Holistic quality evaluation of Hibisci Mutabilis Folium by integrating UPLC-QTOF-MS/MS chemical profiling and UPLC-TQ-MS/MS quantification approaches

In present study, an integrating UPLC-QTOF-MS/MS chemical profiling and UPLC-TQ-MS/MS quantification strategy was developed for the holistic quality evaluation of Hibisci Mutabilis Folium (HMF), a traditional Chinese medicinal herb. Using UPLC-QTOF-MS/MS, a total of 58 components were characterized in HMF sample, of which 36 flavonoids, 3 coumarins, 7 organic acids and 4 triterpene acids were unambiguously identified by comparing the chromatographic behavior and mass spectrum with that of reference compounds, or tentatively assigned by comparing the fragmentation pathways and characteristic fragment ions with that of reference substances and/or published literatures together with mass defect filtering (MDF) screening. Meanwhile, 29 representative major components, including 16 flavonoids, 3 coumarins, 7 organic acids and 3 triterpene acids, were quantified by a newly established UPLC-TQ-MS/MS method that was validated in terms of linearity, sensitivity, precision, repeatability, accuracy and stability. The integrated strategy was applied to simultaneously qualifying and quantifying HMF commercial samples and self-prepared samples harvested in difference periods and dried with different methods. It was found that the contents of 29 major components were obviously different in commercial samples or self-prepared samples, suggesting that the holistic quality of HMF commercial samples was inconsistent, and harvesting period and drying method might be the main factors that affect the holistic quality consistency of commercial HMF samples. Standardized harvesting period and drying method should be established for ensuring the holistic quality consistency of HMF.