National Repository of Grey Literature 260 records found  beginprevious231 - 240nextend  jump to record: Search took 0.01 seconds. 
Assessment of selected pesticides using gas chromatography
Matušková, Monika ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
The submitted thesis deals with determination of selected pesticides in water samples by gas chromatography. The target pesticides belong to the group of organophosphates (chlorpyrifos, diazinon, parathion, dimethoate, phosmet) and carbamates (carbofuran, aldicarb, methiocarb, pirimicarb, and propamocarb). In the theoretical part, the division of pesticides is stated, and their properties are described, as well as their fate in the environment and their negative effects. Then, the possibilities of analytical determination based on gas chromatography are characterized. The experimental part describes the treatment of the samples and their subsequent analysis. Solid phase extraction was chosen as the extraction technique. Two kinds of cartridges were optimized (Oasis HLB and Supelclean ENVI-18) in combination with various elution reagents. The most suitable combination was then used for processing of real samples of waste-water, which was taken from WWTP in Brno Modřice. For the final determination of the target compounds by gas chromatography, two types of detectors were used: mass spectrometer and an electron capture detector.
Synthetic aromatic substances in wastewaters
Tylichová, Petra ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
Synthetic fragrances are artificially synthetised organic compounds which are used as fragrant substances in assorted personal care products, perfumes, cosmetics, soaps, detergents, cleansing articles, etc. So-called musk compounds creates significant group of synthetic fragrances which are distinguished by specific fragrance reminiscent of musk. Recently great attention is devoted to musk compounds because they were proved in different units of environment. The aim of diploma thesis was determination of selected linear musk compounds (arocet, aroflorone, linalool 925, lilial, isoamyl salicylate) in real samples of waste water in the influent and effluent from the sewage treatment plant Brno-Modřice. At first optimization of selected method was performed and then this method was used for own determination. Analytes were extracted by solid phase microextraction (SPME) from sample. Method of gas chromatography with mass spectrometry was used for own analysis. The results were used for evaluation of efficiency of removing linear musk compounds from waste water.
The use of GC/MS for the analysis of drugs
Sýkora, Richard ; Opatřilová, Radka (referee) ; Vávrová, Milada (advisor)
This diploma thesis is based on the current issue of the presence of pharmaceuticals in various components of the environment. Concerning the contamination by residues of pharmaceuticals the most affected environment is the aquatic environment where these substances leaks especially from wastewater treatment plants, which eliminate them during the cleaning process only partially. This work is focused on the selected group of pharmaceuticals, non-steroidal anti-inflammatory drugs (salicylic acid, ibuprofen, caffeine, naproxen, ketoprofen, diclofenac) in waste water. For analysis purposes two types of sampling were used and compared: the conventional spot sampling of wastewater and the sampling using passive samplers POCIS. The sampling took place at the inflow and outflow of the wastewater treatment plant in Brno Modřice. The solid phase extraction (SPE) using Oasis HLB columns was used as the extraction method. Extracted sample was derivatized then. Derivatization agents were: MSTFA (N-methyl-N-(trimethylsilyl)trifluoroacetamid) and BSTFA (N, O-bis(trimethylsilyl) trifluoroacetamid). The final analysis was performed using gas chromatography with mass spectrometric detection Time-of-Flight (GC/TOF-MS).
Passive sampling of polar organic pollutants from water
Vítková, Libuše ; Mravcová, Ludmila (referee) ; Čáslavský, Josef (advisor)
This thesis deals with the passive sampling of polar compounds from water using passive samplers POCIS (Polar Organic Chemical Integrative Sampler). These devices were exposed for 4 weeks in the waste water at the inflow of municipal waste water treatment plant in Brno – Modřice, and also at the outflow of the treated water. After exposition sequestered compounds were released by extraction with a mixture of methanol, toluene and dichlormethane. Extracts were analysed by liquid chromatography/mass spectrometry with electrospray ionization. Further, methylated and trimethylsilylated extracts were analysed by orthogonal comprehensive two-dimensional gas chromatography with mass spectrometric detection. Separated compounds were identified on the base of their retention and mass spectra.
