Abstract: In this study,the total flavonoid content of Salvia scapiformis Hance from Guizhou Province was determined by ultraviolet spectrophotometry with NaNO₂-Al(NO₃)₃-NaOH color-developing system. The dosage of color-developing agent and developing time were investigated. The results showed that:0.5 mL 5% NaNO₂ (placed 6 min),0.5 mL 10% Al(NO₃)₃ (placed 6 min) and 5 mL 4% NaOH (placed 15 min) was the optimal color-developing system with 505 nm as the detection wavelength and rutin was used as the standard. Good linear relationship was achieved within the range of 10-62 μg/mL with recovery rate of 99.2% and RSD of 1.2%. The regressive equation was y=11.0767x+0.0071,r=0.9991. The developed method showed good reproducibility and operability.

Key words: Salvia scapiformis Hance, total flavonoid, UV spectrophotometry