Table 3.
Characterization of degradation products of CQAs determined by HPLC-CID-ESI-MS/MS.
| No. | tR (min) | [M − H]− | ESI-MS2 | ESI-MS3 | Identification | Relative Content * |
|---|---|---|---|---|---|---|
| 5-CQA | 7.3 | 353 | 191 | 173, 127, 111, 85 | 5-CQA | 74.13% |
| 1 b | 10.2 | 353 | 191 | 173, 127, 111, 85 | cis-5-CQA | 24% |
| 2 b | 14.4 | 367 | 191 | 173, 127, 85 | Methylated 5-CQA | 1% |
| 3-CQA | 4.6 | 353 | 191 | 173, 127, 85 | 3-CQA | 91.18% |
| 3 b | 4.3 | 353 | 191 | 173, 127, 85 | cis-3-CQA | 3% |
| 4 a | 7.9 | 353 | 173 | 155, 93 | 4-CQA | 3% |
| 5 b | 14.4 | 335 | 161 | 133 | Dehydrated 3-CQA | 2.8% |
| 4-CQA | 7.9 | 353 | 173 | 155, 111, 93 | 4-CQA | 53.91% |
| 6 b | 6.6 | 353 | 173 | 155, 111, 93 | cis-4-CQA | 26% |
| 7 b | 10.1 | 367 | 161 | 133 | Methylated 4-CQA | 5% |
| 8 b | 13.6 | 367 | 161 | 133 | Methylated 4-CQA | 10% |
| 9 b | 14.3 | 335 | 161 | 159 | Dehydrated 4-CQA | 5% |
| 1,3-diCQA | 11.9 | 515 | 353 | 191, 179, 135 | 1,3-diCQA | 86.97% |
| 10 b | 13.3 | 515 | 353 | 191, 179, 135 | A cis-1,3-diCQA | 1% |
| 11 b | 13.6 | 515 | 353 | 191, 179, 135 | A cis-1,3-diCQA | 3% |
| 12 b | 15.3 | 515 | 353 | 191, 179, 135 | Di-cis-1,3-diCQA | 4% |
| 13 a | 16.6 | 515 | 353 | 173, 135 | 4,5-diCQA | 4% |
| 3,4-diCQA | 15.4 | 515 | 353 | 173, 135 | 3,4-diCQA | 67.75% |
| 14 b | 15.2 | 515 | 353 | 173, 135 | cis-3,4-diCQA | 15% |
| 15 b | 16.1 | 515 | 353 | 173, 135 | cis-3,4-diCQA | 12% |
| 16 b | 16.5 | 515 | 353 | 173, 135 | di-cis-3,4-diCQA | 6% |
| 17 b | 17.6 | 529 | 367 | 161, 193, 135 | Methylated 3,4-diCQA | <1% |
| 18 b | 18.4 | 529 | 367 | 161, 193, 135 | Methylated 3,4-diCQA | <1% |
| 19 b | 23.4 | 497 | 335 | 161, 179, 135 | Dehydrated 3,4-diCQA | <1% |
| 20 b | 24.6 | 497 | 335 | 161, 179, 135 | Dehydrated 3,4-diCQA | <1% |
| 21 b | 25.8 | 497 | 335 | 161, 179, 135 | Dehydrated 3,4-di CQA | <1% |
| 3,5-diCQA | 16.4 | 515 | 353 | 191, 135 | 3,5-diCQA | 55.04% |
| 22 b | 16.1 | 515 | 353 | 191, 135 | A cis-1,3-diCQA | 43% |
| 23 b | 19.1 | 515 | 353 | 191, 135 | A cis-1,3-diCQA | 1% |
| 24 a | 7.4 | 353 | 191 | 173 | 5-CQA | <1% |
| 25 a | 15.4 | 515 | 353 | 173, 135 | 3,4-diCQA | <1% |
| 26 b | 21.0 | 529 | 367 | 335, 161, 135 | Methylated 3,5-diCQA | <1% |
| 27 b | 27.3 | 543 | 381 | 161, 179, 135 | Ethylated 3,5-diCQA | <1% |
| 4,5-diCQA | 16.6 | 515 | 353 | 173, 135 | 4,5-diCQA | 80.01% |
| 28 b | 17.8 | 515 | 353 | 173, 135 | A cis-4,5-diCQA | <1% |
| 29 b | 18.2 | 515 | 353 | 173, 135 | A cis-4,5-diCQA | 5% |
| 30 b | 19.0 | 515 | 353 | 173, 135 | di-cis-4,5-diCQA | 12% |