Collision cross sections of high-mannose N-glycans in commonly observed adduct states – identification of gas-phase conformers unique to [M − H]− ions

Abstract

We report collision cross sections (CCS) of high-mannose N-glycans as [M + Na]⁺, [M + K]⁺, [M + H]⁺, [M + Cl]⁻, [M + H₂PO₄]⁻ and [M − H]⁻ ions, measured by drift tube (DT) ion mobility-mass spectrometry (IM-MS) in helium and nitrogen gases. Further analysis using traveling wave (TW) IM-MS reveal the existence of distinct conformers exclusive to [M − H]⁻ ions.