Organic Surface Analysis by Two-Laser Ion Trap Mass Spectrometry. 2. Improved Desorption/Photoionization Configuration
1998; American Chemical Society; Volume: 70; Issue: 6 Linguagem: Inglês
10.1021/ac971116p
ISSN1520-6882
AutoresOleg Kornienko, Earl T. Ada, Jillian Tinka, Muthu B. J. Wijesundara, Luke Hanley,
Tópico(s)Analytical chemistry methods development
ResumoWe previously described a two-laser ion trap mass spectrometer for molecular surface analysis of organic, biological, and polymeric surfaces (Kornienko, O.; et al. Anal. Chem. 1997, 69, 1536−1542). We have made several improvements in this instrument: a new 118-nm vacuum ultraviolet (VUV) photoionization source and an improved desorption/ionization geometry in the ion trap. The improved surface analysis capabilities of this instrument are demonstrated on C18 alkylsiloxane self-assembled monolayers on silicon, polypeptide thin films, mixed polystyrene thin films, and ion beam-modified polystyrene films. The new instrumental configuration has submonolayer sensitivity and the capability to perform tandem mass spectrometry on monolayer samples. The advantages of VUV photoionization for surface analysis studies are demonstrated to be lower fragmentation and relatively nonselective ionization when compared with multiphoton ionization with ultraviolet light.
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