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Proceedings Paper

Laser-desorption tandem time-of-flight mass spectrometry with continuous liquid introduction
Author(s): Evan R. Williams; Glenn C. Jones Jr.; LiLing Fang; Takeshi Nagata; Richard N. Zare
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Paper Abstract

A new method to combine aqueous sample introduction with matrix assisted laser desorption mass spectrometry (MS) for interfacing liquid-chromatographic techniques, such as capillary electrophoresis, to MS is described. Aqueous sample solution is introduced directly into the ion source of a time-of-. flight (TOF) mass spectrometer through a fused silica capillary; evaporative cooling results in ice formation at the end of the capillary. The ice can be made to extrude continuously by using localized resistive heating. With direct laser desorption, molecular ions from proteins as large as bovine insulin (5734 Da) can be produced. Two-step desorption/photoionization with a variety of wavelengths is demonstrated, and has the advantages of improved resolution and shot-to-shot reproducibility. Ion structural information is obtained using surface-induced dissociation with an in-line collision device in the reflectron mirror of the TOF instrument. Product ion resolution of ~70 is obtained at m/z77. Extensive fragmentation can be produced with dissociation efficiencies between 7-15% obtained for molecular ions of small organic molecules. Efficiencies approaching 30% are obtained for larger peptide ions.

Paper Details

Date Published: 14 May 1992
PDF: 10 pages
Proc. SPIE 1636, Applied Spectroscopy in Materials Science II, (14 May 1992); doi: 10.1117/12.59310
Show Author Affiliations
Evan R. Williams, Stanford Univ. (United States)
Glenn C. Jones Jr., Stanford Univ. (United States)
LiLing Fang, Stanford Univ. (United States)
Takeshi Nagata, Stanford Univ. (United States)
Richard N. Zare, Stanford Univ. (United States)

Published in SPIE Proceedings Vol. 1636:
Applied Spectroscopy in Materials Science II
William G. Golden, Editor(s)

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