(EN) Vernix caseosa is a white creamy substance that covers the skin of a newborn. It is produced during the third trimester by the skin of the baby and remains there until the age of one or even two weeks. It is uniquely human. In utero, vernix protects the skin from maceration, during the birth it serves as a lubricant and after the delivery it protects the baby against infection and regulates the temperature. As vernix is produced in third trimester, prematurely born infants lack it and this may lead to, among other things, suffering from desiccation and therefore heat loss. It is important to study it thoroughly and to find a suitable substitute of vernix for the preterm infants. Vernix consists of lipids, proteins and 80 % water. This project is aimed at the lipids. Vernix is composed of 10 % of lipids. Basic analytical methods of pocessing vernix were searched. The methods of isolation, separation and transesterification have been optimized for the lipids. For separation, thin-layer chromatography has been chosen. The method of the lipid analysis of intact molecules by MALDI-TOF MS has been optimized for these lipids. The results were confirmed using fragmentation spectra and transesterification. Esterified lipids were measured by gas chromatography coupled with mass spectrometry detection....

(EN) The solvation model based on LSER was applied to study the retention behaviour of analytes in liquid and gas chromatography. In a first chapter, a retention description of 21 solutes was investigated by using the solvation model in a wide range of mobile phase composition methanol-water and acetonitrile-water. Generally, the retention of aromatic compounds was better described by the solvation model, compared to aliphatic compounds. Effect of the particular analytes used to formulate the LSER model on ability of retention description was studied. Different results of a retention estimation was achieved by using the regression set of compounds including aromatic solutes only or by contrast aliphatic solutes only. The solvation model developed on the basis of oxygen derivatives provided distinct results in comparison to model formulated with nitrogen derivatives only. The second chapter of this work, focused on gas chromatography, dealt with a description of retention of 152 isomers C5-C8 alkenes by the LSER model. The solvation descriptor L was obtained by using two estimation methods Havelec-Ševčík (HS) and Platts-Butina (PB), the descriptor E was calculated according to its definition. Two models for retention description of alkenes were constructed, the HS model and the PB model, derived...

(EN) Cellulose tris-(3,5-dimethylphenylcarbamate) chiral stationary phase was used for separation of selected 24 analytes. Enantioseparations were realized using two systems, high performance liquid chromatography and supercritical fluid chromatography. Effect of mobile phase composition was studied. Five different aditives (isopropylamine, diethylamine, triethylamine, trifluoroacetic acid, isopropylamine combined with trifluoroacetic acid) and their influence on enantioseparation were tested. Influence of two different modifiers (methanol, propan-2-ol) combined with all aditives was also tested in supercritical fluid chromatography system. The aim of this work was to find optimized composition of mobile phase which was suitable for separation of the analytes studied and to compare separation potential among all mobile phases and also between used separations systems. The supercritical fluid chromatography was shown to yield better results, i.e. better resolution in shorter analysis time. However examples of analytes better resolved under optimized conditions in high performance liquid chromatography system have also been found. Keywords (EN) Chirality, enantiomers, enantioselective separation, chiral stationary phase, high performance liquid chromatography, supercritical fluid chromatography.

This thesis concerns experiments with natural compounds and vitamins. In the first part I described these substances, which I proved by chromatography or I made other experiments with them in the second part. I created four worksheets with instruction for laboratory practise. There are thein solutions in the supplement. I verified these four experiments at Grammar School in Prague 9.

4 Abstract Estrogens are considered to belong to chemicals that negatively affect the endocrine system, even if present at very low concentrations. They are discharged into environment as a result of an increasing application of drugs etc. This work is focused on the separation and quantification of five estrogens, namely estrone (E1), 17β-estradiol (βE2), 17α-estradiol (αE2), 17α-ethynylestradiol (EE2) and estriol (E3) in natural water samples by HPLC-UV method. The chromatographic system consisted of a C18 stationary phase (SunFire® C18, 150 x 4.6 mm, octadecyl bounded to silica gel, particle size 5 µm) and binary mobile phase of acetonitrile/water in various ratios in isocratic separation mode. The effect of acetonitrile content in the mobile phase and flow rate of the mobile phase on retention and separation parameters was tested. Under the optimized separation conditions (acetonitrile/water 40/60 (v/v), 1.3 ml/min), all the compounds were baseline resolved and eluted within 15 min. These experimental conditions were applied to the calibration measurements which were carried out within the concentration range from 0.001 to 1 mg/ml. Limits of detection (LOD) and limits of quantification (LOQ) for the individual estrogens and their mixture (standards dissolved in methanol) were determinated. The detection...

