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Application of Gas Chromatography with Mass Spectrometric Detection for the Assessment of Drug-residue Contamination of Wastewaters and Surface Waters
Lacina, Petr ; Čáslavský, Josef (referee) ; Hajšlová, Jana (referee) ; Sokol,, Jozef (referee) ; Vávrová, Milada (advisor)
This work is based on the current issue of increasing concentrations of pharmaceutical residues in various components of the environment. These new environmental contaminants continuously enter the environment. The most affected environmental component is the aquatic environment. This study is focused on the development and optimization of reliable analytical method, which can determine selected drugs in the aquatic environment (waste waters and surface waters) qualitatively and quantitatively. The target compounds were selected mainly from the group of non-steroidal anti-inflammatory drugs (NSAID): salicylic acid, acetylsalicylic acid, clofibric acid, ibuprofen, acetaminophen, caffeine, naproxen, mefenamic acid, ketoprofen and diclofenac. NSAIDs are one of the most used drugs in Czech Republic. For the final analysis of this study was used the comprehensive two-dimensional gas chromatography with mass spectrometric detection Time-of-Flight (GCxGC-TOF MS). It is a very sensitive and reliable analytical method for trace and ultra-trace analysis. Simultaneously, solid phase extraction (SPE) and derivatization are optimized in this work. Optimized analytical method including SPE, derivatization with MSTFA (N-methyl-N-(trimethylsilyl) trifluoroacetamide) and final analysis by GCxGC-TOF MS were applied successfully for the analysis of real samples. Samples of waste water were collected from the waste water treatment plant in Brno – Modřice and samples of surface water were collected from two river streams Svratka and Svitava in Moravian region. The range of concentrations of selected drug residues varied from one to tens of g/L in wastewater and from tens to hundreds of ng/L in surface waters. The degree of wastewater and surface waters contamination by drug residues is assessed in conclusions of the work. Simultaneously, spontaneous degradation of selected drugs in water and removal efficiency of the wastewater treatment plant is assessed in conclusions of the work. The developed method is usable for monitoring and environmental analysis of water ecosystems. It is usable not only for selected drugs, but even for other organic compounds with similar properties.
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Analysis of tar formed by combustion of biomass
Chytil, Václav ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
This bachelor's thesis is focused on the analysis of the tar formed during combustion of biomass. Samples of the tar were provided by Energy Institute, Faculty of Mechanical Engineering, Brno University of Technology. BTEX, polycyclic aromatic hydrocarbons (PAHs) and n-alkanes were chosen as groups of target compounds. Samples (tar solutions in acetone) were refined before the final analysis. In the case of BTEX and n-alkanes, only filtration and dilution were used. In the case of polycyclic aromatic hydrocarbons, samples were filtered and then cleaned-up by column chromatography using silica gel. Gas chromatography with flame ionization detector (GC-FID) was chosen as an appropriate analytical method for the determination of target compounds from selected groups of BTEX and n-alkanes. Target compounds from the group of polycyclic aromatic hydrocarbons were determined by gas chromatography with mass spectrometric detection (GC-MS).
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Multidimensional Liquid Phase Separations
Šesták, Jozef ; Čáslavský, Josef (referee) ; Pulkrabová, Jana (referee) ; Česla, Petr (referee) ; Kahle, Vladislav (advisor)
This dissertation is dedicated to the topic of multidimensional liquid phase separations. This separation techniques are developed for analysis of complex samples containing thermally labile, low volatile or high molecular weight components that can´t be analysed by two-dimensional (2D) gas chromatography. Concepts of peak capacity and orthogonality are explained and various methods of their determination are stated in theoretical part of dissertation. High performance column liquid chromatography (HPLC) and high performance capillary electrophoresis (HPCE) are suggested as the most suitable methods for automated multidimensional liquid phase separations on-line coupled to mass spectrometry. Configuration of simplified miniaturized liquid chromatograph is described in experimental part of this thesis. Original concept of the system has been extended by simple mobile phase gradient generation technique. Correct function was demonstrated on repeatable separation of alkylphenones, peptides, nitroaromatics, and nitroesters. This system has been utilized as a base for a couple of simple two-dimensional separation platforms for HILIC-MALDI-MS analysis of glycans, for separation of peptides based on off-line coupling of isoelectric focusing and capillary liquid chromatography, and finally for on-line IEC×RPLC, RPLC×RPLC, and HILIC×RPLC two-dimensional liquid chromatography. Correct operation of submitted platforms has been proved.
