Can Sodium Standards be diluted with deionized (DI) water?

Document ID

Document ID TE2690

Published Date

Published Date 27/05/2017
Question
Can Sodium Standards be diluted with deionized (DI) water?
Summary
Sodium standard dilution with DI water
Answer
Deionized water is produced by ion exchange. The water is in contact with resin beds to remove ions. These resin beds are regenerated by using hydrochloric acid and sodium hydroxide. The main problem with the resulting DI water is that it can often contain high levels of sodium. In using DI water to dilute your sodium standard solutions, most likely this adds a lot of sodium and the standard value diluted to is higher than calculated. This can result in inaccurate calibrations and cause calibration and slope errors on instrumentation.

If testing for Sodium via ISE or colorimetric analysis, DO NOT dilute standards. Buy prepared standards that are traceable or determine the concentration of sodium in your DI water and calculate the resulting concentration of the standard solution (standard additions calculation).