The developed online delipidation method -with integrated phospholipid trap -works as follows. 1) After the sample injection, the sample components are fed by an auxiliary solvent manager (ASM) through the phospholipid trap column, where lipids are retained, while the protein passes through. 2) The protein is further guided to the online protease column for digestion, and generated peptides are captured in the peptide trap column for desalting. 3) At the end of the trapping time, the phospholipid trap column is automatically configured off-line with the protease column. While the latter can be selectively flushed with a protease wash solution, the phospholipid trap column is washed with an alternate solvent (which we denote as solvent B2) for removal of retained phospholipids, which are directed to a waste compartment.