The utilisation of waste process grease (WPG) as feedstock for biodiesel production was investigated in this study. WPG is a lubrication oil used in the metalworking industry and is considered a hazardous waste material. WPG contains vegetable oil and animal fat which are used as base oils in the lubricant formulation. Three different production routes were followed to produce biodiesel using WPG as feedstock. The first production route involved the conventional two-step production process comprising the acid esterification of the free fatty acids, followed by alkaline transesterification. The second production route involved the extraction of free fatty acids in the WPG by means of liquid-liquid extraction and the production of biodiesel from the extracted free fatty acids through acid esterification. The produced biodiesel was purified by means of chromatography. A third process route was the saponification of the WPG using aqueous sodium hydroxide followed by acidulation with hydrochloric acid. The resulting acid oil was purified by means of column chromatography, using a hydrophobic resin as the stationary phase prior to esterification through acid catalysis to produce biodiesel. The crude biodiesel was purified using column chromatography with silica gel as stationary phase. The optimum reaction conditions for the reduction of the free fatty acid content of WPG in route 1 to 0.5% were a methanol to oil ratio of 8:1 and a reaction temperature of 65 °C with a catalyst loading of 4 wt%. Acetonitrile was found to be the most effective extraction solvent for the reduction of sulphur compounds in the free fatty acid feedstock in route 2. A reverse phase chromatographic system with a hydrophobic stationary phase and methanol as the mobile phase was found to be an effective system to reduce the sulphur to below 10 ppm as specified by the SANS 1935 biodiesel standard in route 3. Both the conventional two-step process (route 1) and the liquid-liquid extraction process (route 2) were found not to be suitable for the production of biodiesel from WPG as the sulphur content of the produced biodiesel for routes 1 and 2 was 8 141 ppm and 4 888 ppm, respectively. The sulphur content of the produced biodiesel following route 3 was 9 ppm. The latter approach reduced the sulphur content of the biodiesel to acceptable levels that conform to the SANS 1935 standard to be used in a B10 biodiesel blend. A biodiesel yield of 45%, calculated as the mass of biodiesel produced as a percentage of the total mass of dried WPG used, was achieved with route 3. The biodiesel conformed to most of the specifications in the SANS1935 standard for biodiesel. The presence of a relatively high concentration of saturated fatty acids reflected in the higher cetane number of 74.7, the high cold filter plugging point of +10 and the oxidative stability of > 6 hours. A comparative cost analysis for route 3 indicated that the production cost of biodiesel, compared to the cost of petroleum diesel is marginally higher at the current Brent crude oil price of $102.41 per barrel. The production of biodiesel from WPG will be economically viable once the crude oil price has risen to about $113 per barrel. / Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.

The utilisation of waste process grease (WPG) as feedstock for biodiesel production was investigated in this study. WPG is a lubrication oil used in the metalworking industry and is considered a hazardous waste material. WPG contains vegetable oil and animal fat which are used as base oils in the lubricant formulation. Three different production routes were followed to produce biodiesel using WPG as feedstock. The first production route involved the conventional two-step production process comprising the acid esterification of the free fatty acids, followed by alkaline transesterification. The second production route involved the extraction of free fatty acids in the WPG by means of liquid-liquid extraction and the production of biodiesel from the extracted free fatty acids through acid esterification. The produced biodiesel was purified by means of chromatography. A third process route was the saponification of the WPG using aqueous sodium hydroxide followed by acidulation with hydrochloric acid. The resulting acid oil was purified by means of column chromatography, using a hydrophobic resin as the stationary phase prior to esterification through acid catalysis to produce biodiesel. The crude biodiesel was purified using column chromatography with silica gel as stationary phase. The optimum reaction conditions for the reduction of the free fatty acid content of WPG in route 1 to 0.5% were a methanol to oil ratio of 8:1 and a reaction temperature of 65 °C with a catalyst loading of 4 wt%. Acetonitrile was found to be the most effective extraction solvent for the reduction of sulphur compounds in the free fatty acid feedstock in route 2. A reverse phase chromatographic system with a hydrophobic stationary phase and methanol as the mobile phase was found to be an effective system to reduce the sulphur to below 10 ppm as specified by the SANS 1935 biodiesel standard in route 3. Both the conventional two-step process (route 1) and the liquid-liquid extraction process (route 2) were found not to be suitable for the production of biodiesel from WPG as the sulphur content of the produced biodiesel for routes 1 and 2 was 8 141 ppm and 4 888 ppm, respectively. The sulphur content of the produced biodiesel following route 3 was 9 ppm. The latter approach reduced the sulphur content of the biodiesel to acceptable levels that conform to the SANS 1935 standard to be used in a B10 biodiesel blend. A biodiesel yield of 45%, calculated as the mass of biodiesel produced as a percentage of the total mass of dried WPG used, was achieved with route 3. The biodiesel conformed to most of the specifications in the SANS1935 standard for biodiesel. The presence of a relatively high concentration of saturated fatty acids reflected in the higher cetane number of 74.7, the high cold filter plugging point of +10 and the oxidative stability of > 6 hours. A comparative cost analysis for route 3 indicated that the production cost of biodiesel, compared to the cost of petroleum diesel is marginally higher at the current Brent crude oil price of $102.41 per barrel. The production of biodiesel from WPG will be economically viable once the crude oil price has risen to about $113 per barrel. / Thesis (PhD (Chemical Engineering))--North-West University, Potchefstroom Campus, 2013.

