Simultaneous determination of seven alkaloids in Phellodendron chinense Schneid by high-performance liquid chromatography

By optimizing the extraction, separation, and analytical conditions, a reliable and accurate HPLC method coupled with a photodiode array detector was developed for simultaneous detection and quantification of seven alkaloids, i.e., (-)-(R)-platydesmin, noroxyhydrastinine, berberine, skimmianine, canthin-6-one, chilenine, and pteleine in "huangbo" (the bark of Phellodendron chinense), a commonly used herb in Traditional Chinese Medicine. The optimal condition for separation was achieved on a reversed-phase Cis column with a stepwise mobile phase gradient prepared from 0.1% phosphoric acid and acetonitrile. For all the alkaloids, a good linear regression relationship (r > 0.9997) was obtained between the peak area and concentration at the range of 0.5-700 microg/mL. The LODs and LOQs for the analytes ranged from 0.07 to 0.28 microg/mL and from 0.28 to 1.12 microg/mL, respectively. The optimized method was applied to the determination of alkaloids in several P. chinense samples, and found to be feasible and reliable. This method and quantitative results can provide scientific and technical bases for setting up QC standards to assure the safety and quality of P. chinense bark raw material, as well as for proprietary Chinese medicine products containing P. chinense bark.