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The role of p130Cas substrate domain mediated signaling in cancer cell migration, invasiveness and metastasis of cancer cells
Zemanová, Kateřina ; Brábek, Jan (advisor) ; Čáslavský, Josef (referee)
p130Cas (Crk-associated substrate) was first described over 30 years ago as a protein that associates with the v-src and v-crk oncoproteins and undergoes tyrosine phosphorylation. Proteins of the CAS family are an important part of cellular biological processes in normal and pathological situations. The existence of 15 YXXP repetitive motifs is characteristics for substrate domain. p130Cas is an adapter protein that allows interactions between proteins that lead to assembly of multiprotein complexes. The p130Cas protein regulates these multiprotein complexes, which further drive chemotaxis, apoptosis, differentiation and migration. Overproduction of CAS proteins was found in connection with a poor prognosis and an increased incidence of metastases. Also, the elevated expression of proteins of the CAS family is related to resistance to some types of chemotherapeutics.
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Short-term application of elevated temperature and drought influences the isotopic composition of winter wheat grains
Pernicová, Natálie ; Urban, Otmar ; Čáslavský, Josef ; Klem, Karel ; Trnka, Miroslav
The study aimed to determine the differences in carbon (δ13C) and nitrogen (δ15N) stable isotope ratios in grains of three winter wheat varieties grown under optimal and stress conditions. We found that the wheat variety has a significant effect on both δ13C and δ15N isotope ratios. Short-term (nine days) exposure to drought and high temperature during the heading or stem extension development phase significantly enhanced δ13C values, but only high temperature affected δ15N values. Enhanced δ15N values support the assumption that global warming causes a higher representation of the 15N isotope in plants. Moreover, significant interactive effects of temperature and water availability on the values of both isotopes were found implying that C and N metabolisms have been altered under the investigated stress conditions. We conclude that δ13C and δ15N isotope ratios of cereal grains are sensitive indicators of stress conditions, even short-term ones
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Regulation of Epithelial-Mesenchymal transition by the ERK pathway.
Čáslavský, Josef ; Vomastek, Tomáš (advisor) ; Brábek, Jan (referee) ; Gregor, Martin (referee)
Typical epithelium is uniformly polarized solid structure defined by the presence of cell-cell contacts that are connected to well-organized network of actin cytoskeleton. While epithelium is considered to be rather static, during embryogenesis or cancer development epithelial tissues undergo considerable dynamic changes in their integrity that are characterized by loss of epithelial polarity, disruption of cell-cell adhesions and gaining mesenchymal or mesenchymal-like migratory phenotype. These changes, collectively termed as epithelial-mesenchymal transition (EMT), allow cells to effectively invade surrounding tissues and are considered to be a main factor underlying the formation of metastatic cancer. The MAPK/ERK cascade, comprised of protein kinases Raf, MEK and ERK, induces the breakdown of epithelial integrity and cell autonomous migration in various cell lines. In the ERK pathway, ERK is an effector protein kinase which, depending on the cellular context, phosphorylates a number of different substrates. Spatiotemporal phosphorylation of specific constellation of ERK substrates drives specific biologic outcome. The question arises whether, during conversion of multicellular epithelium to autonomously migrating cells, ERK regulates a "master" controller or whether the ERK regulatory function...
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The role of p130Cas substrate domain mediated signaling in cancer cell migration, invasiveness and metastasis of cancer cells
Zemanová, Kateřina ; Brábek, Jan (advisor) ; Čáslavský, Josef (referee)
p130Cas (Crk-associated substrate) was first described over 30 years ago as a protein that associates with the v-src and v-crk oncoproteins and undergoes tyrosine phosphorylation. Proteins of the CAS family are an important part of cellular biological processes in normal and pathological situations. The existence of 15 YXXP repetitive motifs is characteristics for substrate domain. p130Cas is an adapter protein that allows interactions between proteins that lead to assembly of multiprotein complexes. The p130Cas protein regulates these multiprotein complexes, which further drive chemotaxis, apoptosis, differentiation and migration. Overproduction of CAS proteins was found in connection with a poor prognosis and an increased incidence of metastases. Also, the elevated expression of proteins of the CAS family is related to resistance to some types of chemotherapeutics.
