Simultaneous determination of triptolide and tripdiolide in extract of Tripterygium wilfordii Hook. f. by LC-APCI-MS

A novel method using liquid chromatography coupled with atmospheric pressure chemical ionization mass spectrometry in the negative selected ion monitoring mode has been developed and validated for rapid simultaneous determination of triptolide and tripdiolide in the extract of Tripterygium wilfordii Hook. f. The molecular ions m/z [M-H](-) 359 and 375 were selected for the quantification in selected ion monitoring mode for triptolide and tripdiolide. Standard calibration curve was linear over the concentration range of 0.12-24 and 0.15-30 mu g mL(-1) for triptolide and tripdiolide. The relative standard deviations of intra- and inter-day were in the range of 4.7-9.9 and 8.9-12.6%. The average recoveries were between 96.4 and 104.6%. The limits of quantitation were 2.0 x 10(-3) and 2.5 x 10(-3) mu g mL(-1) for triptolide and tripdiolide.