|
|
Electrokinetic chromatography in nonaqueous and mixed solvents: Determination of critical micellar concentration
Hamráková, Katarína ; Křížek, Tomáš (advisor) ; Kubíčková, Anna (referee)
This thesis deals with the investigation of micelle formation following the addition of a surfactant to a background electrolyte in micellar electrokinetic chromatography and the transfer of these systems to nonaqueous and mixed solvents. The addition of organic solvents to the background electrolyte has a significant effect onmicelle formationandhence separation in electrokinetic chromatographyusinga micellar pseudo-stationaryphase. This effect has not yet been studied in depth. Information on the presence and properties of micelles in a given separation system is important for the understanding of separation processes but also for the development and optimization of analytical methods. In this work, the critical micellar concentration (CMC) of two surfactants, sodium dodecyl sulfate (SDS) and cetyltrimethylammoniumbromide (CTAB), was determinedby introducingthem into a mixed environment with non-aqueous solvents, acetonitrile and methanol. The critical micellar concentration was determined from the dependence of three variables on the surfactant concentration in the solution, namely, the effective mobility of the analytes and the viscosity and conductivity of the solution. Prior to the actual measurements of the effective mobility of the analytes, suitable analytes were selected,two which can...
|
|
|
Study of retention and separation of peptides in HPLC
Boudová, Hana ; Kalíková, Květa (advisor) ; Kubíčková, Anna (referee)
This diploma thesis deals with the study of retention and separation of structurally different peptides and digest products of cytochrome c using reverse phase and mixed modes of liquid chromatography. As the model peptides, five unmodified dipeptides, nine dipeptides containing a protective benzoyl group on the N-terminal amino acid and eight therapeutic peptides containing five to ten amino acids were selected. The chromatographic behaviour of the model peptides was tested on three different columns: XBridge C18, XSelect CSH C18 and Atlantis Premier BEH C18 AX under different conditions. The influence of the pH of the aqueous part of the mobile phase, i.e. 2,1; 3,0; 4,7 and 6,8, and the amount of acetonitrile in the mobile phase on retention and separation of model peptides was tested. The effect of the concentration of ammonium acetate buffer, pH = 6,8 in the mobile phase on the retention and peak symmetry in the concentration range of 10-50 mmol L-1 was assessed. The chromatographic conditions for the baseline separation of 20 different model peptides were optimized. The conditions were as follows: XSelect CSH C18 column, mobile phase composed of acetonitrile/10mM ammonium acetate, pH = 6,8 (v/v) under gradient elution. The suitable chromatographic conditions for the analysis and identification...
|
|
|
Enantioseparations of liquid crystalline materials
Vaňkátová, Petra ; Kubíčková, Anna (advisor) ; Čabala, Radomír (referee) ; Kohout, Michal (referee)
(EN) Liquid crystalline materials are an important domain of the material science. Chiral liquid crystals (CLCs) are researched for their unique chirality-derived properties. The development of new CLCs focuses both on appropriate molecular design to fit their intended purpose and also on ways of using widely available and less expensive sources of chirality to enable cost- effective production for a potential large-scale production. Methods capable of enantioseparation are needed mainly for chiral purity control of newly synthesized CLCs and for their potential use in scaling up for preparative purpose. Nowadays, enantioselective chromatography has evolved to be the method of choice for enantioseparations. This thesis aims to establish new approaches to chromatographic enantioseparations of CLCs by developing fast and robust enantioselective methods using two different ultra-high performance chromatographic techniques - sub/supercritical fluid chromatography (UHPSFC) and liquid chromatography (UHPLC). UHPSFC is introduced and successfully employed for the first time for this purpose. For some CLCs, high values of enantioselectivity and enantioresolution were achieved, opening the possibility of scaling up to semipreparative use. In UHPLC, two modes (reversed-phase and polar organic solvent mode)...
|
|
| |
|
| |
|
| |
|
|
Determination of L-tryptophan in food supplements in high performace liquid chromatography
Pešková, Pavlína ; Kalíková, Květa (advisor) ; Kubíčková, Anna (referee)
This bachelor's thesis deals with optimalization of chromatographic conditions for determination of tryptophan by HPLC method with UV detection. The amount of tryptophan has been determined in two food supplements. To find suitable conditions for the determination of tryptophan, the influence of the composition of the mobile phase on analyte retention and peak symmetry was tested in two different chromatographic modes - reversed-phase mode using the Atlantis dC18 column and mixed-mode using the Atlantis PREMIER BEH C18 AX column. Specifically, the effect of the type and amount of organic modifier (acetonitrile/methanol), the effect of the pH of the ammonium acetate buffer (4,7;5,9;7,0) and its concentration (5mM/10mM) in the mobile phase was tested. Based on the obtained data, the optimal chromatographic conditions were selected (in terms of analysis time and peak symmetry). In the optimized conditions selected validation parameters such as repeatability, reproducibility, limits of detection and quantification were determined. The optimized conditions were as follows: mixed-mode Atlantis PREMIER BEH C18 AX column, mobile phase acetonitrile/5mM ammonium acetate, pH 7,0 10/90 (v/v), separation temperature 25 řC, flow rate 1 ml/min and UV detection at 254 nm. Under these conditions, the tryptophan...
|
|
| |
|
|
Employment and Study Opportunities among People with Intellectual Disability in area of Domažlice region
Kukolová, Natálie ; Štrinclová, Marta (advisor) ; Kubíčková, Anna (referee)
This Bachelor thesis is focused on the support of people with intellectual disability living in the area of Domažlice district (Pilsen Region). The thesis consists of a theoretical and an empirical part. The theoretical part is research of specialized literature and it contains fundamental information about the life of people with intellectual disability. The first chapter defines essential terms concerning intellectual disability and it characterizes people with this disability. The second chapter is focused on the education of people with intellectual handicap and it is divided into subchapters, concerning preschool, primary and secondary education. Then follows the third chapter with attention to the employment of people with intellectual disability. It is mainly focused on the right to employment and its importance. This chapter also contains specific options of the support for people with intellectual disability in the labour market. The last chapter includes information concerning non-profit organizations and volunteering, because these are very important aspects in lives of people with intellectual handicap. The main goal of the empirical part of this thesis is creating a comprehensive overview which concerns the providing of social services and the options of education and employment of...
|
|
|
Wellbeing support for children in a children's home
Pražáková, Ellen ; Kubíčková, Anna (advisor) ; Štrinclová, Marta (referee)
The thesis entitled The Well-being of children in children's homes starts with description of characteristics and legislation of institutional education, specifically in children's home. The thesis introduces negative influences in childhood and tries to describe their origin and influence on the child's life. The thesis contains a relatively new concept of well-being, which characterizes important areas of life. The aim of the bachelor thesis is to describe and characterize how the competencies related to areas of well-being are developed directly in the children's home and what are the barriers to fulfilling well-being. Nine respondents who work and interact directly with children in a children's home described the development and barriers to the development of these competencies. All respondents agreed that a big barrier to fulfill well-being is an unsuitable environment and rooms and other spaces where children live. Furthermore, they often mentioned insufficient social interaction with life outside the children's home, mental and psychological disorders that prevent children from further development, the absence of role models and traumatic experiences that children carry from the time they were in their families. According to the respondents, the fundamental barrier to the development of...
|
guest ::
