NMR quantitative analysis - The application of lanthanide shift reagents.

Abstract

Though NMR has many applications in analytical chemistry, it has not been widely used for quantitative analysis. This has been due partly to high instrumental cost and relatively poor sensitivity. With advances in instrumentation and the development of new techniques, the full potential of nmr for quantitative studies is now being investigated. The use of nmr for quantitative analysis has been reviewed with particular reference to pharmaceuticals. The basis of the nmr quantitative analysis and the factors affecting the suitability of the technique have been outlined. The theory and application of lanthanide shift reagents have been considered with emphasis on optical purity determination. Chiral lanthanide shift reagents have been used successfully to determine enantiomeric ratio of many optically active compounds. Three methods, namely, the base line technique, chemical shift difference and peak height difference methods have been developed to overcome the problem of accurate measurement of broad resonance peaks normally associated with the use of lanthanide shift reagents. The application of the base line technique has been extended to nonenantiomeric compounds. Modification of structures of some compounds is sometimes necesarry before the application of lanthanide shift reagents. An account of compounds which need modification has been given. The increasing number and complexity of pharmaceutical preparations encounted in routine analysis of drugs requires the application of techniques that are rapid, specific and accurate. In this thesis nmr as a quantitative tool for pharmaceuticals is fully investigated. Many pharmaceuticals of different, dosage forms have been assayed successfully by the use of nmr. A colorimetric method has been used for the kinetic studies of 'Benoral' suspension, a preparation containing benorylate (4-acetamido-phenyl 2-acetoxybenzoate). The suspension has been found to be quite, stable despite the two ester groups in the benorylate molecule.

Date of Award	1979
Original language	English
Awarding Institution	University of Bath