Wide-bore hydrodynamic chromatography (HDC) is a very simple method based on the passage of analytes through an open capillary. As shown in previous papers, an analyte, which diffuses over the entire cross-section of a capillary before it is detected, gives a Gaussian-shaped peak; such an analyte is called diffusive. In contrast, an analyte with poor diffusivity gives an asymmetrical peak with the apex at the half time of the peak of a diffusive analyte. Their diffusivity is determined by the diffusion coefficients, dimensions of a capillary, and a flow rate. A consideration of the diffusivity evaluated on the basis of these variables allows us to realize fast wide-bore HDC separation. Sub-second separation is demonstrated using test analytes, such as fluorescein and polystyrene latexes.
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http://dx.doi.org/10.1002/jssc.200800504 | DOI Listing |
Int J Mol Sci
September 2020
Department of Analytical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská Dolina CH2, Ilkovičova 6, SK-84215 Bratislava, Slovakia.
Several research disciplines require fast, reliable and highly automated determination of pharmaceutically active compounds and their enantiomers in complex biological matrices. To address some of the challenges of Capillary Electrophoresis (CE), such as low concentration sensitivity and performance degradation linked to the adsorption and interference of matrix components, CE in a hydrodynamically closed system was evaluated using the model compounds Pindolol and Propranolol. Some established validation parameters such as repeatability of injection efficiency, resolution and sensitivity were used to assess its performance, and it was found to be broadly identical to that of hydrodynamically opened systems.
View Article and Find Full Text PDFElectrophoresis
August 2013
Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Moscow, Russia.
A new approach based on the effect of pressure in CZE is suggested for acceleration of particle migration in electrophoretic runs resulting in reduction of the analysis time. It provides conditions for studying fast processes in suspensions. The effect of pressure on the migration of silica spheres with average diameters of 100, 150, and 390 nm was studied by CZE at an applied voltage of 25 kV.
View Article and Find Full Text PDFAnal Sci
August 2012
Department of Chemistry, Tokyo Institute of Technology, Tokyo, Japan.
Wide-bore capillary hydrodynamic chromatography (W-HDC) resolves analytes on the basis of a difference in the extent of radial diffusion simply by their passage through an empty capillary. The combination of this method with ICP-MS proves efficient for the evaluation of the interaction of metal ions with molecular aggregates. Lecithin vesicles are suitable molecular aggregates for the uptake of the lanthanide ions in the presence of the first row transition metal ions, suggesting that the present method is applicable to the screening of the molecular aggregate system suitable for selective extraction of a particular targeted small molecule.
View Article and Find Full Text PDFJ Chromatogr A
March 2011
Analytical Chemistry Group, Faculty of Science, van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
Ultra-high-pressure liquid chromatography (UHPLC) has great potential for the separations of both small molecules and polymers. However, the implementation of UHPLC for the analysis of macromolecules invokes several problems. First, to provide information on the molecular-weight distribution of a polymer, size-exclusion (SEC) columns with specific pore sizes are needed.
View Article and Find Full Text PDFEmerg Med J
March 2011
Emergency Department, Ninewells Hospital, Dundee DD1 9SY, UK.
Aim: To compare the flow rates of readily available intravenous infusion devices and to compare the effect of the addition of pressure or a needle-free intravenous connector device.
Methods: Several intravenous devices with different characteristics had their flow rates determined under a standard set of conditions. The flow rates were then measured with the addition of a pressure bag to the system and then with a needle-free intravenous connector device.
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