Research & Faculty

Default Header Image

A laser desorption-electron impact ionization ion trap mass spectrometer for real-time analysis of single atmospheric particles

TitleA laser desorption-electron impact ionization ion trap mass spectrometer for real-time analysis of single atmospheric particles
Publication TypeJournal Article
Year of Publication2009
AuthorsSimpson, EA, Campuzano-Jost, P, Hanna, SJ, Robb, DB, Hepburn, JH, Blades, MW, Bertram, AK
JournalInternational Journal of Mass Spectrometry
Volume281
Pagination140-149
Date PublishedApr
Type of ArticleArticle
ISBN Number1387-3806
KeywordsAERODYNAMIC LENSES, Aerosol mass spectrometry, AEROSOL-PARTICLES, CHEMICAL-ANALYSIS, CONTROLLED DIMENSIONS, Electron impact ionization, ENVIRONMENTAL PARTICLES, INVERSE FOURIER-TRANSFORM, LENS-NOZZLE SYSTEM, NUMERICAL CHARACTERIZATION, ORGANIC AEROSOLS, Particle laser, Single particle analysis, THERMAL VAPORIZATION, vaporization
Abstract

A novel aerosol ion trap mass spectrometer combining pulsed IR laser desorption with electron impact (EI) ionization for single particle studies is described. The strengths of this instrument include a two-step desorption and ionization process to minimize matrix effects; electron impact ionization, a universal and well-characterized ionization technique; vaporization and ionization inside the ion trap to improve sensitivity; and an ion trap mass spectrometer for MSn experiments. The instrument has been used for mass spectral identification of laboratory generated pure aerosols in the 600 nm-1.1 mu m geometric diameter range of a variety of aromatic and aliphatic compounds, as well as for tandem mass spectrometry studies (up to MS3) of single caffeine particles. We investigate the effect of various operational parameters on the mass spectrum and fragmentation patterns. The single particle detection limit of the instrument was found to be a 325 nm geometric diameter particle (8.7 x 10(7) molecules or 22 fg) for 2,4-dihydroxybenzoic acid. Lower single particle detection limits are predicted to be attainable by modifying the El pulse. The use of laser desorption-electron impact (LD-EI) in an ion trap is a promising technique for determining the size and chemical composition of single aerosol particles in real time. (C) 2009 Elsevier B.V. All rights reserved.

URL<Go to ISI>://000264728600006