1,2,4-丁三醇的双水相萃取

Separation of 1,2,4-butanetriol by aqueous two-phase extraction

对低分子有机溶剂/无机盐双水相体系萃取分离发酵液中1,2,4-丁三醇(1,2,4-butanetriol,BT)进行了深入研究。通过对不同双水相体系的筛选,最终选定无水乙醇/K2HPO4双水相体系来萃取分离BT。使用浊点法对以BT为溶剂的无水乙醇/K2HPO4双水相体系进行相图的绘制,发现在K2HPO4质量分数为19.83%-46.87%范围内均能成相。通过单因素实验,考察双水相体系中无水乙醇/K2HPO4质量分数、pH对BT在两相之间分配系数和萃取效率的影响,得到最佳萃取条件为:系统总量10g、pH 9.5,无水乙醇/K2HPO4的质量分数为28%/28%,分配系数和萃取效率分别可以达到18.35和95.87%。在最佳萃取条件下,进一步探究了放大实验对体系萃取效率的影响,发现其对分配系数和萃取效率影响较小,体系稳定性高,为工业提取发酵液中BT提供新思路。

Aqueous two-phase systems composed of organic solvents and inorganic salts could be used to extract 1,2,4-butanetriol(BT) from fermentation broth.Through the screening of several aqueous twophase systems,the absolute ethanol/K2HPO4 two-phase system was finally selected to separate BT.The absolute ethanol/K2HPO4 two-phase system was investigated in detail,including phase diagram,and effect of phase composition on partition and pH.The results indicated that the phase could be formed in the range of the mass fraction of K2HPO4 being 19.83%~46.87%.The highest partition coefficient(18.35) and recovery(95.87%) of BT were obtained with an aqueous two-phase system composed of the system total10 g,28%(mass ratio) absolute ethanol,28%(mass ratio) K2HPO4 and pH 9.5.Under the optimal extraction condition,the system was further subjected to amplification experiments.The result showed that the amplification experiment had less influence on the distribution coefficient and recovery,which proved that the absolute ethanol/K2HPO4 two-phase system had high stability and potential for industrial application.