Simultaneous determination of four components in Sanhuang tablets by RP-HPLC

Objective To establish a RP-HPLC method for simultaneously determining berberine hydrochloride, baicalin, emodin and chrysophanol in Sanhuang tablets. Methods The analysis was performed on an Thermo Hypersil GOLD aQ column (250 mm×4.6 mm, 5.0 μm) with gradient elution of methanol and 0.1% orthophosphoric acid at the flow rate of 1.0 ml/min. The column temperature was 30 ℃, and the detection wave length was 254 nm. Results The peaks of berberine hydrochloride, baicalin, emodin and chrysophanol were successfully separated from each other. The liner ranges of calibration curves were 0-0.6348 μg (r=0.999 9), 0-1.017 2 μg (r=0.999 9), 0-0.802 4 μg (r=0.999 9), 0-0.967 2 μg (r=0.999 9). The average recoveries (n=9) were 101.03%, 99.81%, 99.35%, 99.54%, respectively. The limits of quantification (LOQs) were 0.036 3, 0.021 0, 0.049 7, 0.079 3 mg/g, respectively. The sample solution was stable within 24 h, the RSD (n=5) were 0.48%, 0.56%, 0.68%, 0.49%, respectively. The robustness was investigated by varying the conditions of column temperature (± 1 ℃) and flow rate (± 0.1 ml/min), with the RSD s 0.57% and 0.42%, 0.44% and 0.65%, 0.74% and 0.29%, 0.46% and 0.56%, respectively. The contents of berberine hydrochloride, baicalin, emodin and chrysophanol in twelve samples were 4.630 3-5.586 6, 14.551 4-18.818 9, 0.171 1-2.798 4, 0.529 9-2.925 4 mg/tablet, respectively. Conclusion The establish method is validated to be suitable for quality control of Sanhuang tablets. Key words: Chromatography, reverse-phase; Sanhuang tablets; Berberine; Baicalin; Emodin; Chrysophanol; Quality control; Assay (TCD)