Abstract:

A method was established for the enantioseparation of atrolactic acids using high performance liquid chromatography with sulfobutyl ether-β-cyclodextrin (SBE-β-CD) as the chiral mobile phase additive, and a C₁₈ reversed-phase column. The influences of the different types of cyclodextrin derivatives, the concentration of chiral mobile phase additive, pH value of the mobile phase, the flow rate and column temperature on the peak resolution were investigated. The separation mechanism for atrolactic acids by high performance liquid chromatography using chiral mobile phase additive, as well as the formation of inclusion complex between SBE-β-CD and atrolactic acid was studied. In addition, the formation constant was calculated. The enantioseparation was carried out on a reversed-phase column YMC-Pack ODS-A C₁₈ (250 mm×4.6 mm, 5 μm) with chiral mobile phase consisted of 0.1 mol/L phosphate buffer at pH 2.68 containing 25 mmol/L SBE-β-CD-acetonitrile (90:10, v/v). The detection wavelength was 220 nm. The flow rate was 0.6 mL/min and the column temperature was 30 ℃. The retention times of atrolactic acids were 26.65 and 28.28 min, and the peak resolution of 1.68 was achieved. The above established method proves to be a simple and economical way for analytical enantioseparation of atrolactic acid with high peak resolution.

Key words: atrolactic acid, chiral mobile phase addition, enantioseparation, high performance liquid chromatography (HPLC), sulfobutyl ether-β-cyclodextrin (SBE-β-CD)