Abstract:

The dual circuits laser detector was used to measure the solubility and super-solubility of uridine-5′-monophosphate disodium salt in the ethanol-aqueous mixture of different ethanol mass fractions at 293.2—318.2 K.In addition, the effects of agitation rate, pH value and Na⁺ concentration on the width of metastable zone were explored respectively.It was found that the solubility data might be described well by the model of λh equation; furthermore the mixing enthalpy and the crystallization enthalpy of uridine-5′-monophosphate disodium salt in mixture were determined.Similar to the solubility, the super-solubility increased with the increase of temperature and decreased with the increase of ethanol mass fraction.Under the same experimental conditions, increase of pH value, Na⁺ concentration or decrease of agitation rate might broaden the width of metastable zone.

Key words:

5′-尿苷酸二钠, 溶解度, 介稳区, λh方程

摘要：

采用双光路激光法，在293.2～318.2 K温度范围内，研究了5′-尿苷酸二钠在不同比例乙醇-水混合溶剂中的溶解与超溶解特性，得到了5′-尿苷酸二钠的结晶介稳区。采用λh方程关联了4个体系的溶解度数据，进而分别求得各体系下的混合焓和结晶焓。同时，探讨了搅拌转速、pH值和钠离子浓度对结晶介稳区的影响。实验结果表明，与温度相比较，乙醇质量分数是影响溶解度和超溶解度的主要因素;随乙醇质量分数的增大，5′-尿苷酸二钠的溶解度和超溶解度显著减小;在相同条件下，溶液pH值和钠离子浓度的升高，以及搅拌转速的降低均会增大5′-尿苷酸二钠结晶介稳区的宽度。

关键词:

5′-尿苷酸二钠, 溶解度, 介稳区, λh方程