Cleavage rules of mass spectrometry fragments and rapid identification of chemical components of Radix Paeoniae Alba using UHPLC‐Q‐TOF‐MS

Abstract Introduction Radix Paeoniae Alba (RPA) presents several pharmacological effects, including analgesia, liver protection, and toxicity reduction. RPA consists mostly of monoterpenes and their glycosides, tannins, flavonoids, and organic acids, with monoterpenes being the main active pharmaceutical ingredients. Objective To establish an effective method for rapid classification and identification of the main monoterpenes, flavonoids, and organic acids in RPA. Methods We used ultrahigh‐performance liquid chromatography quadrupole time‐of‐flight mass spectrometry (UHPLC‐Q‐TOF‐MS) and data post‐processing technology to rapidly classify and identify the monoterpenoids, flavonoids, and organic acids in RPA. We also summarised the diagnostic product ions and neutral losses of monoterpenoids, flavonoids, and organic acids in RPA reported in the literature. Results We identified 24 components, namely 18 monoterpenoids, one flavonoid, and five organic acids. Conclusion In this study, we analysed the chemically active pharmaceutical ingredients and assessed the quality of RPA. In addition, we demonstrated that UHPLC‐Q‐TOF‐MS can be used to qualitatively classify and identify the variety of chemical components of traditional Chinese medicines (TCMs) to a certain extent. Moreover, we confirmed that mass spectrometry can be used to identify the components of TCMs.