Investigation of the silylation of ephedrines using N-methyl-N-trimethylsilyl-trifluoroacetamide.

This paper describes a gas chromatography (GC)--mass spectrometry (MS) method for the simultaneous quantification of ephedrine, pseudoephedrine, cathine, norephedrine and methylephedrine in urine. The sample preparation step includes solid phase extraction and derivatisation with N-methyl-N-trimethylsilyl-trifluoroacetamide (MSTFA). An evaluation of various silylation conditions compatible with screening methods in doping control analysis is presented. The method was found to be well suited for quantification of ephedrines in doping control.