OBJECTIVETo identify the compounds in herb of Polygonum orientale by ultra-performance liquid chromatography with PDA and electrospray ionization tandem mass spectrometry (UPLC-PDA-ESI/MS).

METHODThe chromatographic separation was carried out at 45 degrees C on a BEH C18 column (2.1 mm x 100 mm, 1.7 microm) eluted in the gradient program. The mobile phase consisted of acetonitrile and water containing 0.1% formic acid. The detecion of PDA was set between 190 nm and 400 nm. The mass spectra was obtain by Waters ACQUITY triple quadrupole tandem mass spectrometer in negative ion mode with ion spray voltage 3 kV. The temperature of the source and desolvation were set at 120 degrees C and 350 degrees C, separately. Nitrogen was used as the desolvation gas (750 L h(-1)) and cone gas (50 L h(-1)). For collision induced dissociation (CID), argon was used as the collision gas at a flow rate of 0.18 mL min(-1). The mass range recorde, m/z 100-1000.

RESULTOne phenolic acid, eleven flavonoids were well separated and identified by the method.

CONCLUSIONThe method is simple and rapid for the compound identification in the herb of P. orientale.