Flavonoids were identified and quantified in samples of dry leaves of plant Stevia rebaudiana Bertoni. Content of flavonols (kaempherol, quercetin, myricetin, rutin) and flavons (apigenin, luteolin) were compared in three samples (standard leaves of Stevia rebaudiana Bertoni, Stevia rebaudiana Bertoni origin from Ukraine and from Czech republic), that were extracted by three extraction methods (PSE, ultrasonic extraction, Soxhlet extraction) with two polar solvents, methanol and ethanol, in combination with non-polar hexane. Extracts were analyzed by HPLC with detection UV-VIS. Antioxidant activity and total content of flavonoids in extracts were measured by spectrometry. Stable free radical DPPH. was used for determination of scavenging effect in extracts. PSE was the most effective extraction method with this conditions – 120 °C, dynamic mode and with methanol like solvent.

This work is based on the occurrence of drug residues in the environment. This study is focused on the development and optimization methods for determination of selected drugs in the surface water, aquatic sediment and sewage sludge from waste water treatment plant. From the group of drugs were chosen antibiotics. Antibiotics presented in the environment can cause adverse effects including toxic effects, immunity disorders and indirect bioalteration effects. Sulfonamide antibiotics, which are used in the treatment of urinary and respiratory tract infections as well as in the treatment of other infectious diseases, were chosen as a target compounds. Three optimized analytical methods for determination of sulfonamide antibiotics were developed. For the optimization of extraction were tested: solid phase extraction, pressurized solvent extraction, microwave extraction and ultrasonic extraction. For the final analysis was used liquid chromatography with two detectors - diode array detector and mass spectrometer. These optimized methods were applied for the analysis of real samples. The surface water and sediment samples were collected from two Moravian rivers (the Svratka river and the Svitava river). Samples of sewage sludge were collected from waste water treatment plant Brno-Modřice. Fish samples from the Svratka river were also collected. It was observed that all the selected sulfonamide antibiotics are present in real sediment samples (ug.kg-1). Simultaneously presence of some target analytes in real surface water (ug.l-1) and in sewage sludge (ug.kg-1) samples has been confirmed. In samples of surface water from the Svitava river and in fish samples sulfonamide antibiotics were not detected or their concentrations were below the limit of detection.

In the presented PhD. thesis, problems covering occurrence of polybrominated diphenyl ethers (PBDE) and perfluorinated compounds in the environment were solved. The study was focused on identification and further verification of optimal methods in order to determine PBDEs and perfluorinated compounds sampled from the aquatic ecosystem. Polybrominated diphenyl ethers belong to persistent compounds classified as main pollutants; within the environmental constituents, they have been observed particularly in the last decade. For these studies, there were selected surface water matrices and sediments taken in various localities within the river Svratka basin. The analyses were to demonstrate whether they accumulate and remain in these specific matrices for longer time. There we assessed the congeners of polybrominated diphenyl ethers as follows: BDE-28, 47, 66, 85, 99, 100, 153, 154 and 183. In order to isolate them from matrices, various extraction techniques were used, i.e., ultrasonic extraction, microwave extraction, and pressure solvent extraction. Gas chromatography method with electron capture detection (GC/ECD) was selected for determination. The accomplished studies also assessed basic chemical, physical and environmental characteristics of diphenyl ethers in the environmental constituents. The attention was also paid to perfluorooctanoic compounds (PFOA), (PFOS) and (FOSA); physico-chemical properties of these organic pollutants were characterised and their toxicological and environmental aspects were evaluated. Usability of extraction techniques (ultrasonic extraction, pressure solvent extraction, solid phase extraction) applied to PFCs isolation from sediments samples was assessed. Identification and quantification of these analytes were performed using a high performance liquid chromatography/mass spectrometry method (HPLC/MS). After that, the optimized methods applied to real samples. Surface water and sediments were sampled within the river Svratka basin, in particular, from 19 sampling localities. PBDE occurrence was confirmed in sediments samples from the Svratka river (g.kg-1), PBDE were not detected in the surface water samples, their concentrations were below the detection limit, resp.; perfluorinated compounds were not detected in sediments and water samples at all.

