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Determination of selected mycotoxins in tea
Pustka, Václav ; Maleček, Miroslav (referee) ; Kuchyňa, Jaroslav (advisor)
This diploma thesis deals with the development and validation of an analytical method using high performance liquid chromatography method with fluorescence detection for the simultaneous determination of aflatoxins and ochratoxin A in herbal and fruit tea. The theoretical part describes the most common groups of mycotoxins and the most important methods for their determination in food. The great attention is devoted to HPLC method and the overview of the derivatization techniques for aflatoxins B1 and G1 fluorescence response enhancement. The practical part of this study focuses on the optimization of sample extraction and purification, the settings of the instrumental analysis and the photochemical reactor assembly. The thesis also involves the determination of the basic performance characteristics for the successful method validation.
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The use of GC/MS for the analysis of drugs
Sýkora, Richard ; Opatřilová, Radka (referee) ; Vávrová, Milada (advisor)
This diploma thesis is based on the current issue of the presence of pharmaceuticals in various components of the environment. Concerning the contamination by residues of pharmaceuticals the most affected environment is the aquatic environment where these substances leaks especially from wastewater treatment plants, which eliminate them during the cleaning process only partially. This work is focused on the selected group of pharmaceuticals, non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, caffeine, naproxen, ketoprofen, diclofenac) in waste water. For analysis purposes two types of sampling were used and compared: the conventional spot sampling of wastewater and the sampling using passive samplers POCIS. The sampling took place at the inflow and outflow of the wastewater treatment plant in Brno Modřice. The solid phase extraction (SPE) using Oasis HLB columns was used as the extraction method. Extracted sample was derivatized then. Derivatization agents were: MSTFA (N-methyl-N-(trimethylsilyl)trifluoroacetamid) and BSTFA (N, O-bis(trimethylsilyl) trifluoroacetamid). The final analysis was performed using gas chromatography with mass spectrometric detection Time-of-Flight (GC/TOF-MS).
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Aplication of gas chromatography for determination of drug residuals in waters
Lacina, Petr ; Stoupalová, Michaela (referee) ; Vávrová, Milada (advisor)
Diploma thesis is focused on the choose of methods and optimalisation analysis procedure of selected pharmaceuticals (salicylic acid, ibuprofene, naproxene, ketoprofene and diclofenac) in surface and waste water by using gas chromatography with mass spectrometer (GC-MS). Solid-phase extraction (SPE) with Oasis HLB cartridges was used as an extraction method in this analysis. Extraction is followed by derivatization and their optimalization of selected pharmaceuticals. Derivatization and its optimalization were performed by two silylation reagens N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Different volumes of derivatization reagents, different temperatures and different times were used during the procedure. The best combination is then used for analysis of real samples. Real samples of waste water were collected in sewage treatment plants in Brno – Modřice and real samples of surface water were collected from several rivers and one pond in region Moravia. This thesis also presents and tests SPE methods for extraction and concentration selected sulfonamide residues (sulfamethazine, sulfamethoxazole, sulfapyridine and sulfathiazole) from the aquatic environment.
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Non-target screening of organic pollutants in waters and sediments
Hamalčíková, Veronika ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
This master thesis deals with the potential influence of the waste dump Hrádek u Pacova and the wastewater treatment plant Brno – Modřice on surroundings using the optimized non-target screening method of organic pollutants in water and sediments. The experimental part is focused on the identification of organic compounds in samples of ground water from monitoring wells, the surface water from stream and pond and in sediment samples collected from streams in the vicinity of municipal waste dump. Organic compounds were also identified in water and sediment samples from the river Svratka near the municipal waste water treatment plant Modřice. The sequential liquid – liquid extraction was used for the isolation of organic compounds in water samples. Organic compounds in sediment samples were isolated by pressurized solvent extraction (PSE) with subsequent fractionation of the extract using column chromatography. Final analysis determination was performed using comprehensive orthogonal two-dimensional gas chromatography with mass spectrometric detection (GCxGC-TOF MS).
