DEVELOPMENT OF REVERSED-PHASE CHIRAL HPLC METHODS USING MASS SPECTROMETRY COMPATIBLE MOBILE PHASES

Abstract

The majority of chiral HPLC separations are performed in the normal-phase mode using alcohol-modified hexane mobile phases. Normal-phase chiral HPLC methods are not routinely coupled with electrospray ionization mass spectrometry (ESI-MS) because of the mobile phase incompatibility. In this study, we investigated the use of ESI-MS compatible mobile phases for chiral HPLC methods. This would enable the sensitivity and selectivity of LC/MS to be applied to chiral HPLC analyses. We used a commercially available reversed-phase chiral HPLC column (Chiralcelr® OD-R) that permits the use of aqueous organic-modified mobile phases. This paper describes the development of direct, isocratic, and simple reversed-phase chiral HPLC methods for the separation of enantiomers of benzoin, indapamide, 2-phenylbutyric acid, 3-phenylbutyric acid, trans-2-phenylcyclopropane-1- carboxylic acid, verapamil hydrochloride, and pindolol. In addition, we also demonstrate that the reversed-phase chiral HPLC methods developed in this study can be directly coupled with ESI-MS without any modifications. Examples of reversed-phase chiral high performance liquid chromatography-mass spectrometry (RP Chiral-LC/MS) methods are shown for indapamide and pindolol.