Separation and Determination of Cold Medicine Ingredients by Capillary Zone Electrophoresis Using Sulfated [beta]-Cyclodextrin as an Electrolyte Modifier and Chiral Selector

Capillary zone electrophoretic separations of cold medicine ingredients, including acetaminophen (AC), dextromethorphan (DMF) and racemates of phenylpropanolamine (PPA) and chlorpheniramine maleate (CPM) using randomly sulfated-[beta]-CD (S-[beta]-CD) as an electrolyte modifier and a chiral selector were investigated. The results indicate that S-[beta]-CD is an excellent chiral selector and a suitable electrolyte modifier as well for the separation of those cold medicine ingredients. Influences of S-[beta]-CD concentration and buffer concentration on the separation were examined. Baseline separation of these cold medicine ingredients with 1.0% (w/v) S-[beta]-CD could be simultaneously and successfully achieved within 11.8 minutes. In addition, S-[beta]-CD could also act as a chiral selector for enantioseparation of PPA and CPM. A high enantioselectivity was obtained for these two analytes. Linear relationships between the peak area and its concentration for the calibration curves of AC and DMF were obtained (correlation coefficients: 0.9987 for AC, 0.9965 for DMF, respectively). The relative standard deviations of the migration time and peak area of AC and DMF were 0.19, 2.44% and 0.34, 2.99%, respectively. Detection limits were 0.93 and 2.57µg/mL for AC and DMF, respectively. Recoveries of AC and DMF ranging between 102.42 and 97.28% were observed. The proposed method was successfully applied to the determination of AC and DMF in cold medicines.