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Comparison of methods for detection and determination of enantiomers of theanine in HPLC
Šlechtová, Tereza ; Tesařová, Eva (advisor) ; Bosáková, Zuzana (referee)
This thesis focused on optimization of separation methods for underivatized theanine enantiomers on two teicoplanin-based chiral stationary phases and separation methods for enantiomers derivatized by 9-fluorenylmethyloxycarbonyl chloride and dansylchloride. Using these optimized conditions the limits of detection and quantification were calculated. Under optimized conditions were also investigated the contents of theanine enantiomers in green tea and in selected dietary supplement containing L-theanine.
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Determination of selected terpenoids by HPLC with electrochemical detection
Mužíková, Jana ; Dejmková, Hana (advisor) ; Schwarzová, Karolina (referee)
This thesis deals with the determination of carvacrol, thymol, and eugenol by HPLC with electrochemical detection. Carbon paste electrode and boron doped diamond film electrode were used as the working electrodes. For the comparison, UV spectrophotometric detection at 275 nm was used besides the electrochemical detection. The separation was performed on LiChroCART 125-4, RP-18e (5 µm) column. Optimum separation conditions were found: mobile phase consisting of acetonitrile and acetate buffer in ratio 50:50, the optimum buffer pH was pH 5. The optimum potential of working electrode during electrochemical detection was +0,8 V and +1,2 V for carbon paste electrode and boron doped diamond film electrode, respectively. For both electrodes, repeatability of the measurement was examined; the surface of both electrodes had to be renewed between the measurements. Under the obtained optimum conditions, calibration dependences were measured. The studied substances were determined in real samples, in Thymus vulgaris L. and Achillea millefolium L. and in thyme-containing tea and syrup.
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Speciation analysis of selected mercury compounds using combined technique HPCL-EcMCVG-QFAAS
Leštinová, Veronika ; Červený, Václav (advisor) ; Spěváčková, Věra (referee)
Today, the information about total mercury content in a sample is not enough to know because of different toxicity of various species like inorganic forms such as Hg+ , Hg+II and organic bonded mercury in Methyl-mercury, Ethyl-mercury or Phenyl-mercury. Therefore a speciation analysis is needed to do. The aim of this diploma thesis was to develop and validate a new method for speciation determination of selected mercury compounds. This method comprises a connection of high performance liquid chromatography, electrochemical mercury cold vapor generation as a postcolumn derivatization technique and atomic absorption spectrometer. Using this on-line connection of mentioned techniques, an efficient separation of Hg+II and methylmercury was achieved. Reached limits of detection were 0.3 µgml-1 and 0.5 µgml-1 for Hg+II and methylmercury, respectively. At the end of experimental work, proposed hyphenated technique HPLC- EcMCVG-QFAAS was used for determination of these two mercury compounds in six real tap water samples (Bílý potok, Bílina, Labe, Vltava, Botič, pond Kovošrot). In Bílý potok, inorganic mercury (Hg+II ) was identified on the base of identical of retention time compared to standard. Standard addition method was used in both FIA and HPLC arrangements and determined content of Hg+II was (0.4...
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Optimization of HPLC separation of penicillin derivatives
Šímová, Veronika ; Kalíková, Květa (advisor) ; Tesařová, Eva (referee)
Penicillins are part of β-lactam antibiotics, which are wide spread in human and veterinary medicine. The aim of this bachelor work was to develop and to optimize HPLC method for separation of four derivatives of penicillin - amoxicillin, 4-hydroxyphenoxymethylpenicillin, benzylpenicillin and phenoxymethylpenicillin. The reserved phase HPLC with octodecyl stationary phase was used in this work. The baseline separation of all analytes was not obtained in isocratic elution. For this reason, the gradient elution was examined on the baseline resolution of all analytes was achieved and the analysis time did not exceed 22 minutes. The stability of methanolic solutions of penicillins was tested during eight days. Key words: HPLC, antibiotics, derivatives of penicillins, reverse mod, stability
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Study on stability of triazine based herbicides in water
Petrlíková, Kateřina ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The first aim of this thesis was to find a suitable analytical method for monitoring of stability of four s-triazine herbicides in water samples. Two columns - stationary phases C18, namely products of Waters and Astec were tested in HPLC system. The composition of ACN/H2O mobile phase was changed in the range from 90/10 to 60/40 (v/v). Baseline separation of prometone, propazine and prometryne was achieved on the Astec C18 column with mobile phase ACN/H2O 70/30 (v/v). This separation system was used for the study of stability. The stability of s-triazines was monitored in the period of six weeks. The samples of atrazine, prometone, propazine and prometryne water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples were measured in samples of water - water from Vltava, acidified water from Vltava, water from water tap and acidified water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples.
