Simultaneous determination of seven constituents in Si-Ni-San decoction and a compatibility comparison study using HPLC-UV.

A simple and accurate HPLC-UV method was developed for simultaneous determination of seven constituents in Si-Ni-San decoction. Separation was performed on a Hypersil C18 column and detection was set with gradient wavelength at 240 nm (0-26 min) and 210 nm (26-30 min). The mobile phase consisted of 0.03% phosphoric acid in water (v/v), and acetonitrile was used with a flow rate of 1.0 (- 1). This method provides good linearity (r>0.9992), precision (RSD < 1.9%), repeatability (RSD < 2.9%), stability (RSD < 2.9%) and recovery (97.6-102.0%), which has been successfully applied to quantitative determination of the seven constituents in Si-Ni-San decoction and different compatibility groups.