Abstract: A rapid reversedphase high performance liquid chromatography method was developed for the simultaneous determination of 4 flavonoids,namely baicalin,wogonoside,baicalein and wogonin.The chromatographic separation was performed on an Agilent TC-C₁₈ column(250×4.6 mm,5.0 μm)with 0.4% phosphoric acid(A)and methanol(B)as mobile phases.The gradient elution program was as follows:0-10 min,40%-50%B;10-20 min,50%B;20-30 min,50%-60%B;30-40min,60%-80% B;40-50 min,80%B.The detection wavelength was set at 280 nm.Under the developed HPLC method,the ionic liquid-based microwaveassisted extraction(IL-MAE)of 4 flavonoids from Scutellariae Radix slices was optimized.The optimal IL-MAE conditions were determined as follows:1.0 M 1-butyl-3-Methylimidazolium bromide(［C₄ min］Br)employed as extractant,the ratio of solid to liquid was 1:100,extracting for 3 min,the microwave power was 264 W.Compared with traditional solvent reflux extraction(SRE)recorded in Chinese pharmacopoeia(2010 edition),IL-MAE significantly improved the extraction yields of 4 flavonoids and shortened the extraction duration(from 3 h to 3 min).In conclusion,the developed HPLC method was sensitive,accurate,specific,and applicable for the quality control of Scutellariae Radix slices,and the optimized IL-MAE method was a simple,efficient,rapid,and green extraction technique.

Key words: Scutellariae Radix slices, ionic liquid, microwave-assisted extraction, high performance liquid chromatography, flavonoids