Enantiomeric selection high-performance liquid

The measurement of warfarin enantiomers in serum using coupled achiral/chiral high-performance liquid chromatography" (110), An assay for the serum concentrations of (fi)-warfarin and (S)-warfarin was developed using the BSA CSF coupled to a Pinkerton internal-surface reverse-phase (ISRP) achiral column. The ISRP column was used to separate (R,S)-warfarin from the serum components and warfarin metabolites and to quantitate the total warfarin concentration. The eluent containing the (A,S)-warfarin was then selectively transferred to the BSA CSR where the enantiomers were enantioselectively resolved (a = 1.19) and the enantiomeric composition determined. 

The resulting electropherogram is displayed in Figure 20.7, which shows the separation of all eight molecules. The separation was performed in Tris buffer that contained sulfated-P-cyclodextrin and hydroxypropyl-P-cyclodextrin, which provided the enantiomeric selectivity. Metabolites were quantified from 0.41 to 0.89 p.M with relative standard deviations of 10%. The subcellular analysis shows the preferential production of (-)-(/ )-metabolites (Table 20.1). Compared with a previously reported high-performance liquid chromatography (HPLC) method, " the CE method allowed these researchers to quantify two more metabolites and required less time. 

A unified theory recently proposed to explain the manner of sorption and the form of sorption isotherm in gas, liquid, and ion-exchange chromatography is presented in some detail. Selectivity in reversed-phase high-pressure liquid chromatography is explored at length. Several chapters deal with characterization of bonded phases, relationship of column-packing structure and performance, variability of reversed-phase packing materials, and the differences between silica-based reversed-phase and poly(styrene-divinylbenzene) columns. A short review is included to cover various approaches used in HPLC to achieve the desired selectivity for resolution of enantiomeric compounds. 

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