Hemp (Cannabis sativa) is a crop that people have grown for a lot of years ago. It is amazing by its almost versatile use, whether in medicine, food, industry and power engineering. The aim of this thesis was to evaluate the content of cannabidiol in different parts of hemp and the possibility of using these parts as a source of the compound. Morphologically distinct varieties - Bialobrzeskie and Finola were selected for the experiment. The Cannabidiol content was determined by high performance liquid chromatography (HPLC). Hemp roots, stems, male and female inflorescences and leaves were sampled for the determination of cannabidiol level. The highest content of cannabidiol was found in hemp flowers and leaves of Cannabis sativa. Therefore, theoretically, these parts of hemp grown for fiber could be used as a potential source of cannabidiol.

This work concerns the amount of certain phenols in some of the representatives of families Alliaceae, Lamiaceae and Apiaceae. Phenols in plants are widely represented and highly concentrated. Flavonoids are one of the smallest, yet quite significant classes of phenols. Ingestion of food containing flavonoids can prevent certain diseases such as Arteriosclerosis. cardiovascular and tumor diseases. This work focuses, for their special biological effects, on five flavonoids: Kaempferol, Quercetin, Myricetin, Apigenin and Luteolin. For determining the content of phenols a method of High-performance liquid chromatography (HPLC) was used. Three representative of the family Alliaceae, two representatives of the family Lamiaceae and three representatives of the family Apiaceae were analysed. Only edible parts of the plants were used for the analysis and the amount of phenols was compared in certain plants planted in beddings to the plants planted in greenhouses. At first, the qualitative representantion of phenols was ascertained by the HPLC method. The result is chromatographic profiles, which were then used in calculating the amount of particular phenols. Then the total amounts of kaempferol, quercetin, myricetin, apigenin and luteolin were found out thanks to HPLC method. The biggest amount of total kaempferol was determined in petroselium hortense planted in beddings (588 mg/kg of fresh sample) and in a greenhouse (340 mg/kg of fresh sample). The biggest amount of quercetin was determined in red onion planted in a greenhouse (773 mg/kg of fresh sample) and in ocimum basilicum planted in beddings (535 mg/kg of fresh sample). The biggest amount of apigenin was determined in petroselium hortense planted in a greenhouse (1790 mg/kg of fresh sample) and in petroselium chrispum planted in beddings (3690 mg/kg of fresh sample).

The work has been inquired into the problem of content determination of phenolic substances in medicinal plants traditionally used in Czech Republic. Phenolic substances belong to a group of natural compounds, which are purely plant origin. Flavonoids are a part of this extensive group of compounds. As for flavonoids, most attention is paid to quercetin and rutin. It is caused by their easy availability and very significant biological activity. These compounds embody a lot of positive biological effects. They have expressive antioxidant properties, inhibit lipid peroxidation, scavenge free oxygen radicals and bond into the chelates they inactivate some prooxidant metal ions. The latest researches have shown that thanks to their properties natural flavonoids can occurence of chronical diseases, such as arterosklerosis, cardiovascular or tumor disorder. Flavonoids are exploited both in traditional and modern medicine. Same other studies have evidenced that valuable sources of these biologically effective substances are traditionally used medicinal plants. Content of phenolic substances was determined by method of micellar electrokinetic capillary chromatography (MECC) and liquid chromatography (HPLC) in collection of 8 medicinal plants usually used in Czech Republic. For analysis was used freeze-dried and dried plant material. In freeze-dried material was found the highest content of total quercetin in Filipendula ulmaria L. (14200 mg/kg of dry weight) and in Betula pendula Roth. (11800 mg/kg of dry weight). The highest content of rutin contained Sambucus nigra L. (17700 mg/kg of dry weight). Similar values was measured in dried plant material. The content of total quercetin and rutin during drying was unchanged.

