|
|
Light induced catalytic degradation of a series of common antibiotics and the corresponding HPLC analysis
Smítková, Karolína ; Klusoň, Petr (advisor) ; Krystyník, Pavel (referee)
1 Abstract The continuous advance in industry, general intensification of processes and urbanisation inevitably leads to production of new substances each year, collectively referred to as emerging pollutants (EPs). As the mass production of EPs increases, the demand for wastewater treatment plants also dramatically increases. The inadequacy of conventional tretament plants in removing EPs, such as pharmaceuticals, pesticides, personal care products, and others, results in the presence of these substances in surface and groundwater at significant concentrations. The often negative or unclear impact of EPs to the environment furhter emphasizes the urgency of this issue and requires a corresponding response. Photocatalysis belongs to the co-called advanced oxidation processes, key techniques for ensuring effective wastewater treatment. This thesis is focused on the photocatalytic degradation of tetracycline, trimethoprim and sulfamethoxazole, three common antibiotics frequently found in wastewater. Graphitic carbon nitride, a promising material in research of fotocatalytic degradation, was used as a photocatalyst and was activated by visible light emitted from a mercury xenon lamp. Experiments were conducted in batch setup and in microphotoreactor to compare the efficiency of both systems. Rhodamine B was...
|
|
|
Preparation of new chiral phases for HPLC anchored to silica gel using electrostatic interactions
Tomanová, Adéla ; Jindřich, Jindřich (advisor) ; Smrček, Stanislav (referee)
The focus of this thesis is the synthesis of chiral modifiers for silica gel based on amylose modified with dimethyl or dichlorophenyl isocyanates and positively charged anchors, which will allow strong ionic binding to silica gel. The stability of the stationary phases thus prepared is then studied by liquid chromatography as well as the ability to separate selected enantiomers. Two chiral silica gel modifiers were prepared in which the amylose contained dimethyl phenyl carbamate (DMFKA) or dichlorophenyl carbamate (DCFKA) groups in addition to the covalently bonded anchor. The results of elemental analysis showed incomplete modification of the hydroxyl groups of the second modifier, DCFKA, which also corresponded to the poor chromatographic results obtained on columns packed with this phase. Enantioselective separations of α-(1-naphthyl)benzylamine, fenamiphos and a number of chiral adamantane derivatives were achieved on columns packed with DMFKA phase. The possibility of modifying silica gel in an already packed HPLC column with a modifier from solution was also demonstrated by pumping this solution through a silica gel packed column and subsequent washing into the mobile phase. Keywords: chiral separation, electrostatic interaction, HPLC
|
|
|
Influence of some microbiogenic elements on carotenogenic yeasts
Pulkrábek, Josef ; Holub, Jiří (referee) ; Obračaj, Jan (advisor)
Carotenogenic yeasts of the genus Rhodotorula are well known for their production of a variety of economically valuable and otherwise difficult to produce compounds such as fatty acids, carotenoids, ergosterol, and ubiquinone. This study investigates the effect of the addition of select microbiogenic elements (Fe, Se, I) and their combinations into mineral cultivation media on the production of the mentioned valuable metabolic products and the rate of element sorption into the biomass of the strains of Rhodotorula mucilaginosa, Rhodotorula kratochvilovae, and Rhodotorula toruloides. Additionally, the sorption of zinc oxide, ferrous fumarate, and selenomethionine into previously cultivated biomass was measured with sorption times of 2 and 24 hours. Fatty acid content was determined using GC-FID, while carotenoids, ergosterol, and ubiquinone were analyzed using HPLC-DAD, with element content being quantified using ICP-OES and IC. With a few exceptions, the production of metabolic products was decreased with the addition of elements into the media and inversely correlated with their concentration. Higher concentrations generally showed greater absolute amounts of sorbed elements but lower relative amounts, which, combined with reduced production of metabolic products shows that the media are not ideal for the cultivation of the given species. The elemental contents were such that biomass supplemented with individually sorbed elements would vaguely align with ESFA dietary reference values, but cultivation in media with a mixture of added elements could result in the biomass containing either insufficient iron or excessively high levels of selenium. Sorption levels were relatively low (5 to 22 % for iron and 0.5 to 2.5 % for selenium). Indicating that cultivation in media with lower concentrations of elemental additives is a promising area for future research.
|
|
|
Speciation analysis of arsenic compounds in environmental samples
Pakosta, Lukáš ; Novotná, Marie (referee) ; Vašinová Galiová, Michaela (advisor)
Arsenic is a toxic element that exists in various species, each having different environmental and health impacts. The presence of arsenic in the environment, especially in water and soil, poses a serious risk to human health. In this bachelor's thesis, the time and temperature for the extraction of arsenic and arsenic species in soil and biota samples were optimized. For the separation of arsenic species, high-performance liquid chromatography was used, and the determination of arsenic species content and total arsenic content was carried out using a triple quadrupole mass spectrometer with inductively coupled plasma. Based on the conducted experiment, the optimal conditions were applied to soil and biota samples from Lužánky Park.