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Less common metabolites of steroid hormones in human physiology and pathophysiology.
Máčová, Ludmila ; Hampl, Richard (advisor) ; Rauch, Pavel (referee) ; Černý, Ivan (referee)
The thesis focuses on selected, yet unsolved question of the role of less common steroids and SHBG as a junction of three endocrine systems. Answering these questions may help to understand the complex mechanism of action of these hormones on the human organism. This thesis is based on five author and co-written studies mostly published in foreign scientific journals. In the case of studies of metabolites 16α-OH-DHEA and 7-oxo-DHEA (Zamrazilová et al., 2007; Kazihnitková et al., 2007) were focused on the development of appropriate methodological approach because recently used methods showed a low sensitivity and specificity. We developed and statistically evaluated new RIA methods which are rapid, sensitive and inexpensive. Both of them can be used in other research even in routine practice. New methods were also used to determine the metabolites in a statistically significant sample of healthy human population. In another study (Zamrazilová et al., 2010) we examined the relationships of selected steroid metabolites and SHBG in patients with CAH. We assumed that SHBG may act as a non-steroidal laboratory parameter reflecting the effectiveness of substitution therapy in these patients. Our assumption was not confirmed. We observed lower levels of SHBG which at least in women reflect effects of...
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Biodegradation of polycyclic aromatic hydrocarbon in wood treated with creosote oil
Fabiánová, Tereza ; Cajthaml, Tomáš (advisor) ; Gabriel, Jiří (referee)
Wood contaminated by polycyclic aromatic hydrocarbons (PAH) represent a serious environmental risk. Composting seems to be an effective method for decontamination of such waste material. PAHs are degraded mainly under aerobic conditions the efficiency of composting could be strongly affected by the process conditions. This work is aimed at the comparison of PAH removal by a 340-days-long composting in laboratory scale composting pilots and a 240-days-long process in a pilot scale. To set up composting piles a "green substrate" commercially used for button-mushroom production and a grass substrate were used. The use of the grass substrate led to a higher PAHs removal (97% of the initial sum of PAHs) in comparison to the green substrate (81% of the initial sum of PAHs). Further, the effect of the size of wood particles on the PAHs removal efficiency was demonstrated. Analysis of phospholipid fatty acids showed an enhanced growth of gramm-negative bacteria and fungi during the composting processes. During the degradation process the enzyme activity of laccase was detected. The ecotoxicological test using a bioluminescent bacteria Vibrio fischeri and a seed germination test using seeds of Hordeum vulgare L. showed that probably no toxic products were formed during the PAHs degradation in these experiments.
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Combined drink from wine and juice
Štýblová, Romana ; Vítová, Eva (referee) ; Vespalcová, Milena (advisor)
This diploma thesis deals with preparation of combined drinks. These drinks consist of white wine and fruit concentrate base. This thesis was divided to 2 parts – senzory and chemical. As a fruit component was chosen aronia concentrate. The first sensory analysis was concentrated on a choice of a suitable white wine for this procedure. Second sensory analysis was focused on aditives. We added citric acid and ascorbic acid to the drinks. Evaluators had to choose the most tasty drinks. Next sensory analysis was dedicated to choice of the right drink composition. The last analysis was focused on choice of right fruit composition. Evaluators had to compare between the drink that was prepared from aronia concentrate or a drink prepared from aronia concentrate and other species of fruits. Their duty was to decide which one is more tasty. Chemical part was dealing with puting individual components of drink preparation to the test. Combined drinks had to undergo chemical tests too.
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Determination of the nutritional properties of paprika of different geographic origin
Kovaříková, Tereza ; Vespalcová, Milena (referee) ; Diviš, Pavel (advisor)
This master thesis deals with the analysis of nutritional properties of paprika condiment with different geographic origin. The theoretical part contains botanical description of red pepper (Capsicum annuum L.), its chemical composition, process of production of paprika and then they are described analytical methods suitable for determination of fundamental nutrional properties. Experimental part is focused on the preparation of samples and their analysis. In total, 11 samples were selected for the experiment, 5 of them had a protected designation of origin. These samples were from Slovakia, Hungary, Bulgary, Romania, Turkey and Spain. The Soxhlet extraction was used for the analysis of the fat content, Kjeldahl method was used to determine gross protein. High-performance liquid chromatography (HPLC) was chosen to determine carbohydrates and capsaicin. Induction-coupled plasma emission spectroscopy (ICP-OES) was used for elemental analysis. The results were compared with each other and with available databases and literature. For comparing and finding certain connections, the principal component analysis (PCA) was selected.
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