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Determination of stability constants of charged cyclodextrine complexes by capillary electrophoresis
Beneš, Martin ; Zusková, Iva (advisor) ; Dubský, Pavel (referee)
Martin Beneš Determination of stability constants of charged cyclodextrin comlexes by capillary electrophoresis Abstract Stability constant characterizes binding interaction between an analyte and complexation agent. These interactions play very important role in separation processes of, in other way undistinguishable, compounds, e.g. enantiomers. The most widely used complexation agents are cyclodextrins. Affinity capillary electrophoresis (ACE) belongs to methods suitable for the determination of stability constants. The stability constant is determined from the dependence of the effective mobility of analyte on the increasing concentration of complexation agent in background electrolyte (BGE). If charged CDs are used, the attention must be paid not only to viscosity of the BGE and to the influence of Joule heating on the temperature in the capillary but also to the increasing ionic strength. The thermodynamic stability constants of R,R- and S,S-hydrobenzoin and R- and S-(3-brom- 2-methyl-1-propanol) with cationic modified β-cyclodextrin: 6-monodeoxy-6-mono(3- hydroxy)propylamino-β-cyclodextrin hydrochlorid (PABCD) were determined by affinity capillary electrophoresis. The average temperature (25řC) of the BGE in the capillary was kept constant. This was achieved by decreasing of the cassette temperature...
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Analysis of potasium tetrachloroaurate by capillary electrophoresis
Lebertová, Lucie ; Sobotníková, Jana (advisor) ; Křížek, Tomáš (referee)
This bachelor thesis describes the optimalization of condition for the analysis of potassium tetrachloroaurate by capillary zone electrophoresis with spectrophotometric detection. The theoretical part at first introduces the principle of capillary electrophoresis. The following are basic information about gold and its tetrachloroaurate compound. The experimental part at first describes the procedure of optimization the composition of the basic electrolyte and problems with the instability of the base line. As the most suitable conditions for the analysis of tetrachloroaurate, have been chosen the subsequent experimental conditions: fused silica capillary with a total length of 80 cm, effective length 71.6 cm and inner diameter 50 µm; applied separation voltage -20 kV; applied pressure during analysis 20 mbar; injection with 20 mbar for 20 s; background electrolyte containing 0.01 mol dm-3 HCl and 0.04 mol dm-3 NaCl; detection vawelength at 230 nm. Subsequently, the repeatability of the measurement, and the stability of the tetrachloroaurate stock solution were evaluated. Also the calibration dependence were measured and the limit of detection and the limit of quantification were determined for the optimized experimental conditions. The value of LOD was 7.49 ∙ 10-6 mol dm-3 and the value of LOQ was...
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Utilization of mass spectrometry and other analytical techniques for analysis of rhenium complexes
Vaňátková, Petra ; Jelínek, Ivan (advisor) ; Smrček, Stanislav (referee)
Rhenium complexes coordinated with suitable organic ligand gain increased interest in radiopharmaceutical medicine. Besides suitable radiological properties given by a metal ion itself, detailed knowledge of overall chemical properties of formed complexes, namely their exact structures, chemical stabilities and possible degradation pathways are essential pre-requisites for their clinical application. Selected rhenium complexes with pyrogallol 2,3-dihydroxynaphthalene and catechol as strongly bound ligands were prepared by a reaction of tetrabutylammonium tetrachlorooxorhenate with twofold molar excess of ligand in presence of various amount of triethylamine. The structures of formed complexes and their consequent reaction products were estimated by means of mass spectrometry with electrospray ionization. The kinetics of reactions in course of complex formation and consequent decomposition were primarily followed by UV- Vis absorption spectra measurement, complemented by single or continuous electrospray mass spectrometry analyses. Optimized HPLC and CZE procedures were utilized for monitoring of the composition of reaction mixtures in course of Re complex formation and for purity check of prepared complexes. Semi-preparative HPLC mode was succesfully utilized for isolation and final purification of...
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Determination of stability constants of charged cyclodextrine complexes by capillary electrophoresis
Beneš, Martin ; Dubský, Pavel (referee) ; Zusková, Iva (advisor)
Martin Beneš Determination of stability constants of charged cyclodextrin comlexes by capillary electrophoresis Abstract Stability constant characterizes binding interaction between an analyte and complexation agent. These interactions play very important role in separation processes of, in other way undistinguishable, compounds, e.g. enantiomers. The most widely used complexation agents are cyclodextrins. Affinity capillary electrophoresis (ACE) belongs to methods suitable for the determination of stability constants. The stability constant is determined from the dependence of the effective mobility of analyte on the increasing concentration of complexation agent in background electrolyte (BGE). If charged CDs are used, the attention must be paid not only to viscosity of the BGE and to the influence of Joule heating on the temperature in the capillary but also to the increasing ionic strength. The thermodynamic stability constants of R,R- and S,S-hydrobenzoin and R- and S-(3-brom- 2-methyl-1-propanol) with cationic modified β-cyclodextrin: 6-monodeoxy-6-mono(3- hydroxy)propylamino-β-cyclodextrin hydrochlorid (PABCD) were determined by affinity capillary electrophoresis. The average temperature (25řC) of the BGE in the capillary was kept constant. This was achieved by decreasing of the cassette temperature...
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Polymer inclusion membranes open new way in practical use of in-line coupling of microextraction to CZE
Pantůčková, Pavla ; Kubáň, Pavel ; Boček, Petr
Polymer inclusion membranes (PIMs) have several important features, i.e., PIMs are dry and non-porous membranes, which can be prepared ahead of use and stored without noticeable deterioration in extraction performance. In-line coupling of microextractions across PIMs to commercial capillary zone electrophoresis (CZE) instrument has been demonstrated in this contribution. Purpose-made microextraction devices with PIMs were applied, which ensured complete automation of the entire analytical procedure. Practical 169 applicability of the hyphenated analytical method was demonstrated on direct extraction, injection, CZE separation and quantification of formate (the major metabolite in methanol poisoning) in clinical samples.
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