Table 4: Concentration of chlorogenic acid and caffeic acid in several Xu Duan raw herbs determined by HPLC-PDA.

SampleMean (mg/g) ± %RSDaChlorogenic/caffeic ratio
Chlorogenic acidCaffeic acid

R-I 7.1
R-II 6.7
R-III 16.7
R-IV 65.1

aCalculated from 5 replicates.