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 diastere
oisomeric sympathomimetic amines, and methyl-ephedrine was developed for do
ping control analysis in urine samples. O-Trimethylsilylated and N-mono-tri
fluoroacetylated derivatives of ephedrines - one derivative was formed for
each ephedrine - were prepared and analyzed by CC-MS, after alkaline extrac
tion 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, ac
curacy, and recovery) are also presented. (C) 2001 Elsevier Science B.V. Al
l rights reserved.