滴定法测定三聚磷酸钠的溶解度  

Measurement of solubility of sodium triphosphates by titration

作　　者：公强[1] 于养信[1] 

机构地区：[1]清华大学化学工程系热力学实验室,北京100084

出　　处：《无机盐工业》2008年第11期51-53,共3页Inorganic Chemicals Industry

基　　金：国家自然科学基金(20676065);国家重点基础研究发展计划资助项目(2003CB615700)

摘　　要：采用双指示剂滴定法和电位滴定法测定了三聚磷酸钠的溶解度随温度的变化情况,并对2种实验方法的准确性进行了验证。由验证数据可知,2种测定方法都具有很好的准确性,误差分别是2.53%和1.18%,与双指示剂滴定法相比,电位滴定法更加准确。同时,通过比较实验数据与文献数据,发现测定出的三聚磷酸钠溶解度的实验值与文献值相比偏大。通过对分析方法的验证可以排除分析方法带来的误差,认为可能存在的原因是实验样品不同(工业三聚磷酸钠中含3%焦磷酸钠等)和取样时饱和液的平衡时间不同。测得的溶解度数据对于洗涤剂配方设计和洗涤剂的实际生产过程都具有重要的参考价值。Solubility behavior of sodium triphosphate （ STPP ） with temperature variation was measured by double indi- cator - titration method and electrometric titration method. The accuracy of the two methods was also evaluated. The evaluation data indicated that the two methods beth had good accuracy and their errors were 2.53% and 1.18%, respectively. Compared with double indicator - titration method, electrometric titration method was more accurate. On the other hand, by comparing the solubility data from experiments with those from literature, it was found that the data from this work were larger than those from literature. However,the experimental error broght by the test methods had been ruled out through the evaluation. Therefore, there were two possible reasons, one was that the sample used in the experiment was an industrial product containing pyrophosphate formed during the tripbesphate crystallization, and the another was the time of phase equilibration. The solubility data from this work are helpful for the formulation design and actual production of detergents.

关 键 词：三聚磷酸钠 双指示剂滴定 电位滴定 溶解度 

分 类 号：TQ126.3[化学工程—无机化工]