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The choice between capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) is not easy and depends on many factors. An attempt to facilitate this choice is this work, in which both techniques have been confronted on the basis of the RGB model, offering a transparent and pictorial way to compare individual parameters as well as the overall analytical potential of each tool. To ensure the universal nature of the comparison, a simple in composition and chemically diverse model sample was used, accompanied by the data processing method reducing the potential impact of analyte selection. Moreover, permanent coating of the inner surface of the capillary and addition of a surfactant to the separation buffer were considered as the additional factors that may affect the assessment of the CE technique. The presented analysis can be valuable in any discussions about the intrinsic advantages and disadvantages of CE and HPLC, and divagations on how they affect the overall potential and usability of each. We also provide access to the Excel worksheets used for the assessment, which can be easily modified to reevaluate the methods with a different selection of variables, and analyze other possible scenarios. [ABSTRACT FROM AUTHOR]

The design of novel stationary phases is a permanent demanding challenge in chromatographic and electrophoretic separation science to enable analysis with enhanced selectivity, specificity and speed. Therefore, the characterization of chemical and physical properties is next to calculation of chromatographic parameters essential. Conventionally, column performance is checked by a test run which only enables to prove efficiency column by column. Chemical parameters including surface coverage is normally analyzed by burning combustion or frontal analysis, physical parameters including particle size, pore size, pore volume and surface area by SEM, mercury intrusion porosimetry and Brunauer Emmett Teller. All these methods are extremely time consuming, invasive and require, beside special equipment, some specially trained lab staff. In order to enable a fast high-throughput control of chemical and physical parameters we introduced near-infrared spectroscopy (NIRS, 4,000-10,000 cm) as a non-invasive, easy-to-handle technology enabling simultaneous analysis within only a few seconds at higher precision than the conventional applied methods. The method is applicable to porous/non-porous silica gel, carbon-based nano-materials (e.g. fullerenes), polymer beads, monoliths for solid-phase extraction, liquid chromatography, micro-liquid chromatography, material-enhanced laser desorption ionization and coated capillaries for capillary electrophoresis and capillary electrochromatography. Different carriers themselves and their kind of chemical derivatization (reversed-phase, normal-phase, ion-exchanger, immobilized affinity chromatography, affinity, endcapping) can be determined by applying principal component analysis of spectra recorded. Partial least square regression enables the determination of physical parameters particle size, pore size, pore volume, porosity, total porosity and surface area with one single measurement in an established quantitative model. For a detailed investigation NIRS imaging, which benefits from the combination of a NIR spectrometer with a microscope, allows to analyze materials of interest with resolution down to 4 μm. For the optimized design of polymeric phases real-time in situ monitoring to control polymerization progress can be highly helpful. In this article, the advantages of this novel infrared-based method for the fast high-throughput quality control are introduced. [ABSTRACT FROM AUTHOR]

The performance of different capillary coatings and their ability to reduce peptide/wall interactions in capillary zone electrophoresis (CZE) was evaluated through the separations of standard peptides with PM ranging from 720 to 3500 and pl ranging from 3.0 to 11.5. The study was performed in acidic buffer with untreated fused silica capillary, poly(vinylalcohol) (PVA) modified capillary (generated in our laboratory by immobilization with thermal treatment of a PVA solution) and polybrene coated capillary. PVA and polybrene modified capillaries were shown to produce higher reproducibilities for migration times and superior efficiencies in comparison to the uncoated capillary. Peak efficiencies of acidic peptides were 300000 to 650000 (N/m) with polybrene capillary coating while PVA coating produced high efficiencies (N/m>330000) for the most basic peptides. An efficient peptide mapping of the β-lactoglobulin was obtained in less than 20 min using the polybrene coating. Attempts to separate the peptide digest from a deglycosylated form of the rgp 160, a very complex and heterogeneous HIV envelope glycoprotein, were not fully satisfactory but the results demonstrate the potential of capillary surface treatment in producing peptide maps. [ABSTRACT FROM AUTHOR]