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The Flow Injection Analysis of Procaine and Sulfamethoxazole with Spectrophotometric Detection
Baptistová, Adéla ; Nesměrák, Karel (advisor) ; Červený, Václav (referee)
A derivatization reaction, based on a copulation reaction of diazonium salt of an analyte with a reagent (1-aminonaphthalene or NEDA) producing colour, spectrophotometrically detectable product, has been used for determination of two analytes (procain hydrochloride, sulfamethoxazole) containing amino group in the molecule. The conditions of batch spectrophotometric determination were studied. It was found, that the batch determination is applicable only for procain hydrochloride analysis, because sulfamethoxazole gives time-unstable colour product. FIA arrangement was proposed and effects of selected parameters were optimized using two levels factorial design. The calibration dependences were measured for both analysis with both reagents, and subsequently were applied on determination of analytes in medical forms. Key words: diazotization, flow injection analysis, procaine, spectrophotometry, sulfamethoxazole
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Time-resolved potentiometry on liquid-liquid interface
Mansfeldová, Věra ; Nesměrák, Karel (advisor) ; Opekar, František (referee) ; Gál, Miroslav (referee)
Věra Mansfeldová: Time-resolved potentiometry on liquid-liquid interface (Dissertation thesis) Abstract The aim of this work is to explore the method of temporal resolution in potentiometry as a new prospective electrochemical analytical technique. In connection with interface of two immiscible electrolyte solutions (ITIES) it may find utilization in analytical chemistry. This technique up to my knowledge has not been published yet. Potential response of analyte on liquid/liquid interface includes both distribution processes, their temporal resolution and redox processes, which specificity can modified by changing the composition of individual phases. Unlike "classic" potentiometric techniques, limited just to potential determination, this method, which I have given the working name "time resolved potentiometry at liquid-liquid interface" utilizes time development of potential response, which was found to be an analyte-specific function. The time resolved potentiometry presented in this work includes time course of potential response to analytical parameters specific for particular analyte. It brings series of data characterizing the analyte in given environment in a similar manner as spectra and may allow creating analyte-specific data package - fingerprint. Combination with ITIES allows, unlike...
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Analysis of Historical Pharmaceutical Preparations Containing Alkaloids, Sulphonamide, Derivatives of Barbituric Acid, and Derivative of Pyrazolone
Kudláček, Karel ; Nesměrák, Karel (advisor) ; Bosáková, Zuzana (referee)
Pharmaceutical preparations of quinine (injection solutions), sulfanilamide, aminophenazone, barbital (tablets), caffeine, phenobarbital (dragee), and theophylline (suppositories) about seventy years old were analyzed using RP-HPLC. Samples were quantified by HPLC-UV and UV-spectrophotometry. Products of degradation were identified using HPLC-UV and HPLC-MS. Conditions of separation were optimized. The samples of quinine injection solutions consist of 92% or 87% of declared quinine content. Quinotoxine has been identified as the product of quinine degradation. The quantification of theophylline in suppositories and caffeine in dragee did not show any degradation after more than 67 years from their manufacturing. Decrase of potent amount (decrase about 8-22 %) were found in drugs containing sulfanilamide, barbital, phenobarbital and aminophenazone. Products of degradation of these pharmaceuticals were not found.
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Micro-mechanical Sensor and Laser Photoacoustics for Diagnostics in Gases
Vlasáková, Tereza ; Nesměrák, Karel (advisor) ; Wild, Jan (referee)
The aim of the thesis is to study mechanical properties of nanomaterials (multi-layer graphene, silicon, mica) suitable to be used as novel pressure sensors in laser photoacoustic spectroscopy. Membranes (diameter ~ 4 mm, thickness ~ 100 nm) were prepared by mechanical exfoliation method and then attached to a glass window in several slightly different designs. Movement of these membranes was detected using HeNe laser beam reflected from the membrane's surface onto a position sensitive detector. Methanol was used as a model gas and the signal was collected from studied element and microphone simultaneously. Acoustic wave, induced inside a measuring cell by periodic thermal variations, causes the membranes to move. The movement of a membrane is influenced by its mechanical properties, which is possible to determine by fitting the measured data into a mathematical model. Comparison of the output data of all membranes' measurements shows, that the signal intensity is influenced by the method of attaching membrane to a glass window and by volume of free space on a side of a membrane. Metallization of the membrane's surface (~ 70 nm) decreases its springiness thus decreases the sensitivity. Several membranes reached sensitivity comparable with top class microphone.
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Electrochemical oxidation of Bile Acids on Carbon Based Electrodes. The Possible Use in Electroanalysis.
