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Working performance of vertically aligned carbon nanotubes as platforms for future biosensing applications
Štipková, Tereza ; Nováková, Lucie (advisor) ; Jáč, Pavel (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Tereza Štipková Supervisor: Assoc. Prof. PharmDr. Lucie Nováková, Ph.D. Supervisor specialist: Assist. Prof. Gulnara Safina, Ph.D. Title of thesis: Working performance of vertically aligned carbon nanotubes as platforms for future biosensing applications Blood glucose monitoring is a crucial part of a modern diabetes therapy. In this work, the multi-walled vertically aligned on-chip grown carbon nanotubes (CNT) were applied in construction of a novel third-generation biosensor. The main focus of this work was to investigate the possibility of future application of the sensor in glucose monitoring. The CNT- based amperometric biosensor was developed by immobilising cellobiose dehydrogenase from Corynascus thermophilus onto the CNT surface by physical adsorption. The highly hydrophobic surface of the nanotubes was functionalized with 0.0001% (w/v) polyvinyl alcohol (PVA) in order to enable the enzyme adsorption. X-ray photoelectron spectroscopy measurements confirmed the successful enzyme immobilization onto PVA modified CNT surface. The surface topography and elemental composition of the nanomaterial were examined by scanning electron microscopy and energy-dispersive X-ray spectroscopy...
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Use of capillary electrophoresis with contactless conductivity detection for the analysis of proteins
Vatrasová, Kateřina ; Polášek, Miroslav (advisor) ; Jáč, Pavel (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Kateřina Vatrasová Supervisor: doc. RNDr. Miroslav Polášek, CSc. Consultant: PharmDr. Klára Petrů, Ph.D. Title of Diploma Thesis: Use of capillary electrophoresis with contactless conductivity detection for the analysis of proteins Nowadays there exist many methods for the determination of proteins. The aim of this work was to develop, optimize and characterize method for the analysis of a model mixture of proteins (α-lactalbumin, β-lactoglobulin, carboanhydrase, lysozyme and ribonuclease) by capillary electrophoresis with conductivity detection and to compare it with conventional capillary electrophoresis with UV detection. The influence of the capillary inner wall coating on the adsorption of proteins, the composition and concentration of convenient background electrolyte, and the voltage and temperature were examined as experimental conditions possibly affecting the separation. A 50-cm fused-silica capillary (effective length 35 cm for conductivity detector and 41.5 cm for UV detector) with internal diameter 50 μm was used for the analysis. The UV detection wavelength was 210 nm. The static coating of the inner capillary wall realized by successive multiple soaking with...
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Analysis of biologically active substances by capillary electromigration methods
Jáč, Pavel ; Polášek, Miroslav (advisor) ; Tesařová, Eva (referee) ; Jokl, Vladimír (referee)
This thesis deals with the utilization of capillary electromigration methods for the analysis of biologically active substances. In the Theoretical part historical progress, instrumentation and separation mechanisms of different electromigration methods are discussed. In addition brief overviews mapping chiral separation by means of CE and complex-formation for the separation selectivity enhancement are also included. Two final sections of Theoretical part are focused on specific features of method optimization and method validation in CE. Practical part is presented by comments on published papers, which were attached in full text version to Addendum. The results presented in this thesis cover two areas. First area is focused on the utilization of electromigration methods for the analysis of polyphenols in plant materials while second area is dealing with the development, optimization and validation of CE methods for quality control of pharmaceuticals and/or nutraceuticals. The first area of the practical part overviews new trends (papers published between 1999- 2005) in the analysis of polyphenols by CE. The second paper focused on the analysis of polyphenols is an original investigation of new kind of BGE based on complex-forming reagent - sodium tungstate - that was applied in the assay of...
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Využití nanokompozitů jako povrchů pro SALDI-MS.
Böhmová, Eva ; Jáč, Pavel (referee) ; Solich, Petr (advisor)
Matrix-assisted laser desorption/ionization (MALDI) is a soft ionization method used in mass spectrometry that is important for the analysis of biomolecules and large synthetic molecules. However, it is difficult to use MALDI for the analysis of small molecules because the matrix ions interfere with their analysis. Several surface-assisted laser desorption/ionization (SALDI) mass spectrometry methods have been developed as a solution to this problem. In this thesis, polylactide (PLA) nanocomposites containing halloysite nanoclay, hydroxyapatite, magnesium oxide, montmorillonite nanoclay, silicon dioxide, silicon nitride, titanium dioxide, and graphitized carbon black (GCB) nanoparticles were examined as surfaces for SALDI. The intensities of the signals of three human medicines: acebutolol, carbamazepine, and propranolol, obtained from these surfaces were compared to the signal intensities obtained from stainless steel MALDI plate without use of any matrix. The signal intensity was only enhanced when nanocomposites containing 30% GCB, 10% silicon nitride, and 10% titanium dioxide nanoparticles and analytes in concentration of 150 ppm were used. These results, together with the fact that PLA is a biodegradable polymer and can be obtained from renewable resources, make these materials potential...
