Simultaneous determination of 11 alkaloids in crude and wine-processed Rhizoma Coptidis by HPLC-PAD

A high-performance liquid chromatography method coupled with photo array diode detector has been developed and validated for simultaneous quantification of 11 active alkaloids in Rhizoma Coptidis (R.C.). The analysis was performed on a Benetnach-C18 column (250 × 4.6 mm, i.d., 5 μm) using binary gradient elution with 30 mmol/L ammonium bicarbonate water containing 0.7% ammonia solution and 0.1% triethylamine (A) and acetonitrile (B) at a flow rate of 1 mL/min, a column temperature of 35°C and UV detection at 275 nm. All calibration curves showed good linear regression (r > 0.9993) in the range of 6.94-111.03, 0.625-10.10, 6.27-100.14, 31.88-510.50, 16.25-260.70, 19.88-18.20, 3.13-50.70, 0.125-2.14, 16.44-263, 62.5-1,000, 0.125-2.14 μg/mL for magnoflorine, noroxyhydrastinine, jatrorrhizine, columbamine, epiberberine, coptisine, berberubine, worenine, palmatine, berberine, oxyberberine, respectively. It also showed good precision, repeatability and stability for quantification of these 11 alkaloids. The limit of detections and limit of quantitations for the analytes ranged from 0.031 to 0.423 μg/mL and from 0.094 to 1.27 μg/mL, respectively. This method was effective and rapid. The optimized method, which was applied to the determination of alkaloids in crude and wine-processed R.C. samples, was found to be feasible, reliable and suitable for their routine quality control.