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Determination of flavonoids in food supplements using micellar electrokinetic capillary chromatography
Dvořáková, Martina ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
Charles University in Prague, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate Mgr. Martina Dvořáková Consultant Doc. RNDr. Marii Pospíšilové, CSc Title of Thesis Determination of flavonoids in food supplements using micellar electrokinetic capillary chromatography A new method of micellar electrokinetic chromatography (MEKC) with UV detection for the simultaneous determination of catechin, epicatechin, rutin, quercetin, luteolin, hesperetin, kaempferol, apigenin and isorhamnetin was devised and validated. The MEKC analysis was optimized for the type, concentration and pH* of the background electrolyte, the concentration of sodium dodecyl sulphate (SDS), the type and concentration of cyclodextrins and organic solvents, applied voltage and operating temperature. The analysis was carried out in a fused-silica capillary (internal diameter 75 µm, total length 60 cm, effective length 50 cm) with UV detection at 210 nm, voltage 30 kV, hydrodynamic sample injection at 50 mbar for 6 s and temperature 20řC. The optimal background elektrolyte of pH* 7.6 (adjusted with 17% of ammonia solution) contained 5 mM potassium dihydrogen phosphate + 30 mM boric acid, 60 mM SDS, 20% (v/v) of methanol, 5% (v/v) of butanol and 8 mM 2-hydroxypropyl-γ-cyclodextrin. The calibration curve of...
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Determination of pindolol by sequential injection analysis with chemiluminescence detection
Havelková, Jana ; Polášek, Miroslav (advisor) ; Pospíšilová, Marie (referee)
The oxidation of the drug pindolol, [1-(indol-4-yloxy)-3-(isopropylamino)-2-propanol (I)] by permanganate in the medium of aqueous H2SO4 is accompanied by the emission of chemiluminescence (CL) radiation. The CL signal is enhanced by hexametaphosphate. This CL reaction was used for devising automated sequential injection analysis (SIA) assay of I in pharmaceutical preparations. The PC-controlled SIA setup consisted of a Cavro XL 3000 2.5- ml syringe pump, Vici-Valco 10-port selection valve and Spectra-Physics FS970 flow- through fluorescence detector equipped with a lab-made CL detection module. The net CL signal of I increased by a factor of 4.4 (compared to purely aqueous test solution of I injected) if the test solution contained 80% (v/v) of methanol. Optimal order, concentrations and volumes of aspirated zones of reactants were: 43l of 80mM Na hexametaphosphate, 30 l of I in 80% (v/v) methanol, 28 l of 2M H2SO4 and 1 l of 5mM KMnO4. Calibration curve relating the intensity of CL (peak height) to the concentration of I was linear in the range 1 - 10 M I; the limit of detection (S/N = 3) was 0.15 M I. The sample throughput was 90 h-1 . The repeatability of the peak heights was characterized by RSD 1.8% for 30 replicate injections of 8 M I. The SIA-CL method was used for the assay of I in...
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HPLC method development for determination of vitamin E acetate in Geladrink preparations
Kovářová, Lenka ; Šatínský, Dalibor (advisor) ; Pospíšilová, Marie (referee)
Charles Univerzity in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Lenka Kovářová Consultant: Doc. RNDr. Dalibor Šatínský, PhD. Title of thesis: Development of HPLC method for determination of vitamin E acetate in preparations Geladrink A HPLC method was developed for the determination of content of vitamin E-acetate in preparation Geladrink Forte. The method is based on using Chromolith Performance RP- 18e column (100 x 4.6 mm) and UV detection at 290 nm. The vitamin E-acetate was separated in the presence of internal standard cholecalciferol from ballast matrix. There was used isocratic elution of the mobile phase methanol - water (98:2) at a flow-rate of 2.0 ml/min and at temperature 30 řC during the measurement. The system enabled successful separation in time less than 4 min. The retention time of cholecalciferol was 2.26 min and the retention time of vitamin E-acetate was 3.22 min. Chromatographic resolution between cholecalciferol and vitamin E-acetate was 5.248. Method was applied to analysis of vitamin E-acetate in preparation Pro-Visio, too. The found concentrations of vitamin E-acetate were re-counted on content of vitamin E declared by that the producer. Keywords: vitamin E-acetate, HPLC, Geladrink, Pro-Visio.
