Simultaneous quantification of ephedrines in urine by high-performance liquid chromatography.

A high-performance liquid chromatographic method for the simultaneous determination of ephedrine, pseudoephedrine, phenylpropanolamine, norpseudoephedrine and methylephedrine in urine is described. Samples were extracted at basic pH into diethyl ether and then back extracted into a small volume of acetic acid. These extracts were chromatographed on a Phase Sep Spherisorb ODS 1 column with tetraethylammoniumphosphate-methanol mobile phase and the analytes were detected by UV absorbance at 214nm. Calibration curves were linear over the range 0.5-100 microgram/ml for each analyte. The selectivity of the method was demonstrated for several drugs found with the ephedrines in pharmaceutical formulations. This method has an excellent accuracy, precision and recovery for all the ephedrine at the cut-off concentrations as set by the IOC for a positive doping case and can thus be used to quantify these ephedrines when present in the urine obtained from sportspersons.