Relationship between the flow-rate of the mobile phase and retention of the stationary phase in counter-current chromatography

Preparative isolation and purification of atractylon and atractylenolide III from the Chinese medicinal plantAtractylodes macrocephala by high-speed counter-current chromatography

“…Du et al [16], Sutherland [17], and Booth and Sutherland [18] have also shown the linear relationship between S f and F 0.5 in the countercurrent chromatography. Considering that a higher flow rate results in a lower S f and a lower flow rate results in a longer elution time, a flow rate of 5 mL/min was adopted, where S f and the elution time are both reasonable.…”

Sequential Centrifugal Partition Chromatography: A New Continuous Chromatographic Technology

“…This means that the stationary phase retention, in ascending step and in descending step, should be 0.5. In general, the stationary phase retention is a function of the physical properties of the biphasic liquid system, the column geometry and material, the flow rate of the mobile phase, the centrifugal force (rotor rotation speed) and the operating mode (ascending or descending) [9][10][11][12]. The selected solvent system 14 shows an adequate density difference of the two phases (0.14 g cm -3 at 25°C) and a short settling time of 21 s at 25°C (data measured in our laboratory).…”

Behavior of Oil–Aqueous Solution Systems in Rotating Coil Column

“…Then the planetary centrifuge is set to rotate and the mobile phase (oil or diesel) was pumped through the column. Optimal elution mode when the lighter phase is pumped from tail to head was shown for amount of biphasic organic systems [5][6][7][8][9][10][11][12][13][14][15][16]. The acid solution is retained in a hydrodynamic column due to a complex centrifugal field while the mobile oil phase was pumped through the column.…”

“…It should be mentioned that the influence of coil planet centrifuge parameters and operating conditions on the stationary phase retention are rather well studied for two-phase liquid systems used for organic and inorganic separations. A number of papers, describing the influence of the physicochemical parameters of two-phase liquid systems (interfacial tension, polarity of solvents, difference in the densities and viscosities of the phases, time of phase separation, and the length of capillary waves at the phase boundary) on the retention of the stationary phase in a column, have been published [5][6][7][8][9][10][11][12][13][14][15][16]. So far, stationary aqueous phase retention in oil-aqueous solution systems has not been investigated.…”