Background: It is highly crucial to clarify the pharmacokinetic mechanism for the active
multi-ingredients in Traditional Chinese Medicines so that suggestions could be provided in clinical.
Introduction: A novel, rapid and sensitive Ultra-Performance Liquid Chromatography-Tandem Mass
Spectrometry (UPLC–MS/MS) method was developed for the simultaneous determination of four compounds
(tetrahydropalmatine, danshensu sodium, ferulic acid and rosmarinic acid) after oral administration
of Guanmaitong Granule in rat plasma using puerarin as the Internal Standard (IS).
Method: Acidified plasma samples were extracted by liquid–liquid extraction method with ethyl acetate,
and separated on a Waters ACQUITY UPLC® BEH C18 column (502.1 mm, i.d., 1.7 µm) using a
gradient mobile phase system composed of acetonitrile–water containing 0.1% formic acid. The detection
was performed in multiple reaction monitoring mode with positive and negative-ion mode.
Result: The method was validated over the concentration range of 0.005-20.48 ng/mL for tetrahydropalmatine,
5.4-100 ng/mL for danshensu sodium, 8.8-1000 ng/mL for ferulic acid and 3-60 ng/mL
for rosmarinic acid; the Lower Limit Of Quantification (LLOQ) was between 0.005 ng/mL and 8.8 ng/mL
for the four analytes. The intra-day and inter-day precisions were all less than 15% and the accuracies were
within the range of 85%-115%. Extraction recovery, matrix effect and stability were also satisfactory.
Conclusion: The validated method was successfully applied in a pharmacokinetic study in rats after
oral administration of Guanmaitong Granule.