This diploma thesis deals with plant adaptogens (bioactive substances) in the plant Schisandra chinensis. The theoretical part is focused on characterization of the Schisandra genus, characterization of the Schisandra chinensis as a plant, its properties, occurrence and growing possibilities in the climate zone. Furthermore, The effects of these adaptogens on the organism and the prediction of possible use in food supplements are described. The experimental part deals with the extraction of fruits and leaves from plant Schisandra chinensis. Further, chlorophyll a, chlorophyll b in the leaves extract was determined by UV – VIS spectrophotometry, whereby the optimal amount 3:1 of chlorophyll was confirmed for the plants growing in optimal conditions. Finally, the concentration of the adaptogen schisandrin A in the dried fruits was from different kind of extraction measured by HPLC. In all fruits, schisandrin A was confirmed, but the amount is different in each sample.

Residua of pharmaceuticals represent biologically active compounds which can interfere with some purification processes in WWTP. Control laboratories of many WWTP and water works are equipped with UV-VIS spectrophotometers. Therefore, the main goal of this thesis was the elaboration of the method for the determination of selected drugs in water based on the VIS spectrophotometry.

The aim of this diploma thesis is the assay of total alkaloids in different tobacco types. To measure the content of total alkaloids are utilized types of tobacco used for preparation of tobacco blends and consecutive production of cigarettes. The samples of analyzed tobacco include various countries of cultivation and different crop years. There is described tobacco as a plant, in it contained alkaloids and the utilization of tobacco in the theoretical part. In more detail it deals with the production and construction of cigarettes which is closely related to the content monitoring of total alkaloids in tobacco. The contents of total alkaloids are determined by the continuous flow analyzer- SKALAR. On this spectrophotometer are set the contens of reducing sugars as well. The comparison of total alkaloids contents and reducing sugars from the perspective of single tobacco types, countries of cultivation and crop years is clearly summarized in the experimental part of the thesis that was performed in the company Philip Morris ČR, a.s.

Surfactants are surface-active agents decreasing surface tension to simplify removing dirt. Surfactants can be divided into four basic classes: anionic, cationic, non-ionic and amfolytic. In Czech Republic there are mostly used anionic surfactants nowadays which get into waste water through detergents. The thesis deals with the spectrophotometric determination of anionic surfactants and the study of interferences to this method.

The investigated subject for this diploma thesis is getting know properties of the vanadium redox battery (VRB), especially electrolyte. Specialization is applied to the state of charge of this cell and its measurements using the optical methods. Upon different state of charge is changed oxidation number of vanadium and resultant color of the electrolyte. Using spectrofotometry method that characteristic property is undergone measurement. The basic thing was learning to handle a measurement system. The first practical measurement was executed on example foils. Upon measurement of vanadium cell there was obtained the values of absorbation, which they were used for determination of state of charge.

Surfactants belong to surface-active compounds that have ability to restrain the surface tension; this ability is exploited to eliminate impurities. This study is focused on determination of surfactants in waste water to which these compounds can be transported from various cleaning and washing articles. In theoretical part are listed basic classifications of surfactants, their properties and requests of Czech legislative for their content in waste water. Furthermore here are described chosen analytical procedures for determination of anion-active, cation-active and non-ionic surfactants in waste water. The conclusion of the work is evaluation of measured results of surfactants concentration in inflow and outflow of waste water from waste-treatment plant in University of Veterinary and Pharmaceutical Sciences Brno and waste water from neutralizating station in FCH BUT. To determination of anionic surfactants were used two methods, arbitration method with usage of methylene blue and mobile analytics method which is based on chemical reaction between target compound and chemical agent. This reaction leads to formation of coloured compound able to spectrofotometric determination.

