A simple method for simultaneous determination of six alkaloids (ephedrine, pseudoephedrine, norephedrine, norpseudoephedrine, methylephedrine and methyl-pseudoephedrine) in Ephedrae Herba by high-performance liquid chromatography was developed. It was carried out by using a Cosmosil 5C18-MS column with a gradient solvent system consisted of phosphate buffer and acetonitrile at 210 nm. The contents of alkaloids in non-pretreated Ephedra extracts could easily be determined in 50 min.
