National Repository of Grey Literature 78 records found  beginprevious21 - 30nextend  jump to record: Search took 0.01 seconds. 
The Use of Separation Methods for the Study of Selected Drugs and Pesticides in Water
Burešová, Jitka ; Hajšlová, Jana (referee) ; Chýlková, Jaromíra (referee) ; Kráčmar, Stanislav (referee) ; Vávrová, Milada (advisor)
This work is focused on the study of penetration of pesticides and pharmaceuticals in the aquatic environment. The aim was to develop and verify the optimal method for long-term monitoring of the occurrence of selected pesticides and pharmaceuticals in surface waters. Two frequently used analgesics ibuprofen and diclofenac, and carbamazepine that is used to treat epilepsy, were chosen from the group of drugs. A group of 41 pesticides were selected for monitoring too. The attention was focused on a group of urea pesticides and phenoxyacetic acids, as well as on selected pesticides falling to the group of priority substances or identified as environmental quality standards. Some of pesticides were selected because their consumption in the Czech Republic exceeds 30 tons a year. Liquid chromatography with tandem mass spectrometry (LC / MS / MS) was used for the determination of selected analytes in surface waters. Two optimized analytical method were developed. Ten analytes were determined in negative ion mode and 34 analytes in positive ion mode. Solid phase extraction (SPE) was used for purification and concentration of the samples. Developed methodology was validated and used for monitoring of selected compounds in samples of surface waters from the Morava River basin. Samples were collected on the rivers Morava and Svratka monthly for two years. Samples from the river Blata and stream Nivnička were collected for one year. Surface water samples were also collected from the river Litava. Four samples were taken throughout the length of the flow during one day. Smaller streams were chosen for monitoring because of the probability of occurrence of pesticides. They flow abundantly agriculturally cultivated areas. Drugs ibuprofen and diclofenac were detected in all taken samples, carbamazepine mostly. Among the most commonly occurring pesticides were bentazon, diuron, isoproturon, carbendazim, MCPA, MCPP, propiconazole, tebuconazole and 2,4-D.
Determination of selected drugs (beta-bloskers) in surface water
Kříž, Jiří ; Zlámalová Gargošová, Helena (referee) ; Vávrová, Milada (advisor)
This bachelor's thesis discusses the issue of pharmaceuticals in the environment. -blockers are one of the most prescribed medications with the most frequent detection in the environment. These compounds are clinically important drugs used to cure cardiovascular disorders such as hypertension, arrythmia and angina pectoris. Due to their acute and chronic toxicity towards aquatic organisms it is important to monitor the concentrations levels. This study is focused on optimization of analytical method to determine these compounds. The matrix examined was a waste water from a waste water treatment plant (WWTP) Brno Modřice. A solid-phase extraction (SPE) was used for the isolation of analytes in a waste water samples. A method of high performance liquid chromatography (HPLC) with the UV-VIS detection using a diode array detector (DAD) and mass spectrometry (MS) was used. Target analytes were atenolol, metoprolol and bisoprolol.
Hormones in sewage sludge
Jagošová, Klára ; Vávrová, Milada (referee) ; Čáslavský, Josef (advisor)
Currently there is a spate of interest in the presence of pharmacologically active substances in the environment. These substances are excreted in active or metabolized form and with wastewater pass the wastewater treatment plant. Current treatment technologies do not always eliminate all pharmaceuticals effectively and therefore they enter the environment. One of these active groups is the group of steroid hormones. Steroid hormones belong to the group of endocrine disruptors and they are considered to be dangerous for the ecosystems. Due to the hydrophobic character of steroid hormones they undergo partial or total sorption from wastewater to sludge. Sewage sludge is the by product of wastewater treatment and contains heavy metals, organic contaminants and pathogenic bacteria. A part of produced sewage sludge is used as a fertilizer in the Czech Republic. This issue follows the regulation 347/2016 – conditions of agricultural use of sewage sludge. Waste policy of EU will alter the conditions of sludge disposal, so it is necessary to obtain data about the concentration levels, fate and behaviour of those pollutants. This thesis was focused on five natural female hormones and four synthetic, which are used as a part of contraceptive pills and substitutional hormonal therapy. Determination of hormones was performed in four steps including ultrasonic assisted extraction, clean up by solid phase extraction, derivatization and final analysis by gas chromatography with mass spectrometry on triple quadrupole in MS/MS mode.
