title: Simple and specific electron-capture GLC assay for plasma and urine ephedrine concentrations following single doses.
abstract: An electron-capture GLC procedure for determination of plasma ephedrine concentrations is described. The procedure is capable of determining 2 ng/ml of ephedrine and is adequate for following profiles after 25-mg single doses. Pentane extraction of the drug and the internal standard and formation of the N-pentafluorobenzoyl derivatives were followed by GLC. Plasma ephedrine concentrations following a 24-mg dose of ephedrine hydrochloride to a human volunteer are presented. Formation of N-trifluoroacetyl, N-pentafluoropropionyl, N-heptafluorobutryl, and N-pentafluorobenzoyl derivatives and their GLC-mass spectrometric identification are discussed together with comparative electron-capture sensitivities of these derivatives toward a nickel-63 detector. The detection of the N-pentafluorobenzoyl derivative of ephedrine is at least 100-fold greater in sensitivity than detection of the N-trifluoroacetyl derivative.
mesh_terms: D002849:Chromatography, Gas / Q000379:methods; D004809:Ephedrine / Q000032:analysis* / Q000097:blood / Q000652:urine; D006801:Humans; D007202:Indicators and Reagents; D008297:Male; D008722:Methods
chemical_list: D007202:Indicators and Reagents; D004809:Ephedrine