School of Chemical Engineering, University of Science & Technology Liaoning, Anshan 114051, China.
School of Chemical Engineering, University of Science & Technology Liaoning, Anshan 114051, China.
J Chromatogr A. 2020 Aug 16;1625:461326. doi: 10.1016/j.chroma.2020.461326. Epub 2020 Jun 7.
Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential fatty acids for human body, which are widely used in the field of healthy food and medicine. Meanwhile, there are some differences in their physiological functions, such as "scavenger for blood vessel" of EPA and "brain protector" of DHA. In order to make full use of EPA and DHA, it is necessary to prepare their high-purity component. In this paper, EPA and DHA were separated and purified by three-zone simulated moving bed (SMB) chromatography with C18 used as stationary phase and ethanol-water as mobile phase. For the single column experiment, a separation unit of SMB, the effects of the ratio of ethanol to water, pH value and temperature on the separation were investigated. The equilibrium dispersion (ED) model was used to obtain the adsorption parameters of EPA and DHA by inverse method and genetic algorithm, and the accuracy of the adsorption parameters was verified by fitting the overloaded elution curves under different conditions. Based on the acquired nonlinear adsorption isotherms the complete separation region was found according to triangle theory. The effects of sample concentration, flow ratios of adsorption zone and rectification zone, and column distribution mode of SMB on the separation were investigated. Under the optimized SMB conditions, the experimental result was that without regard to the other components, the chromatographic purity and recovery values of EPA and DHA exceeded 99% with the productivity of 4.15 g/L/h, and the solvent consumption of 1.11 L/g.
二十碳五烯酸（EPA）和二十二碳六烯酸（DHA）是人体必需的脂肪酸，广泛应用于保健食品和药品领域。同时，它们在生理功能上也存在一定差异，如 EPA 具有“血管清道夫”的功能，DHA 则是“脑黄金”。为了充分利用 EPA 和 DHA，有必要对其进行高纯度成分的制备。本文采用 C18 为固定相、乙醇-水为流动相的三区模拟移动床（SMB）色谱法分离和纯化 EPA 和 DHA。针对单柱实验，对分离单元 SMB 中乙醇与水的比例、pH 值和温度对分离的影响进行了考察。采用逆推法和遗传算法获得 EPA 和 DHA 的吸附参数，并通过拟合不同条件下的超载洗脱曲线对吸附参数的准确性进行验证。基于获得的非线性吸附等温线，根据三角形理论找到了完全分离区域。考察了样品浓度、吸附区和解析区的流量比以及 SMB 柱的分布模式对分离的影响。在优化的 SMB 条件下，实验结果表明，在不考虑其他成分的情况下，EPA 和 DHA 的色谱纯度和回收率均超过 99%，产物得率为 4.15 g/L/h，溶剂消耗为 1.11 L/g。