The distribution and potential sources of 15 polycyclic aromatic hydrocarbons (PAHs) in soils and Digitaria eriantha in the vicinity of three South African coal-fired power plants, Matla, Lethabo and Rooiwal were determined by gas chromatography–mass spectrometry. An ultrasonic assisted dispersive liquid-liquid microextraction (UA-DLLME) method was developed for the extraction of polycyclic aromatic hydrocarbon in soil, followed by determination using gas chromatography mass spectrometry. The study showed that an extraction protocol based on acetonitrile as dispersive solvent and C2H2Cl2 as extracting solvent, gave extraction efficiencies comparable to conventional soxhlet extraction for soil samples. The extraction time using ultrasonication and the volume of the extraction solvent was also investigated. Using a certified reference material soil (CRM), the extraction efficiency of UA-DLLME ranged from 64 to 86% in comparison with the Soxhlet result of 73 to 95%. In comparison with the real sample, the CRM result did not show a significant difference at 95% C.I. The UA-DLLME proved to be a convenient, rapid, cost-effective and greener sample preparation approach for the determination of PAHs in soil samples. PAH compound ratios such as phenanthrene/phenanthrene + anthracene (Phen/ Phen + Anth) were used to provide a reliable estimation of emission sources. The total PAH concentration in the soils around three power plants ranged from 9.73 to 61.24 μg g−1, a range above the Agency for Toxic Substances and Disease Registry levels of 1.0 μg g−1 for a significantly contaminated site. Calculated values of the Phen/Phen + Anth ratio were 0.48±0.08, 0.44±0.05, and 0.38+0.04 for Matla, Lethabo and Rooiwal, respectively. The flouranthene/fluoranthene + pyrene (Flan/ Flan + Pyr) levels were found to be 0.49±0.03 for Matla, 0.44±0.05 for Lethabo, and 0.53±0.08 for Rooiwal. Such values indicate a xx pyrolytic source of PAHs. Higher molecular weight PAHs (five to six rings) were predominant, suggesting coal combustion sources. The carcinogenic potency B[a]P equivalent concentration (B[a] Peq) at the three power plants ranged from 3.61 to 25.25, indicating a high carcinogenic burden. The highest (B[a] Peq) was found in samples collected around Matla power station. It can, therefore, be concluded that the soils were contaminated with PAHs originating from coal-fired power stations. Nine metals (Fe, Cu, Mn, Ni, Cd, Pb, Hg, Cr and Zn) were analysed in soil and the Digitaria eriantha plant around three coal power plants (Matla, Lethabo and Rooiwal), using ICP-OES and GFAAS. The total metal concentration in soil ranged from 0.05 ± 0.02 to 1835.70 ± 70 μg g-1, 0.08 ± 0.05 to 1743.90 ± 29 μg g-1 and 0.07 ± 0.04 to 1735.20 ± 91 μg g-1 at Matla, Lethabo and Rooiwal respectively. The total metal concentration in the plant (Digitaria eriantha) ranged from 0.005 ± 0.003 to 534.87 ± 43 μg g-1 at Matla, 0.002 ± 0.001 to 400.49 ± 269 μg g-1 at Lethabo and 0.002 ± 0.001 to 426.91 ± 201 μg g-1 at Rooiwal. The accumulation factor (A) of less than 1 (i.e. 0.003 to 0.37) at power plants indicates a low transfer of metal from soil to plant (excluder). The enrichment factor values obtained (2.4 – 5) indicate that the soils are moderately enriched, with the exception of Pb that had significant enrichment of 20. The Geo-accumulation Index values of metals indicate that the soils are moderately polluted (0.005 – 0.65), except for Pb that showed moderate to strong pollution (1.74 – 2.53). / Chemistry / D. Phil. (Chemistry)

