Water is only released slowly from starch flour. At room temperature, the determination takes 10 – 15 minutes, and the results are too low. Drying, too, is an unsuitable method for determining the actual water content.
It is advisable to carry out the titration at 50°C. In this case the titration takes about 5 minutes, the end point is stable and the results are reproducible.
One- or two-component volumetric titration can be applied. 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.
Download the full Laboratory Report for Starch (L 072) here