Enantiomeric separation of phenylsuccinic acid by cyclodextrin-modified reversed phase high-performance liquid chromatography

The chiral separation of phenylsuccinic acid (PSA) was studied by reversed phase high-performance liquid chromatography (RP-HPLC) with cyclodextrins (CDs) as chiral mobile phase additives. The effects of types of CDs, concentration of hydroxypropyl-β-cyclodextrin (HP-β-CD), percentage of organic modifier, pH value and column temperature on enantioselective separation were investigated. The quantification property of the developed RP-HPLC method was examined. The chiral recognition mechanism of PSA was also discussed. The results show that a baseline separation of PSA enantiomers is achieved on a Lichrospher C18 column (4.6 mm (inner diameter)×250 mm, 5 μm) with HP-β-CD as chiral mobile phase additive. The capacity factors of R-PSA and S-PSA are 3.94 and 4.80, respectively. The separation factor and resolution are respectively 1.22 and 8.03. The mobile phase is a mixture of acetonitrile and deionized water (20:80, volume ratio) containing 10 mmol/L HP-β-CD and 0.05% trifluoroacetic acid (pH 2.5, adjusted with triethylamine) with a flow rate of 1.0 mL/min. The ultraviolet (UV) detector is set at 254 nm. The likely roles are inclusion interaction, induction and hydrogen bonding between HP-β-CD and PSA enantiomers. Foundation item: Project(20776038) supported by the National Natural Science Foundation of China