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Development of CE-C4D method for the analysis of saccharides in honey
Šebestová, Gabriela ; Jáč, Pavel (advisor) ; Šatínský, Dalibor (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Gabriela Šebestová Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of the diploma thesis: Development of CE-C4D method for the analysis of saccharides in honey Honey is a commonly used natural mixture which quality must be monitored due to possible mishandling or adulteration. This diploma thesis is focused on the development of a capillary electrophoresis method with capacitively coupled contactless conductivity detection (CE-C4D) for the determination of carbohydrates in honey samples. Design of Experiments (DoE) was used to optimize the separation conditions. This approach allows to find suitable separation conditions by means of multivariate optimization. During the optimization, the impact of the following factors was investigated: the composition of the background electrolyte, the separation voltage and temperature during separation and the inner diameter of the separation capillary. Two methods were optimized: one with normal electroosmotic flow (EOF) and the other using reversed EOF after CTAB addition. The method in the normal EOF mode was used for validation and analysis of honey samples. A fused silica capillary with an inner diameter of 20 m, a total length of 48.7 cm and an effective...
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The capabilities of capillary electrophoresis in the separation of boswellic acids
Poušková, Jitka ; Jáč, Pavel (advisor) ; Polášek, Miroslav (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Jitka Poušková Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of the diploma thesis: The capabilities of capillary electrophoresis in the separation of boswellic acids The main aim of this work was testing of capabilities of capillary electrophoresis for the separation of boswellic acids in Boswellia serrata extract as well as in a mixture of standards. The effect of five different buffers and some additive (such as cyclodextrins, organic modifiers or surfactants) in the background electrolyte was tested. The most suitable components of the background electrolyte, were examined at different concentrations to achieve complete separation of boswellic acids. First experiments were carried out in a fused silica capillary with 50 μm internal diameter, 48.5 cm total length and 40 cm effective length, followed by the separations in a longer capillary with 83.5 cm total length and 75 cm effective length. The separation voltage was +30 kV. The UV detection was at 200 nm, 250 nm and 280 nm. The best results were achieved with the background electrolyte composed of 80 mM phosphate buffer at pH 7.0 with 10 % (v/v) of methanol and 80 mg/ml of 2-hydroxypropyl-β- cyclodextrin. With this electrolyte, Boswellia...
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Study of α-bromophenylacetic acid suitability as a model analyte for chiral separations using capillary electrophoresis as a separation technique II
Bubáková, Zuzana ; Jáč, Pavel (advisor) ; Lochman, Lukáš (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Zuzana Bubáková Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of diploma thesis: Study of α-bromophenylacetic acid suitability as a model analyte for chiral separations using capillary electrophoresis as a separation technique II Rizvi and Shamsi (Rizvi S.A.A., Shamsi S. A. Anal. Chem. 2006, 78(19), 7061-7069) reported the employment of α-bromophenylacetic acid (BPAA) dissolved in water/methanol mixture (1:1, v/v) as a model analyte for chiral separations in capillary electrophoresis (CE). However, the stability of BPAA in aqueous methanol is questionable (Kováčová G. 2018. Diploma thesis. Charles University, Faculty of Pharmacy). The aim of this work was to determine the reaction order of the decomposition of BPAA (c = 0.47 mM) in 50% aqueous methanol. The reaction kinetic study was performed by capillary electrophoresis in 50 μm (i.d.) poly(vinyl alcohol)-coated capillary (30 cm/24.5 cm) with UV detection. The BPAA and products of nucleophilic substitution (mandelic acid, α-methoxyphenylacetic acid, and Br-) were separated in 60 mM formate buffer (pH 3.0) at -30 kV; the detection was 200 nm. The first order reaction kinetics was confirmed by linear and non-linear regression, yielding the rate...
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Development of capillary electrophoresis method for the determination of three pharmacopoeial impurities in indomethacin
Doubková, Dagmar ; Jáč, Pavel (advisor) ; Sklenářová, Hana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Mgr. Dagmar Doubková Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of Thesis: Development of capillary electrophoresis method for the determination of three pharmacopoeial impurities in indomethacin. This thesis deals with the development of a micellar electrokinetic chromatography method for the determination of indomethacin impurities (4-chlorobenzoic acid, 5-methoxy-2-methyl-3-indolylacetic acid and 3,4-dichloroindomethacin). All separations were performed in a fused silica capillary with 50 µm id; total length 64.5 cm, effective length 56 cm and with extended light path (150 µm id) detection window. 1-naftylacetic acid (10 µg/ml) was used as an internal standard. The separations were carried out at 30 kV. The analytes were detected at the cathodic end of the capillary at 224 nm. A central composite design was applied for the optimization of the separation conditions. The effect of SDS concentration, content of methanol, concentration of phosphate buffer and buffer pH was studied at three levels. The optimized background electrolyte was: 20 mmol/L phosphate buffer (pH 7.57) containing 58 mmol/L SDS and 0% MeOH. The analysis time (with resolution of all compounds Rs ≥ 3.8) was shorter than 10...
