Václav Kašička

Recent developments in CE and CEC of peptides

The article brings a comprehensive survey of recent developments and applications of high‐performance capillary electromigration methods, zone electrophoresis, ITP, IEF, affinity electrophoresis, EKC, and electrochromatography, to analysis, preparation, and physicochemical characterization of peptides. New approaches to the theoretical description and experimental verification of electromigration behavior of peptides and to methodology of their separations, such as sample preparation, adsorption suppression, and detection, are presented. Novel developments in individual CE and CEC modes are shown and several types of their applications to peptide analysis are presented: conventional qualitative and quantitative analysis, purity control, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of CE and CEC techniques to provide important physicochemical characteristics of peptides are demonstrated.

Capillary electrophoresis of peptides

This article gives a review of the recent developments in capillary electrophoresis (CE) of peptides. New approaches to the theoretical description of electromigration behavior of peptides are described, and methodological aspects of CE separations of peptides such as selection of separation conditions, sample treatment, suppression of peptide adsorption to the capillary wall and specificities of CE separation modes are discussed. Progress in application of high performance detection schemes, namely laser‐induced fluorescence and mass spectrometry, in peptide separations by CE is presented. Applications of different CE techniques, zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography and electrochromatography to peptide analysis, preparation and physicochemical characterization are demonstrated.

Recent developments in CE and CEC of peptides (2009-2011).

The review brings a comprehensive survey of the recent developments of high‐performance electroseparation methods in capillary and microchip formats: zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography and electrochromatography. Applications of these techniques to analysis, isolation, purification and physicochemical and biochemical characterization of peptides are described. Advances in the investigation of electromigration properties of peptides, and in the methodology of their analysis, such as sample preparation, adsorption suppression, EOF control and detection, are presented. New developments, in particular, CE and CEC modes are reported and several types of their applications to peptide analysis are described: conventional qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence and chiral analysis, and peptide mapping of proteins. Some micropreparative peptide separations are shown and capabilities of CE and CEC techniques to provide relevant physicochemical characteristics of peptides are demonstrated.

Application of gold nanoparticles in separation sciences

The review article is devoted mainly to the description of applications of gold nanoparticles (GNPs) in separation sciences, especially in electromigration and chromatographic techniques. The applications of GNPs in particular separation methods, CE, microchip CE, MEKC, CEC, HPLC and GC, are classified according to the molecular size of the analytes from low-molecular-mass compounds via medium sized substances to biopolymers (proteins and nucleic acids). A very recent and promising utilization of GNPs for sample preparation, preconcentration and preseparation of selected analytes from complex matrices is presented as well. Moreover, in two introductory sections, typical preparation procedures of the GNPs and their modifications are presented and physico-chemical and analytical methods employed for characterization of the native and modified GNPs are briefly introduced.

Recent advances in CE and CEC of peptides (2007–2009)

The review presents a comprehensive survey of recent developments of high‐performance capillary electromigration methods, zone electrophoresis, ITP, IEF, affinity electrophoresis, EKC and electrochromatography, and their application to analysis, preparation and physicochemical characterization of peptides. New approaches to the theoretical description and experimental investigation of electromigration properties of peptides, and to methodology of their separations, such as sample preparation, adsorption suppression, EOF control and detection, are described. New developments in particular CE and CEC modes are reported and several types of their applications to peptide analysis are presented: conventional qualitative and quantitative analysis, determination in biomatrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid and sequence analysis, and peptide mapping of proteins. Few examples of micropreparative peptide separations are shown and capabilities of CE and CEC techniques to provide important physicochemical characteristics of peptides are demonstrated.

Recent developments in capillary and microchip electroseparations of peptides (2013–middle 2015)

The review brings a comprehensive survey of recent developments and applications of high performance capillary and microchip electroseparation methods (zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography, and electrochromatography) to analysis, micropreparation, purification, and physicochemical and biochemical characterization of peptides in the years 2013, 2014, and ca. up to the middle of 2015. Advances in the investigation of electromigration properties of peptides, in the methodology of their analysis, including sample preseparation, preconcentration and derivatization, adsorption suppression and EOF control, as well as in detection of peptides, are described. New developments in particular CE and CEC modes are presented and several types of their applications to peptide analysis are reported: conventional qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence, and chiral analysis, and peptide mapping of proteins. Some micropreparative peptide separations are shown and capabilities of CE and CEC techniques to provide important physicochemical characteristics of peptides are demonstrated.

