食用土当归中总有机酸的纯化工艺优选

目的：优选食用土当归中总有机酸的纯化工艺。方法：采用酸碱滴定法测定总有机酸含量。以总有机酸质量分数和转移率为指标，联用有机溶剂萃取法与酸碱法，通过单因素试验考察萃取溶剂、碱种类、碱用量、碱化次数、酸沉pH对总有机酸纯化工艺的影响。结果：最佳纯化工艺条件为加2倍量石油醚萃取4次，以1.0% KOH溶液作为碱化试剂，碱化数3次，加盐酸至pH 1，酸沉后用石油醚萃取3次；总有机酸质量分数由提取物的14.71%提高到65.08%，转移率达76.17%。结论：该工艺稳定可靠，可为食用土当归资源的综合利用提供实验依据。

Optimization of Purification Process for Total Organic Acids from Roots of Aralia cordata

Objective: To optimize purification process of total organic acids from roots of Aralia cordata. Method: The content of total organic acids was determined by acid-base titration.With purity and transferring rate of total organic acids as indexes, combining with organic solvent extraction and acid-base method, effects of extraction solvents, reagent for alkalization and its concentration, alkalinizing times and pH of acid settling on purification process of total organic acids were investigated by single factor tests. Result: Optimum purification technology was selected as follows:extracted four times with two-fold volume of petroleum ether, 1.0% KOH as alkalization reagent, three times for alkalization, pH 1 of acid settling by hydrochloric acid, extracted three times with petroleum ether after acid settling;Under these purification conditions, purity of total organic acids increased from 14.71% in extract to 65.08% with transferring rate of 76.17%. Conclusion: This purification process was stable and feasible, which could provide experimental evidence for comprehensive utilization of A. cordata resources.