Enantiomeric separation of chiral amines in biological samples by liquid chromatography with chiral fluorous derivatization

Abstract

AbstractA novel chiral derivatization liquid chromatography method, combined with fluorous separation technology, was developed in this study. N‐(Perfluoroalkylcarbonyl)‐l‐proline succinimidyl ester, synthesized from perfluoroalkylcarboxylic acids (C5F11COOH, C7F15COOH, or C9F19COOH), L‐proline, and N‐hydroxysuccinimide, was used as the chiral derivatization reagent. In this study, chiral compounds containing perfluoroalkyl groups were reacted with enantiomeric amino analytes to form diastereomeric derivatives, which can be chirally separated on a conventional liquid chromatography column. Furthermore, by using a fluorous‐phase liquid chromatography column, the derivatives were strongly retained owing to the fluorous affinity and could be separated from the contaminating components in the matrix. In this study, amino groups were selected as derivatization targets, and (R,S)‐1‐phenylethylamine was used as the model compound. The effect of the perfluoroalkyl chain length of the chiral reagent on enantiomeric separation was investigated using fluorous‐phase and reversed‐phase liquid chromatography columns and the optimal perfluoroalkyl chain length was determined. (R,S)‐1‐Phenylethylamine was added to human serum and urine samples to confirm separation from the contaminants. Consequently, chiral separation was achieved without contaminant detection.