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Journal articles
Orthogonal time-of-flight secondary ion mass spectrometric analysis of peptides using large gold clusters as primary ions
Abstract : Secondary ion mass spectrometry (SIMS) for biomolecular analysis is greatly enhanced by the instrumental combination of orthogonal extraction time-of-flight mass spectrometry with massive gold cluster primary ion bombardment. Precursor peptide molecular ion yield enhancements of 1000, and signal-to-noise improvements of up to 20, were measured by comparing SIMS spectra obtained using Au+ and massive A(400)(4+) cluster primary ion bombardment of neat films of the neuropeptide fragment dynorphin 1-7. Remarkably low damage cross-sections were also measured U41 from dynorphin 1-7 and gramicidin S during prolonged bombardment with 40 keV Au-400(4+). For gramicidin S, the molecular ion yield increases slightly as a function of Au-400(4+) beam fluence up to at least 2 x 10(13) Au-400(4+)/cm(2). This is in marked contrast to the rapid decrease observed when bombarding with ions such as Au-5(+) and Au-9(+). When gramicidin S is impinged with Au-5(+), the molecular ion yield decreases by a factor of 10 after a fluence of only 8 X 10(12) ions/cm(2). Comparison of these 4 damage cross-sections implies that minimal surface damage occurs during prolonged Au-400(4+) bombardment. Several practical analytical implications are drawn from these observations.
http://hal.in2p3.fr/in2p3-00020500
Contributor : Suzanne Robert <>
Submitted on : Tuesday, March 16, 2004 - 4:25:48 PM
Last modification on : Wednesday, September 16, 2020 - 4:07:08 PM
Contributor : Suzanne Robert <>
Submitted on : Tuesday, March 16, 2004 - 4:25:48 PM
Last modification on : Wednesday, September 16, 2020 - 4:07:08 PM