OBJECTIVETo develop an HPLC-electrochemical detection (HPLC-ECD) method for determination of contents of three effective ingredients baicalin, baicalein and wogonin in Scutellaria baicalensis simultaneously.

METHOD70% ethanol extract of S. baicalensis was separated on a Kromasil C18 column (4.6 mm x 250 mm, 5 microm) using a mixture solution of CH3OH and H2O-THF-H3PO4(80:10:0.2) as mobile phase and detected by Waters2465 electrochemical detector at + 800 mV ( vs. ISAAC). Temperature of column was 30 degrees C.

RESULT AND CONCLUSIONThe linear ranges of baicalin, baicalein and wogonin were 0.045 6-1.14 microg (r = 0.999 6), 0.013-0.325 microg (r = 1) and 0.009 5-0.047 5 microg ( r = 0.999 9), respectively. The average recoveries of baicalin, baicalein and wogonin were 97.9% (n = 5, RSD 2.3%), 97.2% (n = 5, RSD 3.3%) and 103.5% (n = 5, RSD 3.5%), respectively. The contents of three effective ingredients from 14 different germplasm resourses and 9 different growing areas of S. baicalensis were determined, the quality of S. baicalensis was evaluated.