National Repository of Grey Literature 109 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Separation of pharmaceutically active compounds by mixed-mode and chiral chromatography: interaction study
Fojtíková, Sofia ; Bosáková, Zuzana (advisor) ; Kozlík, Petr (referee) ; Fischer, Jan (referee)
During the drug development process, the pharmaceutical industry often relies on chromatographic techniques. High-performance liquid chromatography (HPLC) is among the most commonly used chromatographic techniques for these purposes, with reverse phase and HILIC being the most common choices. However, despite their popularity, these techniques have several drawbacks, such as the contribution of secondary interactions that arise from the nature of the carrier material, and limitations in terms of analyzing molecules with certain properties. In this sense, multimodal (also called mixed-mode) chromatography (MMC) appears to be a promising technique capable of addressing these challenges. The first part of the dissertation is focused on the comparison of the retention of structurally different molecules in different chromatographic systems using seven different multimodal stationary phases and the effort to elucidate the interaction mechanisms applied to the individual studied stationary phases. By observing the trends, obtained under different conditions for molecules with different physicochemical properties, it was at least partially achieved. Chiral chromatography is another key tool in the analysis of pharmaceuticals. Its main purpose in the development of medicinal products is to separate...
Determination of calcium, magnesium and phosphorus in selected types of animal bones
Škardová, Alice ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
This research focuses on the elemental analysis of selected elements (calcium, magnesium, and phosphorus) within the bones of various animal species, aiming to make comparative nutritional assessments. The obtained bone samples were subjected to mechanical grinding and then quantitatively weighed into collapsible cartridges. Using high-pressure microwave decomposition with the incorporation of nitric and hydrochloric acid, the samples were transformed into solution form, which was then appropriately diluted. The analysis of the liquid samples was carried out using a mass spectrometer with inductively coupled plasma. The observed composition for each sample was calculated using the calibration curve, accounting for both sample mass and dilution factors. All results obtained exceeded the detection limit for calcium 0.38 mg/l, magnesium 0.037 mg/l, and phosphorus 0.078 mg/l. The main finding of this research is the complete understanding of the elemental makeup present within the bones of distinct animal species.
Analysis of bilirubin's relevant photoproducts and their biological significance in the issue of neonatal jaundice
Křepelka, David ; Kozlík, Petr (advisor) ; Zelenka, Jaroslav (referee)
Neonatal jaundice occurs in almost 60% of full-term and 80% of premature babies, where a slightly increased concentration of bilirubin protects against oxidative stress just after birth. When a specific bilirubin level is exceeded in serum (usually above 340 µmol·l-1 ), bilirubin-could induce kernicterus. These negative states are prevented by blue-green light phototherapy (420-510 nm), which converts bilirubin into more polar photoproducts that are more easily excreted via bile and/or urine. Published data have shown that newborns with indicated phototherapy may develop clinical problems later in life (higher incidence of e.g. asthma, allergies, type 1 diabetes was observed at a later age). A possible reason for the occurrence of these diseases is the specific biological activity of photoproducts. This study aims to purify an unknown photoproduct (band P), formed after 8 hours of irradiation of a bilirubin solution with blue light, and to establish a quantitative analytical method for its measurement in relevant matrices. This product was isolated and separated by a thin layer and subsequent column flash chromatography. In the next part, an LC-MS/MS method was developed for quantification of band P. Finally, urine, plasma, and feces samples collected from 15 newborns before and after phototherapy...