Influence of technological processes on the content of priority contaminants in wastewater treatment plants
Mikulíková, Iva ; Čáslavský, Josef (referee) ; Vávrová, Milada (advisor)
Water is one of the most abundant substances on Earth and it is an essential part of our lives. Its pollution has an impact on the whole ecosystem. Polybrominated diphenyl ethersare synthetic persistent organic pollutants used as flame retardants in various commercial and household products. This thesis is focused on assesing the degree of elimination of PBDEs in wastewater treatment plants with different technological processes of purification. The samples were collected in the three wastewater treatment plants in the south-moravian region, that means WTP Brno – Modřice, WTP Mikulov and WTP in VFU Brno.
Application of Gas Chromatography with Mass Spectrometric Detection for the Assessment of Drug-residue Contamination of Wastewaters and Surface Waters
Lacina, Petr ; Čáslavský, Josef (referee) ; Hajšlová, Jana (referee) ; Sokol,, Jozef (referee) ; Vávrová, Milada (advisor)
This work is based on the current issue of increasing concentrations of pharmaceutical residues in various components of the environment. These new environmental contaminants continuously enter the environment. The most affected environmental component is the aquatic environment. This study is focused on the development and optimization of reliable analytical method, which can determine selected drugs in the aquatic environment (waste waters and surface waters) qualitatively and quantitatively. The target compounds were selected mainly from the group of non-steroidal anti-inflammatory drugs (NSAID): salicylic acid, acetylsalicylic acid, clofibric acid, ibuprofen, acetaminophen, caffeine, naproxen, mefenamic acid, ketoprofen and diclofenac. NSAIDs are one of the most used drugs in Czech Republic. For the final analysis of this study was used the comprehensive two-dimensional gas chromatography with mass spectrometric detection Time-of-Flight (GCxGC-TOF MS). It is a very sensitive and reliable analytical method for trace and ultra-trace analysis. Simultaneously, solid phase extraction (SPE) and derivatization are optimized in this work. Optimized analytical method including SPE, derivatization with MSTFA (N-methyl-N-(trimethylsilyl) trifluoroacetamide) and final analysis by GCxGC-TOF MS were applied successfully for the analysis of real samples. Samples of waste water were collected from the waste water treatment plant in Brno – Modřice and samples of surface water were collected from two river streams Svratka and Svitava in Moravian region. The range of concentrations of selected drug residues varied from one to tens of g/L in wastewater and from tens to hundreds of ng/L in surface waters. The degree of wastewater and surface waters contamination by drug residues is assessed in conclusions of the work. Simultaneously, spontaneous degradation of selected drugs in water and removal efficiency of the wastewater treatment plant is assessed in conclusions of the work. The developed method is usable for monitoring and environmental analysis of water ecosystems. It is usable not only for selected drugs, but even for other organic compounds with similar properties.
A new approach to the electroanalysis of primary bile acids and related steroids
Klouda, Jan ; Schwarzová, Karolina (advisor) ; Skopalová, Jana (referee) ; Vyskočil, Vlastimil (referee)
In this doctoral thesis, a novel method for the determination of primary bile acids cholic acid and chenodeoxycholic acid is presented. Bile acids play various vital roles in the mammalian body. Moreover, their determination is extremely helpful in liver and biliary disease diagnosis and management. These saturated organic compounds lack strong chromophores and fluorophores in their structure, and thus are usually hard to detect in spectroscopy. For this reason, either instrumentally advanced but expensive methods, such as mass spectrometry, or less reliable enzymatic methods are commonly employed in bile acids quantitation. Hence, the demand for simple and reliable methods for their determination is strong. Bile acids are also known to be virtually inert for direct electrochemical oxidation. Herein, a simple method for their chemical activation for electrochemical oxidation on bare electrode materials was developed, optimized and applied to cholic acid and chenodeoxycholic acid determination. The activation is based on a dehydration reaction of a primary bile acid with 0.1 mol L-1 HClO4 in acetonitrile (water content 0.55%) that introduces double bond(s) into the originally fully saturated steroid core. This naturally increases the electron density in the structure, and thus allows electrochemical...
Effect of elution solution on the enrichment and purification of glycopeptides using SPE-HILIC
Chobotová, Michaela ; Kozlík, Petr (advisor) ; Křížek, Tomáš (referee)
Changes in protein glycosylation are related to various diseases such as cancer or Alzheimer's disease. Unfortunately, the analysis of glycoproteins remains a difficult task due to the low proportion of glycopeptides compared to peptides obtained after glycoprotein cleavage. As a result, it is almost impossible to analyze glycopeptides without specific enrichment steps. A suitable method for the enrichment of glycopeptides is solid phase extraction (SPE) using the principle of hydrophilic interaction liquid chromatography (HILIC). Since the choice of solvent significantly affects the enrichment of glycopeptides, the aim of this thesis was to compare the effect of different solvents on the efficiency of glycopeptide extraction using SPE-HILIC. The extraction was carried out on a silica column modified with aminopropyl groups. Model analytes were glycopeptides obtained by tryptic digestion of human IgG. During the comparsion of acetonitrile, methanol and isopropanol, acetonitrile was chosen as a suitable elution solvent. During the conditioning and washing step, the content of acetonitrile was changed (65%, 75% and 85%), whereby the elution of glycopeptides is accelerated as the amount of acetonitrile decreases. In the elution step, the effectiveness of different acetonitrile contents (5%, 10% and...