|
|
|
Development of mass spectrometric methods for structural analysis of fatty acids and estolides
Cudlman, Lukáš
(EN) This doctoral thesis summarizes the use of modern mass spectrometric methods for the structural identification of fatty acids and triacylglycerol estolides (TG-EST) and their subsequent characterization in the lipidome of vernix caseosa, i.e., the biofilm covering the skin of the human fetus during the last trimester of in-utero development. Vernix caseosa has mainly antimicrobial properties and the ability to heal wounds and burns. The first part of the doctoral thesis focuses on the diversity of fatty acids in the lipidome of vernix caseosa. These acids form the structural subunits of complex lipids, such as the abundant triacylglycerols and wax esters. By studying fatty acids and their structural features, this thesis has provided valuable insights into the structural variability of the vernix caseosa lipidome. Without a full understanding of the structure of these key subunits, it would be impossible to complete the analysis of this lipidome in the future. In this thesis, fatty acids using high-performance liquid chromatography (HPLC) and modern mass spectrometry methods, namely ultraviolet photodissociation (UVPD) and ozone-induced dissociation (OzID), were characterized. The coupling of HPLC and mass spectrometry (HPLC-MS) provided unambiguous information on the positions and geometry of...
|
|
|
Production of pates with the addition of mushrooms
Tóthová, Martina ; Holub, Jiří (referee) ; Mikulíková, Renata (advisor)
This bachelor thesis deals with the sensory evaluation of pâté with mushrooms. First the 3 samples of pâtés were made to select the right concentration of mushrooms for sensory evaluation. Then the 7 samples of pâtés which contained different texture and types of mushrooms were produced. In the theoretical part pâtés are characterised, their manufacturing and types of pâtés are described. The part of literature search is description of mushrooms in general, their composition and description of mushrooms which were used for production of pâtés. Another topic is description of conditionals and methods of sensory analysis. The experimental part is focused on the production of pâtés for two sensory analyses, evaluating the heat treatment and sensory analysis. The content of vitamin D in the samples of pâtés was analysed by liquid chromatography. Processing of results of sensory analysis of pâtés was determined that the best samples were pâtés with milled champignons and champignons which were add in blender.
|
|
|
Phloridzin content in selected apple varieties
Křehlíková, Jana ; Mikulíková, Renata (referee) ; Diviš, Pavel (advisor)
Phloridzin, a phenolic compound found in Malus genus, was targeted in this study for detection in apples and apple-based foods via HPLC. The research aimed to assess phlorizin’s potential as a marker for confirming apple presence in food, addressing food authenticity concerns. The methodology encompassed method optimization for sample preparation, considering solvent selection and oxygen impact on stability. Analysis revealed significant phloridzin distribution among apple varieties (Golden Delicious, Red Delicious, Granny Smith, Gala, Champion, Jonagold), averaging 17 ± 10 mgkg1. Further, 15 fruit products were surveyed for phloridzin content, with 5 non-apple-labelled foods also analysed. Phloridzin proved effective in detecting undeclared apple presence in jams, fillings, and fruit purees, highlighting potential for authenticity verification. However, fruit drinks and juices exhibited inconclusive results, suggesting a need for improved sample preparation and analysis methods.
|
|
|
Development of mass spectrometric methods for structural analysis of fatty acids and estolides
Cudlman, Lukáš ; Cvačka, Josef (advisor) ; Kozlík, Petr (referee) ; Lísa, Miroslav (referee)
(EN) This doctoral thesis summarizes the use of modern mass spectrometric methods for the structural identification of fatty acids and triacylglycerol estolides (TG-EST) and their subsequent characterization in the lipidome of vernix caseosa, i.e., the biofilm covering the skin of the human fetus during the last trimester of in-utero development. Vernix caseosa has mainly antimicrobial properties and the ability to heal wounds and burns. The first part of the doctoral thesis focuses on the diversity of fatty acids in the lipidome of vernix caseosa. These acids form the structural subunits of complex lipids, such as the abundant triacylglycerols and wax esters. By studying fatty acids and their structural features, this thesis has provided valuable insights into the structural variability of the vernix caseosa lipidome. Without a full understanding of the structure of these key subunits, it would be impossible to complete the analysis of this lipidome in the future. In this thesis, fatty acids using high-performance liquid chromatography (HPLC) and modern mass spectrometry methods, namely ultraviolet photodissociation (UVPD) and ozone-induced dissociation (OzID), were characterized. The coupling of HPLC and mass spectrometry (HPLC-MS) provided unambiguous information on the positions and geometry of...
|
|
| |
|
|
Comparison of microbial metabolic production from waste and powder whey
Elefantová, Petra ; Vítová, Eva (referee) ; Babák, Libor (advisor)
The master’s thesis discusses the comparison of microbial metabolic production from waste and powder whey. Whey is obtained as a by-product of cheese production. Lactose (preferably whey) using lactic acid bacteria (eg. Lactobacillus) under suitable temperature conditions is converted to lactic acid. Effect of temperature, effect of salts and effect of yeast extract on lactic acid production by L. casei were investigated. HPLC metod was determined lactid acid. In the practical part were used bacteria of the genus Lactobacillus. It was found that for dried and waste whey is the optimal temperature of 35 °C. At this temperature is the greatest gain of lactic acid. The highest concentration of lactic acid was obtained by using 20 g of yeast extract for dried whey and for waste whey were used 24 g of yeast extract. When monitoring the effect of salt concentration on the production of lactic acid, it was found that using only MnSO4·H2O gain most of lactic acid.
|
guest ::
