This dissertation thesis deals with the diagnotics of power oil transformer. It consists of the theoretical and practical part At its beginning, the theoretical part deals with an general description of the transformer and its connection. Focus is given to aspects of the life of the transformer insulation system (oilpaper). Further, the technical diagnostics is analyzed, with description of quantities of gasliquid chromatography, the oil condition and condition of conductor insulation. Another important part of the thesis consists of an expert system, which is described generally from the past to the present. Characteristics, types and structure of expert systems are mentioned here, with its advantages and disadvantages. The practical part starts with a description of the data file, which is further used in the thesis. Main practical part is divided into three parts - the results of gas-liguid chromatography, selected results and expert systems. In the section entitled "Results of gasliquid chromatography", there is an analysis of selected properties of time series and temperature dependency of gases. Moreover, the methods of the ratios of gases such as Duval Triangle method are described. The second part entitled "Selected other results" shows the time dependency of variables and the neutralization number, along with the breakdown voltage dependency, and time of dependency, gas and moisture content in insulating oils. There is also a temperature dependency of moisture content dissolved in insulating oil discussed, as well as results of selected correlations, such as the correlation values of gas chromatography with state variables insulation of wires. The last part, "Expert systems", provides specific information about developed expert system. It describes the environment chosen for its development, followed by a description, features and verification of the expert system. Examples of the consultation results are included. All achievements of the individual parts are always summarized at the end of each section. The thesis contains chapters "Objectives of the work" and "Conclusion". The most important chapter is "The contribution of the work." It contains original work results and the results applicable in industry.

Phospholipids are dominant components of bacterial cell membranes, where they create double layers. Bacteria differ in their phospholipid composition determination of which can help in identification of important groups of microorganisms. Phospholipid composition of bacteria is influenced by many environmental factors, therefore its variation can be observed within one bacterial stem also. Because of its simplicity, thin layer chromatography is usually applied to identification and determination of bacterial phospholipids. Disadvantage of this method are the high demands of time, carefulness and skills of the analytical personnel. The increasing interest in the phospholipid double-layer promotes the detailed investigation of their fatty acid composition because the more detailed analyses allows for more information yield about bacteria. Gas chromatography hyphenated with mass spectrometry seems to be the best choice for these purposes. Fatty acid identity and total fatty acid content in phospholipid molecules could be determined by this method. Additionally, number, position and isomerism of double bonds and presence of other functional groups on hydrocarbon chain could be determined. Whereas a suitable and...

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.

Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Ivo Vrobel Supervisors: Prof. RNDr. Petr Solich, CSc; Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague Prof. Seppo Auriola, MSc.(Chem.) Marko Lehtonen; Department of Pharmaceutical Chemistry, School of Pharmacy, University of Eastern Finland in Kuopio Title of master's thesis: LC-MS/MS analysis of acetylcholine in brain microdialysis samples Novel fast and simple LC-MS/MS method of ACh quantification in brain microdialysis samples utilizing stable-isotope-labeled IS was developed. The chromatographic step is based on revered-phase mode of pentafluorophenylpropyl (PFPP) column. The satisfactory retention of ACh is achieved with highly aqueous mobile phase containing 0.05% of the ion-pairing agent TFA and 4% of ACN in 4 min analytical run. Ionization of ACh and IS with low background noise and tolerant towards use of TFA was performed with atmospheric pressure thermospray ionization (APTSI). The selectivity of ACh and IS detection was obtained by SRM modes of MS/MS in the linear ion trap mass analyzer. The performance of developed method was cross validated to the validated method used in the laboratory for ACh measurements. The set of microdialysis...

Fluorinated stationary phase in Rtx-200MS column have been characterized by determination of system constants of Abraham equation. Retention on this phase is driven by dispersive and orientation/induction forces. Significant interaction contribution of lone pair electrons or π- electrons provides unique selectivity for analytes with excess of electron density. Unusual behavior of this phase have been determined by study of separation mechanism of polar and nonpolar analytes, in comparison of their separation on polar and nonpolar phases. This behavior is due to medium polarity of the phase (system constant s), which is not so pronounced to cancel separation of nonpolar analytes due to induction forces. In some cases contribution of lone pair electrons or π-electrons can contribute to this separations. Key words fluorinated stationary phase Rtx-200MS, inverse gas chromatography, LFER method, Abraham's equation