Recent advances in capillary electrophoresis of peptides.

The article gives a comprehensive review on the recent developments in the applications of high‐performance capillary electromigration methods, including zone electrophoresis, isotachophoresis, isoelectric focusing, affinity electrophoresis, electrokinetic chromatography and electrochromatography, to analysis, preparation and physicochemical characterization of peptides. The article presents new approaches to the theoretical description and experimental verification of electromigration behavior of peptides, and covers the methodological aspects of capillary electroseparations of peptides, such as strategy and rules for the rational selection of separation mode and experimental conditions, sample treatment, suppression of peptide adsorption to the inner capillary wall, new developments in individual separation modes and new designs of detection systems. Several types of applications of capillary electromigration methods to peptide analysis are presented: conventional qualitative and quantitative analysis for determination of purity, determination in biomatrices, monitoring of physical and chemical changes and enzymatic conversions, amino acid and sequence analysis and peptide mapping of proteins. Some examples of micropreparative peptide separations are given and capabilities of capillary electromigration techniques to provide important physicochemical characteristics of peptides are demonstrated.

Recent developments in capillary and microchip electroseparations of peptides (2013-middle 2015): CE and CEC

The review presents a comprehensive survey of recent developments and applications of capillary and microchip electroseparation methods (zone electrophoresis, ITP, IEF, affinity electrophoresis, EKC, and electrochromatography) for analysis, isolation, purification, and physicochemical and biochemical characterization of peptides. Advances in the investigation of electromigration properties of peptides, in the methodology of their analysis, including sample preseparation, preconcentration and derivatization, adsorption suppression and EOF control, as well as in detection of peptides, are presented. New developments in particular CE and CEC modes are reported and several types of their applications to peptide analysis are described: conventional qualitative and quantitative analysis, determination in complex (bio)matrices, monitoring of chemical and enzymatical reactions and physical changes, amino acid, sequence and chiral analysis, and peptide mapping of proteins. Some micropreparative peptide separations are shown and capabilities of CE and CEC techniques to provide relevant physicochemical characteristics of peptides are demonstrated.

Theory of the correlation between capillary and free-flow zone electrophoresis and its use for the conversion of analytical capillary separations to continuous free-flow preparative processes. Application to analysis and preparation of fragments of insulin.

A basic theoretical description of the correlation between capillary zone electrophoresis (CZE) and free-flow zone electrophoresis (FFZE) is presented. The theory of the correlation between CZE and FFZE results from the fact that both methods are based on the same separation principle, zone electrophoresis, and both are performed in the carrierless separation medium with the same composition of the background electrolyte. The equations describing the movement of the charged and noncharged particles in the d.c. electric field applied in the capillary and in the flow-through electrophoretic chamber are presented and used for the quantitative description of the correlation between CZE and FFZE. Based on the theory of the correlation between CZE and FFZE a procedure has been developed for conversion of analytical, microscale CZE separations into continuous preparative separation processes realized by FFZE. Practical application of the developed procedure is demonstrated by CZE analysis and FFZE preparation of an octapeptide fragment of human insulin.

Capillary zone electrophoresis with electroosmotic flow controlled by external radial electric field.

A new way of regulation of electroosmotic flow (EOF) in capillary zone electrophoresis (CZE) by external electric field has been developed. A set of three high‐voltage power supplies is used to form a radial electric field across the capillary wall. One power supply is applied in the usual way as a driving force of CZE and EOF to the ends of the inner capillary compartment dipped into the electrode vessels and filled with background electrolyte. Two power supplies are connected to the ends of the outer low‐conductivity coating of the capillary which is formed by the dispersion of copolymer of aniline and p‐phenylenediamine in polystyrene matrix. The difference between electric potentials on the outer capillary surface and inside the capillary determines the voltage of radial electric field across the capillary wall and affects the electrokinetic potential at the solid‐liquid interface inside the capillary. The effect of magnitude and polarity of external radial electric field on the flow rate of EOF, on the migration times of charged analytes and on the separation efficiency and resolution of CZE separations of synthetic oligopeptides, diglycine, triglycine and octapeptide fragments of human insulin was evaluated. Through the EOF control by external electric field the dynamic effective length of the capillary was obtained and the speed of analysis and resolution of CZE separations of peptide analytes could be optimized.