Enantiomeric separation of synthetic 2,3-dihydroxy-3-phenylpropionate compounds by β-cyclodextrin-modified capillary electrophoresis

A new capillary electrophoretic method was developed for enantiomeric separation and optical impurity analysis of three synthetic 2,3-dihydroxy-3-phenylpropionate compounds using native β-cyclodextrin (β-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in uncoated capillary (58.5 cm × 75 μm I.D., effective length 48.5 cm). The results showed that β-CD as the chiral selector exhibited good enantioselectivity and the baseline separation was obtained at pH 9.8, 200 mM borate buffer containing 1.7% β-CD at applied voltage 15kV and capillary temperature 20 °C within 15 min. The precision of each tested compound was less than 1.0% at migration time and 5.0% in corrected peak area and the accuracy of the method was in the range of 98.7–105%. Furthermore, the developed method was successfully applied to the determination of the undesirable trace (2S,3R)-(+)-form impurity in the synthetic (2R,3S)-(−)-2,3-dihydroxy-3-phenylpropionate samples.