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Determination of biologically active substances by sequential injection analysis with chemiluminescence detection.
Štěpánková, Lucie ; Polášek, Miroslav (advisor) ; Sklenářová, Hana (referee)
1.1 Abstrakt A simple and rapid automated method for the assay of norepinephrine by sequential injection analysis (SIA) with chemiluminescence detection was devised and optimised. The optimised parameters were aspirated volumes of the norepinephrine bitartrate sample and reagents, flow rate, composition of the carrier stream and the photomultiplier voltage. Optimum sample volume was 80 μl and the optimum reagent concentrations (and aspirated volumes) were - 25 mM sodium polyphosphate (44 μl), 0,1 M sulphuric acid (24 μl) and 1 mM potassium permanganate (21 μl)., The optimum flow rate (for pushing the luminescent zone to the detector) was 91 μl/s and the photomultiplier voltage was 450 V. The carrier stream was ultrapure water. The calibration curve was rectilinear in the range 1 - 40 µmol/l of norepinephrine bitartrate. The parameters of the calibration curve y = kx + q (where y is the intensity of chemiluminescence in nA and x stands for the concentration of norepinephrine bitartrate in µmol/l) were calculated by the linear regression method. The slope k was 33.923 and the intercept q was 34.839. The correlation coefficient was 0.9997. The relative standard deviations were 2.78 or 1.18 % (n = 10) when determining 4.75 or 18.98 µmol/l norepinephrine bitartrate in pure standard solutions respectively. The...
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Determination of septonex in pharmaceutical preparations by capillary zone electrophoresis with conductivity detection.
Šindelková, Martina ; Polášek, Miroslav (advisor) ; Pospíšilová, Marie (referee)
DETERMINATION OF SEPTONEX IN PHARMACEUTICAL PREPARATIONS USING CAPILLARY ZONE ELECTROPHORESIS WITH CONTACTLESS CONDUCTIVITY DETECTION A new method of capillary zone electrophoresis with contactless conductivity detection for the determination of septonex in pharmaceutical preparations was devised. Optimal conditions for the separation and determination of septonex were: background electrolyte 30mM MES of pH 7.0 (adjusted with 20mM TRIS) containing 12.5mg/ml of (2- hydroxypropyl)-β-cyclodextrin, voltage 25kV, temperature 25řC and sample injection for 15 seconds under the pressure of 50mbar. N,N-dimethylethanolamine (200µg/ml) was used as internal standard. The peak of septonex was satisfactorily separated from the peak of internal standard as well as from the EOF. The analysis was carried out in a fused-silica capillary (internal diameter 50μm, total length 75cm and the length to the detector 45cm). The separation took less than 4 minutes and the overall analysis time involving appropriate rinsing of the capillary was less than 16 minutes. The calibration curve was linear in the range 75µg/ml - 300µg/ml of septonex, correlation coefficient r = 0.9976. The LOD was 9μg/ml and LOQ was 30μg/ml of septonex. Unsuitable repeatability of peak areas of septonex (caused probably by insufficient elimination of...
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Use of micellar electrokinetic chromatogramy for the assay of degradation products of the pharmaceutical compounds
Vančura, Luboš ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
Use of micellar electrokinetic chromatography for the determination of pharmaceutical impurities A new method of micellar electrokinetic chromatography (MEKC) for the separation and selective determination of clotrimazole and its degradation product (2- chlorophenyl)diphenylmethanol in pharmaceutical preparations was developed and validated. 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 34.5 mbar for 7 s and temperature 25 o C. The optimum background electrolyte consisted of 15 mM potassium dihydrogen phosphate, 20 mM sodium dodecyl sulphate, 30 mM sodium cholate and 10 mM β-cyclodextrin (pH = 8.2); sodium diclophenac was used as internal standard. The separation took less than 12 min.
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Metal content in medicinal plants - empirical and chemometric approach
Komínková, Michaela ; Polášek, Miroslav (advisor) ; Solich, Petr (referee)
Metal content in medicinal herbs - empirical and chemometric approach Abstract The content of metals: Cr (0.01 - 13.9 ppm), Zn (25 - 96 ppm), Fe (84 - 2240 ppm), Mn (20 - 91 ppm), Ni (0.2 -5.4 ppm), Cu (1.5 -10 ppm) and Mg (0.3 - 1.3%) was determined in dried medicinal herbs, namely folium Melissae, flos Matricariae, herba Urticae, folium Menthae piperitae, fructus Foeniculi amari, flos Tilie, herba Hyperici and herba Filipendulae ulmariae originated from the Czech Republic, Poland and France. The samples of the herbs were decomposed by microwave-assisted mineralization and the metal ions were determined by atomic-absorption spectrophotometry. The results were subjected to statistical analysis in order to point out metals that could serve as indicators of the country of origin of the drugs.
