| Popis: |
To study the diterpenoids of Tripterygium wilfordii by electrospray ionization tandem (ESI) and electron impact (EI) mass spectrometry and establish the methods for quickly and on line identification of these diterpenoids.The diterpenoids were analyzed by ESI-MS and EI-MS under positive ion model.In ESI-Trap-MS (+) model, the quasi-molecular ions [M + H] + of the diterpenoids took place bond cleavage and generally lost neutral molecules such as H2O, CH2CHCH3, CO and CH2CO, then generated characteristic fragment ion series (m/z 197, 183, 169). In ESI-TOF-MS (+) model, the quasi-molecular ions [M + H] + of the diterpenoids took place bond cleavage and generally lost neutral molecules such as H2O, CO, then generated characteristic fragment ion series (m/z 277, 185, 93). In EI-MS model, the molecular ions of the diterpenoids took place bond cleavage and generally lost neutral molecules such as H2O, CO, CH4, and isopropyl radical, then generated characteristic fragment ion series (m/z 149, 105, 91, 71, 55, 43).The ESI-MS and EI-MS characteristics of diterpenoids of Tripterygium wilfordii are reported for the first time. Based on these characteristics, the methods for quickly and on line identification of diterpenoids are established. |
