Improvement of the immobilization method of a chiral selector, (S)-α-(1-naphthyl) ethylamine, for high performance liquid chromatography and its separation properties

Abstract

Monoamide type chiral stationary phases for high performance liquid chromatography were synthesized from (S)-α-(1-naphthyl)ethylamine using a new immobilizing method. In this procedure, the silanol groups on silica gel, which hinder the interaction between sample molecules and chiral selector, were initially treated with dimethylchlorosilane. The enantioselectivity was evaluated by changing the coverage density of the chiral selectors. It was found that when the coverage density was 0.268 groups/nm² (0.156 mmol/g), the enantioselectivity was great. This indicates that chiral selector can interact with sample molecules more efficiently without silanol interference.