PNNL

Abstract

Differential ion mobility spectrometry (FAIMS) in conjunction with mass spectrometry has emerged as a powerful tool for biological and environmental analyses. Large proteins occupy regions of FAIMS spectra free from peptides, lipids, or other medium-sized biomolecules, arguably because strong electric fields align huge dipoles common to macroions. Here we confirm this phenomenon in first separations of proteins at extreme fields using micro-FAIMS and demonstrate its use to detect and identify even minor amounts of large proteins in complex matrices of smaller proteins and peptides.