title: Determination of dextro- and levomethorphan mixtures using chiral lanthanide NMR shift reagents.
abstract: Europium and praseodymium chiral NMR shift reagents were used to differentiate between dextro- and leveomethorphan. The enantiomeric shift differences (delta delta delta) demonstrated by the singlet associated with the methoxy protons were large enough to identify the levo- and dextro-isomers and to allow for the determination of as little as 10% of one enantiomer in the presence of the other in a prepared mixture. The analytical method is rapid and can analyze samples as small as 1 mg.
mesh_terms: D003915:Dextromethorphan / Q000032:analysis*; D007202:Indicators and Reagents; D007981:Levorphanol / Q000031:analogs & derivatives*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008674:Metals, Rare Earth; D013237:Stereoisomerism
chemical_list: D007202:Indicators and Reagents; D008674:Metals, Rare Earth; D007981:Levorphanol; D003915:Dextromethorphan