The Significance of the HPLC Time Scale: An Example of Interconvertible Enantiomers

Abstract

Racemization during high-performance liquid chromatography (HPLC) on optically active sorbents generates peak coalescence/decoalescence phenomena. It is shown that they may serve useful in proving the interconvertibility of enantiomers or, in other cases, the chirality of molecules. In addition, racemizations during HPLC at certain temperatures give advice concerning the preparative separation and the subsequent experimental investigation of interconvertible enantiomers. HPLC of (MP)-1-dimethylamino-8-dimethylcarbamoylnaphthalene (Fig. 1) on triacetylcellulose at variable temperature and variable flow rate exemplifies these stereochemical applications. The «HPLC time scale» is discussed with reference to the time scale of nuclear magnetic resonance (NMR).