A Useful Strategy to Evaluate the Quality Consistency of Traditional Chinese Medicines Based on Liquid Chromatography and Chemometrics

Table 3

Identification of common peaks by HPLC/IT-.

Number	Retention time (min)	Assigned identity	UV (nm)	(−)ESI-	HPLC-ESI- () (% base peak)
13	24.9	Puerarin	250, 310	415 [M-H]^−	MS^2  415]: 295 (100), 267 (82); MS^3  415→295]: 267 (100)
15	27.5	3′-Methoxypuerarin	250, 300	445 [M-H]^−	MS^2  445]: 325 (100), 297 (21), 282 (21),; MS^3  445→325]: 297 (100), 282 (88)
16	28.5	Mirificin	250, 310	547 [M-H]^−	MS^2  547]: 295 (100), 267 (82); MS^3  547→295]: 267 (100)
19	32.4	Daidzin	250, 310	461 [M-H+	MS^2  461]: 415 (37), 253 (100); MS^3 -
20	34.5	3′-Methoxydaidzin	250, 310	491 [M-H+	MS^2  491]: 445 (21), 283 (100), 268 (4.7); MS^3  491→283]: 268 (100), 240 (2)
26	40.9	Lithospermic acid	254, 310	537 [M-H]^−	MS^2  537]: 493 (28), 295 (100); MS^3  537→295]: 277 (100)
29	49.9	Daidzein	250, 310	253 [M-H]^−	MS^2  253]: 225 (100), 211 (22), 135 (45), 91 (22); MS^3 -

(−) in negative scan mode in HPLC/IT-.