The standard water content test method is D1364, based on Karl Fischer reagent
The water molecules are then dissolved in the methanol and titrated to an end point with a Karl Fischer reagent
to measure the water content from a nearly unlimited range of 10-4% to 100% (results can also be provided in parts per million).
The Metrohm KF Drying Oven Model 768 is designed for use with Metrohm Karl Fischer Volumetric and Coulometric Titrators, and is ideal for samples that react with Karl Fischer reagent
or have problems releasing water in solvent.
The Karl Fischer reagent
for moisture determination was from Merck.
An overview of Karl Fischer reagents
is presented to assist in selecting the most suitable chemicals for analysis in the third and final section.
The water content of many samples is difficult to determine because they are only slightly soluble in alcohols, contaminate the titration cell or undergo side reactions with the Karl Fischer reagents
. In this situation the sample is not put in the oven in a sample boat, but instead is weighed into a vial and sealed.
With one single KF titrator it is now possible to have Karl Fischer reagents
of different concentration or type permanently available.