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Comparison of APSI and ESI ionization for the development of UHPLC-MS/MS method for the determination of steroid compounds estrogens and progestins
Rabatinová, Martina ; Jáč, Pavel (referee) ; Nováková, Lucie (advisor)
In this study a new analytical method for determination of endocrine disruptors is pre- sented. The endocrine-disrupting phenomena is an area of growing concern. Potential ef- fects of endocrine-disrupting pollutants on wildlife and humans has been increased. Since 1980s deformities in fish are observed. Compounds associated to these effects include nat- ural compounds, such es estrogens, progestins and phytoestrogens, synthetic estrogens and a wide variety of organic pollutants, inluding pesticides, surfactants and plasticizers. Among them, estrogens are extraordinary due to their high estrogenic potency, with phys- iological active concentrations ranging from fg/ml to pg/ml. Endocrine disruptors might cause breast cancer in woman, abnormalities in the human reproductive system and differ- ent expressions of biological disorders in wildlife such as hermaphroditism, feminization, and decreased fertility. The presence of numerous endocrine-disrupting compounds in sur- face waters and sediment has been primarily atributed to their incomplete removal in the sewage-treatment process. Determination of these chemicals is required in order to assess their environmental impact. A new ultra high performance liquid chromatography/tandem mass spectrometry method (UHPLC-MS/MS) is presented in this study. The...
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Separace chirálních pesticidů pomocí cyklodextrinů kapilární elektroforézou
Denková, Barbora ; Polášek, Miroslav (referee) ; Jáč, Pavel (advisor)
In this diploma thesis, a preliminary study on the applicability of EKC-PF (with CD as chiral selector) to the separation of chiral pesticides was performed. In introduction, theoretical informations are presented concerning electrophoresis instrumentation and theory as well as different electrophoresis modes. Then, enantiomeric separation is introduced through cyclodextrins and possibilities of partial filling mode to finally terminate with a definition of chiral pesticides and some information about their enantioseparation. Concretely, in the experimental part, the evaluation of enantioresolution of several chiral pesticides (trichlorphon, cyproconazole, hexaconazole, imazalil, myclobutanil, penconazole, tebuconazole, propiconazole, and benalaxyl) using CM-β-CD as chiral selector was performed. First of all, a univariate optimization of variables (CM-β-CD injection time, voltage, temperature, pH, and buffer nature and concentration) was carried out for benalaxyl. Finally a screening, involving the effect of the CM-β-CD injection time, was performed for the other pesticides to check the potential of this CD as chiral selector.
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Analysis of cough-cold preparations by electrophoretic methods.
Kubíková, Drahomíra ; Jáč, Pavel (referee) ; Pospíšilová, Marie (advisor)
In this study, micellar elektrokinetic chromatography method (MEKC) was developed for the determination of paracetamol (PA), caffein (CO), ascorbic acid (AA) and phenylephrine (FE) in a pharmaceutical preparation. Separation was carried out in a fused silica capillary (31,2 cm x 50 m i.d. effective length 21 cm) at 20 kV with UV detection at 190 nm and 265 nm. Optimized background electrolyte (BGE) was 100 mM boric acid containing 100 mM sodium dodecyl sulfate (SDS) as a surfactant and 10 % (v/v) of methanol. pH* 7,8 was found to be optimal (modified by 50 mM sodium tetraborate). Methylparaben (MP) was used as internal standard. This validated method has been successfully applied for the analysis of commercially available pharmaceutical product (Coldrex tbl.).
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Application of UHPLC with various types of detection in the field of environmental and food analysis.
Rejman, David ; Jáč, Pavel (referee) ; Nováková, Lucie (advisor)
The use of UHPLC with various types of detection in the field of environmental and food analysis Abstract The aim of this work was to inform about possible use of UHPLC instrumentation in connection with various types of detection when chromatographic separating of substances in the field of environmental and food analysis is performed. The next aim was to search and study a number of articles referring to UHPLC methodology, which are at present available in the internet databases ScienceDirect and Web of Science. On the basis of the information from the articles there is a graphic summary in this work relating to the number of found articles and the groups of analysed substances within years. In the introduction of the work van Deemter's, Gidding's and Knox's theories about the efficiency of the chromatographic system are mentioned. These theories are substantial for understanding the principle of chromatographic separation. Following chapters deal with the problems of the development of chromatography in the last decades, especially concerning the length and type of analytical columns, the size of filling particles or the temperature and pressure in the chromatographic system. Now thanks to the development, the columns dimensions are 50 x 1 mm and are filled with particles less than 2 μm in diameter and...
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