A novel, differential mobility spectrometry tandem mass spectrometric method for the in vivo quantitation of ursolic acid

•Providing new knowledge relating to the bioassay of compounds exhibiting high biomatrix interference and poor CID efficiency.•Developed an LC-DMS-MS/MS with MIM based assay to determine polycyclic triterpenoids in rat plasma using low sample volume.•DMS provides a new separation dimension which significantly decreases interference and increases selectivity.•A non-derivatization sample preparation step while ensuring high selectivity and low quantitation limit.