Simultaneous determination of eight active components in Chinese medicine 'YIQING' capsule using high-performance liquid chromatography.

An effective, accurate and reliable method for the simultaneous separation and determination of eight active components (berberine, aloe-emodin, rhein, emodin, chrysophanol, baicalin, baicalein and wogonin) in Chinese medicine 'YIQING' capsule was developed using reverse phase high-performance liquid chromatography (RP-HPLC) coupled with diode array detection. The chromatographic separation was performed on a Lichrospher C18 column (250 mm x 4.6 mm i.d. with 5.0 microm particle size) with a simple linear gradient elution programme. Due to the different UV characteristic of these components, three detection wavelengths were utilized for the quantitative analysis (UV wavelength 254 nm for anthraquinone derivatives, 278 nm for flavones compounds, and 345 nm for protoberberine alkaloids, respectively). Excellent linear behaviors over the investigated concentration ranges were observed with the values of R2 higher than 0.99 for all the analytes. The recoveries, measured at three concentration levels, varied from 94.9% to 105.3%. The validated method was successfully applied to the simultaneously determination of these active components in 'YIQING' capsules from different production batches.