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Analysis of Calcium Pantothenat, Methylparaben and Propylparaben by Micellar Electrokinetic Chromatography
Balcar, Josef ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
1. ABSTRACT 1.1. ANALYSIS OF CALCIUM PANTOTHENAT, METHYLPARABEN AND PROPYLPARABEN BY MICELLAR ELECTROKINETIC CHROMATOGRAPHY Josef Balcar Charles University in Prague, Faculty of Pharmacy in Hradec Králové, Department of Analytical Chemistry, Heyrovského 1203, Hradec Králové In this study, a new micellar electrokinetic chromatography (MEKC) has been developed for the simultaneous analysis of calcium pantothenat, methylparaben and propylparaben. Separations were carried out in a fused silica capillary (7,5 cm × 75 μm i.d.) at 20 kV with UV detection at 200 nm. The optimal background electrolyte was 40 mM tricine buffer (pH* 8.2) containing 50 mM sodium dodecyl sulfate as a surfactant and 20 % (V/V) methanol. Rectilinear calibration ranges were 50.0 - 500.0 mg/100ml for calcium pantothenat, 2.0 - 20.0 mg/100ml for methylparaben and 0.5 - 5.0 mg/100ml for propylparaben. The validated MEKC method was applied to the determination of the analytes in a pharmaceutical preparation. The total analysis time was <3 min.
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Determination of selected impurities in quaternary ammonium compounds with potential antibacterial effect by capillary zone electrophoresis
Prskavcová, Pavla ; Polášek, Miroslav (advisor) ; Pospíšilová, Marie (referee)
In this study, capillary zone electrophoresis with UV detection was developed for separation and determination of impurities pyridine and isoquinoline in quaternary ammonium compounds. The analysis was performed in a fused silica capillary at 20 kV and 25 řC with UV detection at 210 nm and 254 nm. The total length of the capillary was 58 cm, the effective length was 49,5 cm and its inner diameter was 75 µm. The injection was carried out for 6 seconds and under pressure of 50 mbar. The analysis took less than 5 minutes. The optimal background electrolyte consisted of 70 mM acetic acid with 5% (v/v) of methanol. pH was adjusted to 4,7 with sodium hydroxide. As internal standard was chosen imidazole. The calibration graphs were linear for both pyridine (0,1 - 10,4 µg/ml; r2 = 0,9988) and isoquinoline (0,1 - 9,98 µg/ml; r2 = 0,9972). The limits of detection were 0,06 µg/ml for pyridine and 0,02 µg/ml for isoquinoline. The optimized method has been used to determine the content of pyridine and isoquinoline as impurities in samples of quaternary ammonium compounds.
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Case study of friendship in MMMORPG games
Kolář, Šimon ; Pospíšilová, Marie (advisor) ; Blahovec, Václav (referee)
Bachelor thesis Case study of friendship in MMORPG Games aims to find out what meanings for MMORPG players have friendships within game, how these relationships are formed and what are the dynamics based on sociological theories of self-presentation. The theoretical part describes the concepts MMORPG, friendship and self-presentation and explanis context to the reader. At the same time it acts as a basis for the practical part of the work. Practical part presents the methodology of qualitative research based on interviews with informants. It further discusses the analysis of these interviews and their subsequent intepretation. The study shows that social relationships are important part of the game for MMORPG players. It also shows that personal contact is needed to establish a friendship.
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Electrophoretic determination of selected muscle relaxants using contactless conductivity detection
Lužová, Veronika ; Polášek, Miroslav (advisor) ; Pospíšilová, Marie (referee)
A novel capillary electrophoretic method for the separation of pancuronium (PM) and vecuronium (VM) ions utilizing capacitively coupled contactless conductivity detection (C4 D) was devised and validated. The separation was carried out in bare fused-silica capillaries (50 µm i.d., 75/45 cm) at 25 řC. Optimal background electrolyte was 50 mM borate buffer of pH 9.5 containing 12.5 mg/ml of hydoxypropyl-γ-cyclodextrine; (phenyltrimethylammonium iodide was used as internal standard). The samples were injected hydrodynamically at 1000 mbar for 3 s. The separation was performed at +30 kV. Under such conditions the PM and VM were base-line resolved and the separation took < 4 min. Calibration curves were linear for both PM bromide and VM bromide in the range 25-250 μg/ml with r > 0.9968. The limits of detection were 7 and 6 μg/ml for PM bromide and VM bromide, respectively. The accuracy tested by recovery experiment at three concentration levels of added PM bromide and VM bromide was satisfactory (95.7-102.7 %, n=3, with RSD < 2.61 %). The method was successfully applied to the assay of PM bromide and VM bromide in commercial injection solutions.
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