Analysis of saikosaponins in Bupleuri Radix and Caihu‐shugan‐san using reversed‐phase HPLC with pulsed amperometric detection

Abstract A simple and sensitive reversed‐phase (RP) HPLC coupled with pulsed amperometric detection (PAD) method was developed to determine the saikosaponin content in Bupleuri Radix or Caihu‐shugan‐san. Four saikosaponins in Bupleuri Radix and Caihu‐shugan‐san were extracted with a 6:4 solution of 10 mM sodium phosphate buffer (pH 8)/100% ethanol. Pulsed amperometric detection of carbohydrates in four major saikosaponins was highly sensitive when used with a water–acetonitrile gradient on an alkaline RP column with a post‐column delivery system. The limits of detection ( S / N =3) and of quantification ( S / N =10) of saikosaponins were 0.01–0.02 and 0.03–0.05 μg/mL, respectively. The intra‐ and inter‐day precision (RSDs) were each <9.7% and the average recoveries were 95.0–97.6% in Bupleuri Radix. This method can be used to analyze saikosaponins in Bupleuri Radix and Caihu‐shugan‐san.