / Chapter 4. --- Conclusion --- p.69 / References --- p.71

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In the first part of this work, magnetized nanoporous silica based microparticles (MMPs) are used for horseradish peroxidase (HRP) immobilization and applied in amperometric peroxidase-based biosensors. A homemade magnetized carbon paste electrode permits the MMPs attraction close to the electrode surface. The resulting original biosensor is applied to the investigation of enzymatic oxidation of model drug compounds namely, clozapine (CLZ) and acetaminophen (APAP) by HRP in the presence of hydrogen peroxide. The biosensor operates at a low applied potential and the signal corresponds to the electro-reduction of electroactive species enzymatically generated. The biosensor allows performing the quantitation of the two drug compounds in the micromolar concentration range. It allows also the study of thiol compounds based on the inhibition of the biosensor response. Interestingly, distinct inhibition results are observed for HRP entrapped in the silica microparticles compared to the soluble HRP. We expect that this type of biosensors holds high promise in quantitative analysis and in biotransformation studies of drug compounds. In the second part of this thesis work, HRP immobilized magnetic nanoparticles are injected on-line and magnetically retained, as a microreactor, in the capillary of a CE setup. The purpose of such a configuration is to develop an analytical tool for studying “in vitro” drug biotransformation. The advantages expected are (i) minimum sample (drug compound) and biocomponent (enzyme) consumption, (ii) high analysis throughput, (iii) selectivity and sensitivity. In order to illustrate the potential of such an instrumental configuration, it has been applied to study acetaminophen as model drug compound. The mechanistic information obtained by the HRP/H2O2 system is in agreement with literature data on acetaminophen metabolization. Horseradish peroxidase kinetic studies are realized by this setup and the apparent Michaelis constant is determined. Capillary electrophoresis permitted the identification of APAP off-line biotransformed products such as N-acetyl-p-benzoquinone imine (NAPQI), the APAP dimer and APAP polymers as inferred from literature data. The formation of the APAP dimer was further confirmed by electrospray ionization mass spectrometry.

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Determination of lead and iodine species by capillary electrophoresis inductively coupled plasma mass spectrometry.

Thesis (Ph. D.)--University of Texas at Austin, 2000. / Vita. Includes bibliographical references. Available also in a digital version from Dissertation Abstracts.