Establishment of Quality Evaluation Method for Yinqiao Powder: A Herbal Formula against COVID-19 in China

Table 2

Mass spectrometry information of reference substances.

Reference substance	tR (min)	Ion mode	Theoretical (m/z)	Measured (m/z)	Fragment ions (m/z)
Neochlorogenic acid	5.80	[M − H]^−	353.0867	353.0876	191.0554, 179.0341, 135.0439
Chlorogenic acid	6.93	[M − H]^−	353.0867	353.0876	191.0554, 179.0341, 135.0439
Caffeic acid	7.34	[M − H]^−	179.0339	179.0341	135.0439
Liquiritin	10.00	[M − H]^−	417.1180	417.1196	255.0662, 135.0074, 119.0488
Rutin	10.02	[M − H]^−	609.1450	609.1464	300.0279, 271.0250, 255.0299
Cynaroside	10.41	[M − H]^−	447.0922	447.0936	285.0407
Forsythoside A	10.93	[M − H]^−	623.1970	623.1980	461.1674, 161.0232
Isochlorogenic acid A	11.80	[M − H]^−	515.1184	515.1195	353.0882, 191.0554, 179.0446, 135.0439
Isochlorogenic acid C	11.83	[M − H]^−	515.1184	515.1195	353.0882, 191.0554, 179.0446, 135.0439
Hesperidin	11.54	[M − H]^−	609.1814	609.1813	301.0721
Phillyrin	13.05	[M + HCOO]^−	579.2072	579.2091	371.1507
Arctiin	13.34	[M + HCOO]^−	579.2072	579.2091	371.1504