Determination of ephedrines in urine by gas chromatography-mass spectrometry

A selective gas-liquid chromatographic method with mass spectrometry (GC-MS) for the simultaneous confirmation and quantification of ephedrine, pseudo-ephedrine, nor-ephedrine, nor-pseudoephedrine. which are pairs of diastereoisomeric sympathomimetic amines, and methyl-ephedrine was developed for doping control analysis in urine samples. O-Trimethylsilylated and N-mono-trifluoroacetylated derivatives of ephedrines - one derivative was formed for each ephedrine - were prepared and analyzed by CC-MS, after alkaline extraction of urine and evaporation of the organic phase, using d(3)-ephedrine as internal standard. Calibration curves, with r(2)>0.98. ranged from 3.0 to 50 mug/ml depending on the analyte. Validation data (specificity. % RSD, accuracy, and recovery) are also presented. (C) 2001 Elsevier Science B.V. All rights reserved.