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Characterization of atmospheric particulate matter by diffusive gradient in thin film (DGT) technique
Gregušová, Michaela ; Dočekal, Bohumil
In this study, characteristics of heavy metal contamination in road dust collected from urban area with heavy traffic in Brno, Czech Republic was investigated. The DGT probes were exposed in aqueous suspensions of particulate matter for different time periods to monitor responses of the sample matter. The road dust and DGT sorption gels were decomposed by microwave assisted extraction and analyzed by inductively coupled plasma mass spectrometry for estimation of trace metals contents. The results revealed that the traffic appears to be responsible for the high levels of Cu, Pb, Ni and Sb and also that DGT technique, as alternative to conventional extraction procedures is a useful tool for characterization of metals mobility.
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Photolithographic technique for controlled fabrication of metal structures
Jusková, Petra ; Hegrová, Jitka ; Foret, František
We are describing two strategies for controlled (geometry and dimension) preparation of metal micro-nano structures. Both techniques are based on photolithographic processes with selective pattern transfer. First technique utilizes agarose gel containing photosensitive silver chloride as the photosensitive layer. Silver structures are formed after irradiation of the gel through the photolithographic mask which defines shape of the resulting structures. Second approach utilizes photolithographic process to form particles from vacuum deposited thin metal layer deposited over soluble sacrificial layer.
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Iron oxide nanoparticle modified monolithic pipette tips for selective enrichment of phosphopeptides
Křenková, Jana ; Foret, František
We have developed iron oxide nanoparticle modified monolithic pipette tips for selective and efficient enrichment of phosphopeptides. Iron oxide nanoparticles were synthesized using a co-precipitation method and stabilized by citrate ions. A stable coating of nanoparticles was obtained via multivalent interactions of citrate ions on the nanoparticle surface with a quaternary amine functionalized surface of the methacrylate based monolithic tips. The performance of the developed and commercially available tips was demonstrated with the enrichment of phosphorylated peptides from tryptic digests of caseins followed by MALDI/MS detection.
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Silica-based monolithic capillary columns modified to zwitterionic stationary phase for hydrophilic interaction liquid chromatography
Moravcová, Dana ; Planeta, Josef ; Kahle, Vladislav ; Horká, Marie ; Roth, Michal
Zwitterionic monolithic capillary columns intended for isocratic gradient hydrophilic interaction chromatography (HILIC) separations are introduced. Silica-based capillary columns (150 mm x 0.1 mm) were prepared by acidic hydrolysis of tetramethoxysilane in the presence of polyethylene glycol and urea. The modification by a 3-(trimethoxysilyl)propyl methacrylate and then by a zwitterionic [2-(methacryloyloxy)ethyl]-dimethyl-(3-sulfopropyl)-ammonium hydroxide to HILIC stationary phase bearing sulfoalkylbetaine groups on its surface followed. Prepared columns were characterized in HILIC separation mode employing mobile phase containing 10% (v/v) of 5 mM ammonium acetate pH = 4.5 in acetonitrile. Comparison with the commercially available ZIC-HILIC® column (Merck SeQuant®) under the same separation conditions using a mixture of aromatic carboxylic acids as a sample was done on the basis of separation efficiency of tested columns as well as retention factors and peak asymmetry of individual solutes.
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Micropreparative solution isoelectric focusing of peptides and proteins in nonwoven strip
Duša, Filip ; Šlais, Karel
Recently we devised a new instrument for micropreparative analysis [1]. It is based on solution phase isoelectric focusing (sIEF) performed in a narrow channel (approximately 2 – 4 mm wide) with a strip of nonwoven fabric serving as the analysis bed. The strip can be precut before an analysis to make harvesting of fractions easier. Isoelectric focusing is driven by a programmable electrophoretic power supply. Progress of analysis is monitored by addition of colored isoelectric point (pI) markers. Usually sIEF runs are performed overnight. Evaporation of water is one of crucial features of analysis and it forces free liquid to shrink into the nonwoven fabric strip. Moreover, water evaporation increases liquid viscosity by altering ethylene glycol/water ratio. Fractions can be harvested simply by collecting and washing precut segments after the sIEF run. In this paper we used sIEF device for purification of caseinomacropeptide (CMP) from crude whey. Obtained fractions were further analyzed by HPLC. From acquired data a plot with chromatograms of all fractions was constructed to show purification profile of CMP. We proved that the new instrument is capable of quantitative purification of CMP complex from a globulin fraction.
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