National Repository of Grey Literature 11 records found  1 - 10next  jump to record: Search took 0.02 seconds. 
Application of Mass Spectrometry for Analysis of Biologically Active and Clinically Significant Compounds.
Štícha, Martin ; Jelínek, Ivan (advisor) ; Smrček, Stanislav (referee) ; Tůma, Petr (referee)
- 8 - ABSTRACT (EN) The thesis is submitted as a commented set of reviewed publications documenting and depicting the possibilities of mass spectrometry in the field of chemical, biological and pharmaceutical research; namely for the purposes of structure elucidation of selected organometallic complexes, analyses of drugs and their metabolites, monitoring of important biological markers. In course of experimental work, the following objectives were studied and solved:  Proposal and realization of micro-scale preparation of selected rhenium complexes with aromatic ligands, utilizing tetrabutyammonium tetrachlorooxorhenate as a starting material; preparation and structure characterization of oxorhenium(V) complexes with 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3- dihydroxynaphtalene as ligands by means of ESI/MS, APPI/MS and LDI-MS; ESI/MS and UV/Vis study of kinetic behavior of complexes arising from the reaction of tetrabutylamonnium tetrachlooxorhenate with pyrogallol and catechol as ligands. Special aim was devoted to the study of subsequent chemical transformation of primarily formed Re(V) complexes; structure characterization of selected ferrocene complexes with copper, gold and silver by means of ESI/MS.  Proposal of methodology of structure characterization and quantification of the...
Photochemical vapor generation of rhenium with a detection by inductively coupled plasma mass spectrometry
Hašlová, Karolína ; Musil, Stanislav (advisor) ; Nováková, Eliška (referee)
This bachelor thesis deals with an optimization of the conditions of photochemical vapor generation of rhenium with detection by inductively coupled plasma mass spectrometry. Photochemical vapor generation was realized using an ultraviolet irradiation in a high-efficiency photochemical reactor with an inner reaction channel from a formic acid based medium in presence of reaction modifiers. Optimizations of parameters affecting the generation efficiency was implemented step by step - reaction medium flow rate (irradiation time), formic acid concentration, addition of acetic acid and reaction modifiers (transition metals) and carrier gas flow rate. The addition of an appropriate combination of reaction modifiers - cadmium(II) and iron(II) ions, had a key impact on photochemical generation of volatile species of Re and led to more than 40-fold increase in generation efficiency. A further (2-fold) increase in generation efficiency was achieved by wrapping the high-efficiency photochemical reactor with an aluminum foil, probably due to more efficient irradiation of the sample in the generator. The limit of detection and quantification were determined as 0.24 ng dm-3 and 0.80 ng dm-3 Re, respectively. The repeatability of the method 100 ng dm-3 Re was 4.8%. Key words photochemical vapor generation,...
Novel photochemical vapor generation of rhenium for its ultratrace determination
Vyhnanovský, Jaromír ; Hašlová, K. ; Musil, Stanislav
The presentation focused on novel photochemical vapor generation of rhenium. Details on optimization of generation conditions and other important parameters regarding this sensitive methodology, as well as its possible applications were pointed out and discussed.
Utilization of mass spectrometry for analysis of biologically active compounds
Kaliba, David
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...
Utilization of mass spectrometry for analysis of biologically active compounds
Kaliba, David
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...
Utilization of mass spectrometry for analysis of biologically active compounds
Kaliba, David ; Jelínek, Ivan (advisor) ; Pacáková, Věra (referee) ; Smrček, Stanislav (referee)
This PhD thesis provides a commented set of four publications. These publications are focused on capillary electrophoresis, liquid chromatography, and UV/Vis spectrometry used to study complexes of rhenium with aromatic ligands. The methods of mass spectrometry with soft ionization techniques, 1 H and 13 C nuclear magnetic resonance, and infrared spectrometry were used for structural characterization of the individual complexes. The complexes were synthetized in reactions of the rhenium precursor tetrabutylammonium tetrachlorooxorhenate with the corresponding ligand under both aerobic and anaerobic conditions. In the course of the research, it was revealed that the prepared complexes (with Re in the oxidation number +V and +VI) are unstable and their oxidation numbers change to another more stable form (Re+VII ). Sub-projects which were successfully implemented during the research were as follows:  Design and successful realization of the process of synthesis of selected rhenium complexes with aromatic ligands 1,2-dihydroxybenzene, 1,2,3-trihydroxybenzene, and 2,3-dihydroxynaphthalene in reactions with and without air access, and their structural characterization by ESI-MS, APPI- MS, LDI-MS, ESI-MS/MS, NMR, and IR.  ESI-MS SRM and UV/Vis time studies of the behaviour of primary rhenium complexes...