This work is concerned with lipidic substances, in particular vegetable oils, used as pigment binders or as a protective varnishes for finishing artwork. The introduction reviews the recent knowledge of this subject, in particular with respect to the identification of the most used drying oils, and of the methods to study their changes in the course of time. Both can be achieved using determination of the relative representation of fatty acids, most characteristic being the ratio of stearic/palmitic a oleic/palmitic acids. This parameter is changing as the artwork is getting older and the oils are drying. Because of the availability of the instrumentation needed, we have chosen the high- performance liquid chromatography method for further experimental work. The first step was optimalization of the analytical method by standards of fatty acids. For derivatization of fatty acids, reagents 2,4-dinitrophenylhydrazine and 2-nitrophenylhydrazine were examined. Whereas we were unable to get any results with the first one (the method based on the article: Bravo, B. et al., Talanta 64, 1329-1334, 2004) for unknown reasons, good results were obtained with the second one. Derivates of fatty acids have been analyzed by high performance liquid chromatography (HPLC) on column with revesed phase (C18). The...

The aim of the diploma thesis was to find optimal conditions of high pressure liquid chromatography for the detection and quantification of two common nucleotides, namely adenosine diphosphate and adenosine triphosphate, as well as to perform an analysis of these in real life samples of citrus fruits and plant extracts. Further aim of the project was to determine the limits of detection and quantification of adenosine diphosphate and adenosine triphosphate under the optimized conditions and using these to compare the sensitivity of given detectors. To achieve this HPLC-UV, capillary HPLC-DAD and HPLC-MS apparatus were used. With the help of HPLC with UV detection and capillary HPLC with diode array detector, the calibration curves of the mixture of analytes were measured and the limits of detection as well as quantification of adenosine diphosphate and adenosine triphosphate were determined. Separation of the analytes up to the base line using HPLC-UV and capillary HPLC-DAD was achieved under the conditions of ion pairing chromatography. Column C18 was chosen as an appropriate column. The mobile phase included phosphate buffer, acetonitrile and tetrabutylammonium bisulphate as an ion pairing reagent. The separation was performed with gradient elution. Conditions for analysis using LC-MS were...

In this work we report the formation of inclusion complexes of the pesticides 1-naphthylacetic acid, 1-naphthylacetamide, napropamide and carbaryl with cucurbit[n]uril (n=7 and 8) and -cyclodextrin hosts. We also report results of the photochemistry of these compounds when free in aqueous solution and included within these nano-containers. The formation of inclusion complexes was studied by electrospray ionization mass spectrometry (ESI-MS) which gave us information about stoichiometry of the complexes and about their reactivity in the gas phase. The photodecomposition and formation of products was followed by high performance liquid chromatography coupled to both mass spectrometry (HPLC-MS) and UV/VIS detector, and spectrophotometry. The studied CBs and their host-guest complexes were readily detected in the gas phase by ESI-MS, mainly as single and double charged ions containing either H+ , Na+ or K+ . The assignments were made based on the m/z values of the observed signals and further confirmed by fragmentation (tandem mass spectrometry - MSn ). All pesticides formed 1:1 (host:guest) complexes. Carbaryl, napropamide and 1-naphthylacetamide also formed 1:2 (host:guest) complexes. Under some solution chemistry conditions, namely for concentrations of cucurbiturils above 50 µM and at low acid and...

This dissertation thesis is focused on development and optimization of high- performance liquid chromatography (HPLC) and tandem mass spectrometry (LC-MS/MS) methods, and its utility for diagnosis of inherited metabolic diseases. The first thematic part describes a comprehensive laboratory approach to diagnostics of patients with hereditary xanthinuria by determination of specific markers and enzyme activity. For this purpose HPLC method with diode array detection for measurement of hypoxanthine, xanthine, allopurinol and oxypurinol in urine and plasma and HPLC method with fluorimetric detection for analysis of pterin and isoxanthopterin in plasma were employed. These methods were successfully applied in clinical practice to ascertain two patients with hereditary xanthinuria type I. The second thematic part aims at developing and clinical application of new LC-MS/MS method for simultaneous determination of total homocysteine (tHcy), methionine (Met) and cystathionine (Cysta) in dried blood spots (DBS) and plasma. The results demonstrated the clinical utility of this method for detection of patients with homocystinuria and possibility to distinguish between defects in the remethylation and transsulfuration pathways of homocysteine metabolism. Due to ease of DBS collection and sample transportation...

This thesis is focused on the development of an analytical method for the determination of volatile fatty acids in aqueous samples using GC-MS/MS. The theoretical section provides general information on a selected group of acids, their significance in the biogas plants, the means of their derivatization and the analytical techniques used. The practical part mainly deals with optimizition of various parameters in the derivatization reaction to achieve optimal conditions. Finally, the analytical method was successfully validated and applied to the analysis of a real sample.