Preparation and Evaluation of New Cellulose Acetylsalicylate Chiral Stationary Phase

Cellulose acetylsalicylate chiral stationary phase (ACSP) was synthesized by using cellulose and o-acetylsalicylryl chloride, and its enantioseparation ability was evaluated by high performance liquid chromatography (HPLC). Commercial Chiralcel OJ column was evaluated for comparison. The effects of mobile phase composition and double ester carbonyls of derivative on enantioseparation were investigated. The structure of the obtained derivative was characterized by infrared (IR) spectroscopy and thermogravimetric analysis. Hexane-isopropanol (90:10–80:20, V/V, 0.1% DEA or TFA) was selected by comparison of four mobile phases, namely hexane-isopropanol, hexane-ethanol, hexane-methanol-isopropanol and hexane-methanol-dichloroethane. Seven racemates of catecholamines and amides were used to evaluate its chiral recognition ability in normal phase elution mode, and the regularity and characteristics of the novel chiral stationary phase were explored. The chromatographic results showed that cellulose ACSP exhibited high enantioseparation ability for catecholamines and some racemates with amide group due to the hydrogen-bond, dipole interaction of carbonyls of acetylsalicylate and the π-π interaction with benzene ring, and the optimum amount of diethylamine or trifluoroacetic acid was 0.1%.

Cellulose acetylsalicylate exhibited high enantioseparation ability for catecholamines and some racemates with amide group due to the hydrogen bonding and dipolar interaction of double esterfunctions in cellulose derivative. In addition, different mobile phases showed different chiral recognition abilities on this new chiral stationary phase.Figure optionsDownload as PowerPoint slide