Chemical treatment of weakly ionizable uncharged complexes of rhenium for the possible identification by ESI-HRMS
Málková, Nikola ; Štícha, Martin (advisor) ; Kozlík, Petr (referee)
Detailed characterization of rhenium complexes is necessary for the potential use in clinical practice and nuclear medicine. For structure characterization and quantification of coordination compounds, mass spectrometry exceeds other analytical methods in sensitivity and selectivity. The advantage of this method for coordination chemistry is the possibility of determination of the analyte directly in the reaction mixture. The compounds need to be ionized to get relevant mass spectra. The ionization of these compounds is often very difficult and it is necessary to develop a special derivatization procedures. Complexes of rhenium with 1,2-dihydroxybenzene and 4-methyl-1,2-dihydroxybenzene and it's derivatives with p- chloroaniline and p- bromoaniline have been prepared and characterized by ESI-HRMS. The fragmentation mechanisms of these complexes have been studied using a mass spectrometry technique collision-induced dissociation (CID). Keywords Rhenium complexes, rhenium, 1,2-dihydroxybenzen, 4-methyl-1,2-dihydroxybenzen, mass spektrometry, derivatization, ESI-MS, CID
Analytical study of reduction of ammonium perrhenate using selected reduction agents
Lišková, Jana ; Jelínek, Ivan (advisor) ; Dian, Juraj (referee)
This thesis is focused on analysis of reduction of ammonium perrhenate using less frequent reducing agents. Ascorbic acid and acetylhydrazine were chosen as less common reducing agents. Reductions were observed leveraging capillary zone electrophoresis and UV/Vis spectroscopy. Measurements were carried out both in acidic and in basic environments. Reduction of peak area of ammonium perrhenate was observed using capillary zone electrophoresis after addition of reducing agent. Rate of absorption of ammonium perrhenate was monitored with UV/Vis spectroscopy. Furthermore, the possibility of shifting the equilibrium of the reaction to the benefit of the reduction products was monitored by the addition of the complexing agent. Py- rogallol (benzene-1,2,3-triol) was used as the ligand and acetylhydrazine was selected as the reducing agent. The reduction was monitored by capillary zone electrophoresis. The identity of the resulting complex was confirmed with ESI/MS. Keywords rhenium, rhenium complexes, ascorbic acid, acetylhydrazine, capillary zone electrophore- sis, UV/Vis spectroscopy, mass spectrometry
MS Characterization of Rhenium complexes
Vlk, Mikuláš ; Štícha, Martin (advisor) ; Kozlík, Petr (referee)
Ideal radiochemical properties make rhenium complexes coordinated with suitable organic ligands relevant for use in nuclear medicine. They find a wide range of uses as diagnostic and palliative agents. However, detailed characterization and availability of suitable analytical methods is needed for use in clinical practice. Rhenium complexes with 1,2-dihydroxybenzene, 4-methyl-1,2-dihydroxybenzene and 2,3- dihydroxynaphtalene were prepared and characterized by HRMS. Fragmentation mechanisms of the complexes were studied using information gathered from collision cell experiments.
Theoretical study of spin-orbit coupling on spectra and photophysics of rhenium complexes
Heydová, Radka ; Záliš, Stanislav (advisor) ; Slavíček, Petr (referee) ; Srnec, Martin (referee)
Title: Theoretical study of spin-orbit coupling on spectra and photophysics of rhenium complexes Author: RNDr. Radka Heydová Department: Physical and Macromolecular Chemistry Supervisor: Ing. Stanislav Záliš, CSc., JHI AS CR, v.v.i. Supervisor's e-mail address: stanislav.zalis@jh.inst-cas.cz Abstract: Relativistic effects, especially spin-orbit coupling (SOC), play an essential role in transition metal chemistry and SOC treatment is indispensable for a correct theoretical description. To demonstrate the importance of SOC, the energies and oscillator strengths of vertical transitions for a series of [ReX(CO)3(2,2'-bipyridine)] (X = Cl, Br, I) and [Re(imidazole)(CO)3(1,10-phenanthroline)]+ complexes were calculated in the spin-free (SF) and spin-orbit (SO) conceptual frameworks. Two different computational approaches were adopted: SO-MS-CASPT2 where SOC was added a posteriori using a configuration interaction model (SO-RASSI), and the approximate perturbative SO-TD-DFT method. Relativistic effects were included via the two-component Douglas-Kroll-Hess transformation and the zeroth-order regular approximation in the former and the latter technique, respectively. The SF (i.e. accounting only for the scalar relativistic effects) and SO results from both methods were compared with each other and to available...

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