Evaluation of the performance of commercially available polysaccharide-based chiral stationary phases after multicycle operation in multimodal elution mode

The performance of four commercially available polysaccharide-based chiral stationary phases, Chiralcel OD, Chiralcel OJ, Chiralpak AD and Chiralpak AS was evaluated after several cycles of extended multimodal operations. Acetonitrile, methanol, ethanol and their mixtures were chosen for polar-organic mobile phases, ethanol-n-heptane mixture and n-heptane were selected for normal-phase mode. Retention factor (k), selectivity (α), resolution (Rs) and theoretical plate count (N) were the chosen parameters to describe the column performance. One racemate for which all four columns have shown enantioselectivity was chosen as test compound. After 15 cycles of multimodal operations a slight decrease was seen in the retention factors (k) however, column efficiency, selectivity (α) and resolution (Rs) were maintained.