The distribution and potential sources of 15 polycyclic aromatic hydrocarbons (PAHs) in soils and Digitaria eriantha in the vicinity of three South African coal-fired power plants, Matla, Lethabo and Rooiwal were determined by gas chromatography–mass spectrometry. An ultrasonic assisted dispersive liquid-liquid microextraction (UA-DLLME) method was developed for the extraction of polycyclic aromatic hydrocarbon in soil, followed by determination using gas chromatography mass spectrometry. The study showed that an extraction protocol based on acetonitrile as dispersive solvent and C2H2Cl2 as extracting solvent, gave extraction efficiencies comparable to conventional soxhlet extraction for soil samples. The extraction time using ultrasonication and the volume of the extraction solvent was also investigated. Using a certified reference material soil (CRM), the extraction efficiency of UA-DLLME ranged from 64 to 86% in comparison with the Soxhlet result of 73 to 95%. In comparison with the real sample, the CRM result did not show a significant difference at 95% C.I. The UA-DLLME proved to be a convenient, rapid, cost-effective and greener sample preparation approach for the determination of PAHs in soil samples. PAH compound ratios such as phenanthrene/phenanthrene + anthracene (Phen/ Phen + Anth) were used to provide a reliable estimation of emission sources. The total PAH concentration in the soils around three power plants ranged from 9.73 to 61.24 μg g−1, a range above the Agency for Toxic Substances and Disease Registry levels of 1.0 μg g−1 for a significantly contaminated site. Calculated values of the Phen/Phen + Anth ratio were 0.48±0.08, 0.44±0.05, and 0.38+0.04 for Matla, Lethabo and Rooiwal, respectively. The flouranthene/fluoranthene + pyrene (Flan/ Flan + Pyr) levels were found to be 0.49±0.03 for Matla, 0.44±0.05 for Lethabo, and 0.53±0.08 for Rooiwal. Such values indicate a xx pyrolytic source of PAHs. Higher molecular weight PAHs (five to six rings) were predominant, suggesting coal combustion sources. The carcinogenic potency B[a]P equivalent concentration (B[a] Peq) at the three power plants ranged from 3.61 to 25.25, indicating a high carcinogenic burden. The highest (B[a] Peq) was found in samples collected around Matla power station. It can, therefore, be concluded that the soils were contaminated with PAHs originating from coal-fired power stations. Nine metals (Fe, Cu, Mn, Ni, Cd, Pb, Hg, Cr and Zn) were analysed in soil and the Digitaria eriantha plant around three coal power plants (Matla, Lethabo and Rooiwal), using ICP-OES and GFAAS. The total metal concentration in soil ranged from 0.05 ± 0.02 to 1835.70 ± 70 μg g-1, 0.08 ± 0.05 to 1743.90 ± 29 μg g-1 and 0.07 ± 0.04 to 1735.20 ± 91 μg g-1 at Matla, Lethabo and Rooiwal respectively. The total metal concentration in the plant (Digitaria eriantha) ranged from 0.005 ± 0.003 to 534.87 ± 43 μg g-1 at Matla, 0.002 ± 0.001 to 400.49 ± 269 μg g-1 at Lethabo and 0.002 ± 0.001 to 426.91 ± 201 μg g-1 at Rooiwal. The accumulation factor (A) of less than 1 (i.e. 0.003 to 0.37) at power plants indicates a low transfer of metal from soil to plant (excluder). The enrichment factor values obtained (2.4 – 5) indicate that the soils are moderately enriched, with the exception of Pb that had significant enrichment of 20. The Geo-accumulation Index values of metals indicate that the soils are moderately polluted (0.005 – 0.65), except for Pb that showed moderate to strong pollution (1.74 – 2.53). / Chemistry / D. Phil. (Chemistry)