Isotherm selection for band profile simulations in preparative chromatography

Abstract

Equilibrium adsorption data for the N-benzoyl derivatives of D-and L-

A closer study of chiral retention mechanisms

“…e., b 1,I = b 2,I and q 1,I,s = q 2,I,s ), one of the two contributions obtained is nearly the same for the two enantiomers. 8,9,30 This contribution corresponds to the nonselective type-I sites, as demonstrated by the numerical values of the coefficients. This result validates the assumption that it is the other contribution that accounts for the chiral recognition mechanism.…”

“…Note that the reliability of the isotherm is verified by the excellent agreement between measured and calculated band profiles. [7][8][9]24,26,[30][31][32][33][34][35][36] The two Langmuir contributions correspond, respectively, to the enantioselective and the nonselective interactions. If the data are fitted to the set of Eqs.…”

“…This explains why some workers have been able to derive wrong conclusions. 29 Using this procedure, we studied the separation of several pairs of enantiomers: N-benzoyl derivatives of several amino acids and methyl mandelate on immobilized BSA, 6,30,31 ketoprofen and methyl mandelate on an immobilized cellulose derivative; 7,32 Tröger's base on microcrystalline cellulose triacetate; [33][34][35][36] and propranolol on cellobiohydrolase I (CBH I), a protein bonded to silica. 9,24 Only in the case of Tröger's base was it not possible to resolve the two contributions, because the more retained S-isomer has an S-shaped isotherm while the R-isomer follows Langmuir adsorption behavior.…”

Separation of enantiomers of a chiral epoxide by simulated moving bed chromatography

“…Hence, response curves to a step change in feed concenchiral stationary phases provide two types of adtration (adsorption) followed by the desorption of the sorption sites: one responsible for non-selective column with pure eluent. A complete description of achiral interactions, the other for chiral selective these and other methods of adsorption isotherms interactions between the enantiomers and the stationmeasurements with applications to preparative chroary phase [42,43,48]. matography can be found in Seidel-Morgenstern and Racemic (50%) and 90% pure solutions were used Nicoud [47].…”

Packing materials for enantioselective preparative chromatography

“…There has been little work on the determination of competitive adsorption isotherms in enantioselective separations. One paper in this area considered the p rep a rat ive sep a ration of the enantiomers of N-benzoylphenylalanine on a protein-based CSP [5]. This separation was shown to be well represented by a bi-Langmuir isotherm.…”