OBJECTIVETo study relationships between the main active ingredients and physical and chemical parameters of dangguibuxue decoction, and to explore the feasibility of characterization the quality of decoction by physical and chemical parameters.

METHODSolutions of ferulic acid and astragaloside with different concentrations were prepared, of which physical and chemical parameters such as surface tension, pH value and conductivity, etc were determined at 25 degrees C. And polynomial regression analysis was used to analyze these data.

RESULTWith the increase of concentration of ferulic acid, pH value was decreased and conductivity was increased. And surface tension was decreased in the aqueous solution of astragaloside. In the combined solution of ferulic acid and astragaloside, ferulic acid was the main influencing pH value and conductivity, while astragaloside was the main factor influencing surface tension.

CONCLUSIONOn one hand, astragaloside concentration has a significant correlation with surface tension, but almost no correlation with pH value and conductivity. On the other hand, ferulic acid concentration has a strong correlation with pH value and conductivity, but almost no correlation with surface tension. In addition, each parameter has strong anti-interference ability and almost didn't change with the addition of another material. These preliminary results suggested that such characteristic parameters could be used to characterize the decoction quality.