The Liquid Chromatographic Determination of Chlorogenic and Caffeic Acids in Xu Duan (Dipsacus asperoides) Raw Herb

Table 4

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

Sample	Mean (mg/g) ± %RSD^a		Chlorogenic/caffeic ratio
	Chlorogenic acid	Caffeic acid
R-I	4.46±1.0	0.63±0.7	7.1
R-II	2.76±3.0	0.41±2.7	6.7
R-III	1.66±1.8	0.10±4.7	16.7
R-IV	4.56±0.6	0.07±9.5	65.1

 ^aCalculated from 5 replicates.