Determination of two kinds of alkaloids in Zhitong Capsule by HPLC / 中成药

ABSTRACT

AIM:To establish a HPLC method for determining contents of tetrahydropalmatine and pepper alkali in Zhitong Capsule(Rhizoma Corydalis,Fructus Piperis,Radix Paeoniae alba,etc.)to control its quality.METHODS:The samples were extracted in water by ultrasonic wave,and then extracted by aether to refine after being acidized by 1 mol/mL HCl.Following that the pH of water solution was adjusted to 9.0-10.0 by NH_3?H_2O,and then extracted by aether again.After that,the aether solution was collected to evaporation to dryness and metered by methanol.The sample solution was determined by high performance liquid chromatography on a Hypersil ODS 2 C_ 18 column(4.6 mm?250 mm,5 ?m)with mobile phase composed methanol-0.1% phosphoric acid water solution(the pH was adjusted to 6.0 by triethylamine)(55∶45).The flow rate was 1.0 mL/min,the column temperature was at 30 ℃ and the signal from 0 to 14.5 minutes were acquired at 280 nm,and that from 14.5 to 22 minutes were detected at 328 nm.RESULTS:The resolution of tetrahydropalmatine and pepper alkali was good,with no miscellaneous peak.The linear range was at 0.196-1.96 ?g(r=0.999 6)for tetrahydropalmatine,0.03-0.3 ?g(r=0.999 7)for pepper alkali.The average rate of recovery of tetrahydropalmatine was 97.74%(RSD= 0.42%,n=6),and that of pepper alkali was 104.51%(RSD=2.01%,n=6).CONCLUSION:The method is simple,reliable,accurate and can be applied to the quality control of the preparation.