What are possible reasons for a massive baseline drift (hill) in denatured ESI-MS with human serum albumin?

We experience a massive baseline drift, it more or less looks like a hill, when injecting human serum albumin purified from Pichia pastoris in a Q-TOF SYNAPT G2 HDMS (Waters). I have attached a...

15 April 2016 9,486 4 View