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Determination of polar pesticides in waste and surface waters
Borůvková, Tereza ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
This work is focused on the determination of polar pesticides in surface and waste waters. In this study Mecoprop-P, MCPA, Dichlorprop-P, 2,4-D and MCPBA in differently loaded surface waters and communal waters from sewage treatment plants were analyzed. These herbicides are included in the group identified as environmental quality standards. Some of herbicides (2,4-D and MCPA) were selected because their consumption in the Czech Republic exceeds 30 tons a year. Samples were collected prom three rivers near town of Jaroměř (Elbe, Úpa and Metuje Rivers), from one river near the town of Brno (Svratka River) and from inflow and outflow of two sewage treatment plants (WWTP Jaroměř, WWTP Brno – Modřice). Particular rivers were chosen for monitoring due to the probability of occurrence of herbicides, because they flow through agriculturally cultivated areas. Solid phase extraction (SPE) was used for the isolation of target compounds and their concentration. Gas chromatography with tandem mass spectrometry (GC/MS/MS) was used for the determination of target analytes in surface and waste waters. Selected herbicides were detected in all collected samples.
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Monitoring of the plasmachemical process using mass spectrometry
Ondra, Zdeněk ; Čáslavský, Josef (referee) ; Čech, Vladimír (advisor)
This bachelor thesis deals with plasma-enhanced chemical vapor deposition (PECVD) and the use of mass spectrometry to monitor the processes in plasma during the deposition of thin film. Tetravinylsilane plasma was used in the process of forming a thin film on the silicon wafer. The background of the spectrometer, the residual gases in the plasma reactor at basic pressure were characterized and the plasma polymerization process was monitored. This process was monitored with increasing effective power (2-150 W). The obtained mass spectra were assigned and described in detail. The plasma species that showed the greatest change were then characterized as a function of time during film deposition.
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Determination of toxic elements in wines
Hajdučková, Iva ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
The aim of this study was to determine the occurrence of selected toxic elements in wine. The theoretical part described technology of wine production and selected toxic elements (cadmium, lead, copper, zinc, nickel and chromium) in the terms of their impact on wine quality and their effects on the human organism. It provides an overview of instrumental analytical methods, which can be used for the analysis of toxic metals. In the experimental part inductively coupled mass spektrometry technique was used for the analysis of wine samples. The measured values are statistically processed and compared with current legislation.
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Application of separation methods with mass spectrometric detection for the study of degradation products of new polymeric materials
Čumová, Martina ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Synthetic polymer materials have been a part of human life since the 20th century. A variety of their use had resulted in a growing demand for their mass production, which then led to their increasing accumulation at waste dumps. After their deposition, these materials are exposed to many environmental factors causing their decomposition and subsequent release of the degradation products into the environment. This thesis is focused on the analysis of the photodegradation products from synthetic polymer materials and particularly polyurethane foams modified with the biodegradable fillers. One dimensional GC/MS and two dimensional comprehensive gas chromatography with time-of-flight mass spectrometry (GCxGC/TOF-MS ) were used for the measurements. The most of photodegradation products of polyurethane foams are injurious to health and environment.
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Analysis of flavonoids in beer by LC-MS
Měřínská, Radana ; Kočí, Radka (referee) ; Márová, Ivana (advisor)
Presented diploma thesis is focused on analysis of phenolic compounds in various types of beers. The aim of this work was to find possible differences among several types of beers and also between Czech beers and beers of foreign production. Theoretical part contains detailed description of beer technology, review of important analytical methods for determination of phenolic compounds and total antioxidant activity. The main attention is focused on instrumental technique LC/MS. In the experimental part values of total phenolics and total flavonoids and results of antioxidant status in analyzed beers were determined spectrophotometrically. Basic brewing characteristics were determined by pycnometry. On-line liquid chromatography with photo diode array detection and mass spectrometry detection was used for identification and quantification of individual phenolic compounds. Spectrophotometric analysis of phenolic and flavonoid levels seems to be less specific, that is consistent with findings in accessible literature. It was proved, that iso- bitter compounds exhibit about 65.44 – 90.93 % of the total bitter substances. These components are responsible for the main part of beer bitterness. The HPLC/PDA/ESI-MS was necessary to use for determination of characteristic phenolic compounds in individual types of beer. Within our measurement three columns were tested, the most favourable results were obtained using the column Restek C18. When compared with foreing beers, in Czech beers higher level of majority of phenolic compounds was detected and specific distribution of individual derivatives was found as well.
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Study of microplastic sorption properties
Hlaváčková, Hana ; Kučerík, Jiří (referee) ; Řezáčová, Veronika (advisor)
There is currently an effort to replace conventional plastics with biodegradable products that will have the ability to replace these substances. One of the possible biodegradable felt, which is currently being studied in detail, is also poly (3-hydroxybutyrate), which is produced by bacteria. This bachelor thesis deals with the sorption of selected substances on poly(3-hydroxybutyrate) microparticles. Substances whose contamination of water sources is a significant problem today have been selected for this work. Specifically, the sorption of the nonsteroidal anti-inflammatory substance ibuprofen, the triazole fungicide tebuconazole and the most common drug caffeine on PHB particles, which fall in the size of the microplastic group, were studied. The method of liquid chromatography with mass detection was used for analyzes.