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Application of Diffusive Gradients in Thin Films Technique in Food and Environmental Analysis
Reichstädter, Marek ; Čáslavský, Josef (referee) ; Urík,, Martin (referee) ; Diviš, Pavel (advisor)
Tato dizertační práce zkoumá vývoj techniky difúzního gradientu v tenkém filmu (DGT) pro stanovení rtuti (Hg) a dalších stopových kovů a dále rozšířené možnosti použití této techniky. Technika DGT je v této práci vyvinuta pro stanovení Hg a dalších stopových prvků v různých kapalných médiích. Dvě rozdílná sorpční média specifická pro rtuť byla testována pro použití v technice DGT – Purolite S924 a cysteinem modifikovaná aminopropyl silika (CAPS). Purolite S924 je komerčně dostupný chelatační iontoměnič, CAPS byla připravena v laboratorních podmínkách imobilizací cysteinu na 3-aminopropyl funkcionalizovanou siliku pomocí glutaraladehydu. Obě testovaná sorpční média ukázala slibný aplikační potenciál pro užití v technice DGT díky funkčnosti v roztocích o širokém rozsahu pH i iontové síly. Funkčnost DGT s novými sorpčními médii byla porovnána s technikami DGT s běžně používanými sorbenty Chelex-100 a 3-merkaptopropylfunkcionalizovanou silikou. Hlavní výhodou sorpčních médií Purolite S924 a CAPS je schopnost současného stanovení Hg a dalších stopových kovů (Cd, Pb, Co, Ni, Cu). Vzhledem k odlišným požadavkům na sorpční média používaná v technice DGT nebylo dosud současné kvantitativní stanovení Hg a dalších stopových kovů možné. Doposud byly zapotřebí dvě samostatné techniky DGT – jedna pro Hg a druhá pro další stopové kovy, což zvyšuje množství vzorků pro analýzu a množství použitého spotřebního materiálu. Technika DGT s CAPS byla použita pro stanovení koncentrací kovů v námořních přístavech v Oostende a Zeebrugge na belgickém pobřeží Severního moře. Přestože byla technika DGT původně představena pro použití v analytické chemii životního prostředí, byla v této práci zkoumáno i použití této techniky v analýze potravin. V prostředí rybí omáčky byla ověřena funkčnost techniky DGT a stanoveny difúzní koeficienty Hg a dalších stopových prvků. Technika DGT byla následně použita pro stanovení koncentrace rtuti a dalších stopových kovů v různých komerčně dostupných vzorcích rybí omáčky. Výsledky nově navrhnutého analytického postupu s použitím techniky DGT byly porovnány s výsledky přímé analýzy atomovou absorpční spektroskopií s termální dekompozicí a amalgamací zlatem (TD-AAS) a po mikrovlnném rozkladu vzorků omáčky také s výsledky sektorové hmotnostní spektrometrie s indukčně vázanou plazmou (SF-ICP-MS). Díky předkoncentrační schopnosti techniky DGT byly dosaženy nižší detekční limity ve srovnání s TD-AAS nebo SF-ICP-MS. Technika DGT díky schopnosti oddělení analytů z komplexní matrice rybí omáčky rovněž snížila opotřebení a koroze kovových částí použitých instrumentálních technik.
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Infrared spectroscopy of thin films
Kiss, Andrej ; Čáslavský, Josef (referee) ; Čech, Vladimír (advisor)
Cílem této bakalářské práce je literární rešerše v oblasti tenkých vrstev, plazmochemické depozice z plynné fáze a infračervené spektroskopie Fourierovou transformací, a měření infračervených spekter tenkých vrstev a charakterizace jejich chemické struktury na základě změřených spekter. Pomocí infračervené spektroskopie Fourierovou transformací bylo měřeno pět vzorků tenkých polymerních vrstev z tetravinylsilanu, vytvořených na křemíkovém substrátu pomocí plazmochemické depozice z plynné fázi s efektivním výkonem v rozmezí od 2 W do 150 W. Měření odhalilo chemické vazby přítomné ve vzorcích a jak se struktura měnila s měnící se efektivním výkonem. Snížení absorpčních pásů s přítomností vodíku naznačuje zvýšení zesítění se zvýšeným efektivním výkonem. Také snížení absorpčních pásů s přítomností křemíku poskytuje důkaz pro zvýšení poměru C/Si. Tyto výsledky nám pomáhají porozumět charakteristikám těchto tenkých vrstev a přispívají k pochopení procesu plazmochemické depozice z plynné fáze.
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