23 (2017) Scientific papers, Series A
Permanentní URI k tomuto záznamuhttps://hdl.handle.net/10195/75253
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Článek Otevřený přístup peer-reviewedpublisher's version 30 years with carbon paste electrodes at the University of Pardubice(University of Pardubice, 2017) Švancara, Ivan; Metelka, Radovan; Mikysek, Tomáš; Vytřas, KarelIn this review (with 425 Refs), three decades of the electrochemistry and electroanalysis with carbon paste electrodes characterising the research activities of the electroanalytical group at the University of Pardubice (EAG UPa) are summarised, when presenting all the achievements and, where applicable, also highlighting research outputs throughout the time. In more detail, reminded are the very beginnings in the mid-1980s and the early era at the University of Chemical Technology. The article contains the complete list of publications plus a great majority of conference presentations associated with the field and having been prepared by the EAG UPa in the period 1987-2016.Článek Otevřený přístup peer-reviewedpublisher's version A zwitterionic (poly)methacrylate monolitic capillary column with dual HILIC – reversed-phase mechanism for uni- and two-dimensional HPLC(University of Pardubice, 2017) Staňková, Magda; Jandera, PavelSulfobetaine zwitterionic monolithic columns were synthesized by in-situ polymerization (in fused silica capillaries) of a N,N-dimethyl-N-metacryloxyethyl- N-(3-sulfopropyl) ammonium betaine (MEDSA) functional monomer in combination with different cross-linking monomers. From among the ten crosslinkers tested, bisphenol A glycerolate dimethacrylate provides monolithic capillary columns with best chromatographic efficiency (60 000-70 000 theoretical plates per meter). The respective columns show excellent column-tocolumn reproducibility of pore morphology, separation selectivity, good permeability and low mass transfer resistance, so that being suitable for fast and selective separation of various samples. Monolithic sulfobetaine polymethacrylate (BIGDMA-MEDSA) micro-columns designed in our laboratory exhibit a dual retention mechanism, in acetonitrile-rich mobile phase, polar (hydrophilic) interactions control the retention (HILIC separation mode), whereas in more aqueous mobile phases the column shows essentially non-polar with a major role of hydrophobic interactions properties (reversed-phase, RP mode). The dual-mode retention mechanism was investigated and applied to the HILIC and reversedphase HPLC separations of barbiturates, sulfonamides, nucleobases, nucleosides, phenolic, and other carboxylic acids, polyphenols, flavonoids plus other lowmolecular compounds. The separation selectivities in the HILIC and RP dimensions are highly complementary to each other, so that a zwitterionic sulfobetaine polymethacrylate micro-column can be used in the first dimension of two-dimensional LC in alternating RP and HILIC modes, coupled with a short (3- 5 cm) alkyl-bonded core-shell or silica-based monolithic column in the second dimension, for HILIC×RP and RP×RP comprehensive two-dimensional separations. During the HILIC×RP period, a programme with the decreasing acetonitrile gradient is used for separation in the first dimension, so that at the end of the gradient the polymeric monolithic micro-column is equilibrated with a highly aqueous mobile phase and is ready for repeated sample injection, in this case, for separation under reversed-phase gradient conditions with the increasing concentration of acetonitrile in the first dimension.Článek Otevřený přístup peer-reviewedpublisher's version Analysis of volatile organic compounds in rose petals using headspace solid-phase microextractor coupled to gas chromatography-mass spectroscopy(University of Pardubice, 2017) Eisner, Aleš; Surmová, Silvie; Bajer, Tomáš; Kosová, Tereza; Ventura, KarelHeadspace solid-phase microextraction coupled to gas chromatography and mass spectrometry (HS-SPME-GC/MS) has been optimised for the analysis of volatile compounds in six samples of rose petals (Rosa Mariyo, Rose Tara, Rosa Rhodos, Rosa Sudoku, Rosa Deep Purple, Rosa Tacazzi). Volatiles from roses were extracted using a SPME fibre by carrying out the subsequent separation and identification by comparison of their mass spectra with mass spectra libraries and retention indexes. Several factors influencing the SPME were taken into account; namely, extraction time, extraction temperature and the sample weight. The optimal parameters of the extraction of volatile compounds were obtained based on statistical evaluation; the most suitable conditions being the extraction time of 60 min., the extraction temperature of 90 °C and the sample weight of 0.7 g.Článek Otevřený přístup peer-reviewedpublisher's version Catalitic activity of Agaricus bisporus mushroom tyrosinase to acetaminophenon in the presence of L-proline(University of Pardubice, 2017) Sýs, Milan; Klikarová, Jitka; Česlová, Lenka; Vytřas, KarelSecondary reaction of amino acid L-proline with 4-acetamido-o-benzoquinone as a product of the enzymatic oxidation of acetaminophen mediated by mushroom tyrosinase isolated from Agaricus bisporus has been studied by amperometric detection in the batch injection analysis configuration and by ultraviolet-visible spectrophotometry. Actually, this scientific work is focused on finding out whether it would be possible to develop an indirect electrochemical method based on the amperometric biosensing suitable for monitoring of the L-proline in various honey samples. For optimum content of acetaminophen (100 :mol dm–3) and tyrosinase (3.33 :g cm–3), a satisfactory linear range from 0.1 to 0.5 mmol dm–3 L-proline was obtained for absorption maximum at 332 nm. However, it is necessary to mention that the indirect determination of L-proline by the amperometric tyrosinase biosensor still presents a challenge in the field of developing biological sensors for monitoring of this amino acid.