Table 2.
Transformation of multiple reaction monitoring (MRM) settings of main metabolites from UPLC–QTOF/MS to LC–MS/MS.
| Metabolites | ESI Mode | QTOF/MS | MS/MS | ||
|---|---|---|---|---|---|
| Precursor ion (M + H) | Fragments | Precursor Ion | Product Ion | ||
| 3-epi-bufalin | ES+ | 387.2527 | 369.24; 351.23; 333.22; 255.21 | 387.40 | 369.60 |
| Dihydroxylated bufalin | ES+ | 419.2424 | 401.24; 383.22; 365.21; 347.20 | 419.24 | 365.21 |
| Hydroxylated bufalin | ES+ | 403.2473 | 385.24; 367.23; 349.22; 331.21; 253.19 | 403.25 | 349.22 |
| Hydroxylated bufalin | ES+ | 403.2470 | 385.24; 367.23; 349.22; 331.21; 253.19 | 403.25 | 349.22 |
| Hydroxylated bufalin | ES+ | 403.2471 | 385.24; 367.23; 349.22; 331.21; 253.19 | 403.25 | 349.22 |
| Hydroxylated bufalin | ES+ | 403.2451 | 385.24; 367.23; 349.22; 331.21; 253.19 | 403.25 | 349.22 |