高效液相色谱手性流动相添加法拆分奥昔布宁对映体

采用C18固定相,以羟丙基-β-环糊精为手性流动相添加剂,建立了奥昔布宁对映体的高效液相色谱拆分方法。考察了手性添加剂、有机极性调节剂、缓冲盐的种类和浓度以及流动相的pH值和流速及柱温等因素对对映体分离的影响。在最佳分离条件下,奥昔布宁对映体的分离度为1.54,检测限为1.0 ng。该方法简便,重复性好,比手性固定相法更加经济。

High performance liquid chromatographic separation of oxybutynin enantiomers using chiral mobile phase additive

A simple and effective method for the separation of oxybutynin enantiomers was developed using high performance liquid chromatography with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as the chiral mobile phase additive and a C18 reversed-phase column as the stationary phase. beta-CD and HP-beta-CD were investigated as chiral mobile phase additives separately. The results showed that oxybutynin enantiomers could not be separated when adding beta-CD in the mobile phase, but optimal resolution was obtained when using HP-beta-CD as the chiral mobile phase additive. Excellent enantioseparation was achieved with the mobile phase composed of 30 mmol/L KH2PO4-acetonitrile(80:20, v/v) mixed with 60 mmol/L HP-beta-CD at pH 4.0. The detection wavelength was set at 223 nm and the column temperature was set at 28 degrees C with a flow rate of 0.8 mL/min. Under the optimized conditions, the resolution of enantiomers was 1.54 and the limit of quantitation was 1.0 ng. Comparing with chiral stationary phase chromatography, the method was simple, economic and considerably reproducible.