title: Ion mobility spectrometer with radial collisional focusing.
abstract: An ion mobility spectrometer that has its mobility cell as a 20-segment quadrupole and functionally the q2 of a triple-quadrupole mass spectrometer has been assembled and tested. The combination of high cell pressure (maximum of 4 Torr of helium) and low axial field (20-160 V per 20.2 cm) results in negligible internal excitation of the ions despite applications of rf and axial fields. The presence of collisional focusing ensures efficient ion transmission and good sensitivity. Collision cross sections of atomic, cluster, peptide, and protein ions were measured and found comparable to literature and calculated cross sections.
authors.affiliation: Department of Chemistry and Centre for Research in Mass Spectrometry, York University, 4700 Keele Street, Ontario, Canada M3J 1P3.
authors.forename: Yuzhu
authors.initials: Y
authors.lastname: Guo
authors.forename: Jiaxi
authors.initials: J
authors.lastname: Wang
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Javahery
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Thomson
authors.forename: K W Michael
authors.initials: KW
authors.lastname: Siu