Super/Subcritical Fluid Chromatography Separations with Four Synthetic Polymeric Chiral Stationary Phases

Abstract

New synthetic polymeric chiral selectors were developed recently as chiral stationary phases. They were tested with supercritical fluid mobile phases made of CO2 plus an alcohol modifier and 0.2% v/v trifluoroacetic acid. The polymeric N,N′-(1S,2S)-1,2-cyclohexanediyl-bis-2-propenamide (P-CAP), the polymeric N,N′-[(1R,2R)]-1,2-diphenyl-1,2-ethanediyl] bis-2-propenamide (P-CAP-DP), the polymeric trans-9,10-dihydro-9,10-ethanoanthracene-(11S,12S)-11,12-dicarboxylic acid bis-4-vinylphenylamide (DEABV) and the polymeric N,N′-[(1R,2R)-1,2-diphenyl-1,2-ethanediyl] bis-4-vinylbenzamide (DPEVB) were bonded to 5 μm silica particles and used to prepare four columns that were tested with a set of 88 chiral compounds with a wide variety of chemical functionalities. All 88 test compounds were separated on one or more of these “related” polymeric CSPs. Forty-three enantiomeric pairs were separated in SFC conditions by only one of the CSPs. Twenty pairs were separated by two CSPs and 18 and 7 enantiomeric pairs were separated by 3 and all 4 CSPs, respectively. The three P-CAP, P-CAP-DP and DEABV CSPs have equivalent success being able to separate 49 enantiomeric pairs of the studied set with respectively 12, 14 and 20 at baseline (Rs > 1.5). The DPEVB CSP was significantly less efficient separating only 18 chiral compounds with only one at baseline. The great advantage of the SFC mobile phases is the rapid separation, witch most achieved in less than 5 min.