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Artificial sweeteners and their potential impact on the ecosystem
Vavrčíková, Veronika ; Mravcová, Ludmila (referee) ; Zlámalová Gargošová, Helena (advisor)
This diploma thesis deals with the determination and ecotoxicological assessment of artificial sweeteners. The diploma was focused on monitoring the most commonly used sweeteners, which includes acesulfam-K, cyclamate, saccharin and sucralose. These sweeteners were analyzed by liquid chromatography with mass spectrometry, using solid phase extraction for their concentration. The samples for their determination were taken from wastewater treatment plant in Modrice. Artificial sweeteners are synthetically produced substances, which is the main reason for their occurrence in waste water. Some of them are not efficiently removed from the wastewater treatment plant and penetrate into the environment. Analysis of the samples was found, that sucralose penetrates into the environment. The ecotoxicological effect of the sweeteners was evaluated via aquatic organisms, namely on the freshwater crustaceans Thamnocephalus platyurus and Daphnia magna, on the water plant Lemna minor, and the battery of tests was supplemented by a representative of the destructors Vibrio fischeri. For all sweeteners, LC20, EC20 and IC20 values were determined. For some sweeteners, LC50, EC50 and IC50 values were also determined. During testing, saccharin represented the highest toxicity.
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Determination of estrogen pollutants in real water sample by HPLC-UV after solid phase extraction.
Kozlík, Petr ; Coufal, Pavel (referee) ; Bosáková, Zuzana (advisor)
4 Abstract Estrogens are considered to belong to chemicals that negatively affect the endocrine system, even if present at very low concentrations. They are discharged into environment as a result of an increasing application of drugs etc. This work is focused on the separation and quantification of five estrogens, namely estrone (E1), 17β-estradiol (βE2), 17α-estradiol (αE2), 17α-ethynylestradiol (EE2) and estriol (E3) in natural water samples by HPLC-UV method. The chromatographic system consisted of a C18 stationary phase (SunFire® C18, 150 x 4.6 mm, octadecyl bounded to silica gel, particle size 5 µm) and binary mobile phase of acetonitrile/water in various ratios in isocratic separation mode. The effect of acetonitrile content in the mobile phase and flow rate of the mobile phase on retention and separation parameters was tested. Under the optimized separation conditions (acetonitrile/water 40/60 (v/v), 1.3 ml/min), all the compounds were baseline resolved and eluted within 15 min. These experimental conditions were applied to the calibration measurements which were carried out within the concentration range from 0.001 to 1 mg/ml. Limits of detection (LOD) and limits of quantification (LOQ) for the individual estrogens and their mixture (standards dissolved in methanol) were determinated. The detection...
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Portable and Miniaturized Separation Techniques Applicable for Food and Biotechnology Analysis
Dvořák, Miloš ; Pospíchal, Jan (referee) ; Bednář,, Petr (referee) ; Rittich, Bohuslav (advisor)
Capillary electrophoresis was used for determination of 6 fractions of caseins. Those fractions were measured in 144 samples of cow’s milk originated from the feeding experiment focused on explanation the influence of the feeding onto casein productions. In this work were separated 6 fraction of caseins first time with total resolution of the peaks. Capillary electrophoresis was applied for determination of short-chain organic acids during fermentation of wine must. It was compared the fermentation of must fermented by different yeast. The difference of profile short-chain organic acids during fermentation were not statistically significant. The once difference was in the utilisation of the malic acid and production of the lactic acid. A portable miniaturized system for medium pressure liquid chromatography was developed. The components were tested and system was used for the isocratic and gradient elution of various analytes (food dyes, parabens). New line of electroluminescent diodes (LEDs) for deep-UV areas of wavelength based on a different materials substrate was characterised. The new line was compared with old line LEDs. The new line LEDs was incorporated in deep-UV absorbance detectors. Detectors were characterised and tested for a detection various analytes in modes flow injection analysis and chromatography separation. First time was characterised this new line of the LEDs and the origin of the parasitic emission band produced by deep-UV LEDs light sources was explained. This origin is given by disturbances of a materials substrates. This work is a contribution for an advance of low-cost and portable systems and detection devices in the field of analytical chemistry.
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Surfactants in Surface and Waste Water
Štefka, Michal ; Vávrová, Milada (referee) ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Čáslavský, Josef (advisor)
This work is focused on the occurrence of surface-active substances in the environment. It deals with the development and optimization of methods for the determination of selected surfactants in samples from rivers and from influent and effluent of wastewater treatment plants. Representatives of anionic, nonionic and zwitterionic surfactants were selected as target compounds. Based on optimization of analytical methods and their pilot testing abroad on samples of surface water, the selection of analytes for the conditions in the Czech Republic were corrected and operatively expanded. For the final analysis liquid chromatography with mass spectrometry was used. Analysis of cationic surfactants was realized using liquid chromatograph with UV-VIS detector. This optimized method for analysis of anionic surfactants was applied to real samples. Samples of surface running water were from the River Thurso in Scotland and then from watercourses in the catchment area of Moravia river were collected. In addition to the grab sampling also continuous weekly sampling of water from Tvaroženský potok and Litava was realized. Waste water was collected at inflow and outflow of three wastewater treatment plants (WWTP) in South Moravia (Brno – Modřice, Břeclav and Hodonín).
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Vývoj, optimalizace a validace analytické metody na stanovení neurotoxinu \recke{beta}-N-methylamino-L-alaninu ve vodě pomocí LC/MS
HOŘEJŠÍ, Karel
This bachelor thesis deals with the development, optimization and validation of an analytical method for determination of neurotoxin \recke{beta}-N-methylamino-L-alanine in water using LC/MS. At first, the development and optimization of the analytical method was performed. For the optimization of the analytical method following parameters were selected: temperature of HESI and MS capillary, gases flow rate, voltage on S-lens, F-lens and capillary, collision energy. In addition, mobile phase composition, flow rate of mobile phase and injection volume of sample were optimized too. Then, the analytical method was successfully validated. Finally, the method was applied to the analysis of real samples of surface water.
