Karl Fischer Moisture Determination in Pharmaceutical and Fine Chemical Materials

Moisture Determination in Solid Pharmaceutical Materials

Many pharmaceutical and fine chemical materials are supplied as powders, granules, or crystalline solids, which may exhibit limited solubility or slow moisture release when analyzed by direct Karl Fischer injection. In such cases, solid sample evaporation combined with Karl Fischer titration provides a reliable and widely accepted analytical approach.

Using controlled thermal evaporation, moisture is released from the solid matrix and transferred quantitatively to the Karl Fischer titration cell for measurement. This technique avoids direct contact between the solid sample and the Karl Fischer reagent, minimizing matrix effects and improving analytical reproducibility.

Solid evaporation methods are particularly well suited for active pharmaceutical ingredients (APIs), excipients, intermediates, and fine chemical powders where dissolution is impractical or may introduce chemical interferences.