高效液相色谱法对泡菜中L-乳酸和D-乳酸的手性分离和测定

采用高效液相法和手性分离柱对泡菜发酵上清液中的L-乳酸和D-乳酸进行分离和测定.泡菜的培养上清液用8000 r/min 离心20 min,再用0.45 μm滤膜过滤.滤液用配备二极管阵列检测器的高效液相系统检测,检测波长为254 nm.检测色谱柱为手性柱Chirex 3126 (D)-penicillami (4.6 mm i.d×250 mm L, 5 μm),流动相为2 mmol/L CuSO4溶液(溶剂为5 %的异丙醇溶液).L-乳酸和D-乳酸的标准曲线在2.5-20.0 g/L范围线性良好,两者的线性相关系数都为0.999.泡菜滤液的L-乳酸和D-乳酸的回收率分别是99.82 %和100.02 %.该方法操作简便,精密度和准确度高,适用于泡菜中L-乳酸和D-乳酸的测定.

Chiral Separation and Determination of L-and D-lactic Acid in Pickles by High-performance Liquid Chromatoraphy

A new method for the separation and determination of L- and D-lactic acid in pickles supernatants by high-performance liquid chromatography (HPLC) with a chiral colomn was studied here. The culture supernatants of pickles were centrifuged for 20 min at 8000 r/min and the supernatant fractions were filtered through a 0.45 µm membrane. The samples were then analyzed by HPLC on chiral columns with a PDA detector at 254 nm. High separation efficiency was achieved by using a Chirex 3126 (D)-penicillami column (4.6 mm ID×250 mm L, 5 µm) and a mobile phase consisting of CuSO4 (2 mmol/L) and isopropyl alcohol-water (5:95). The calibration curves of L-and R- lactic acid were linear with regressions being of 0.999 in the concentration range of 2.5~20.0 g/L. The average recovery was 99.82% for D--lactic acid and 100.02% for L-lactic acid in filtrate of pickles. The method was simple and easy to operate with high accuracy and reproducibility and it was suitable for detection the concentration of L- and D-lactic acid in pickles.