The use of sodium-glass electrode for the determination of sodium

Abstract

A method with sodium-glass electrode has been studied for determination of sodium in raw sodium metatitanate.
With proper calibration with standard solution of sodium chloride, the sodium-glass electrode can indicate the values of pNa provided the pH of sample solution is from 6.8 to 7.3. The adjustment of pH is preferrably done by triethanolamine, whereby the electrode indicates correct pNa value of the solution, while ammonia gives erroneous results. About 0.5 g of tartaric acid should be added before the pH adjustment if Ti, Fe and Al ions are present in the solution.
Coefficient of variation 6.7% and relative error ±10.4%-4.2% were obtained for raw sodium metatitanate by the proposed method.