ABSTRACT
0.999). The relative standard deviation (RSD) of chromatogram area was less than 1.0% for all of them after six successive injections. The detection limit was 0.05 ?g/mL for norephedrine (NE), 0.04 ?g/mL for norpseudoephedrine (NPE), 0.1 ?g/mL for E and PE, and 0.2 ?g/mL for mephedrine (ME) and mepseudoephedrine (MPE), respectively (S/N≥3). The recovery rate was more than 97.1% for six ephedrine alkaloids. Under this method system, all of the above-mentioned six samples were tested and found to contain some of the impurity at different levels. Conclusion This developed method, which is very simple, perfect precision, high sensitivity, and selectivity, can be used for the qualitative and quantitative determination of impurities of ephedrine alkaloid-type samples.