Simultaneous determination of seven compounds in flowers of Polygonum Orientale by ultra performance liquid chromatography coupled with photo diode array detection

Abstract

To establish a UPLC method for simultaneous determination of seven chemical markers (gallic acid, catechin, alphitonin, taxifolin, kaempferol-3-O-beta-D-glucoside, quercetin-3-O-alpha-L-rhamnoside, and kaempferol-3-O-alpha-L-rhamnoside) of the flowers of Polygonum Oriental collected from Guizhou province. Separation was performed at 45 degrees on a ACQUITY UPLC BEH C18 column (2.1 mm x 150 mm, 1.7 microm) with a gradient solvent system of 0.1% formic acid in acetonitrile-0.1% aqueous formic acid as the mobile phase. The flow rate was 0.3 mL x min(-1), the detection wavelength was 280 nm, and the sample injection volume was 1 microL. In the selected linear range, all calibration curves of the seven chemical markers showed good linearity. The recoveries (n = 6) were in the range of 97.90% -101.4% and RSD were less than 3.8%. The results showed that the seven compounds contained in all the samples of the flowers of P. orientale can be chosen as their chemical markers and that this UPLC-PAD method is simple, reliable and suitable for the quality control of the flowers of P. orientale. However, the chemical markers may be present at different levels for samples collected in different areas and at different times. A collection time of mid-to-late August with relatively high content of the chemical markers was suggested for the flowers of P. orientale.