Quality evaluation of rhubarb based on qualitative analysis of the HPLC fingerprint and UFLC-Q-TOF-MS/MS combined with quantitative analysis of eight anthraquinone glycosides by QAMS.

Rhubarb is one of the most ancient and important herbal medicines, but its current quality evaluation (QE) methods have some limitations. In this study, a new method was developed for the comprehensive QE of rhubarb. First, fingerprints of 28 batches of three species of rhubarb samples were determined by HPLC, the reference fingerprint was established and the common peaks were assigned. Second, the components of common peaks in the fingerprints were identified by ultrafast liquid chromatography quadrupole time-of-flight mass spectrometry. Finally, a method for the simultaneous determination of the contents of eight anthraquinone glycosides in rhubarb using quantitative analysis of multiple components by a single marker (QAMS) was established, and the contents of these eight components in 28 batches of rhubarb determined by QAMS and the external standard method were compared. The results showed that there were 31 common peaks in the rhubarb fingerprint. The components of these 31 common peaks were identified, and 20 of them were unambiguously confirmed by reference substances, including eight anthraquinone glycosides. The contents of eight anthraquinone glycosides in the 28 batches of rhubarb determined by QAMS and the external standard method were not significantly different. In conclusion, the method established in this study can be used for the comprehensive QE of rhubarb and can also provide a reference for the QE of other herbal medicines.