Gas-phase reaction rate constants for atmospheric pressure ionization in ion-mobility spectrometry

Thesis/Dissertation · Thu Jan 01 00:00:00 EST 1987

OSTI ID:7001158

Vandiver, V J

Ion-mobility spectrometry (IMS) is an instrumental technique in which gaseous ions are formed from neutral molecules by proton and charge transfer from reactant ions through collisional ionization. An abbreviated rate theory has been proposed for atmospheric pressure ionization (API) in IMS, but supporting experimental measurements have not been reported. The objectives of this thesis were (1) assessment of existing API rate theory using positive and negative product ions in IMS, (2) measurement of API equilibria and kinetics for binary mixtures, and (3) investigating of cross-ionizations with multiple-product ions in API reactions. Although IMS measurements and predictions from rate theory were comparable, shapes and slopes of response curves for both proton transfer and electron capture were not described exactly by existing theory. In particular, terms that are needed for calculation of absolute rate constants were unsuitable in the existing theory. These included recombination coefficients,initial number of reactant ions, and opposing ion densities.

• Research Organization: New Mexico State Univ., Las Cruces (USA)
• OSTI ID: 7001158
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

47 OTHER INSTRUMENTATION
74 ATOMIC AND MOLECULAR PHYSICS
ION MOBILITY
ION SPECTROSCOPY
ION-MOLECULE COLLISIONS
IONIZATION
CHARGE EXCHANGE
PROTON TRANSPORT
CHARGED-PARTICLE TRANSPORT
COLLISIONS
ION COLLISIONS
MOBILITY
MOLECULE COLLISIONS
PARTICLE MOBILITY
RADIATION TRANSPORT
SPECTROSCOPY
440300* - Miscellaneous Instruments- (-1989)
640304 - Atomic
Molecular & Chemical Physics- Collision Phenomena