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Study of α-bromophenylacetic acid suitability as a model analyte for chiral separations using capillary electrophoresis as a separation technique
Kováčová, Gabriela ; Jáč, Pavel (advisor) ; Špulák, Marcel (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Gabriela Kováčová Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of diploma thesis: Study of α-bromphenylacetic acid suitability as a model analyte for chiral separations using capillary electrophoresis as a separation technique This thesis deals with the stability of α-bromphenylacetic acid, that was used as the model analyte for chiral separations using capillary electrophoresis as a separation technique (see reference Rizvi, S. A. A., Shamsi, A. S.. Synthesis, Characterisation, and Application of Chiral Ionic Liquids and Their Polymers in Micellar Electrokinetic Chromatography. Anal.Chem. 2006, Volume, 7061-7069). Stability of α- bromphenylacetic acid in methanol and in 50% aqueous methanolic solution has been studied by means of capillary zone electrophoresis under the employment of different background electrolytes (50 mM phosphate buffer at pH 7.5, 60 mM acetate buffer at pH 5.0 and 60 mM formate buffer at pH 3.0). The separation was conducted in 50 μm id fused-silica capillary. UV detection was at 200 nm. The successful separation of all theoreticaly possible products of nucleophilic substitution (mandelic acid, α- methoxyphenylacetic acid and bromide) has been reached only in the 60 mM...
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Analysis of Psilocybe constituents II.
Gunčagová, Andrea ; Jahodář, Luděk (advisor) ; Jáč, Pavel (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of pharmaceutical botany and ecology Candidate: Bc. Andrea Gunčagová Supervisor: prof. RNDr. Luděk Jahodář, CSc. Title of diploma thesis: The analysis of Psilocybe constituents II. The aim of this thesis was to analyse Psilocybe constituents, to plot the places of occurence of chosen Psilocybe brands and also to determinate their water content. The thesis deals with 22 samples that originate in 10 habitats in Slovakia and Moravian- Silesian region. Accuracy of brand specification was supervised by a member of mycological society. Psilocybe serbica var. bohemica was identified in 2, whereas Psilocybe semilanceata in 8 habitats. The average content of H20 in samples was 87,07 % ± 10,91 %. All of the samples were analysed by LC-MS/MS (LIT) method. The qualitative analysis of determinated substances showed the presence of psilocine (PSC) and psilocybine (PSB) in all samples. The results of quantitative analysis (expressed in percentage of dry matter) are similar in particular habitats, but there is a significant difference between two specific brands of Psilocybe mushrooms. The content of determinated alkaloids in P. bohemica was: PSC 0,001-0,011 % a PSB 0,01-0,07%. P. semilanceata contained 0,0005 - 0,011 % PSC a 0,074 - 0,763% PSB....
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Development of UHPSFC-PDA method for impurity profiling in active pharmaceutical ingredient atomoxetine
Roubíčková, Lucie ; Nováková, Lucie (advisor) ; Jáč, Pavel (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Bc. Lucie Roubíčková Supervisor: Assoc. Prof. PharmDr. Lucie Nováková, Ph.D. The title of Diploma Thesis: Development of UHPSFC-PDA method for impurity profiling in active pharmaceutical ingredient atomoxetine This diploma thesis deals with an optimization of UHPSFC method for determination of atomoxetine and its impurities mandelic acid, o-cresol, phenol, phenoxyatomoxetine, benzylatomoxetine and atomoxetine carbamate. Atomoxetine is used as centrally acting sympathomimetic agent for the treatment of hyperkinetic disorders such as Attention Deficit Hyperactivity Disorder (ADHD). Measurements were carried out on the UHPSFC system Aquity UPC2 with PDA detector and Torus Diol 1.7 µm (3.0 x 100 mm) column. ABPR pressure was optimized at 2000 psi and the column temperature at 40řC. Flow rate of mobile phase was 1.5 ml/min. Additional optimization parameters were the mobile phase composition, gradient elution conditions (initial composition of mobile phase, gradient slope, gradient time, gradient curves) and the effect of analysis time on the resolution of critical peak pairs. PDA detector parameters were examined, including comparison of data acquisition in 3 D and 2 D mode, selection of detection...
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Testing of potential capability of chiral ionic liquids with long alkyl chain in capillary electrophoresis chiral separations I
Mrázová, Veronika ; Jáč, Pavel (advisor) ; Polášek, Miroslav (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Veronika Mrázová Supervisor: PharmDr. Pavel Jáč, Ph.D. Title of diploma thesis: Testing of potential capability of chiral ionic liquids with long alkyl chain in capillary electrophoresis chiral separations I The main aim of this diploma thesis was testing of novel chiral ionic liquids as chiral selectors in capillary electrophoresis for the potential application in chiral separations of model compounds (mainly of pharmaceutical importance). The analysis was realized by micellar electrokinetic chromatography since the tested chiral ionic liquids were cationic surfactants. The examined electrolytes were formed by different buffers of various pH values and with different concentration of chiral ionic liquids. The separation took place in fused silica capillary (50 µm diameter, 48.5 cm total length, 40 cm effective length). The UV detection was performed at different wavelengths according to the structural features of model compounds. The separation always resulted in one peak; it means that the tested chiral ionic liquids did not show any capability in enantioseparation of model analytes. This observation can probably be explained by electrostatic interaction (between negatively charged...
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