The goal of this master's thesis was to develop a method for gas chromatography using the Controlled Evaporation Mixer (CEM) for gas mixture sampling. Gas mixture contained chemical substances formed during manufacturing of acrylic acid by two-step oxidation of propylene. The analyzed mixture composed of permanent gases, light hydrocarbons and compounds containing oxygen. During the method development several capillary columns with polar and nonpolar stationary phase were used. After selection of the most suitable column (SPB-1 Sulfur, Supelco, USA) the method was further optimized for the maximal possible separation efficiency. However, it was impossible to separate propane and propene on SPB-1 Sulfur column. These gases were possible to determine on TCD detector and separate on respective columns prior to the detector. For that purpose, the optimization of multiple-port valves switching inside the gas chromatograph was performed. The next step was calibration of gas chromatograph for a purpose of quantitative analysis of selected substances. The calibration solution containing solvent and an analyte was evaporated and diluted with nitrogen by CEM to obtain desired analyte concentration. Formaldehyde and propane had a very low response on detectors, acetaldehyde was undetectable in desired...

Phospholipids are an important group of polar lipids constituting the main component of cell membranes. Their proportion may vary depending on many factors of the surrounding environment in which the cell is located. Determination of membrane phospholipids is essential in many scientific, industrial and economic sectors. The aim of this work has been to develop a separation method for determination of membrane phospholipids by which it was possible to analyze phosphorylated parts of phospholipids and fatty acids from one sample. Comprehensive gas chromatography with mass detection (GC×GC-MS) was chosen for the assay. This method allows the separation of the entire sample on two serially connected different columns, among which is the interface called modulator. The preparation of the sample includes a cleavage of the phospholipid molecule by the enzyme phospholipase C, which released the phosphorylated polar headgroups. These polar parts had to be derivatized before analysis. The principle of the chosen derivatization consisted in the use of two different silylation agents (hexamethyldisilazane and N,O-Bis(trimethylsilyl) trifluoracetamide) in two steps. Conditions were selected for efficient separation of the silylderivatives of phosphorylated headgroups using GC×GC-MS using a cryogenic...

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).

Copper radionuclides possess physical properties suitable for utilization in nuclear medicine. Important part of their preparation is separation from mother elements, usually zinc or nickel. Currently used methods of separation have their limits, what opens field for finding new ways. One part of the Thesis contains preparation of simple ion exchangers and their selectivity study. The other part of the Thesis is dedicated to optimization of synthetic steps leading to new bifunctional ligands in suitable form for binding to macromolecular carriers and preparation of new set of exchangers.

The aim of this diploma thesis is the determination of selected organic pollutants with a focus on artificial sweeteners in waste water from wastewater treatment plant (WWTP) Modřice and the subsequent degradation of the thus obtained concentrations in model water using advanced oxidation processes (AOP). Two sweeteners were determined, namely sucralose and saccharin found in waste water. Synthetic sweeteners are not sufficiently cleaned in the WWTP and penetrate the environment. Effective processes for removing organic substances, including alternative sweeteners, are AOP processes. These processes are based on reactions of highly reactive hydroxyl radical (OH·), which is produced by many chemical reactions. Generally, they use ozone (O3) and hydrogen peroxide (H2O2). On sampling, wastewater samples were treated with Solid Phase Extraction (SPE) and then evaluated by HPLC/MS (High Performance Liquid Chromatography). In observing the degradation of selected sweeteners, three AOP methods were used: O3/UV, H2O2/UV and O3/H2O2. For each of these methods, the efficiency of degradation of sucralose and saccharin was investigated. From the evaluated data it was found that the most efficient AOP process for removing artificial sweeteners from water is the O3/H2O2 method.