[Simultaneous determination of seven flavonoids in Nervilia fordii with HPLC]

The study is to develop an HPLC method for simultaneous determination of rhamnazin (1), rhamnocitrin (2), rhamnetin (3), rhamnazin-3-O-beta-D-glucopyranoside (4), rhamnazin-3-O-beta-D-xylopyranosyl-(1-->4)-beta-D-glucopyranoside (5), rhamnazin-3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside (6), and rhamnocitrin-3-O-beta-D-glucopyranosyl-(1-->4)-beta-D-glucopyranoside (7) in Nervilia fordii. The separation was performed on a Kromasil C18 column (250 mm x 4.6 mm, 5 microm) with 0.4% phosphoric acid-acetonitrile as the mobile phase in a gradient elution at a flow rate of 1.0 mL x min(-1). The detect wavelength was set at 256 nm, and the column temperature was set at 40 degrees C. There were good linear relationships between the logarithm values of concentrations and those of the peak areas of seven flavonoids (1-7) in the range of 0.55-70.00 microg x mL(-1) (r = 0.9997), 0.86-110.00 microg x mL(-1) (r = 0.9997), 0.39-50.00 microg x mL(-1) (r = 0.999 7), 0.55-70.00 microg x mL(-1) (r = 0.999 5), 1.33-170.00 microg x mL(-1) (r = 0.9998), 1.33-170.00 microg x mL(-1) (r = 0.9998), 0.16-20.00 microg x mL(-1) (r = 0.9995), respectively. The recoveries of the seven flavonoids were between 97.19%-99.45%, the relative standard deviations (RSDs) were between 0.91%-2.69%. The established method is rapid, accurate with high repeatability, which could provide scientific evidence for the quality control of Nervilia fordii.