The behaviour of humic acids in aqueous solutions is closely connected to the content of acid functional groups and their dissociation abilities. The titration methods are the most often used for the research of acid-base characteristics of humic acids, their results should lead to the determination of the content of functional groups and their pKa. However the determined values depend on many factors including the titration speed. The spectrophotometric determination of dissociation constant was used in this diploma thesis. Reliability of this method was confirmed in bachelor thesis where is mentioned that spectrophotometric determination of pKa corresponds with realistic dissociation behaviour of humic acids in the water much more better than values obtained from titration methods. The principle of newly used spectrophotometry method is the preparation of humic acids solutions in three different media with different pH values. Acid groups of humic acids are practically completely dissociated in intensely basic environment and the measured absorbance is caused by anion of „humate“. On the contrary their dissociation in acid environment is suppressed so much that we measure the absorbance of non-dissociated molecules of humic acids. Deionized water was used like neutral solvent. Water was replaced by acetic buffer in this thesis because of water’s properties which have significant influence on solutions' pH. Buffer was used for diluting or for solubilisation and in these both cases more stable pH values were occurred. The aim of this diploma thesis is investigate UV/VIS spectra of various solutions of humic acids with different values of pH and determinate mean value of pKa of humic acids which could be used like comparison of dissociation behaviours for vary samples. Values of acid dissociation constant were determined from measured dates and compared with values obtained by titration method. The UV/VIS spectra gained in combination with the results of pH measuring and the conductivity next showed the differences in the behaviour of differently prepared samples of humic acids.

This thesis is focused on the application of two working electrodes of graphite suitable for determination of oxidizable tumour biomarkers. It deals with the study of electrochemical behavior of urinary indican. For the determination the technique of differential pulse voltammetry (DPV) was used on carbon paste electrode and film composite paste electrode in Britton-Robinson (BR) buffer. In the first step optimal conditions were determined to find the lowest limit of determination (LQ) of this substance. BR buffer of pH 3 was chosen as the optimum medium for determination on a carbon paste electrode and BR buffer of pH 2 was used as the optimum medium for the determinaton using a film composite electrode. Performance for both electrodes was observed in a concentration range of from 1 · 10-6 to 5 · 10-5 mol·l-1 . The limit of determination for measurements on a carbon paste electrode was 0.7 µmol·l-1 and the film composite electrode was 1.7 µmol·l-1 . Possibility of the acummulation of indican was examined in order to increase sensitivity and decrease of limit of quantification. However, after 5 minute sorption, no increase in response was observed and the accumulation step was not inserted. Developed method was tested on the determination of urinary indican in human urine matrix after solid phase...

This master´s thesis deals with the study of the incorporation of low and high molecular weight substances into liposomal systems. The aim of the work was to determine the encapsulation efficiency (EE) of the active substance and the influence of individual components of the liposomal system on EE. Liposomes were prepared from dipalmitoylphosphatidylcholine. They were stabilized by cholesteroland and phosphatidic acid was added to give a negative charge. Stealth properties gain the binding of polyethylene glycol and other trimethyl chitosan we enabled the entry of liposomes into the bloodstream by the paracellular pathway. Vitamin C and the enzyme bromelain were used for incorporation into liposomes. UV-VIS spectrophotometry was used to determine the encapsulation efficiency of liposomes prepared by combining the individual components. It has been suggested that vitamin C and the enzyme can be incorporated into liposomes, but an enzyme with a higher EE. Furthermore, phosphatidic acid and trimethyl chitosan have been found to affect EE, which increases the EE of vitamin C and decreases the EE of the enzyme.

The objective of this study was the calculation and optimalization methods of the indirect spectrophotometric determination of fluoride based on the zirconium complex. Three organic reagent eriochromcyanin R chromazurl S and xylenol orange were tested. As the most sensitive system was shown the complex of zirconium with xylenol orange. Linear standard curve was ranged from 1,5.10-6 to 7,5.10-5 mol.dm-3. H2PO4-, Fe3+ and the highest concentrations of Fe2+, SO42- were tested for interferent. The Fe2+ and SO4- interfere only above the concentration which cannot be found in natural water. The optimized method was applied for the determination of fluoride in the model and real drinking, mineral and surface water.