Quantitative analysis and chromatographic fingerprinting for the quality evaluation of Scutellaria baicalensis Georgi using capillary electrophoresis

Quantitative analysis and chromatographic fingerprinting for the quality evaluation of a Chinese herb Scutellaria baicalensis Georgi using capillary electrophoresis (CE) technique was developed. The separation was performed with a 50.0 cm (42.0 cm to the detector window) × 75 μm i.d. fused-silica capillary, and the CE fingerprint condition was optimized using the combination of central composite design and multivariate analysis. The optimized buffer system containing 15 mM borate, 40 mM phosphate, 15 mM SDS, 15% (v/v) acetonitrile and 7.5% (v/v) 2-propanol was employed for the method development, and the baseline separation was achieved within 15 min. The determination of the major active components (Baicalin, Baicalein and Wogonin) was carried out using the optimized CE condition. Good linear relationships were provided over the investigated concentration ranges (the values of R(2): 0.9997 for Baicalin, 0.9992 for Baicalein, and 0.9983 for Wogonin, respectively). The average recoveries of these target components ranged between 96.1–105.6%, 98.6–105.2%, and 96.3–105.0%, respectively. CE fingerprints combined with the quantitative analysis can be used for the quality evaluation of S. baicalensis.