Abstract: Objective To propose a method to determine the total polyphenols in agrimonia pilosa ledeb. Methods Folin-Ciocalteus reagent and gallic acid as the standard were used to determine the total polyphenols in agrimonia pilosa ledeb by the spectrophotometry. 0.5mL of Folin-Ciocalteus reagent and 1.7mL of 20% Na₂CO₃ solution were added into 10mL volumetric flask which contained the certain amounts of agrimonia pilosa ledeb sample. The reaction continued of 90 min at room temperature, and then determined absorption value at 660nm and 760nm. Results The mass concentrations of polyphenols in the interval of 0~10.4 mg/L were linearly related to the absorption values. The standard curve at 760nm was y=0.091 8x+0.012 9, R²=0.999 3 and the recovery of total polyphenols was 98.4%~99.8%. The standard curve at 660nm was y=0.084 7x-0.002 6, R²=0.999 7 and the recovery of total polyphenols was 101.2%~101.9%. Conclusion It showed good precision, repeatability and recovery to determine total polyphenols both at 760 nm and 660nm. This research provided a reference for quantitative analysis total polyphenols of agrimonia pilosa ledeb.

Key words: agrimonia pilosa ledeb, spectrophotometry, Folin-Ciocalteus reagent, plant polyphenol