A novel technique for producing highly uniform structures from silica microspheres has been developed and tested. It is based on exploiting the temperature- and pressure-dependent solvent properties of sub/supercritical water toward silicon dioxide. The initial concept aimed to create a "hybrid" capillary chromatographic column on the border between a packed and a monolithic column that would combine the benefits of both. The resultant method that integrates dissolution and coalescence in a continuous process enabled the production of a range of permeable columns with high efficiency and varying sizes. Their internal structures were examined using scanning electron microscopy and characterized using microHPLC chromatography. The structures produced using this method may have diverse applications beyond the scope of analytical chemistry. They prove useful in scenarios where high pressure is necessary because of the high hydraulic resistance of small particles and/or the passing medium with a high flow rate. A simple test of a bridged-microsphere monolithic column and a discrete microsphere-packed column, both after chemical modification to the C18 stationary phase, indicated superior performance of the new type of monolithic columns.

• Klíčová slova
• close-packed bed, homogeneous three-dimensional structure, liquid chromatography, monolithic column, silica microspheres, supercritical water,
• Publikační typ
• časopisecké články MeSH

The properties of staphylococcal phages from the Siphoviridae, Podoviridae, and Myoviridae families were monitored using capillary electrophoretic methods on fused-silica capillaries with different morphology of surface roughness. Isoelectric points of the examined phages were determined by capillary isoelectric focusing in the original, smooth fused-silica capillary, and they ranged from 3.30 to 3.85. For capillary electrophoresis of phages, fused-silica capillaries with the "pock" and "cone" roughened surface types were prepared by etching a part of the capillary with supercritical water. The best resolution of the individual phages (to range from 3.2 to 4.6) was achieved with the "cone" surface-type fused-silica capillary. Direct application of phage K1/420 at the infection site, represented by human plasma or full blood spiked with Staphylococcus aureus, was on-line monitored by micellar electrokinetic chromatography. The phage particles were dynamically adhered onto the roughened surface of the capillary from 10 μL of the prepared sample at the optimized flow rate of 6.5 μL min-1. The limit of detection was determined to be 104 phage particles. The linearity of the calibration lines was characterized by the regression coefficient, R2 = 0.998. The relative standard deviation (RSD) of the peak area, calculated from ten independent measurements, was (±) 2%. After analysis, viability of the detected phages was verified by the modified "double-layer drop assay" method, and collected phage fractions were simultaneously off-line analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Graphical abstract.

• Klíčová slova
• Capillary electrophoresis, MALDI-TOF mass spectrometry, Nano-etched fused-silica capillary, Phage propagation, Staphylococcal bacteriophages, Supercritical water,
• MeSH
• bakteriofágy patogenita   MeSH
• lidé MeSH
• odběr vzorku krve přístrojové vybavení   MeSH
• oxid křemičitý chemie   MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• oxid křemičitý MeSH