Nitrilases are well known for their unique property to effectively convert nitriles into corresponding carboxylic acids and ammonia. They can also form amides as by-products. In contrast to nitrile hydratases they do not require cofactors or prosthetic groups. The research in this work is focused on nitrilase from filamentous fungus Arthroderma benhamiae and cyanide hydratase from Aspergillus niger K10. Genes of these enzymes were expressed using pET-30a(+) plasmid in the bacterium Escherichia coli strain BL21-Gold (DE3). The products obtained were purified by a series of ion exchange chromatography and gel filtration and subsequently characterized with respect to oligomeric state of the protein and its usability for protein crystallography. To obtain information regarding the structural arrangement of the individual proteins, electrophoretic separation in polyacrylamide gel, gel filtration, analytical ultracentrifugation, mass spectrometry, dynamic light scattering and drop coating deposition Raman spectroscopy were used. Keywords: nitrilase, cyanide hydratase, Aspergillus niger, Arthroderma benhamiae, liquid chromatography (In Czech)

A method employing solid-liquid extraction with methanol and solid-phase extraction (SPE) clean-up step using Supelco SupelcleanTM ENVITM -Carb 3 mL cartridges (0.25 g graphitized carbon adsorbent) followed by gas chromatography - mass spectrometry with negative chemical ionization (GC-NCI-MS) has been optimized and applied for determination of ultratrace concentrations of C6 - C12 perfluorinated carboxylic acids (PFCAs) in soil samples. A sophisticated multifactorial statistic method, response surface methodology, employing 1/16 fractional factorial design and the face centered central composite design as well has been applied to find the significant parameters which influence the extraction procedure of PFCAs and SPE clean-up step and to set the optimum extraction and clean-up levels of eight parameters evaluated yielding the maximum extraction recovery of all PFCAs. The analyte extraction recoveries and the limits of detection and quantification have been obtained. The recoveries of individual PFCAs were within a range from 85 to 100 % for analyte spiked concentration level of 1.1 ng g−1 and within a range from 91 to 107 % for analyte spiked level of 2.1 ng g−1 . The values of limits of detection were 1.9 - 3.0 pg g−1 and limits of quantification 6.4 - 10.1 pg g−1 . This analytical method has...

The simplification of the historical pieces of work samples' treatment is described in the dissertation. The recent methods have been inappropriate therefore, modification of the treatment was necessary. The dammar and copal resin, important restoration materials, were used in the experiment. HPLC-MS, HPLC-ELSD, GC-FID, GC-MS and pyrolysis GC- MS were applied. The concentration of fatty acids in the historical sculpture was determined by GC-MS, and it was compared to the content of fatty acids inside an egg. For identification of monosaccharide in the gum, GC-MS (hexamethyldisilazan, trimethylchlorsilan, and pyridine) is the suitable method. GC-MS determines the same composition of dammar resin as stated in the cited sources. The simple process for the samples' treatment was designed.

Charles University in Prague Pharmaceutical Faculty in Hradec Králové Department of Pharmaceutical Botany and Ecology Candidate: Miloslava Ďuráčová Consultant: RNDr. Jitka Vytlačilová, Ph.D. Title of thesis: HPLC-MS determination of active biological compounds in Elbe river Biologically active compounds have a various ways to enter environment. They can occur as pesticides, cosmetics and pharmaceutics and their metabolites. Such compounds are classified as environmental contaminants. There is a increased environmental concentration connected with increasing consumption of biologically active compounds. There is a urgent need to follow the effect on the different parts of ecosystem and levels of biologically active compounds. This work was prepared during the cooperation with Povodí Labe state enterprise. A novel analytical method was described in the experimental part of this thesis. I was employed to evaluate biologically compounds levels in the surface water samples. This method is now routinely used. 10 out of 19 evaluated compounds reached concentrations higher than LOD. Acetaminophene (559 ng/l, Králický stream), gabapentine (457 ng/l Elbe, LB Schmilka), cotinine (139 ng/l, Králický potok) were the biologically active compounds with the highest found concentrations. Keywords: HPLC-MS analysis,...

Endocrine disruptors represent a group of chemical compounds that are able to negatively influence the hormonal system of vertebrates. Environmental Protection Agency (U.S.EPA) defines these compounds as exogenous substance or mixture that interferes with the synthesis, secretion, transport, binding, activity, or degradation of natural hormones. This can be observed at the level of the individual organism, its progeny, populations and subpopulations. All these changes have negative effects on homeostasis, reproduction, development or change the behavior of the affected animals. This work focuses on 7 endocrine disruptors - natural estron, 17β estradiol, estriol, and synthetic 17α-ethynylestradiol, irgasan (triclosan), 4-nonylfenol, bisphenol A in the influent and effluent of wastewater plants in the Czech Republic. The thesis contains an optimization of endocrine disruptors determination in wastewater, a preliminary screening to determinate concentration levels, 24 hours composite samples and monitoring of one selected wastewater plant during a day. The analytical procedure is based on filtration, solid-phase extraction (SPE), gel permeation chromatography (GPC), derivatization and gas chromatography coupled with mass spectrometry (GC/MS). Keywords: endocrine disruptors, wastewaters, Czech...