Simultaneous Determination of 4 Flavonoids in Scutellaria Baicalensis Extract by UHPLC-MS/MS

Water was added in the sample of Scutellaria baicalensis extract. The mixture was extracted twice with methanol ultrasonically. after centrifugation, the combined supernatant was made up to 50.0 mL with water. The solution was filtered on 0.22 μm microporous membrane. UHPLC-MS/MS was applied to the simultaneous determination of 4 flavonoids, i.e. baicalein,baicalin,oroxindin and scutellarin in the filtrate. ACQUITY UPLC HSS T3 chromatographic column was used as stationary phase, and the mixture of 0.01% (mass fraction) ammonia and acetonitrile mixed in different ratios was used as mobile phase in gradient elution. ESI^- and multi-reactions monitor mode were adopted in MS/MS. Linear relationships between response values of mass spectrometry and mass concentration of the 4 flavonoids were kept in the same range of 5.0-500.0 μg·L^-1, with detection limits (3S/N) in the range of 0.3-1.5 μg·kg^-1 and lower limits of determination (10S/N) in the range of 1.0-5.0 μg·kg^-1. On the base of blank sample of Scutellaria baicalensis extract, test for recovery was made by standard addition method; values of recovery found were in the range of 91.1%- 99.1%, with RSDs (n=6) of determined values in the range of 2.0%-4.1%.