How do I know when to replace the molecular sieve in the drying tubes on my Karl Fischer titrator?
The most practical solution to this question is to add some blue silica gel to the top of the drying tube to serve as an indicator. As soon as the first trace of pink appears in this gel layer, it is time to change or regenerate the molecular sieve. Naturally, an increase in background drift can also indicate that it is time to replace the molecular sieve.
