|
|
Use of derivatization methods in gas chromatography
Kaprinay Bréda, Boglárka ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This study is focused on verifying the possibility of derivatization in gas chromatography for the determination of fatty acids in oil samples and on the use of derivatization for the determination of organic substances in a sample of vine seed extract. The theoretical part deals with the characteristics of individual analytes. In the next section derivatization methods and transesterifications for fatty acid determination are described. The last chapter deals with the basic knowledge of gas chromatography and its instrumentation. The experimental part was divided into three chapters: analysis of fatty acids by transesterification, determination of mono- , di-, and triglycerides by derivatization and analysis of grape seed extracts. Three types of oils were analyzed in the experimental part: poppy, linseed and nut oil. The most common fatty acids in plant oils are palmitic, stearic, oleic, linoleic and linolenic acids. The optimization method was carried out using the derivatizing agent MSTFA. The determination of fatty acid methyl esters was measured on a gas chromatograph with a flame ionization detector. To confirm the presence of fatty acids, additional analysis was used on gas chromatograph with a mass spectrometer. Analysis of the grape extract was also performed on GC/MS. The method was most convenient using MSTFA, BSTFA and BSA+ TMCS derivatizing agents.
|
|
|
Chiral analysis of musk compounds in water ecosystem
Švarcová, Lucie ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
Diploma thesis summarizes available information about chiral analysis of synthetic musk compounds in the aquatic environment. In the theoretical part of the thesis chirality and importance of chiral analysis by means of examples of different environmental pollutants is documented. Further consideration is aimed on musk compounds, their classification, characteristics and their fate in the environment, especially in the aquatic environment. After that methods for chiral analysis of synthetic musk compounds are reviewed. The aim of the experimental part of this diploma thesis was to carry out the determination of thirteen representatives of musk compounds (2-cyclohexylethanol, allylcyklohexylpropionate, Arocet, Aroflorone, Citronellol, Fresco Menthe, Galaxolide, hexyl cinnamic aldehyde, HSA, isoamylsalicylate, isobornylacetate, Lilial and Linalool), out of which some compounds are chiral and some are achiral. For the analysis samples of wastewater from the wastewater treatment plant Brno - Modřice were taken. Target compounds were isolated by solid phase microextraction (SPME) and were subsequently analyzed by gas chromatography with flame ionization and mass spectrometric detection. On the basis of data evaluation the removal efficiency forgiven musk compounds in the wastewater treatment plant was assessed.
|
|
|
Determination of organic acids in wine
Michálková, Kateřina ; Mravcová, Ludmila (referee) ; Řezáčová, Veronika (advisor)
This bachelor thesis deals with determination of organic acids in wine by capillary zone isotachophoresis method. The theoretical part is devoted to the properties of wine, its composition, its benefit to human health and capillary zone isotachophoresis and its practical use. The practical part deals with determination of organic acids in wine by capillary zone isotachophoresis. Organic acids are determined in three phases of white and red wine production.
|
|
|
Determination of beta-blockers in wastewater
Csabová, Dominika ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
The thesis discusses the issue of pharmaceuticals in the environment. Beta – blockers are clinically important drugs which are highly used to treat cardio-vascular diseases such as hypertension, arrhytmia and angina pectoris. This group of drugs was chosen because of their already proven toxicity on aquatic organisms. The matrix examined was a wastewater from a wastewater treatment plant of a University of Veterinary and Pharmaceutical Sciences in Brno. The thesis focuses on an optimization of an analytical method for the identification and quantification of analytes in this group of drugs. A solid- phase extraction ( SPE) was used for the isolation of analytes in a wastewater sample. A method of ultra - high performance liquid chromatography (UHPLC) with the UV-VIS detection using a diode array detector (DAD) was used for the final analysis. Target analytes were metoprolol and propanolol.
|
|
|
Contamination of environment of musk compounds
Tobková, Lenka ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
Synthetic musk compounds are artificial organic substances commonly used as fragrant constituents of personal care products as parfums, cosmetics, detergents, in-house cleaning and washing agents. Given their large area of applications and their ability to be persistent, they leaked into all parts of ecosystem, especially aquatic one. There have been a big focus on studiyng these compounds, their properties and fate in the different parts of ecosystems in the last years. The aim of master's thesis was carry out the determination of five representatives (habanolide, exaltolide, ambrettolide, musk MC4 and ethylene brassylate) of macrocyclic musk compounds in waste water samples from influent and effluent of three water treatment plants (WWTP Brno-Modřice, WWTP Lednice and WWTP Mikulov). One of the main tasks was to perform a method optimisation for the determination of selected musk compounds in waste water and evaluation and interpretation of the results. Solid phase microextraction (SPME) technique was used for the extraction of analytes, consequently gas chromatography-mass spectrometry was used for analysis of selected analytes. Following evaluation the removal efficiency of musk compounds in the waste water treatment plant was assessed.