Klouda, Jan ; Nesměrák, Karel (advisor) ; Zima, Jiří (referee)
The goal of this master's thesis was to examine the possibility of oxidation of seven selected bile acids and evaluate whether such processes are suitable for analytical purposes. The secondary goal was to describe the oxidation products of bile acid electrolysis. The experiments were carried out in a non-aqueous medium of acetonitrile and in a mixed medium of acetonitrile:water using linear sweep and cyclic voltammetry. The working electrode materials employed for voltammetric experiments were: highly oriented pyrolytic graphite, -cyclodextrin modified glassy carbon and boron doped diamond. Preparative electrolysis was carried out on a platinum electrode in the non-aqueous medium of acetonitrile. Experiments have shown that neither the highly oriented pyrolytic graphite electrode nor the -cyclodextrin modified glassy carbon electrode are suitable for analytical purposes under conditions used. The results achieved on the boron doped diamond electrode, on the other hand, have not yet been described in the literature. Primary bile acids cholic and chenodeoxycholic were oxidized at approximately 0.5 V lower potential in the mixed medium of acetonitrile:water than in the papers using carbon electrodes published until now. Products of oxidation on the platinum electrode were separated by TLC and...
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Determination of Heparin by Sequential Injectin Analysis with Spectrophotometric Detection
Lišková, Růžena ; Hraníček, Jakub (advisor) ; Nesměrák, Karel (referee)
In this work the determination of heparin using Sequential Injection Analysis (SIA) technique with spectrophotometric detection was studied. The principle of this method was measuring the decrease of absorbance of phenothiazine dyes in its maximum wavelength caused by its interaction with heparin. The decrease is proportional to concentration of heparin in sample. The aim of this work was to find optimum conditions for determination of heparin by the SIA with spectrophotometric detection and to try to apply this measurement to real sample under these conditions. Three phenothiazine dyes were used: Methylene Blue, Azure A and Azure B and for each of them an optimum concentration was found. Their values were for methylene blue 4.0 ∙ 10-5 mol/dm3 and 5.0 ∙ 10-5 mol/dm3 for Azure A and Azure B. 150 µl was chosen as an optimum amount of heparin and reagent aspirated. Optimum reaction time was 0 s and flow rate during measurement 1.5 ml/min. Working concentration range was found between 0.23 and 15 mg/dm3 for methylene blue, 1.2 and 13 mg/dm3 for Azure A and 0.67 and 12 mg/dm3 for Azure B. Limit of detection varied between 0.09 - 0.35 mg/dm3 and limit of quantification between 0.30 and 1.2 mg/dm3 for different dyes. Relative standard deviation was determined as a measure of repeatability. Its values were...
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Electrochemical Oxidaction of Thioxoacetamides in Acetnonitrile Medium
Kudláček, Karel ; Nesměrák, Karel (advisor) ; Schwarzová, Karolina (referee)
Electrochemical oxidation of eight newly synthesized derivatives of 2-(fenylamino)-2-thioxoacetamidein 0,1 mol dm-3 sodium perchlorate - including effects of acid, base, and water - was studied. It was found that oxidation carried out in two subsequent steps, each of them is connected with exchanging of one electron. The oxidation is localised on sulphur atom, it is exchanged by oxygen atom in the final oxidation product. The effect of substituents on the course of electrochemical oxidation was also studied.
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The Comparison of Methods for Determination of Procaine in Medical Formulations
Baptistová, Adéla ; Nesměrák, Karel (advisor) ; Červený, Václav (referee)
The aim of this bachelor thesis was to compare four analytical methods for determination of procaine hydrochloride in medical formulations in terms of precision and measurement trueness, and its time, and financial cost. The selected methods are: titration with potassium bromate, titration with sodium nitrite, UV spectrophotometry, VIS spectrophotometry. Three injection solutions of different concentrations (0.2%, 0.5%, and 1.0% of procaine) were analysed. VIS spectrophotometry provides the most precise results, whereas determination by UV spectrophotometry is the least precise. Measurement trueness is found for UV spectrophotometry and both titrations. UV spectrophotometry is the cheapest method, while titration with sodium nitrite is the most expensive method. Titration with potassium bromate is the least time-consuming method, while VIS spectrophotometry is the most time- consuming method. Keywords: procaine, bromatometric titration, titration with sodium nitrite, UV and VIS spectrophotometry
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Cyclic Voltammetry as a Detection Technique in High Performance Liquid Chromatography
Burešová, Helena ; Nesměrák, Karel (advisor) ; Schwarzová, Karolina (referee)
The aim of the thesis was to study the possibility of employment of cyclic voltammetry as a detection technique in liquid chromatography. The phenothiazine derivatives (chlorpromazine hydrochloride, diethazine hydrochloride, and thioridazine hydrochloride) were used as model compounds. Firstly, the comparison of two potential detectors (tubular detector and bulk "wall-jet" detector) was accomplished. Only bulk "wal-jet" detector satisfied. Next, the conditions for the separation and detection of studied phenothiazines on RP-select B LiChrospher® 60 (250×4 mm) column with cyclic voltammetry as the detection techniques were optimized. The best separation is achieved in mobile phase consisted from the solution of 0.1 mol dm-3 sodium perchlorate in acetonitrile-water (80:20) mixture. The effect of flow rate of mobile phase and scan rate of polarization of the electrode on the symmetry of chromatographic peak was also followed, and optimal values of 0.5 ml min-1 for flow rate, and of 0.5 V s-1 for scan rate, were found. Under optimized conditions the calibration dependences of studied phenothiazines were measured in the range from 5×10-5 to 1×10-3 mol dm-3 for chlorpromazine, and in the range from 8×10-5 to 1×10-3 mol dm-3 for diethazine and thioridazine. The developed method was applied to...
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