Optical purity determination by NMR: use of chiral lanthanide shift reagents and a base line technique.
A method for optical purity determination of a range of chiral drug molecules by NMR spectroscopy is reported. This technique involves the use of optically active lanthanide shift reagents and a newly developed base line analysis. Its applicability was demonstrated for a variety of drugs including nonsteroidal antiinflammatory agents and some adrenergic agents. It is established that successful application of the method depends on a constant shift reagent to sample molar ratio, constant instrumental conditions for all solutions, and the use of a calibration curve derived from solutions containing the same total concentration of the two enantiomers. For the examples cited, the correlation coefficient is not less than 0.97, and a mathematical treatment is included which supports the basis of the method.
D000893:Anti-Inflammatory Agents / Q000302:isolation & purification; D004809:Ephedrine / Q000302:isolation & purification; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008674:Metals, Rare Earth; D004364:Pharmaceutical Preparations / Q000302:isolation & purification*; D011433:Propranolol / Q000302:isolation & purification; D013237:Stereoisomerism
D000893:Anti-Inflammatory Agents; D007202:Indicators and Reagents; D008674:Metals, Rare Earth; D004364:Pharmaceutical Preparations; D011433:Propranolol; D004809:Ephedrine