Development of the UHPLC-PDA method to determine the active substances in the tablet Ataralgin
Chocová, Natálie ; Kozlík, Petr (advisor) ; Hraníček, Jakub (referee)
The Ataralgin tablet is an over-the-counter drug that helps against pain and elevated body temperature. The tablet contains three active substances - paracetamol, caffeine and guaifenesin. The aim of this thesis was to develop a rapid, effective, selective and simple UHPLC-PDA method suitable for the determination of active substances in the Ataralgin tablet which would subsequently serve for quality control during the production of this drug in the pharmaceutical industry. Separation was performed on the Acquity UPLC BEH C18 column (50 × 2.1 mm, 1.7 µm), the column temperature was set at 40 řC, autosampler temperature was 10 řC, the mobile phase was composed of methanol (B) and distilled water with the addition of 0.1% formic acid (A), sample injection volume was 1 µl and the flow of mobile phase was 0.4 ml·min-1 , gradient elution (time: 0-0.5-1.5-2.5-3-5.5 min, A: 85-85-30-30- 85-85% v/v). UV detection at 275 nm and the total analysis time was 5.5 minutes. The trueness (relative error) was in the range of 0.05 - 2.73 % and the accuracy (relative standard deviation) was in the range of 2.38 - 5.79 %. The LOD values were: 9.25·10- 4 mg·ml-1 for paracetamol, 2.15·10-4 mg·ml-1 for caffeine and 7.93·10- 4 mg·ml-1 for guaifenesin and values for the LOQ were 3.08·10-3 mg·ml-1 for paracetamol, 7.17·10-4...
Determination of inorganic corrosion inhibitors by ion chromatography
Kapiasová, Anna ; Kubíčková, Anna (advisor) ; Kozlík, Petr (referee)
Corrosion inhibitors are substances that prevent the internal surface of the cooling system from corrosion. Inorganic corrosion inhibitors contain inorganic anions that passivate the surface, thereby preventing the diffusion of oxygen into the system and protecting the surface from oxidation. This study is aimed at the development and validation of a method for the determination of inorganic corrosion inhibitors (specifically chlorides, nitrites, nitrates, hydrogen phosphates, sulfates and molybdates) by ion chromatography. The optimal separation of anions was achieved with a mobile phase consist of 3.3 mM sodium carbonate and 3.3 mM sodium bicarbonate (pH= 10.1) at 45 řC using the column Metrosep A Supp 7 (250 × 4.0 mm with particle size of 5 µm) (Metrohm, Switzerland). Under these conditions the analysis took 48 minutes. After validation, the method was used to determine corrosion inhibitors in real coolant samples. The peaks of the individual anions contained in the coolants were verified by spiking with standards of anions. The anion concentrations were determined from the areas of these peaks using the calibration curves. Key words ion chromatography, engine coolants, corrosion inhibitors, inorganic ions
Analysis of composition of residues of inorganic pharmaceuticals from the 18th century
Janoušková, Eva ; Nesměrák, Karel (advisor) ; Kozlík, Petr (referee)
In this bachelor thesis, sixteen samples of inorganic pharmaceuticals from the 18th century were analyzed by inductively coupled plasma mass spectrometry, atomic absorption spectrometry, atomic emission spectrometry, UV/VIS spectrometry, capillary zone electrophoresis, titrations, and gravimetric analysis. The analysis confirmed that the composition of fourteen of the analyzed samples corresponded with their respective Latin inscriptions on the apothecary jars, while two of the samples proved to be a completely different substance. All samples, except for one, contained a relatively high number of impurities. These impurities helped determine if the source of the sample was a mineral commonly occurring in nature or a chemical reaction. Keywords: History of pharmacy, ICP-MS, F-AAS, F-AES, UV/VIS spectrometry, historical pharmaceuticals
Sequential Injection Analysis for Spectrophotometric Determination of Biseptol Components
Kroiherová, Anna ; Nesměrák, Karel (advisor) ; Kozlík, Petr (referee)
A method using the sequential injection analysis technique for the spectrometric determination of two analytes, sulfamethoxazol and trimethoprim, in a mixture in the drug Biseptol® 480 without the need for their separation, was developed and optimized. Both analytes absorb in the UV spectrum, but only sulfamethoxazol, as primary amine, gives a colour product after derivatization reaction with sodium nitrite and N-(1-naphthyl)ethylenediamine, that can be detected in the VIS spectrum. The concentration of sulfamethoxazol is directly proportional to the absorbance of the colour product and by subtracting this concentration from the concentration of both analytes measured in the UV spectrum, the concentration of trimethoprim in the sample can be determined.
