OBJECTIVEIntegrating column switching for on-line concentration and programmed injection, a novel HPLC method is developed for simultaneous determination of high-content water-soluble components (danshensu, protocatechualdehyde, salvianolic acid B) and trace nerolidol in Xiangdan injection. The concentrations of water-soluble components in Xiangdan injection are roughly 1000 times of that of nerolidol.

METHODThe on-line concentration was performed on a Zorbax SB-C18 guard column. The separation was carried out on Lichrospher C18 column (4.6 mm x 250 mm, 5 microm). The mobile phase of guard column was mixtures of acetonitrile and 1.0% acetic acid water, and the flow rate was 0.5 mL x min(-1). The mobile phase of the analytical column was mixtures of acetonitrile and 0.05% acetic acid water, and the flow rate was set at 1.0 mL x min(-1). The column temperature was maintained at 40 degrees C, and the detection wavelength was 280 nm at 0-40 min, 210 nm at 40-55 min. The program injection was 10 microL of sample solution 1 at 0 min, 200 microL of sample solution 2 at 15.3 min.

RESULTThe calibration curves of danshensu, protocatechualdehyde, salvianolic acid B and nerolidol showed good linear regression (R2 > 0.9990) within investigated concentration ranges. The average recoveries of the four analytes were between l00% and 102%, and the RSD values were less than 3.0%. For danshensu, protocatechualdehyde, salvianolic acid B and nerolidol, the limits of detection at a signal-to-noise (S/N) ratio of 3 were 17.1, 0.473, 60.2, 50.6 microg x L(-1), respectively.

CONCLUSIONThe method is a simple, sensitive and repeatable approach. More importantly, results indicate that the present method shows promising prospect for quality control of Xiangdan injection.