Recurring lipid injections require the phospholipid trap column to be cleaned to retain delipidation capacity over a long period of time. We tested the suitability of different MS-compatible solvents, such as acetonitrile, isopropanol, and methanol, for cleaning the phospholipid trap column. Standard protocols in phosphoproteomics apply an increasing basicity with ammonium hydroxide (NH 4 OH) to elute phosphopeptides from TiO 2 , providing an alternative to organic solvents. To investigate the lipid cleaning capacity of the different solvents, we loaded 1 pmol POPC on the ZrO 2 column and subsequently applied a saw-tooth gradient of 5 x two minutes washes from 0-100% solvent B2 (Figure ). Success, i.e.