Determination of antibiotics in the soil ecosystem
Brož, Tomáš ; Zlámalová Gargošová, Helena (referee) ; Mravcová, Ludmila (advisor)
This work deals with a current issue of increasing drug concentrations and thus the growing number of resistant bacteria in the soil. One of the problem helping this issue is the fertilization of agricultural fields with animal faeces, in which antibiotics occur in an unchanged and still active form, as well as the insufficient effectiveness of conventional methods used in wastewater treatment plants. In an effort to improve the monitoring of this problem, a method for the determination of these antibacterial agents in the soil matrix, using solid phase extraction, and also a UPLC/MS method for their evaluation have been developed and optimized. From the group of sulfonamide antibiotics, sulfacetamide, sulfadiazole, sulfamerazine, sulfamethazine, sulfamethoxazole, sulfapyridine, sulfasalazine, sulfathiaosal and trimethoprim were selected. The lowest limit of detection for the method is 0.3 µg/g for sulfathiazole and the highest of 8.1 µg/g for sulfasalazine. The highest average yields were achieved with sulfamethoxazole, namely 63 ±8 %.
Analysis of drug residues in waters from small wastewater treatment plants
Pešková, Karolína ; Repková, Martina (referee) ; Mravcová, Ludmila (advisor)
This diploma thesis is focused on the analysis of pharmaceuticals residues in wastewater from wastewater treatment plants used for smaller sources of pollution (up to 2000 population equivalent). Pharmaceuticals entering the environment are a highly discussed topic, especially due to the emergence of antibiotic resistance, negative effects on non-target organisms, vegetation etc. The theoretical part of the thesis deals with smaller wastewater treatment plants or root sewage treatment plants, which achieve excellent results in the field of organic pollution removal. It deals with their detailed description, functioning or division. Attention is paid to pharmaceuticals in general, mechanisms of their removal and methods of their determination in wastewater. In total of 24 drugs from the group of beta-blockers, macrolide antibiotics, non-steroidal anti-inflammatory drugs, antiepileptics, antidepressants and sulfonamides were selected for analysis. In the experimental part of this diploma thesis, wastewater samples were taken from domestic wastewater treatment plants (type AT 6, AT 12 Plus, AT 30 and AT 150) and from the root sewage treatment plant of Dražovice. The samples were first processed using optimized extraction method (solid phase extraction) and then analyzed using optimized UPLC-ESI-MS method. The presence of pharmaceuticals residues was confirmed in all analysed wastewater. The highest concentrations were detected for the non-steroidal anti-inflammatory pharmaceuticals – ibuprofen and diclofenac.
Determination of estrogen pollutants in real water sample by HPLC-UV after solid phase extraction.
Kozlík, Petr ; Bosáková, Zuzana (advisor) ; Coufal, Pavel (referee)
4 Abstract Estrogens are considered to belong to chemicals that negatively affect the endocrine system, even if present at very low concentrations. They are discharged into environment as a result of an increasing application of drugs etc. This work is focused on the separation and quantification of five estrogens, namely estrone (E1), 17β-estradiol (βE2), 17α-estradiol (αE2), 17α-ethynylestradiol (EE2) and estriol (E3) in natural water samples by HPLC-UV method. The chromatographic system consisted of a C18 stationary phase (SunFire® C18, 150 x 4.6 mm, octadecyl bounded to silica gel, particle size 5 µm) and binary mobile phase of acetonitrile/water in various ratios in isocratic separation mode. The effect of acetonitrile content in the mobile phase and flow rate of the mobile phase on retention and separation parameters was tested. Under the optimized separation conditions (acetonitrile/water 40/60 (v/v), 1.3 ml/min), all the compounds were baseline resolved and eluted within 15 min. These experimental conditions were applied to the calibration measurements which were carried out within the concentration range from 0.001 to 1 mg/ml. Limits of detection (LOD) and limits of quantification (LOQ) for the individual estrogens and their mixture (standards dissolved in methanol) were determinated. The detection...

National Repository of Grey Literature : 78 records found   beginprevious21 - 30nextend  jump to record:
Interested in being notified about new results for this query?
Subscribe to the RSS feed.