Článek Otevřený přístup peer-reviewedpublisher's version Determination of selected fatty acids in dried blood spot by gas chromatography-flame ionization detection(University of Pardubice, 2017) Andrlová, Lenka; Řeháková, Zuzana; Kanďár, RomanWith the aim to minimize the amount of biological material needed for analysis, a new type of sample preparation has been used for the determination of the percentage content of fatty acids in human blood. The blood samples from the volunteers (n = 30) were processed in two ways, as a plasma and as dried blood spot (DBS) samples. The fatty acids were firstly derivatized into the respective esters and, subsequently, separated and detected using gas chromatography (GC) with a flame ionization detector (FID). The results obtained from the DBS sample analysis were compared with those obtained by the established method for the determination of fatty acids in plasma.Článek Otevřený přístup peer-reviewedpublisher's version Extended release tablets containing co-processed dry binders and tramadol hydrochloride – determination of the content uniformity(University of Pardubice, 2017) Myslíková, Kateřina; Komersová, Alena; Lochař, Václav; Mužíková, JitkaAn automated method for the extended release tablet processing and determination of tramadol hydrochloride in matrix tablets containing coprocessed dry binders has been developed by using a bench-top robotic system connected with HPLC system. The automated operations include (i) disintegration steps of the dosage form, (ii) homogenisation, (iii) setting time, (iv) filtration, (v) dilution, and (vi) injection of a sample into the HPLC vials or chromatographic system. The method developed has been optimized and validated; recoveries of spike tests being found in the range of 97.8-99.6 %. The relative standard deviation representing the precision of the method was 1.02 % for tramadol hydrochloride in tablets with DisintequikTM MCC 25 and 1.15 % for tramadol hydrochloride in tablets with Prosolv® SMCC 90. The validated method was applied to the determination of the target substance in samples of two commercial pharmaceutical formulations: Tralgit SR 100 and Tramadol Retard Actavis 100 mg.Článek Otevřený přístup peer-reviewedpublisher's version The synthesis of Zn-Al hydrotalcites under different conditions and testing in aldol condensation(University of Pardubice, 2017) Hájek, Martin; Muck, Jáchym; Kozáček, Pavel; Kocík, Jaroslav; Lederer, Jaromír; Vávra, AlešThe Zn-Al hydrotalcites (materials with the layered structure) with constant molar ratio of Zn/Al 2:1 were synthesized by co-precipitation method under different reaction conditions, such as pH, the concentration of ions, temperature throughout co-precipitation, the intensity of stirring, etc. The mixed oxides were formed from hydrotalcites by calcination at 450 °C. All synthesized materials were characterized by X-ray diffraction, thermogravimetric analysis, and via the specific surface area. The influence of the synthesis conditions on the crystallite size and specific surface area were studied. The formation of hydrotalcites as well as mixed oxides was confirmed by X-ray diffraction. The mixed oxides chosen were rehydrated, which enabled to restore their layered structure. Both mixed oxides and rehydrated (mixed) oxides were tested in the aldol condensation of furfural, resulting in finding that the rehydration would decrease the conversion of furfural when using all the rehydrated mixed oxides.Článek Otevřený přístup peer-reviewedpublisher's version Crystallization in Sb0.5Se99.5 glass studied under and without protective atmosphere(University of Pardubice, 2017) Honcová, Pavla; Pilný, Petr; Stehlík, Stanislav; Košťál, PetrThe crystallization in a Sb0.5Se99.5 glass was studied by DSC method. The manipulation with amorphous samples was done under the protective atmosphere of argon and also without this protection, by simply exposing to the air. The obtained DSC traces as well as their kinetic characterization have shown that the atmosphere during the manipulation with amorphous material has significant influence on its crystallization behaviour.Článek Otevřený přístup peer-reviewedpublisher's version Preparation of zinc oxide nanoparticles for polymeric systems(University of Pardubice, 2017) Matysová, Edita; Cousy, Simon; Zelenka, Jiří; Svoboda, LadislavThe aim of the work was the synthesis of zinc oxide nanoparticles incorporated into water-based polymer systems together with assessment of their effect on the mechanical properties of the prepared nanocomposites. ZnO nanoparticles were prepared by basic precipitation of zinc salts in water. To ensure perfect compatibility with the polymeric systems and to control the particle size, the ZnO nanoparticle surface was modified by polymeric surfactants tailored for this purpose. ZnO particles were physically bonded to the water-based system via electrostatic interactions. All the composites have shown improved mechanical properties compared to the unmodified systems depending on the ZnO concentration in the water-based system.Článek Otevřený přístup peer-reviewedpublisher's version Primer or primer-free gluing: problems of adhesives in automotive industry(University of Pardubice, 2017) Prokůpek, Luboš; Večeřa, Miroslav; Machotová, JanaThe presented work aims at the comparison of physical and mechanical properties of commercially available black polyurethane adhesives designed for the glass bonding in automotive industry and at the assessment of adhesive systems with a primer. These adhesives require application and drying out of the appropriate polymer or a primer-free adhesive layer before bonding. UV stability is additionally measured in a view of the changing colours and mechanical properties.