Objective: To establish a UPLC-MS/MS method for the content determination of dehydrotumulosic acid and pachymic acid in Poria. Method: Chromatographic separation was carried out on ZORBAX Eclipse XDB-C18 column (2.1 mm×100 mm

1.8 μm) with acetonitrile-1.0 mmol·L-1 ammonium acetate (80:20) as the mobile phase. The flow rate was 0.3 mL·min-1

and the column temperature was 40℃. The injection volume was 5.0 μL. Electrospray ionization (ESI-) under negative ion mode was used

and the quantization of dehydrotumulosic acid and pachymic acid was performed with multiple reaction monitoring (MRM) mode. The detected ion-pairs were dehydrotumulosic acid m/z 483.20/421.20 and pachymic acid m/z 527.40/465.30. Result: The linear range was 24.2-488 μg·L-1(r=0.999 9) for dehydrotumulosic acid

and 26.2-524 μg·L-1 (r=0.999 8) for polyporenic acid. The retention time was 6 min. The average recoveries of dehydrotumulosic acid and polyporenic acid were 99.8% with RSD of 1.2% (n=6) and 101.4% with RSD of 1.2% (n=6)

respectively. Conclusion: The proposed UPLC method is rapid

accurate

selective

sensitive

and suitable for the content determination of dehydrotumulosic acid and polyporenic acid in Poria.