碘标准溶液配制方法改进

Improvement of Iodine Solution Preparation

提出了直接法配制碘标准溶液。首先在强碱性环境下完成碘的歧化，然后以碘化钾作助溶剂，强酸环境下实现反歧化，再静置36h，即可得到碘标准溶液。进行了硫代硫酸钠标定实验和维生素C测定实验，探讨了碘溶液浓度的稳定性。结果表明，直接法配制的碘标准溶液，准确度高，保存时间长，标定误差小于0．1％；样品分析偏差小于0．29／5。

A simple method for the preparation of iodine standard solution was proposed. Io- dine disproportionation was completed in strong alkaline environment quickly, inverse-dispropor- tionation of mixed solution occurred in strong acid environment when potassium iodide as a co-sol- vent and the iodine standard solution was then obtained after standing 36 h. Sodium thiosulfate calibration and vitamin C determination were performed to explore the accuracy of iodine solution concentration. The concentration stability of iodine standard solution was discussed also. The rusuhs showed that the method have many advantages, such as simple, easy to operate, high ac- curacy, long storage time, calibration error is less than 0.1% and analysis deviation of samples is less than 0.2 %.