Simultaneous Determination of Contents of Matrine and Oxymatrine in Sophora tonkinensis Gagnep. by HPLC

Objective To purificate matrine and oxymatrine in Sophora tonkinensis Gagnep. by ion exchange resin and to establish a method for determining the two components by RP-HPLC. Methods The separation was performed on a C 18 column with a mobile phase composed of acetonitrile-0. 2 % phosphoric acid solution-triethanolamine( 8∶ 92∶ 0. 01; V / V / V) after the sample was extracted and purified with ion exchange resin. The detection wavelength was set at 208 nm. Results Matrine and oxymatrine had a retention time of approximately 5. 5 min and 8. 1 min,respectively. The peak shape was clear and symmetrical,and the analysis time was about 10 min per injection. Good linear correlations were observed when the amount of injection ranged from 1. 0 to 300. 0 μg·ml- 1for matrine( r2= 0. 9996) and 2. 0 to 600. 0 μg·ml- 1for oxymatrine( r2=0. 9998). The average recovery of matrine and oxymatrine was 90. 5% and 91. 6% respectively for the Sophora tonkinensis Gagnep. samples. Conclusion A simple HPLC method has been established and validated for simultaneous analysis of matrine and oxymatrine in Sophora tonkinensis Gagnep.