OBJECTIVETo establish a high performance liquid chromatographic (HPLC) amalgamated to double UV waves method for simultaneous determination of loganin and paeonol in Liuwei Dihuang pills.

METHODA HPLC method was developed. The separation was carried out on a Agilent Zorbax SB C18 column (5 microm, 4.6 mm x 250 mm). The mobile phase consisted of water (A) and acetonitrile (B) with linear linear gradient elution [0-8 min, (B) from 1% to 12%; 8-21 min, B keep 12%; 21-40 min, (B) from 12% to 90%; 40-50 min, B keep 90% for 10 min]. The detection was Photodiode Array with the detection wavelengths were at 236 nm and 274 nm. The column temperature being 30 degrees C and the flow rate was 1.0 mL min(-1). Extracting the chromatergraph from 274 nm and 236 nm, we amalgamated the two chromatographs by matlab programmed.

RESULTThe calibration curves of loganin and paeonol were linear in the ranges of 0.0362-1.09 microg (r =0. 9998) and 0.0450-1.35 microg (r =0.9998), respectively. The average recoveries of loganin and paeonol were 97.3% (RSD 1.4 %) and 103.0% (RSD 1.9%), respectively. Three different batches of Liuwei Dihuang pills were determined with this method.

CONCLUSIONThis is a more convenient, reasonable and credible quality control method for the traditional Chinese medicine.