Robustness testing of chiral separations by capillary electrophoresis using highly-sulfated cyclodextrins

The robustness of a generic method for chiral separation in capillary electrophoresis using highly-sulfated cyclodextrins in a low pH phosphate buffer and the "short-end injection technique" was studied. In this study, we focused on the robustness of the separations and not of the quantitative analysis of the enantiomers. The robustness was evaluated for the enantiomeric separation of a basic (propranolol), a neutral (praziquantel) and an acidic (warfarin) compound. The influence of eight factors which were believed to affect significantly the separations was studied using a 11-factor, 12-experiment Plackett-design. Statistical interpretation of the factor effects on different analytical responses (selectivity and resolution) was performed. The separations of the three compounds could be considered as rather robust as the factor effects were generally not significant (alpha = 0.05) and small.