title: The effective temperature of ions stored in a linear quadrupole ion trap mass spectrometer.
abstract: The extent of internal energy deposition into ions upon storage, radial ejection, and detection using a linear quadrupole ion trap mass spectrometer is investigated as a function of ion size (m/z 59 to 810) using seven ion-molecule thermometer reactions that have well characterized reaction entropies and enthalpies. The average effective temperatures of the reactants and products of the ion-molecule reactions, which were obtained from ion-molecule equilibrium measurements, range from 295 to 350 K and do not depend significantly on the number of trapped ions, m/z value, ion trap q z value, reaction enthalpy/entropy, or the number of vibrational degrees of freedom for the seven reactions investigated. The average of the effective temperature values obtained for all seven thermometer reactions is 318 ± 23 K, which indicates that linear quadrupole ion trap mass spectrometers can be used to study the structure(s) and reactivity of ions at near ambient temperature.
authors.affiliation: School of Chemistry, Bio21 Institute of Molecular Science and Biotechnology, & Australian Research Council Centre of Excellence for Free Radical Chemistry and Biotechnology, University of Melbourne, Victoria 3010, Australia. w.donald@unsw.edu.au
authors.forename: William A
authors.initials: WA
authors.lastname: Donald
authors.forename: George N
authors.initials: GN
authors.lastname: Khairallah
authors.forename: Richard A J
authors.initials: RA
authors.lastname: O'Hair
mesh_terms: D006371:Helium / Q000737:chemistry; D007477:Ions / Q000737:chemistry; D013058:Mass Spectrometry / Q000295:instrumentation* / Q000379:methods*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D007477:Ions; D006371:Helium