Abstract: To establish a UPLC-MRM-MS method for the determination of gallic acid,protocatechuic acid,que-3-O-β-D-Glc,quercitrin,catechin,que-3-O-(2″-O-galloyl)β-D-Glc and quercetin in Polygonum capitatum. The analysis was achieved by BEH C₁₈ column with a mobile phase composed of 0.1% formic acid in acetonitrile and 0.1% formic acid in water using gradient elution.A TQD tandem mass spectrometry was used as detector and operated by multiple reaction monitoring (MRM) mode.Good linearity was achieved for these components in the range of 0.136-32.965,0.031-7.481,0.022-5.300,0.076-18.433,0.085-20.737,0.017-4.147,0.128-31.029 μg/mL,respectively.The average recoveries were 91.23%-105.33%,with RSD less than 3%.Precision,repeatability and stability were good.The developed method was simple,rapid,sensitive and suitable for the determination of the main active constituents in P.capitatum. It provided a new method for the quality control of P.capitatum.

Key words: Polygonum capitatum, UPLC-MRM-MS, gallic acid, protocatechuic acid, quercetin, content determination