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

Table 3

Comparison of intensities of the qualifier ion(s) for chlorogenic acid (m/z 85) and caffeic acid (m/z 89, 135) obtained for the standard and raw herb.

Analyte	m/z ion (relative intensity (%)^a)		Relative diff. (%)^b	Permitted tolerances
	Standard	Raw herb
Chlorogenic acid	85 (7)	85 (6)	14^c	±50%
Caffeic acid	89 (61)	89 (50)	18^c	±20%
	135 (39)	135 (33)	15^c	±25%

 ^aAverage calculated from 5 replicates.
^bRelative difference (absolute difference/relative intensity of standard) × 100.
^cMaximum permitted tolerance of the European Union guidelines [11].