With the exception of prolin, amino acids are hardly soluble in alcohols. Therefore, only the adherent moisture can be determined by the direct volumetric method.
Foodstuffs encompass the most diverse products. Depending on whether carbohydrate-rich, fatty or proteinrich substances are under investigation, different working techniques are favourable. Complex matrices that dissolve slowly, or where the water can only be slowly extracted, necessitate the use of
During titration of sulphonic acids it should be noted that these can shift the pH of the KF solution into the acidic range, thus rendering further buffering of the system through the addition of a base (e.g. Aquastar® buffer solution
The article describes Karl Fischer titration (coulometry with oven and direct volumetric titration with external extraction) in comparison to the loss on drying method for accurate determination of water content in hemp samples.