Intermittent counter-current extraction (ICcE) has proved itself as a method for splitting compounds into streams and/or concentrating compounds in the column. In this paper a model mixture sample based on a modified GUESSmix (containing salicin, caffeine, aspirin, coumarin, salicylic acid, carvone, ionone and biphenyl) was separated into two eluant streams across a range of HEMWat phase system polarities from the polar system 11 through to non-polar system 23. ICcE could provide throughput of over 1 kg/day with this model sample, at the preparative scale, Changing the time cycle to adjust where the sample mixture is split into two streams was demonstrated. It is established that for the continuous running of ICcE, on a conventional twin bobbin counter-current chromatograph instrument, it is necessary to adjust the dead volumes of the flying leads to maintain similar phase retention in each column so the instrument does not become hydrodynamically and mechanically unbalanced due to the difference in densities between the upper and lower phases.
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http://dx.doi.org/10.1016/j.chroma.2011.03.072 | DOI Listing |
J Chromatogr A
August 2022
Kurnakov Institute of General & Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 31, Moscow 119991, Russia.
To improve the efficiency of countercurrent chromatography (CCC) separations, we have previously proposed a new sample loading method called intermittent sample loading (ISL), in which continuous sample feed alternates with short periods of "clean" mobile phase feed to the CCC device. In semi-continuous separation processes, during sample feed periods, the sample is loaded in separate batches, each consisting of a series of intermittent sample loads. It was shown that the application of the intermittent sample loading method in the conventional isocratic CCC separations significantly increased process productivity and the concentration of compounds in the separated fractions.
View Article and Find Full Text PDFJ Artif Organs
December 2022
Department of Applied Chemistry, Graduate School of Science and Engineering, Hosei University, 3-7-2, Kajino-cho, Koganei, Tokyo, 184-8584, Japan.
An infusion of dialysate into the blood compartment across the membrane using back filtration in dialysis therapy provides a stabilizing blood pressure and a membrane flushing during treatment. We devised a method to flush the membrane effectively and tried to find the optimum infusion patterns for intermittent infusion hemodiafiltration (I-HDF) from the aspect of solute removal by computing the pressure distribution in a diafilter. Bovine blood experiments were performed under following three modes: control HD in which no intentional filtration was involved, and two I-HDF in which back filtration was made either under counter current or under parallel flow.
View Article and Find Full Text PDFJ Chromatogr A
June 2021
Kurnakov Institute of General & Inorganic Chemistry, Russian Academy of Sciences, Leninsky Prospekt 31, Moscow 119991, Russia. Electronic address:
A new modification of the conventional multiple sample loading (MSL) mode - sequential sample loading (SSL) - is suggested to enhance further the performance of the counter-current chromatography (CCC) separation processes. The sequential sample loading technique is simple and easy to implement: the continuous sample solution supply to a CCC column is alternated (interrupted) with short periods of the "pure" mobile phase supply. Periodic (batch) and continuous SSL CCC separations can be designed and implemented.
View Article and Find Full Text PDFJ Chromatogr A
January 2021
Bioseparation Technology Laboratory, Biochemistry and Biophysics Center, NHLBI, National Institutes of Health, Bethesda, MD, USA.
An impurity in the color additives D&C Red No. 30 (R30) and D&C Red No. 30 lakes (R30L) was newly identified and characterized as 7-chloro-5-methyl-2H-1,4-benzothiazin-3(4H)-one (BTZ), and its extent and level in certified batches of these color additives was determined.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
November 2018
Laboratory of Bioseparation Technology, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda 20892, USA. Electronic address:
In our recent study, the design and performance of type-I counter-current chromatography (CCC) were changed and improved by multilayer coil. In the present study, the performance of protein separation using the multilayer coil configuration in type-I CCC was investigated under various flow rates. In order to overcome the noise signal interrupting the target peaks, a hollow fiber membrane dialyzer was inserted between CCC column outlet and inlet of the monitor.
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