Table 1. LC-TQ-MS and LC-TOF-MS Identification of EC and Its Potential Colonic Metabolites, Based on Relative Retention Time and MS (or MS Fragmentation) Values.
| analytical platform | chemical | parent ion (m/z) | product ion (m/z) | collision energy (V) | retention time |
|---|---|---|---|---|---|
| LC-TQ-MS | EC | 289.1 | 245.10, 109.10, 203.00 | 14, 25, 18 | 5.72 |
| 3,4-diHPVA | 209.0 | 135.10, 191.05, 122.10 | 18, 15, 21 | 7.60 | |
| 3,4-diHPV | 207.1 | 163.05, 122.15, 161.10 | 16, 21, 21 | 5.00 | |
| 3-HPVA | 193.1 | 106.15, 149.05, 175.05 | 23, 17, 15 | 7.88 | |
| 3-HPV | 191.1 | 147.05, 102.90, 135.00 | 8, 15, 15 | 6.93 | |
| 3,4-diHPPA | 181.1 | 137.10, 59.00, 109.00 | 14, 17, 15 | 3.95 | |
| 3-HPPA | 165.1 | 121.20, 106.10, 119.15 | 13, 22, 16 | 6.33 | |
| 3-HPAA | 151.0 | 107.10, 65.00 | 12, 25 | 4.30 | |
| 4-HPAA | 151.0 | 107.10, 79.15, 93.20 | 10, 20, 22 | 3.82 | |
| catechol | 109.2 | 90.95, 81.10, 53.15 | 22, 21, 20 | 1.85 | |
| LC-TOF-MS | 3,4-diHPP-2-ol | 291.09 | 19.6 | ||
| 3-HPP-2-ol | 275.09 | 23.1 | |||
| 4H-diHPVA | 225.08 | 15.7 | |||
| 4H-HPVA | 209.08 | 15.2 |