Influence of the various incubation time on the value of BOD
Debnárová, Andrea ; Dolejš, Petr (referee) ; Rozkošný, Miloš (advisor)
Biochemical Oxygen Demand (BOD) is commonly used for determining how fast biological organisms use up oxygen in a body of water. It is one of the essential methods used in water quality management and assessment. BOD could be considered as a quality level indicator of biologically treated water. This process is very time-dependent but most common period of incubation is five days - BOD(5). In this thesis different periods of incubation are compared - for BOD(5) with five days incubation period and BOD(2+5) with five days incubation period but also placed for two days to lowered temperature environment. These comparative tests were made for different types of water (surface water, waste water - water from mechanical level and biological level of treatment) For all kinds of determination of BOD the dilution method was used (ČSN EN 1899).
Assesment of basic characteristics of waste water from the Dermacol Company
Fribertová, Marcela ; Zlámalová Gargošová, Helena (referee) ; Vávrová, Milada (advisor)
This master thesis is focused on waste waters from cosmetics industry and basic indicators of these waters. The pollution of the environment caused by increase industrial development has a negative effect on ecosystem. Waste waters are part of the pollution. In theoretical part a basic indicators of waters (its definition and way of determination) have been described. Membrane processes for water purification have been mentioned as well – particularly the ultrafiltration. The experimental part of thesis deals with practical determination of indicators mentioned in methods described in the theoretical part. Results are discussed at the close. The discussion is focused on evaluation of efficiency of the device for waste waters adjustment, which is in use in the Dermacol company, which produces cosmetics products.
Aplication of gas chromatography for determination of drug residuals in waters
Lacina, Petr ; Stoupalová, Michaela (referee) ; Vávrová, Milada (advisor)
Diploma thesis is focused on the choose of methods and optimalisation analysis procedure of selected pharmaceuticals (salicylic acid, ibuprofene, naproxene, ketoprofene and diclofenac) in surface and waste water by using gas chromatography with mass spectrometer (GC-MS). Solid-phase extraction (SPE) with Oasis HLB cartridges was used as an extraction method in this analysis. Extraction is followed by derivatization and their optimalization of selected pharmaceuticals. Derivatization and its optimalization were performed by two silylation reagens N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) and N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA). Different volumes of derivatization reagents, different temperatures and different times were used during the procedure. The best combination is then used for analysis of real samples. Real samples of waste water were collected in sewage treatment plants in Brno – Modřice and real samples of surface water were collected from several rivers and one pond in region Moravia. This thesis also presents and tests SPE methods for extraction and concentration selected sulfonamide residues (sulfamethazine, sulfamethoxazole, sulfapyridine and sulfathiazole) from the aquatic environment.
Metal species in aquatic systems.
Němec, Tomáš ; Čelechovská, Olga (referee) ; Dočekalová, Hana (advisor)
The diffusive gradient in thin films technique (DGT) was used to measure concentration of labile metal-species (Cu, Ni, Pb) in the waste water from Faculty of Chemistry, Brno University of Technology.
The issue of determination of beta-blockers in surface waters
Košík, Juraj ; Píšťková, Veronika (referee) ; Vávrová, Milada (advisor)
This bachelor´s thesis deals with the issue of increasing concentration of pharmaceuticals in the environment. The most worldwide prescribed medications with the most frequently detection in the environment are -blockers. These compounds are clinically important drugs which are extensively used for the treatment of cardiovascular disorders such as hypertension, arrhythmia and angina pectoris. It is important to monitor the concentration levels of blockers in aquatic environment due to their acute and chronic toxicity towards aquatic organisms. This study is focused on development and optimization of analytical method of determination of these compounds. The monitored matrixes were surface water from two rivers, Váh (Slovakia) and Dyje (Czech Republic) and waste water form waste water treatment plant (WWTP) Brno-Modřice. The analytes from water samples using solid phase extraction (SPE) were isolated. For the final analysis ultra-high performance liquid chromatograph with UV-VIS detection using diode array detector (DAD) was used. As the target compounds atenolol, metoprolol and propranolol were selected.
The issue of penicillin antibiotics in water
Landová, Pavlína ; Oborná, Jana (referee) ; Vávrová, Milada (advisor)
This bachelor thesis deals with the occurrence and determination of penicillin antibiotics in wastewater. Penicillin V was selected as a representative of this class of antibiotics due to its frequent prescribing. Solid phase extraction (SPE) was selected as a method of isolation of the analyte from the wastewater. Optimal conditions were found for Bakerbond C18 SPE column. Drug analysis was carried out on ultra-high performance liquid chromatography (UHPLC) with diode array detection (UV-VIS/DAD). Under optimized conditions, the analysis of wastewater from the WWTP Brno Modřice influent and effluent was performed.

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