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Chemiluminescence determination of thioridazinem, promethazine and levomepromazine using the flow injection analysis
Kolouchová, Gabriela ; Dolejšová, Jana (advisor) ; Polášek, Miroslav (referee)
1. SOUHRN V literatuře jsem vyhledala články týkající se různých způsobů stanovení fenothiazinových derivátů ( thioridazinu, promethazinu a levomepromazinu ) a práce zabývající se využitím FIA metody s chemiluminiscenční a fluorimetrickou detekcí ve farmaceutické analýze. Otestovala jsem systém FIA řízený počítačem a nastavila jsem vhodné parametry přístroje ( doba dávkování, rychlost čerpání roztoků do systému, časové parametry ), které jsem zachovávala po celou dobu měření konstantní. Určila jsem optimální složení nosného proudu a otestovala vliv některých látek na intenzitu chemiluminiscence. Největší vliv na intenzitu chemiluminiscence byl prokázán u polyfosfátu sodného. Ten jsem použila při proměřování kalibrační závislosti. Za optimalizovaných podmínek jsem proměřila kalibrační křivky thioridazinu, promethazinu a levomepromazinu bez a s přídavkem PFS o desetkrát nižší koncentraci thioridazinu, promethazinu a levomepromazinu. Tu jsem poté použila k odečtení koncentrací léčiv ve farmaceutických přípravcích. Zjištění obsahu levomepromazinu v přípravku Tisercin® inj. jsem nemohla FIA metodou uskutečnit. Intenzitu chemiluminiscence zvyšuje obsažená antioxidační přísada acidum ascorbicum. Podniková norma nebyla k dispozici. Obsah thioridazinu v přípravku Thioridazin ® 25 mg, tbl. obd. a obsah promethazinu v...
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Vývoj elektrochemického glutamátového biosenzoru
Doležalová, Julie ; Solich, Petr (advisor) ; Polášek, Miroslav (referee)
DEVELOPMENT OF A GLUTAMATE ELECTROCHEMICAL BIOSENSOR Julie Doležalová (Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague) In cooperation with: Sofia A.L.P. Gomes, Alberto N. Araújo (Department of Physical Chemistry, Faculty of Pharmacy, University of Porto) L-Glutamic acid and monosodium glutamate are used to enhance flavour in food prepared at home, restaurants, and by the food processing industry [1]. Glutamate also plays an important role in many metabolic processes. Nevertheless its use is being kept under certain limits as some people have experienced adverse effects, such as stiffness and tension, after its ingestion. Moreover, some studies demonstrate its connection with the appearance of neurological manifestations, such as Parkinson's and Alzheimer's disease. The determination of L-glutamic acid is therefore of major importance. In this work a novel L-glutamate biosensor was developed using a dehydrogenase enzyme (L-glutamate dehydrogenase). These redox enzyme requires for its activity nicotinamide (NAD(P)+ /NAD(P)H) coenzyme, which reduced form was electrochemically regenerated by the water-soluble dye, methylene green. Graphite electrodes were modified with a poly(methylene green) thin film by means of methylene green electrochemical polymerization...
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Analysis of ketoprofen, methylparaben and propylparaben by micellar electrokinetic chromatography
Balcar, Josef ; Pospíšilová, Marie (advisor) ; Polášek, Miroslav (referee)
1. ABSTRACT ANALYSIS OF KETOPROFEN, 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 ketoprofen, methylparaben and propylparaben. Separations were carried out in a fused silica capillary (50 cm × 75 μm i.d.) at 30 kV with UV detection at 200 nm. The optimal background electrolyte was 50 mM tricine buffer (pH* 8.3) containing 30 mM sodium dodecyl sulfate as a surfactant and 15 % (V/V) methanol. Rectilinear calibration ranges were 10.0 - 200 mg/100ml for ketoprofen, 0.2 - 4.0 mg/100ml for methylparaben and 0.1 - 2.0 mg/100ml for propylparaben. The MEKC method was applied to the determination of the analytes in pharmaceutical preparation. The total analysis time was <13 min.
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Sequential injection chromatography
Chocholouš, Petr ; Solich, Petr (advisor) ; Polášek, Miroslav (referee) ; Blešová, Marie (referee)
This work brings extending of applications of sequential injection analysis in area of pharmaceutical analysis. It is focused on integration of monolithic columns into SIA system that enables simultaneous determination of few analytes in samples with matrix (biologic samples) or simple mixtures (pharmaceutical preparations). A new created method was called Sequential Injection Chromatography (SIC) and represents a new generation of flow methods. Integration of short monolithic column with low back-pressure leads into creation of low pressure flow separation method. Commercially produced monolithic columns with reverse phase sorbent C18 are suitable for determination of active compounds and adjuvants in pharmaceutical preparations. This enables fast determination of samples without or only with simple off-line pre-treatment of sample. Employment of various lengths of monolithic columns used in SIC was studied. First experimental work (appendix I) was first SIC experiment. The aim of it was trouble-free connection of monolithic column with SIA manifold and application on determination of pharmaceutical preparation Diclofenac HBF emulgel (ointment contains diclofenac nitrate, methylparaben and propylparaben). All parts of system were optimized for higher work pressure. Sample of ointment was...
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Determination of bopindolol by the technique of sequential injection analysis with chemiluminescence detection
Holá, Petra ; Polášek, Miroslav (advisor) ; Šatínský, Dalibor (referee)
The oxidation of bopindolol [ 4-(2-benzoyloxy-3-tert-butylaminopropyl)-2-methylindole (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 3 (compared to purely aqueous test solution of I injected) if the test solution contained 60% (v/v) of methanol. Optimal order, concentrations and volumes of aspirated zones of reactants were: 61l of 80mM Na hexametaphosphate, 60 l of I in 60% (v/v) methanol, 40 l of 30mM H2SO4 and 9 l of 0.5mM KMnO4. Calibration curve relating the intensity of CL (peak height) to the concentration of I was linear in the range 1 - 8 M I; the limit of detection (S/N = 3) was 0.2 M I. The sample throughput was 100 h-1 . The repeatability of the peak heights was characterised by RSD 1.8% for 15 replicate injections of 2 M I. The SIA-CL method was used for the assay of I...
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