|
|
|
Substituted polyaromatic compounds in environmental components
Kubalík, David ; Mravcová, Ludmila (referee) ; Vávrová, Milada (advisor)
This work is focused on substituted polycyclic aromatic hydrocarbons (PAHs) in environmental compartments. The thesis examined the development of these compounds and their entry into the ecosystem. Due to their proven negative characteristics to be addressed also their toxicology. The next section discusses the appropriate methods, including sampling, sample preparation and final determination. The conclusion of this work forms draft standard operating procedure for their determination.
|
|
|
Study of pesticide degradation using advanced oxidation processes
Vlach, Tomáš ; Repková, Martina (referee) ; Mravcová, Ludmila (advisor)
In the master’s thesis are expleined and described proceses and terms related by problematic degradation of pesticides using advenced oxidation proceses and their possibilities of determinations. The essence of the experimental work was development and validate created method for determination of chosen pesticides. Degradation of this pesticides by advenced oxidation proceses and their determination after degradation. The aim of the work was compare chosen oxidation methods and summary of results for designe of the most appropriate method.
|
|
|
The development of a TGA-MS based method for determination of microplastics in soils
Šilhánková, Lenka ; Mravcová, Ludmila (referee) ; Kučerík, Jiří (advisor)
Plasty, pronikající do životního prostředí ať už neúmyslně či záměrně, mohou být fragmentovány za vzniku částic v řádu mikrometrů (tzv. mikroplastů) a znečišťovat tak půdní systémy. Doposud vyvinuté analýzy pro stanovení mikroplastů v půdách jsou především zaměřeny na kvalitativní stanovení, nicméně i jejich provedení se zatím stále potýká s různými úskalími. Navíc, téměř všechny tyto analýzy vyžadují časově náročnou předúpravu vzorku. V této studii jsme se zaměřili na vývoj nové analytické metody pro kvantitativní stanovení mikroplastů polyvinylchloridu (PVC) a polystyrenu (PS) v půdách bez předchozí úpravy vzorku pomocí termogravimetrické analýzy spojené s hmotnostní spektrometrií (TGA-MS). Pro analýzu byly použity vzorky modelové půdy s nízkým obsahem organického uhlíku, které byly spikovány na výslednou koncentraci 0,23–7 hm% PVC či PS. Vzorky byly pyrolyzovány s teplotním krokem 5 K min–1 až na teplotu 1000 °C. Pyrolýzní plynné produkty byly následně analyzovány s využitím hmotnostního spektrometru. Získaná data byla normalizována pomocí externího standardu (šťavelan vápenatý). Limity detekce se pohybovaly v rozmezí 0,08–5,3 hm% pro PVC a 0,005–0,7 hm% pro PS v závislosti na zvoleném m/z. Limity kvantifikace pak byly 0,3–17,7 hm% pro PVC a 0,002–2,2 hm% pro PS. Výsledky dokazují, že spojení TGA-MS může být konkurující semikvantitativní metodou pro stanovení mikro-PVC a mikro-PS v půdě s nízkým obsahem organického uhlíku.
|
|
|
Determination of antibiotics in the soil ecosystem
Brož, Tomáš ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
This work deals with a current issue of increasing drug concentrations and thus the growing number of resistant bacteria in the soil. One of the problem helping this issue is the fertilization of agricultural fields with animal faeces, in which antibiotics occur in an unchanged and still active form, as well as the insufficient effectiveness of conventional methods used in wastewater treatment plants. In an effort to improve the monitoring of this problem, a method for the determination of these antibacterial agents in the soil matrix, using solid phase extraction, and also a UPLC/MS method for their evaluation have been developed and optimized. From the group of sulfonamide antibiotics, sulfacetamide, sulfadiazole, sulfamerazine, sulfamethazine, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfathiaosal and trimethoprim were selected. The lowest limit of detection for the method is 0.3 µg/g for sulfathiazole and the highest of 8.1 µg/g for sulfasalazine. The highest average yields were achieved with sulfamethoxazole, namely 63 ±8 %.
|
|
|
Analysis of organic substances present in biochar
Bača, Ondřej ; Řezáčová, Veronika (referee) ; Mravcová, Ludmila (advisor)
This master's thesis deals with the analysis of organic substances, which are present in biochar. Biochar contains a number of organic compounds, that can be toxic and also carcinogenic to living organisms. In order for biochar to be used to improve soil quality or to be used for other applications, its safety must be declared by European or international certifications. Relevant European and international standards have been created for the determination of organic substances, that could be present in biochar. The theoretical part of the thesis was focused on selected organic substances, the process of pyrolysis and thermochemolysis, biochar characterisation and the used analytical methods. The experimental part of the thesis consisted of extraction with toluene and after that the determination of concentration of the 38 polycyclic aromatic hydrocarbons was performed. Qualitative analysis was performed by two-dimensional gas chromatography. Biochar samples were also subjected to thermochemolysis method and then they were analysed on GC-MS again. In both analytical methods, a large number of substances from groups such as PAHs, carboxylic acids, amines, substituted naphthalenes etc. was found, as well as smaller number of eg. polychlorinated biphenyls.
|
guest ::
RSS feed.