Chemometric method to optimize chiral separation of imidazole derivatives by capillary electrophoresis

A chemometric methodology was proposed to optimize the migration time, height equivalent to a theoretical plate and separation of a mixture of a series of imidazole compounds by capillary electrophoresis. The optimization process was based on a special polynomial from 9 or 18 preliminary experiments. This method connects a general simplex method to a computer. A simplex two or three optimization–capillary electrophoresis (STO-CE) method has been developed in our laboratory. The most efficient separation was achieved with acetonitrile–phosphate buffer, pH 4.70, (5.30+94.70 (v/v)) with a β-cyclodextrin concentration in the background electrolyte equal to 5.80 mM and a capillary temperature of 35°C. Similar results were obtained using simple step-wise scanning. The higher relative difference obtained for these values with these two methods (simplex and step-wise scanning) was 5% for the β-cyclodextrin concentration factor.