Microflow size exclusion chromatography to preserve micromolar affinity complexes and achieve subunit separations for native state mass spectrometry

•Evaluation of microflow (15 µL/min) small bore dimension (1 mm) SEC with hydroxy PEO BEH particles and column hardware treated with hydrophilic hybrid surface technology inorganic/organic surfaces for UV and MS.•Reduced on-column chemical interactions shown to preserve quaternary structures.•Higher recovery of large non-covalent complexes and the detection of antibody hexamers previously undetected by LC-MS.