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Detailed characterization of macrocyclic glycopeptide-based chiral stationary phases in SFC
Folprechtová, Denisa ; Kalíková, Květa (advisor) ; Křížek, Tomáš (referee) ; Kohout, Michal (referee)
The choice of a suitable chiral stationary phase is a key factor for successful enantioseparation in chromatographic methods. Macrocyclic glycopeptides are chiral selectors that, due to their unique structure, allow to interact with the analyte by various types of interactions simultaneously, which contributes to their complex retention and enantiodiscrimination mechanisms. Macrocyclic glycopeptides are widely used chiral stationary phases in liquid chromatography, but they have not been thoroughly tested in sub/supercritical fluid chromatography, which currently rank among important separation techniques in terms of chiral analyses. Therefore, the aim of this thesis is a detailed characterization of the enantiodiscrimination and retention mechanisms of macrocyclic glycopeptide-based chiral stationary phases packed with core-shell particles, namely TeicoShell, VancoShell, and NicoShell columns in sub/supercritical fluid chromatography. First, the effect of the mobile phase composition, especially the type and amount of organic modifiers and additives, on individual chromatographic parameters, i.e., retention, resolution of enantiomers, and peak shapes was studied in detail using selected sets of structurally different biologically active chiral compounds and materials. Based on the obtained...
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Determination of testosterone esters in injectable dosage form by HPLC-DAD
Folprechtová, Denisa ; Kozlík, Petr (advisor) ; Kubíčková, Anna (referee)
Anabolic steroids are currently very controversial issue not only for its therapeutic use but especially because of the illegal abuse in the sport branch. The aim of this thesis was to develop a rapid, selective, effective and simple method of high performance liquid chromatography suitable for the determination of anabolic steroids in injectable dosage form. The analyzed sample of pharmaceutical product Sustamed contained four testosterone esters: testosterone propionate, testosterone phenylpropionate, testosterone isocaproate and testosterone decanoate. Optimized HPLC-DAD conditions suitable for determination of the selected testosterone esters were as follows: core-shell column Poroshell HPH-C18 (3.0 x 100 mm, 2.7 mm), mobile phase consisted of 10mmol/l ammonium acetate, pH 4.5 and acetonitrile, gradient elution was used. The column was thermostated at 50 řC, injection volume was 1 µl, flow rate was set at 1ml/min and UV detection at 240 nm. Total analysis time was 6 minutes. Key words anabolic steroids, testosterone esters, HPLC-DAD
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Enantioselective potential of sulfobutylether-β-cyclodextrin based chiral stationary phase
Folprechtová, Denisa ; Kalíková, Květa (advisor) ; Kubíčková, Anna (referee)
The aim of this diploma thesis was to prepare two new chiral stationary phases by dynamic coating of sulphobutylether-β-cyclodextrin (SBE-β-CD) with varying degrees of substitution onto strong anion-exchange stationary phases. The enantioselective potential and stability of the newly prepared chiral stationary phases were tested using a set of chiral analytes. The set contained structurally diverse analytes, i.e. benzodiazepines (oxazepam, lorazepam), phenothiazines (thioridazine, promethazine), β-blockers (labetalol, pindolol, propranolol, alprenolol), profens (carprofen, fenoprofen, flurbiprofen, indoprofen), flavanones (6-hydroxyflavanone, 7-hydroxyflavanone), DL-tryptophan and its derivatives (5-OH-DL-tryptophan, 5-F-DL-tryptophan, DL-tryptophan butylester and blocked aminoacid (t-Boc-DL-tryptophan)), dipeptides (glycyl-DL-phenylalanine, glycyl-DL-tryptophan) and Troger's base. Measurements were carried out in reversed-phase high-performance liquid chromatography. Mobile phases consisted of methanol/formic acid (pH 2.10) and methanol/10mmol l-1 ammonium acetate buffer (pH 4.00) in various volume ratios. The chiral stationary phase containing hexasubstituted SBE-β-CD was suitable for enantioseparation of eleven analytes. Four of them were baseline enantioresolved and seven partially. The chiral...
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Determination of testosterone esters in injectable dosage form by HPLC-DAD
Folprechtová, Denisa ; Kozlík, Petr (advisor) ; Kubíčková, Anna (referee)
Anabolic steroids are currently very controversial issue not only for its therapeutic use but especially because of the illegal abuse in the sport branch. The aim of this thesis was to develop a rapid, selective, effective and simple method of high performance liquid chromatography suitable for the determination of anabolic steroids in injectable dosage form. The analyzed sample of pharmaceutical product Sustamed contained four testosterone esters: testosterone propionate, testosterone phenylpropionate, testosterone isocaproate and testosterone decanoate. Optimized HPLC-DAD conditions suitable for determination of the selected testosterone esters were as follows: core-shell column Poroshell HPH-C18 (3.0 x 100 mm, 2.7 mm), mobile phase consisted of 10mmol/l ammonium acetate, pH 4.5 and acetonitrile, gradient elution was used. The column was thermostated at 50 řC, injection volume was 1 µl, flow rate was set at 1ml/min and UV detection at 240 nm. Total analysis time was 6 minutes. Key words anabolic steroids, testosterone esters, HPLC-DAD
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