The Use Of Supercritical Fluid Chromatography (sfc) And Liquid Chromatography (lc) For The Separation Of Pharmaceutical Products, Natural Products And Chiral Phosphoric And Sulfonic Acids

Abstract

This dissertation focuses on two chromatographic techniques, supercritical fluid chromatography (SFC) and high performance liquid chromatography (HPLC). The goal of the SFC work is to describe the synthesis of new stationary phases based upon ionic liquids and to discuss their application to the separation of pharmaceutical compounds. The tunable nature of immobilized ionic liquids will be demonstrated by the variation of the cation-anion combination.The goal of the remaining chapters is to demonstrate HPLC applications for analyzing natural products and for performing enantiomeric separations. The usefulness of HPLC in separating antioxidants in rosemary and in conducting a degradation study of the main antioxidants will be demonstrated. The sections dealing with enantiomeric separations will show, firstly, the important role vancomycin-based chiral stationary phases (CSPs) play in providing answers regarding the stereoisomeric distribution of flinderole B in nature and in separating its related bisindole alkaloid enantiomers. Secondly, novel separations of chiral anionic compounds will be presented for the new cyclo-oligosaccharide, cyclofructan 6, by exploiting its ionophoric proclivity for barium cations. The ability to tune retention and enantioselectivity of cyclofructan-barium CSPs by varying the kosmotropicity/ chaotropicity of the counter anion will be demonstrated.