This work deals with the determination of L-carnitine in food supplements. L-carnitine is a substance naturally occurring in organism, essential for metabolism of fatty acids. In food supplements is used especially for reducing body weight as a "fat burner". L-carnitine is popular with athletes for improve athletic performance. While data are not available to support these positive effects of carnitine, the positive results of carnitine supplementation in the medicine were found, mainly on cardiovascular system. The literary part of this study describes the properties and the use of carnitine in the diet of human. Furthermore, a review of methods used for determination of L-carnitine in variety of samples is mentioned. In the experimental section the efficiency of SPE method for preparation matrix of real samples was investigated. A cation exchange solid phase extraction seems to be the most effective. The optimal conditions for isolation of L-carnitine by SPE extraction were not developed. L-carnitine was determined in six various food supplements by reverse phase chromatography with UV/VIS detection.

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.

The aim of the diploma thesis is the determination of macrolide antibiotics in drinking water by using of high performance liquid chromatography. Erythromycin and clarithromycin were selected such as representative macrolides due to frequently prescribed pharmaceuticals in this time. Solid phase extraction (SPE) by using of Oasis HLB cartridges was applied for pre concentration and purification of chosen analytes in real samples of drinking water. Optimalization of method and analysis were performed by using of high performance liquid chromatography with mass spectrometry detection (HPLC-MS). The suitable method was selected for determination of macrolides in real samples taken from two sources of drinking water, the interception of water in Litovel and Černovír Olomouc.

From viewpoint of environmental analysis in the whole world became popular in the latest years the question of drugs’ breakthrough to the component of environment. These contami-nants belong to the biological active compounds, with different physical-chemical and biolog-ical properties and evince great tendency to bioaccumulation. They penetrate to the environ-ment because of their increasing of usage and wrong techniques of liquidation. The most often use drugs are preparations against pain – analgetics, and from this category there are non-steroidal anti-inflammatory drugs. The frequent usage of this compounds relate to their easy accessibility. From this large group of compounds was chosen for monitoring: diclofenac, ibuprofen, ketoprofen, salicylic acid, naproxen and acetaminophen; because they include in favorite preparations. The monitoring matrix was the wastewater from two waste water treat-ment plants (WWTP). The sampling was performed in inflow and outflow because the com-paring of concentration of selected contaminants and discovering of efficiency of removing the polutants reliance on treatment technology. For extraction of selected contaminants was used solid phase extraction (SPE) and for determination was used capillary zone electrophore-sis (CZE) with diode array detection (DAD). There was identified and quantified all of se-lected analgetics in inflow and so in outflow of WWTP. That means, this polutants infuse into surface water and then into other components of environment.

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.

Diploma thesis is focused on determination of macrolide antibiotics in wastewater. Environmental contamination with drugs currently represents a major problem. To determine the level of contamination is necessary to develop the appropriate analytical techniques. From the group of macrolide antibiotics were selected four representatives: erythromycin, clarithromycin, azithromycin and roxithromycin due to their frequent use in Czech Republic. For their isolation from wastewater was selected solid phase extraction and for analysis high performance liquid chromatography with mass spectrometric detection was chosen. Under optimized conditions, the ten days analysis of wastewater from the WWTP Brno-Modřice, two days analysis of wastewater from the WWTP Mikulov and one day analysis of wastewater from WWTP of University of Veterinary and Pharmaceutical Sciences Brno was performed.

This work focuses on optimization and application of voltammetric methods for determination of 5-nitroquinoline in model samples of drinking and river water using carbon film electrode (CFE). The advantages of carbon film electrode are primarily its wide potential window in both cathodic and anodic regions and also low environmental stress compared to mercury electrodes. In this contribution, CV and AdSV were used to observe electrochemical processes. For determination of 5-nitroquinoline DPV and FIA were used. Solid phase extraction was investigated as a method for preliminary separation and preconcentration for DPV. Determination of 5-nitroquinoline at CFE is based on cathodic reduction of nitrogroup. This work demonstrates the application of carbon film electrode for determination of 5-nitroquinoline in submicromolar concentrations in model samples of water.

Lipidomics as a part of metabolomics is a fast-growing area of research due to the improvement in analytical techniques. This master thesis is focused on lipid extraction techniques optimization, using liquid liquid extraction and solid phase extraction as pre-separation methods and ultra performance liquid chromatography coupled with mass spectrometry for extraction and subsequent identification of branched-chain fatty acid esters (FAHFA - branched-chain Fatty Acid esters of Hydroxy Fatty Acids). This newly discovered class of lipid molecules is associated with insulin secretion, which could improve whole body and local glucose metabolism, providing potential for diabetes 2 type treatment. Solid phase extraction of biological samples was optimized on columns regarding to sorbent composition using reversed phase columns with modified styrene divinylbenzene polymer or octadecyl-bonded polymer and normal phase columns packed with silica gel. Column Strata SI-1 Silica was the most effective for FAHFA separation from biological samples. Chromatographic separation of FAHFA was performed on UPLC Ultimate 3000 RSLC equipped with Kinetex C18 1,7 µm, 2,1 x 150 mm column using gradient program. UPLC was coupled to QTRAP 5500/SelexION, a hybrid, triple quadrupole, linear ion trap mass spectrometer equipped...

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...

A solid phase extraction (SPE) method was developed for simultaneous extraction of dicarboxylic acids and diols formed during hydrolysis of poly(butylene succinate), PBS, and poly(butylene adipate), PBA. The developed SPE method and subsequent GC-MS analysis were used to extract, identify and quantify low molecular weight products migrating from linear and branched poly(butylene adipate) (PBA) and poly(butylene succinate) (PBS) during aging in aqueous media. The combination of SPE and GC-MS proved to be a sensitive tool, able to detect small differences in the degradation rate during early stages of hydrolysis before any significant differences were observed by weight loss and molecular weight measurements. The detected low molecular weight products included monomers i.e. adipic acid and 1,4-butanediol for the PBA polymers and succinic acid and 1,4-butanediol for PBS. Several dimers and trimers i.e. hydroxybutyl adipate, hydroxybutyl succinate, di(hydroxybutyl) adipate, di(hydroxybutyl) succinate and hydroxybutyl disuccinate were also detected. Best extraction efficiency for 1,4-butanediol and succinic acid was achieved with a hydroxylated polystyrene-divinylbenzene resin as solid phase. Linear range for the extracted analytes was 1-500 ng/ml for adipic acid and 2-500 ng/ml for 1,4-butanediol and succinic acid. Detection and quantification limits for all analytes were between 1-2 ng/ml (S/N=3) and 2-7 ng/ml (S/N=10) respectively. Relative standard deviations were between 3 % and 7 %. Comparison of measured weight loss and the amount of monomeric products showed that weight loss during early stages of hydrolysis was mainly caused by the release of water-soluble oligomers that on prolonged ageing were further hydrolyzed to monomeric species. Significant differences in degradation rate could be assigned to degree of branching, molecular weight, aging temperature and degradation medium. Linear and branched PBA was mixed with PVC in solution cast films to study the effects of molecular weight and branching on plasticizer efficiency. Used as polymeric plasticizer, PBA formed a semi-miscible two-phase system with PVC where the amorphous part exhibited one single glass transition temperature and the degree of polyester crystallinity was dependent on molecular weight, degree of branching and blend composition. Plasticizing efficiency was favored by higher degree of branching and a 40 weight-percent polyester composition. / QC 20101209