Determination of the “enantiomeric excess” of hexahelicene and its methyl-substituted derivatives by high-performance liquid chromatography

Abstract

Resolution of the enantiomers of hexahelicene and several of its derivatives using an improved high-performance liquid chromatographic technique is described. The procedure allows the determination of a less than 0.5% enantiomeric excess with an high accuracy and reproducibility within a short elution time. (20 min for hexahelicene). The results of the resolution of substituted hexahelicenes are discussed. Two types of columns are described which are capable of the partial resolution of helicene enantiomers on a larger scale. The columns are also suitable for the separation of polycyclic aromatic hydrocarbons. This is illustrated by the analysis and separation of a distillation fraction of creosote containing several polycyclic aromatic components.