Online Microextraction Coupled with HPLC-ABTS for Rapid Analysis of Antioxidants from the Root of Polygonum bistorta

Table 1

MS data of components in PB.

No.	t/min	Formula	Adducts	Fragment	Identification	REAC
1	1.922	C6H10O3	131.0629 [M + H]^+	113.0596, 89.0232,61.0284	Unknown	2.52 ± 0.34
2	2.133	C7H6O5	169.0090 [M-H]^−	125.0204, 97.0264, 79.0160	Gallic acid	10.98 ± 0.13
3	5.773	C16H18O9	353.0836 [M-H]^−	191.0524, 179.0312, 135.0422	Neochlorogenic acid	1.85 ± 0.08
4	10.038	C9H8O4	179.0325 [M-H]^−	135.0431, 107.0492, 89.0385, 59.0128	Caffeic acid	1.74 ± 0.07
5	11.079	C16H18O9	353.0863 [M-H]^−	191.0538, 135.0430, 85.0285	Chlorogenic acid	8.71 ± 0.60
6	12.150	C30H26O12	577.1317 [M-H]^−	425.0384, 407.0730, 289.0694, 125.0221	Procyanidin B2	+
7	12.535	C15H14O6	290.0790 [M-H]^−	245.0782, 203.0686, 109.0286	Catechin	−
8	15.294	C21H20O12	464.0955 [M + H]^+	345.0609, 315.0474, 369.0604	Quercetin-8-C-glucoside	−
9	17.007	C21H20O12	463.0858 [M-H]^−	301.0328, 151.0018	Quercetin-4′-O-glucoside	+
11	18.567	C21H18O13	477.0657 [M-H]^−	477.0652, 301.0330, 151.0019	Quercetin-3-O-glucuronide	+

+: negative peak was too low to quantify; −: without negative peak.