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Application of gas chromatography for determination of drug residuals
Sýkora, Richard ; Lisá, Hana (referee) ; Vávrová, Milada (advisor)
Analgesics are nowadays widely used group of drugs in human and also in veterinary medicine. Residuals of these drugs enter surface waters via discharges from the waste water treatment plants as the result of insufficient efficiency of their removal during cleaning process. In this bachelor thesis the possibilities of the analgesics residuals determination in waters using derivatization followed by gas chromatography with mass spectrometric detection were experimentally evaluated. Individual derivatization procedures were compared too. Several derivatization agents were tested and experimental parameters for selected analgesics were optimized (reaction time and temperature, amount of derivatizing agent). Further, several procedures of isolation of target compounds from water based on Solid Phase Extraction were verified. In all cases, gas chromatography with TOF-based mass spectrometric detection acts as final analytical method.
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Bisphenol A in water ecosystem
Nohelová, Gabriela ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
This diploma thesis deals with Bisphenol A, especially with its impact on the aquatic ecosystem. Information about its properties, production and current use are summarized here. Its harmful impact on the environment, especially on the aquatic ecosystem and the human body is characterized. Also the methods of its degradation within the aquatic environment have been described. A summary of the options of a determination of Bisphenol A in water samples is incorporated and the method of gas chromatography with mass spectrometry (GC/TOF MS) and comprehensive two-dimensional gas chromatography with mass spectrometry (GCxGC/TOF-MS) is compared in the experimental part. Analytical determination precedes the isolation of the analyte from the water samples by solid phase extraction (SPE) using SupelcleanTM ENVITM - 18 and derivatization using the silylation reagent, N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). The result of this work is the analysis of a series of real samples from wastewater treatment plants Brno Modřice and Luhačovice by a two-dimensional gas chromatography with mass spectrometry (GCxGC/TOF-MS).
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Passive sampling of polar organic pollutants from water
Vítková, Libuše ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
This thesis deals with the passive sampling of polar compounds from water using passive samplers POCIS (Polar Organic Chemical Integrative Sampler). These devices were exposed for 4 weeks in the waste water at the inflow of municipal waste water treatment plant in Brno – Modřice, and also at the outflow of the treated water. After exposition sequestered compounds were released by extraction with a mixture of methanol, toluene and dichlormethane. Extracts were analysed by liquid chromatography/mass spectrometry with electrospray ionization. Further, methylated and trimethylsilylated extracts were analysed by orthogonal comprehensive two-dimensional gas chromatography with mass spectrometric detection. Separated compounds were identified on the base of their retention and mass spectra.
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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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On-line derivatization of saccharides in capillary electrophoresis
Mareš, Vít ; Křížek, Tomáš (advisor) ; Coufal, Pavel (referee)
Saccharides chains may suffer from various inaccuracies during their biosy- thesis, that effects their biologic functions. Therefore, they can be used for dia- gnosis of some diseases or quality control in biopharmaceutics. Capillary electro- phoresis has its place in diagnosing these occuring errors. In this thesis a method of on-line derivatization of saccharides in fused-silica capillary with 50 cm in lenght and 50 µm in inner diameter was developed. Gluco- se was used as a model molecule, which was labeled by a fluorescent derivatization reagent, 7-aminonaphthalene-1,3-disulfonic acid. Derivatization of glucose and its separation needed optimalization. First was determined an electrophoretic mo- bility of the derivatization reagent in 0.5; 1.0 and 2.5M acetic acid and 20mM phosphate buffer (pH = 3.5). Both, 2.5M acetic acid and 20mM phosphate buffer, were tested as solvents for 7-aminonaphthalene-1,3-disulfonic acid. The reaction with glucose was the best in acetic acid solution. On the contrary, phosphate buf- fer was found to be the best background electrolyte for the separation. Derivatized glucose was detected by UV detector at 229 nm. Henceforth, the reaction con- ditions were adjusted such as reaction time, voltage and time of its application. Input voltage was applied negative due to the...
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Formation of nucleobases from formamide initiated by high-power density energy events
Michalčíková, Regina ; Civiš, Svatopluk (advisor) ; Šponerová, Judit E. (referee)
This Master's thesis deals with determination of nucleobases in formamide samples (pure or catalyzed form) after their initiation by high-power density energy events. The theoretical part states the reader to the problems of prebiotic chemistry and acquaints him with the various theories of the origin of the nucleobases. The experimental part deals with the analysis of the samples initiated by Laser System PALS, which was used for the simulation high-power density energy events. For the identification and determination of the final products of laser plasma initiated chemical reactions in the gaseous phase of the samples was used the Fourier Transform Infrared Spectroscopy. The liquid part of the samples and the nucleobases in this part were analyzed by the gas chromatography with the mass detection.
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