Elemental analysis of dendrochronological Norway spruce sample
Zámečník, Karel ; Hraníček, Jakub (advisor) ; Kozlík, Petr (referee)
The subject of this bachelor's thesis is the determination of lithium, sodium, magnesium, potassium, calcium, manganese, iron, zinc, selenium, rubidium, strontium, cadmium, antimony, cesium, barium, and thallium in dendrochronological samples of Norway spruce using inductively coupled plasma mass spectrometry. The samples of the Norway spruce were collected in the autumn of 2018 on the southern slope of hill Melechov in the Vysočina region. The stem sample was first divided into pieces according to the distance from the bark and labelled A1a to A1g. The ash sample was obtained by burning a cross-section of the stem and separating the bark, from which the A3b sample was created. The remaining two samples were made up of needles and twigs and labelled as samples E and F. For elemental analysis, the samples needed to be converted into a solution, which was achieved by dissolving them in a mixture of hydrochloric, nitric, and hydrofluoric acid, using a microwave digestion device. After dissolution, a solution of boric acid was added to each sample solution to complex any unreacted hydrofluoric acid, which could damage the internal components of the ICP-MS. Calibration solutions were then created with concentrations of 0,0016; 0,008; 0,04; 0,2 and 1,0 mg/l from stock solutions containing the analysed...
Development of a UHPLC-MS/MS method suitable for the determination of cabozantinib in blood serum
Kleinová, Jana ; Kozlík, Petr (advisor) ; Hraníček, Jakub (referee)
The aim of this Bachelor thesis was to develop a UHPLC-MS/MS method for the determination of Cabozantinib in blood serum. This method was used to monitor the release of the active substance in a model organism - the rat. First, the mass spectrometer setup was optimized, where MRM transitions for Cabozantinib and isotope-labelled Cabozantinib-D4 were found. For Cabozantinib, an MRM transition of 502.2 → 323.1 was found with optimal energy levels of Q1 = -26.0 V, CE = -40.0 V and Q2 = -22.0 V. For Cabozantinib-D4, the MRM transition of 506.2 → 327.0 was found with optimal energy levels being Q1 = -26.0 V, CE = -39.0 V and Q2 = -22 V. The method setup parameters were as follows: The chromatography column used was a Poroshell 120 EC-C18, 2.1x50 mm, 1.9 um, (Agilent Technologies). The mobile phase consisted of acetonitrile (B) and formic acid (A), the flow rate of the mobile phase was 0.350 ml/min, the analysis time was 5.5 min and the injection volume was 1 μl at gradient elution (time: 0; 0.5; 2.0; 3.0; 3.5; 4.0; 5.5 min, B: 10; 10; 60; 100; 10; 10 %). The method was linear (weighted regression 1/x2 ) with a regression coefficient equal to 0.9978, showing an excellent linearity of the method. The precision (relative standard deviation) of the method was within 14 %. The accuracy (relative error) was...
Comparison of different tandem mass detection scans in the analysis of cannabidiol
Tichá, Tereza ; Kozlík, Petr (advisor) ; Kubíčková, Anna (referee)
The aim of this bachelor thesis was to compare different tandem mass spectrometer scans in order to develop an LC-MS/MS method suitable for the determination of cannabidiol in rat serum. In this bachelor thesis the mass spectrometer and high-performance liquid chromatography method were optimized. The optimum parameters were as follows: chromatographic column Acquity UPLC BEH C18 50 × 2,1 mm, 1,7 μm from Waters (Wexford, Ireland). The mobile phase consisted of methanol and water of LC-MS purity. The flow rate of the mobile phase was 0,4 ml/min, the column temperature 40 řC, the temperature in an autosampler 15 řC, the sample injection volume was 1 μl and the analysis time was 7 minutes under gradient elution conditions. The MRM transitions of highest intensity were monitored. For CBD, the MRM transition in positive mode was 315,2 → 193,1 (Q1 = -10 V, CE = -24 V, Q3 = -20 V), for isotopically labeled cannabidiol D3 was chosen 318,4 → 196,0 (Q1 = -10 V, CE = -23 V, Q3 = -20 V). The calibrations in solvent and rat serum were performed in MRM and SIM mode. No calibration was constructed for the SCAN mode due to its low selectivity, which made it able to detect cannabidiol only from concentration of 312,5 ng/ml. The highly selective MRM was able to operate over the entire observed concentration range of...

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