Indirect enantioseparation of proteinogenic amino acids using naproxen-based chiral derivatizing reagent and HPLC.

Diastereomers of 18 proteinogenic amino acids were synthesized under microwave irradiation and by vortexing using (S)-naproxen-benzotriazole as chiral derivatizing reagent. The diastereomers synthesized by two approaches were found to be identical in terms of their characterization and chromatographic data. A linear gradient of triethylammonium phosphate (pH 3.5)-acetonitrile (30-65%, within 35 min) was found to be successful using reversed-phase high-performance liquid chromatography for their separation. Detection was carried out at 231 nm and sharp peaks were obtained. The method was validated for accuracy, precision and limit of detection.