Water Determination in di-Sodium Hydrogen Phosphate Dodecahydrate

Water Determination in di-Sodium Hydrogen Phosphate Dodecahydrate

This substance only dissolves slowly in the methanolic working medium of the KF titration. Addition of formamide considerably improves solubility.

In a sample tested by us, the duration of the titration was about 7 minutes with a result of 59.66% H₂O. The theoretical water content of this sample is 60.36% H₂O.

Procedure for volumetric one-component titration:

Add 20 mL Hydranal-Methanol dry or Hydranal-Methanol Rapid and 20 mL Hydranal-Formamide dry to the titration vessel and titrate to dryness using Hydranal-Composite 5. Accurately weigh-in by difference approximately 100 mg sample and titrate with Hydranal-Composite 5.

Procedure for volumetric two-component titration:

Add 20 mL Hydranal-Solvent and 20 mL Hydranal-Formamide dry to the titration vessel and titrate to dryness using Hydranal-Titrant 5. Accurately weigh-in by difference approximately 100 mg sample and titrate with Hydranal-Titrant 5.

Hydranal-Water Standard 10.0, Hydranal-Water Standard 1.0, and Hydranal-Standard Sodium Tartrate Dihydrate are suitable for determination of the titer or control of the volumetric determination.

Note: A Suitability test including protocol according to Ph. Eur. is available on request (hydranal@honeywell.com).