Additional precursor purification in isobaric mass tagging experiments by traveling wave ion mobility separation (TWIMS).

We investigated if additional peptide purification by traveling wave ion mobility separation (TWIMS) can reduce precursor contamination using a mixture of S. cerevisiae and HeLa proteomes. In accordance with previous reports on FAIMS-Orbitrap instruments, we find that TWIMS provides a remarkable improvement (on average 2.85 times) in signal to noise ratio for sequence ions. We also report, that TWIMS reduces reporter ions contamination by around one third (to 14 - 15% contamination) and even further (to 6-9%) when combined with narrowed quadrupole isolation window.