mono-Brominated-Propyphenazone as a New Derivatization Reagent for High Performance Liquid Chromatography of Ephedrine with UV-Detection

mono-brominated-propyphenazone was used as a derivatization reagent for the detection and quantification of ephedrine by high performance liquid chromatography using Zorbax-XDB C18 column, and 0.02 M sodium acetate (pH 4.4): acetonitrile (52:48 v/v) as mobile phase and UV detection at 280nm. The cited reagent reacts with the secondary amino group of ephedrine in acetone using anhydrous potassium carbonate as hydrobromide acceptor. The reaction was completed within 20 minutes in 100 μL acetone with heating at 90 ± 5°C in a capped mini reaction vial. The stoichiometry of the reaction was one-to-one mol from each mono-brominated-propyphenazone and ephedrine. The linear concentration range of ephedrine was 30 to 900 ng per injection (50 μL). The detection limit was 9 ng/injection (50 μL). The derivatized ephedrine was synthesized and confirmed with spectral analysis. This method was applied for determination of spiked ephedrine in human urine and after extraction with charcoal column using methanol: 0.2 M NaOH (20:0.2, mL:mL) as eluant.