LAUSR

Abstract A new instrument combining a two meter long ion mobility drift tube fabricated of resistive glass with a high-resolution time-of-flight (TOF) mass spectrometer is presented and new features are discussed in detail. Ions are formed by electrospray ionization. An ion gate positioned at the exit of the drift tube allows analysis of mobility-selected ions. A quadrupole mass filter and a collision cell are located between the drift tube and the TOF analyzer, an arrangement which allows collision-induced dissociation experiments of mass-selected and/or mobility-selected ions. The ability of the TOF spectrometer to resolve isotopologues differing by 1 Da in mass even for multiply charged ions opens up exceptional possibilities for ion selection and mobility analysis. The unique combination of instrument attributes including gentle ion production and analysis, the first principles measurement of cross sections, and high mobility (R∼100) and mass (R>20k) resolving powers allows for the analysis of a broad range of analytes including amino acid oligomer clusters (e.g. Phe97), peptides, and proteins.