Simultaneous determination of four compounds in Erzhiwan by HPLC

Abstract

To establish an HPLC method for simultaneous determination of nuzhenide, specnuezhenide, wedelolactone and oleanic acid in Erzhiwan. The DIKMA C18 (4.6 mm x 200 mm, 5 microm) column was adopted with acetonitrile and 0.1% phosphoric acid solution as the mobile phase and gradient elution. The flow rate was 1.0 mL x min(-1) and the volume of injection was 20 microL. The column temperature was maintained at 30 degrees C and the detective wavelength was set at 215 nm. There were good linear relationships between the peak area and concentration at the range of 2.008-80.32 (r = 0.999 6), 5.872-234.88 (r = 0.999 7) , 0.9-36 (r = 0.999 9), 13.24-529.6 mg x L(-1) (r = 0.999 6) for nuzhenide, specnuezhenide, wedelolactone and oleanic acid, respectively. The average recovery rates of nuzhenide, specnuezhenide, wedelolactone and oleanic acid were 99.25%, 98.70%, 96.23% and 101.5%, respectively, with RSD of less than 3%. The established method was so easy, rapid and accurate that it can be used as an effective way for quality control of Erzhiwan.