Using the liquid nature of the stationary phase. VI. Theoretical study of multi-dual mode countercurrent chromatography

Modeling of closed-loop recycling liquid–liquid chromatography: Analytical solutions and model analysis

“…(12), represents the inverse value of the dimensionless solute retention time for the first cycle. Here, it has also another physical meaning, namely, it is equal to the dimensionless concentration in the mobile phase after achieving the uniform distribution of the solute in the loop.…”

“…The mobility of both phases in CCC allows the implementing of cyclic dual-mode counter-current processes, in which the CCC separation consists of a succession of two isocratic counter-current steps and is carried out in series alternating between normal phase and reversed phase operation, each phase eluting alternately through the opposite ends of the column [3][4][5][6][7][8][9][10][11][12][13][14]. The sample is fed at the beginning [8,[10][11][12][13][14] or into the middle section [3][4][5][6][7] of a column and moves forward and back with the phases inside the column. This shuttle movement of the sample actually corresponds to an increase in length of the column, which requires no increase in the column inlet pressure.…”

Steady state preparative multiple dual mode counter-current chromatography: Productivity and selectivity. Theory and experimental verification

“…(14) describes the distribution of the solute in the column after the second step of the current cycle j. Eq. (15) describes the elution profile in the "y" phase for the current cycle j.…”

“…[14,21]. Analytical solutions for MDM separations were presented, where the timing of the alternating phase elution steps can be adjusted [23].…”

“…A general and distinctive feature of counter-current chromatography (CCC) separation processes is the mobility of both phases [1][2][3][4][5][6][7][8], which allowed to develop and implement various dual-mode (DM) operating schemes, where both phases are countercurrently moving through a chromatographic column [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. As is well known, the separation power of the countercurrent processes is much higher than that of conventional chromatography processes, as they require a much smaller number of theoretical plates to solve separation problems.…”