Yes, ketones can potentially affect moisture readings in Karl Fischer titration. This is because ketones can react with the methanol in common Karl Fischer reagents, forming acetals, which also react with the reagent and produce water. This additional water is then titrated and can cause the moisture reading to be too high. In order to avoid this, it is important to ensure that the titration cell is cleaned thoroughly after each analysis to remove any traces of ketones that may be present. If traces of ketones are left in the cell, it can cause erroneous readings and affect the overall accuracy of the moisture measurement. Additionally, there are some specialty reagents, Coulomat AK and Coulomat CGK, that can be used to help limit this side reaction....and also you have the option of using a Volumetric Karl Fischer Titrator to get around this problem.