Fast determination of isomeric triterpenic acids in Osmanthus fragrans (Thunb.) Lour. fruits by UHPLC coupled with triple quadrupole mass spectrometry

[Display omitted] •Eleven triterpenic acids of three group isomers were well separated for the first time.•Conventional Shim-pack GIST C18 column and alkaline mobile phase were feasible.•The method was simple without derivatization and sensitive detected in MRM mode.•The developed method is of benefit to explore O. fragrans fruits resources. Triterpenic acids possess rich biological activity. Due to slight differences in structure and polarity, the simultaneous determination of isomeric triterpenic acids is challenging. In the present work, a simple and effective approach to chromatographic separation of such compounds based on conventional C18 stationary phase with gradient elution was developed, which allowed the simultaneous separation of eleven analytes including euscaphic, arjunic, tormentic, arjunolic, asiatic, pomolic, maslinic, corosolic, oleanolic, ursolic and 2-Epi tormentic acid (internal standard). This approach with mass spectrometric detection and ultrasonic extraction was fast, sensitive and accurate for analyzing isomeric triterpenic acids in O. fragrans fruits with a toal duration of the analytical cycle (including pretreatment) within one hour. The LODs lie in ranges of 0.8–12 ng/mL (30 ng/mL for asiatic and corosolic acid). The developed method was validated and successfully applied in ten batches of O. fragrans fruits, which could reflect the detail content difference of triterpenic acid components.