Rapid resolution liquid chromatography–electrospray ionisation tandem mass spectrometry method for identification of chemical constituents in Citri Reticulatae Pericarpium

Citri Reticulatae Pericarpium (CRP) is one of the most commonly used traditional Chinese medicines with great medicinal and dietary values. In this work, we developed an approach utilising rapid resolution liquid chromatography/electrospray ionisation tandem mass spectrometry (RRLC–ESI-MS/MS) for the identification and profiling of chemical composition in CRP. On the basis of RRLC retention times, cochromatography with available authentic standards, mass spectral fragmentation patterns and literature information, a total of 41 chemical compounds, including 4 flavone-C-glycosides, 7 flavonoid-O-glycosides and 19 polymethoxyflavones were unambiguously identified or tentatively characterised in CRP. The occurrence of 1 flavone-C-glycoside and 3 cyclic peptides in particular has not yet been described. The results indicated that the developed method could serve as a rapid, effective tool for structural characterisation of chemical constituents in CRP.