毛细管电泳法同时测定发酵制品中D-和L-乳酸含量

摘要

Usually,both D-and L-lactic acids exist in the fermentation products. But D-lactic acid intake should be limited. So,developing an accurate method for the determination of D-and L-lactic acids in fermentation products is very important for controlling food quality and guaranteeing food security. We established a capillary electrophoresis assay for the simultaneous determination of D-and L-lactic acids in fermentation products, and investigated the effects of 2-hydroxypropyl-β-cyclodextrin concentration,pH value of buffer solution,separation voltage,and separation temperature on the chiral separation of lactic acid. Results showed that D-and L-lactic acids reached the baseline separation,and the resolution was 1. 5 under the conditions as follows:using neutral capillary,500 mmol·L-12-hydroxypropyl-β-cyclodextrin as a chiral selector, 200 mmol·L-1 phosphate buffer (pH value 6. 0) as electrophoretic buffer,separation voltage of -20 kV,and column temperature of 20 ℃.%发酵制品中的乳酸通常是D,L-混合型,而D-乳酸的每日摄入量是有限制的.因此开发准确测定发酵制品中D-和L-乳酸含量方法,对于控制食品品质、保障食品安全具有重要意义.建立了同时测定发酵制品中D-和L-乳酸含量的毛细管电泳分析方法,考察了2-羟丙基-β-环糊精浓度、缓冲溶液pH值、分离电压、分离温度等因素对乳酸手性分离的影响.结果表明,使用中性毛细管,以500 mmol·L-12-羟丙基-β-环糊精为手性选择剂,200 mmol·L-1磷酸缓冲液(pH值为6.0)为电泳缓冲液,在分离电压为-20 kV、分离温度为20℃条件下可使D-和L-乳酸达到基线分离,分离度为1.5.