高效液相色谱手性固定相法拆分和测定乳酸左氧氟沙星中乳酸对映体

Separation and Determination of Lactic Acid Enantiomers in Levofloxacin Lactate by HPLC Chiral Stationary Phase Method

建立了高效液相色谱手性固定相法拆分和测定乳酸左氧氟沙星中乳酸对映体的方法。考察了CuSO4溶液浓度和异丙醇比例对乳酸对映体和左氧氟沙星分离情况的影响。采用Phenomenex 3126(D)-Penicillamine手性色谱柱,优化流动相为2.5 mmol/L CuSO4溶液-异丙醇(体积比为93∶7),乳酸对映体达到基线分离。以L-乳酸锂和水解后的D-乳酸为标准品,解决了直接采用乳酸为标准品导致测定结果有偏差的问题。L-乳酸和D-乳酸在20~400μg/mL范围内线性良好,相关系数R^(2)分别为09999和0.9998。重复性实验得到的相对标准偏差(RSD)为0.7%~0.8%,回收率为98.77%~100.1%(RSD≤1.0%),准确度和精密度良好。该方法简便,适用于乳酸左氧氟沙星中乳酸对映体含量的测定。

A method was established for the separation and determination of lactic acid enantiomers in levofloxacin lactate by HPLC chiral stationary phase method.The chromatographic separation was performed on a Phenomenex 3126(D)-Penicillamine chiral chromatography column with the optimized mobile phase consisting of 2.5 mmol/L copper sulfate solution-isopropanol(93∶7,V/V).As a result,the lactic acid enantiomer peaks reached baseline separation.To solve the problem of deviation in the determination result of lactic acid as standard,L-Lactic acid lithium and D-lactic acid after hydrolysis were used as the standards.The calibration curves of L-lactic acid and D-lactic acid exhibited good linearity throughout the range 20-400μg/mL(R^(2)=0.9999 and 0.9998,respectively).Method validation parameters were showed good accuracy and precision(0.7%-0.8%for the RSD of reproducibility,98.77%-100.1%and RSD≤1.0%for recoveries,respectively).The method is simple and suitable for the determination of lactic acid enantiomers content in levofloxacin lactate.