葡萄糖酸钠的结晶热力学研究

Crystallization thermodynamics of sodium gluconate

对葡萄糖酸钠的结晶热力学特性进行了研究,考察了温度、溶剂组成、pH、杂质等对葡萄糖酸钠溶解度的影响。结果表明,葡萄糖酸钠在水中的溶解度很高,25℃时的溶解度达到61.53g;葡萄糖酸钠微溶于乙醇,乙醇的加入可明显降低葡萄糖酸钠的溶解度;pH在4～7之间对葡萄糖酸钠溶解度无明显影响;发酵液中残留的葡萄糖对葡萄糖酸钠溶解度没有影响,而柠檬酸钠会略微降低葡萄糖酸钠的溶解度。同时测定了发酵处理液中葡萄糖酸钠的介稳区宽度,为发酵液中葡萄糖酸钠的结晶提供了热力学依据。

The crystallization thermodynamics of sodium gluconate were explored.The influences of temperature,solvent composition,pH and impurities on its solubility were studied.The result showed that sodium gluconate had very high solubility in aqueous solution,it reached 61.53g at 25℃.Sodium gluconate was slightly soluble in ethanol.The solubility of sodium gluconate decreased with adding ethanol.The solubility of sodium gluconate was independent of pH between pH 4 and 7.The residual glucose in the fermentation borth had little effects on solubility of sodium gluconate,but the solubility of sodium gluconate decreased with adding sodium citrate.The width of crystallization metastable zone was also obtained,all of these provided a thermodynamic basis for studying on the crystallization of sodium gluconate.