液气射流技术改进单宁酸氧化制备高纯度鞣花酸

针对鞣花酸在实际生产过程中耗时长、纯度低等问题，以单宁酸为基质采用液气射流氧化法制备鞣花酸，考察了金属离子、单宁酸质量浓度、反应温度和反应时间对鞣花酸得率及纯度的影响。进一步探究了溶剂法、结晶法、碱溶酸沉法、反溶剂法对鞣花酸纯度的影响，并通过HPLC、FTIR、UV-Vis光谱和TG对鞣花酸高纯样进行表征。得到液气射流氧化的较优工艺条件为：质量浓度25g/L单宁酸溶液中引入金属离子Na+（即NaOH）调节反应液pH至8.5，反应温度20℃，反应时间6h。

Aiming at the issues of long processing time and low purity of ellagic acid in actual production, ellagic acid was prepared via liquid-gas jet oxidation using tannic acid as the substrate. The effects of metal ions, tannic acid mass concentration, reaction temperature and reaction time on the yield and purity of ellagic acid were investigated. Furthermore, the impacts of solvent method, crystallization method, alkali dissolution-acid precipitation method and anti-solvent method on the purity of ellagic acid were explored. The high-purity ellagic acid samples were characterized by HPLC, FTIR, UV-Vis spectroscopy and TG. The optimal process conditions for the liquid-gas jet oxidation were determined as follows: add metal ion Na+ (i.e., NaOH) to adjust the pH of the reaction solution to 8.5 in a 25 g/L tannic acid solution, with a reaction temperature of 20 ℃ and reaction time of 6 h.