Determination of 5 Kinds of Flavonoids in Scutellaria baicalensis by HPLC

OBJECTIVE: To establish an HPLC method for the determination of the contents of 5 kinds of flavonoids in Scutellaria baicalensis and quality analysis of these from 15 retail drug stores in Tianjin. METHODS: The separation was performed on Agilent Zorbax SB-C18 column (150 mm×4.6 mm,5 μm) with mobile phase consisted of 0.1% formic acid acetonitrile-water (gradient elution). The detection wavelength was set at 278 nm. RESULTS: The linear range were 0.085～2.727μg for baicalin (r=0.999 9),0.021～0.672 μg for wogonoside(r=0.999 9), 0.037～1.181μg for baicalein(r=0.999 9), 0.016～0.504 μg for wogonin (r=0.999 3) and 0.006～0.185 μg for oroxylin A(r=0.999 7). The average recoveries were 102.5%(RSD=2.63%),97.09%(RSD=2.49%), 102.1%(RSD=2.87%), 97.5%(RSD=2.41%) and 100.4%(RSD=2.86%),respectively(n=6). CONCLUSION: This method is simple, accurate and reproducible for the quality control of S. baicalensis.