Simultaneous determination of honokiol and magnolol in Magnolia officinalis by liquid chromatography with tandem mass spectrometric detection

An optimized high-performance liquid chromatographic method coupled with tandem mass spectrometric detection (LC-MS/MS) was developed for the simultaneous determination of honokiol and magnolol in Magnolia officinalis. Honokiol and magnolol were separated from the extracts using a reversed-phase C(18) column with a mobile phase consisted of acetonitrile and water (75:25, v/v) at a flow-rate of 0.8 mL/min. Selected reaction monitoring (SRM) mode was used for all sample quantification by the precursor-ion/product ion pair m/z 265 --> m/z 224 for honokiol and m/z 265 --> m/z 247 for magnolol. Validation data showed that this method has good linearity (r(2) > 0.995) over the concentration range of 0.0025-0.5 microg/mL for honokiol and magnolol, and both intra- and inter-day variability were acceptable within 15% at the lowest concentrations for this method. This proposed method provides excellent specificity, higher sensitivity and shorter run time than conventional methods and was applied successfully to determine the contents of honokiol and magnolol in M. officinalis.