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Vliv kvasinkové mikroflóry na finální jakost vína
Machalínková, Tereza
This thesis examines the influence of yeasts on the final stage of wine, consists of theoretical and practical parts. The theoretical part deals with the yeast themselves, their description, nutrition, the most important yeast for wine fermentation methods and influences that affect the fermentation process. The second part is devoted to work for bridges for optimal fermentation, there must be engaged in expanding and methods of sludge. The next section is devoted to chemical reactions during fermentation, wine composition and in the last part describes the training and maturation of wine. In the practical part is devoted to the production of wine from Pinot Blanc and his subsequent analytical analysis, determination of individual elements such as alcohol, glucose, fructose, glycerol and total acidity. In the last phase is devoted to the evaluation of individual analysis and discussion.
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Monitoring flavonoidních látek ve vybraných druzích medu
Sojková, Tereza
This work deals with flavonoid substances contained in honey. The work is to develop a theoretical part, which is focused on the composition of honey, its effects on human health and on the description of flavonoid substances. In the next section of the work is experimental part, which is shown in tables occurrence of phenolic compounds in different types of honey.
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Antioxidanty v bylinných čajích
Fadrhoncová, Pavla
Thesis on the topic Antioxidant in herbal teas is divided into two parts. The first part theortical is concerned with the description and division of antioxidants. There are mentioned some synthetic antioxidants, some major intracellular antioxidant and natural antioxidant, which are represented by polyphenolic compounds as the main components of herbal teas. Furthmore, there is described the determination of biologically active compounds by extraction techniques to chromatographic methods. In the theoretical part are also described individual samples of herbs used for analysis. The second part is concerned with the practical determination of polyphenolic acids in selected samples of herbal teas. Two extraction techniques were chosen for separation of polyphenolics acids. The first was Soxhlet extraction accelerated and the second was exctraction shaker. For the determination of polyphenolic acids was used high performance liquid chromatography (HPLC) coupled with a diode array detector (DAD) and with mass detector type triple quadrupole. The measured results show that in most samples of herbs were the most represented chlorogenic acid and caffeic acid.
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Probiotics and prebiotics and their co-encapsulation
Šnajdarová, Karolína ; Bokrová, Jitka (referee) ; Márová, Ivana (advisor)
This bachelor thesis is focused on study of probiotic cultures and options of coencapsulation with specific substrates called prebiotics. Lactobacillus acidophilus and Bifidobacterium breve were used as encapsulated microorganisms. As the specific substrates inulin, psyllium, apple fiber and hemp fiber were tested. Prebiotics was added to probiotics both in untreated form and in hydrolyzed form. The stability and viability of the cells have been studied by microscopy for the period of 6 weeks. Particles were stored in the enviroment of 2.5% citric acid. As the best substrate for cell growth the hemp fiber was found. The hemp fiber exhibited the highest increase of cells count. During observation of long-term stability in the model digestive conditions, particles with hemp fiber were destroyed in instestinal juices. For that reason, particles with hemp fiber could be used in food supplements with targeted transport. The bachalor thesis is also focused on characterisation of prebiotics components. The highest amount of total sugars in the group of non-hydrolyzed prebiotics exhibited psyllium. The highest content of reducing sugars both in the groups of non-hydrolyzed and hydrolyzed prebiotic had hemp fiber. By the method of thin-layer chromatography was found out that the main components of hydrolyzed prebiotics are glucose and fructose. Further, some disaccharides and oligosaccharides were obtained by TLC analysis. For characterisation of prebiotics by HPLC the column Rezex exhibited better sensitivity. HPLC analysis confirmed that the main components of prebiotics are glucose and fructose, some more complex carbohydrates were found too.
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The Use of Separation Methods for the Study of Selected Drugs and Pesticides in Water
Burešová, Jitka ; Hajšlová, Jana (referee) ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Vávrová, Milada (advisor)
This work is focused on the study of penetration of pesticides and pharmaceuticals in the aquatic environment. The aim was to develop and verify the optimal method for long-term monitoring of the occurrence of selected pesticides and pharmaceuticals in surface waters. Two frequently used analgesics ibuprofen and diclofenac, and carbamazepine that is used to treat epilepsy, were chosen from the group of drugs. A group of 41 pesticides were selected for monitoring too. The attention was focused on a group of urea pesticides and phenoxyacetic acids, as well as on selected pesticides falling to the group of priority substances or identified as environmental quality standards. Some of pesticides were selected because their consumption in the Czech Republic exceeds 30 tons a year. Liquid chromatography with tandem mass spectrometry (LC / MS / MS) was used for the determination of selected analytes in surface waters. Two optimized analytical method were developed. Ten analytes were determined in negative ion mode and 34 analytes in positive ion mode. Solid phase extraction (SPE) was used for purification and concentration of the samples. Developed methodology was validated and used for monitoring of selected compounds in samples of surface waters from the Morava River basin. Samples were collected on the rivers Morava and Svratka monthly for two years. Samples from the river Blata and stream Nivnička were collected for one year. Surface water samples were also collected from the river Litava. Four samples were taken throughout the length of the flow during one day. Smaller streams were chosen for monitoring because of the probability of occurrence of pesticides. They flow abundantly agriculturally cultivated areas. Drugs ibuprofen and diclofenac were detected in all taken samples, carbamazepine mostly. Among the most commonly occurring pesticides were bentazon, diuron, isoproturon, carbendazim, MCPA, MCPP, propiconazole, tebuconazole and 2,4-D.
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