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Application of Mass Spectrometry for the Determination of Oxidative Stress Markers and Mycotoxins
Čumová, Martina ; Večeřa, Zbyněk (referee) ; Hajšlová, Jana (referee) ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
The first topic presented in the dissertation thesis is determination of isoprostanes as markers of oxidative stress and other compounds affected by presence of oxidative stress. Isoprostanes iPF2-III, iPF2-VI, iPF2-VI, astaxanthin and polyunsaturated fatty acids (PUFA), especially arachidonic acid (AA) were monitored in Atlantic salmon eggs (Salmo salar). Methods for the determination of these compounds have been developed and optimized using chromatographic separation coupled to conventional or mass spectrometric detection. Freshly laid eggs, eyed embryos and non-viable eggs were used to test a general hypothesis that egg viability can be affected by susceptibility to oxidative stress, either through the specific fatty acid concentration and/or the antioxidant capacity of the eggs. Levels of isoprostanes and arachidonic acid (AA) were significantly higher in non-viable eggs than in control (eyed embryos) as well as relative abundance of PUFA. While no difference of isoprostanes was found between freshly laid and control those from the Atlantic stock except iPF2-VI which was observed under the LOQ in the control. Higher levels of PUFA and AA in comparison with the control were observed in the freshly laid eggs. However, the only statistically significant difference was observed in the amount of astaxanthin. Different levels of PUFA and astaxanthin may be related to their biochemical consumption during the development of eggs. This work evaluated potential effect on the viability of eggs Salmo salar due to the presence of oxidative stress. The monitoring of mycotoxins in food and feed was the subject of the second topic. Mycotoxins are secondary metabolites produced by fungi. They are ubiquitous undesirable natural contaminants that are toxic for humans and animals. Today are known more than 500 mycotoxins. However, only few of them are regulated by the European Union. The European Food Safety Authority (EFSA) was asked by the European Commission to provide a scientific opinion on other mycotoxins for which statutory limits could be developed. In this study is proposed simultaneous screening allowing fast, reliable and sensitive approach, identification and quantification of 17 mycotoxins in food and feed sample. The method includes both mycotoxins regulated by the EU and selected mycotoxins required by the EFSA (aflatoxins, deoxynivalenol, nivalenol, zearalenone, fumonisin, ochratoxin A, T-2 toxin, HT-2 toxin, enniatins and beauvericin). Analytes are isolated by the modified QuEChERS method. For separation and target mycotoxins detection, ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC –MS/MS) was employed. The method also allows determination of ergot alkaloids (ergocornine, ergosine, ergocryptine, ergocristine and their respective epimers). The developed method was used either for monitoring mycotoxins and ergot alkaloids in feed and raw materials and barley and malt prepared from it.
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Analysis of breath by mass spectrometry
Hoffmann, Pavel ; Vašinová Galiová, Michaela (referee) ; Mravcová, Ludmila (advisor)
This thesis is focused on analysis of volatile organic compounds in breath by mass spectrometry. For on-line analysis of breath, proton-transfer reaction mass spectrometry (PTR MS) was used. For off-line analysis, gas chromatography-mass spectrometry (GC-MS) and PTR-MS were used. For off line analysis breath sampling, Tedlar bags were used. For extraction and preconcentration of breath sample, solid-phase microextraction (SPME) was used. PTR-MS analysis was performed both qualitative and quantitative. GC-MS was performed only qualitative. Using PTR-MS, 7 different volatile organic compounds were found. Their concentrations were compared between sapmles. Namely, formaldehyde, methanol, acetaldehyde, ethanol, acetone, dimethyl sulfide and isoprene were found in ppb concentrations. Using GC-MS, 142 unique volatile organic compounds were found. Selected compounds were compared between selected samples.
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Determination of the presence of phosphodiesterase inhibitors in municipal wastewater
Smutná, Michaela ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
This diploma thesis is focused on the determination of phosphodiesterase 5 selective inhibitors in communal waste waters. In this study phosphodiesterase inhibitors levels in municipal waste waters from sewage treatment plants with different numbers of equivalent inhabitants were analyzed. Namely it was sewage treatment plants in Brno – Modřice, Luhačovice and Hodonín. In each of the above mentioned facilities 24 - hour cumulated samples of the influent and effluent waste water were collected. On the Brno - Modřice sewage treatment plant also weekly monitoring of the concentration of phosphodiesterase inhibitors was realized.
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Stability of Soil Organic Matter
Heldesová, Michaela ; Doskočil, Leoš (referee) ; Kalina, Michal (advisor)
This bachelor thesis summarizes available information about current research of soil organic matter stability and it divides them into two logical units. The first part includes environmental, physical and chemical factors, including human activities, which affect the stability or decomposition of soil organic matter. The methods used for the study of organic matter in the soil are summarized in the second part of this thesis. There the attention is paid to the accumulation of organic matter in specific pools, the ways of extraction of organic compounds and the use of quantitative and qualitative analytical methods to describe various characteristic of organic matter.
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