A simple sensitive UFLC-MS/MS method for the simultaneous quantification of artesunate, dihydroartemisinin and quercetin in rat plasma and its application to pharmacokinetic studies.An ultrafast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method was developed for the simultaneous estimation of artesunate (ART), dihydroartemisinin (DHA, an active metabolite of ART) and quercetin (QRT) in rat plasma. 
UFLC-MS/MS
The separation was achieved using a Zorbax C18 column (3 μm, 50 mm × 4.6 mm) as a stationary phase with a mobile phase of 0.1% formic acid (10% by volume) and methanol (90% by volume) at a flow rate of 0.4 mL min-1 and an injection volume of 10 μL. 
Zorbax C18 column
Mass detection was performed by electrospray ionization (ESI)-tandem mass spectrometry via multiple reaction monitoring (MRM) in positive mode except for QRT, where negative ionization was used. 
electrospray ionization (ESI)
Mass detection was performed by electrospray ionization (ESI)-tandem mass spectrometry via multiple reaction monitoring (MRM) in positive mode except for QRT, where negative ionization was used. 
multiple reaction monitoring (MRM)