Dear Friends, 1 - I am having degradation of my major peak (Norethynodrel) with Acetonitrile (HPLC grade). 2 - Other Acetonitrile (different mark) do not causes it. 3 - Is this problem common with someone? Best Regards, Add a Message This is a private posting area. A valid username and password combination is required to post messages to this discussion. Username: Password: