A krypton VUV photoionization source for gas chromatography and mass spectrometry.
AuthorHoman, Mark Eugene.
AdvisorDenton, M. Bonner
MetadataShow full item record
PublisherThe University of Arizona.
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
AbstractThe use of a coaxial krypton discharge lamp to selectively photoionize samples in a complex matrix is described. The lamp produces a krypton line emission spectrum with available photon energies of 10.0 and 10.6 eV. When used as a photoionization mass spectrometer source, conditions can be created where molecular ions can be produced which do not undergo fragmentation. This effect can greatly simplify spectral interpretation in the case of either direct sample introduction or coelution from a chromatographic column. Mixtures containing 6 to 8 components can be analyzed by direct injection with detection limits for most of the components below the 100 x 10⁻⁹ g level. Data is also presented demonstrating the lamps ability to switch between photoionization conditions producing primarily molecular ions and conditions producing spectra similar to those produced by electron impact sources. This ability would allow two complimentary sets of mass spectrometric information to be gathered during a single run. Using the lamp as a photoionization GC detector, a LOD of 12 x 10⁻¹² g for benzene has also been determined.