Determination of Ephedrine and Pseudoephedrine in Yanyangke Mixtures by HPLC
Objective: To establish a method for the simultaneous determination of ephedrine and pseudoephedrine in Yanyangke mixtures by HPLC. Method: The quantitative analysis was earned out on an Agilent ZORBAX SB-C18( 250 mm x4. 6 mm,5 μm )col-umn using the mobile phase of acetonitrile-0. 01 mol · L-1 potassium dihydrogen phosphate ( adjusting pH to 2.5 with phosphoric acid )-triethylamine( 5: 95 :0. 15 ) at a flow rate of 1. 0 ml · min-1. The detection wavelength was 208 ran. Result: The linear range of ephedrine was 9. 0-56. 3μg · ml -1( r =0. 999 6 ) and that of pseudoephedrine was 6. 9-42. 9μg · ml ( r =0. 999 6 ). Both the recoveries were between 95% and 105%( RSD <2% ). Conclusion: The method is simple, reproducible and specific.