Determination of serum astragaloside in rats fed with Buyanghuanwu dicoction using solidphase extraction, chemical derivatization and fluorospectrophotometry.

OBJECTIVE: To develop a method for determining the serum astragaloside in rats fed with Buyanghuanwu dicoction (a preparation of a traditional Chinese medicine). METHODS: A solid-phase extraction column was employed for pretreating the serum samples. The fluorescence characteristics of the extract were measured following chemical derivatization with anisic acid-sulphuric acid. RESULTS: The endogenous interference was removed by solid-phase extraction. The excitation and emission maxima of the reaction product from astragaloside and anisic acid were at 310 nm and 376 nm respectively. The linear range of the calibration curve was 1.0 to 10.0 microg/ml with r=0.999 9. The average recovery rate of the method was 97% with relative standard derivation of 2.59%(n=5). CONCLUSION: This method is rapid and highly sensitive, and useful for monitoring the concentration of astragaloside in rat serum.