Counter-current Chromatography Liquid Research Articles

Determination of chlorophenols in red wine using ionic liquid countercurrent chromatography as a new pretreatment method followed by high-performance liquid chromatography.

A countercurrent chromatography method for the enrichment and cleanup of chlorophenols from food samples was successfully established by using an ionic-liquid-modified two-phase solvent system composed of dichloromethane containing 2% 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide and water. The column was firstly filled with the organic stationary phase, and then a large volume of sample was pumped into the column after it was equilibrated with pure water at the rotation speed. Finally, the trace amounts of chlorophenols extracted and enriched in the stationary phase were eluted out by an alkaline mobile phase and determined by high-performance liquid chromatography. Under optimized conditions, the enrichment and cleanup of the chlorophenols can be fulfilled online with enrichment factors (34-65) and high recoveries (84.69-95.23%). The method has been applied to the determination of chlorophenols in real red wine samples with the limits of detection in the range of 1.89-4.21 μg/L. The present method is highly suitable for the pretreatment of large volume of aqueous sample for the determination of trace amounts of contaminants in food and environmental samples.

Pulsed cyclic device for liquid countercurrent chromatography

A new apparatus for the chromatographic separation of liquid mixtures is investigated. The apparatus contains a number of vertical columns connected in a serpentine shape and consisting of cells placed on top of each other. The cells in the columns are separated by perforated septa. A special dosing unit is used to provide a discrete (cyclic) mobile-phase feed [flow?] into the apparatus and a pulsed cyclic mode of phase contact in column cells. Studies on a single column and on an apparatus consisting of four columns have been performed to assess the efficiency of the pulsed cyclic device. The results of experimental investigations have confirmed the potential of the newly developed topic in the area of liquid mixture separation processes.

Liquid countercurrent chromatography: A new approach to creating a concentration gradient in the stationary phase

The capability of dynamic phase mixing in a two-phase liquid system in a rotating coiled column, which is used to separate substances in liquid countercurrent chromatography, was studied. The effects of the hydrodynamic conditions of the chromatographic process and the physicochemical properties of the two-phase liquid systems now in use on the efficiency of phase mixing in a rotating coiled column were found. A new approach to creating a concentration gradient in the stationary phase was proposed. The following three modes of mixing stationary-phase regions within a column were found: the formation of a stable reagent concentration gradient within the rotating coiled column, the slow mixing of zones, and the complete mixing of zones.

The Efficiency of Substance Separation in Countercurrent Liquid Chromatography

The effect of hydrodynamic parameters and the specific features of instrument design on the efficiency of substance separation in countercurrent liquid chromatography (CCC) was studied using a constant retention factor of the stationary phase in the column. The study was conducted with the separation of benzyl alcohol and p-cresol in a two-phase liquid system heptane–ethyl acetate–methanol–water (1.4 : 0.6 : 1 : 1) in as an example. It was shown that the peak resolution is improved with an increase in the rotational speed of the column and a decrease in the flow rate of the mobile phase. The best peak separation was attained using columns for which the ratio of the column rotation radius to the radius of column revolution was 0.615. It was shown that countercurrent chromatography allows the separation of substances with low partition constants (K < 1) in dilute solutions. The volume of the test sample may be up to 15% of the total volume of the chromatography column.

Optimum liquid and solid-phase velocity for minimum shock layer thickness in counter-current chromatography

The shock-layer theory is applied to counter-current liquid chromatography, in the single-component case. This model uses a Langmuir isotherm to account for nonlinear effects, a finite axial dispersion coefficient and a linear driving force (LDF) kinetics to account for the nonideal effects, e.g., the axial dispersion and the mass transfer resistance. The shock-layer velocity and its thickness are explicitly formulated in closed forms. Based on these expressions, the optimum velocities of the solid and liquid phases are derived for minimum shock-layer thickness.

Purification of specific restriction fragments of human deoxyribonucleic acid by using liquid countercurrent chromatography [proceedings

Conference Article| April 01 1980 Purification of specific restriction fragments of human deoxyribonucleic acid by using liquid countercurrent chromatography ROBERT ELLES; ROBERT ELLES 1Department of Biochemistry, St. Mary's Hospital Medical School, Norfolk Place, London W2 1PG, U.K. Search for other works by this author on: This Site PubMed Google Scholar IAN SUTHERLAND IAN SUTHERLAND 2Department of Mechanical Engineering, National Institute for Medical Research, Mill Hill, London NW7 1AA, U.K. Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1980) 8 (2): 173. https://doi.org/10.1042/bst0080173 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share MailTo Twitter LinkedIn Cite Icon Cite Get Permissions Citation ROBERT ELLES, IAN SUTHERLAND; Purification of specific restriction fragments of human deoxyribonucleic acid by using liquid countercurrent chromatography. Biochem Soc Trans 1 April 1980; 8 (2): 173. doi: https://doi.org/10.1042/bst0080173 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1980 Biochemical Society1980 Article PDF first page preview Close Modal You do not currently have access to this content.