Electron-Transfer Ionization in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Terthiophene and anthracene, both of which in positive mode form only molecular radical cations (M+?) upon laser irradiation (? = 337 nm) at near-threshold laser powers, were used as matrices for matrix-assisted laser desorption/electron-transfer ionization of metallocenes (1,2-diferrocenylethane, ferrocene, and decamethylferrocene) and a methylene-bridged bisphenol, 2,2?-methylenebis(6-tert-butyl-4-methylphenol). In the mass spectra of these matrix/analyte combinations, the formation of protonated molecules was not observed. Instead, each analyte formed a molecular radical cation (A+?) when either matrix was used. Experiments utilizing anthracene-d10 as the matrix confirmed the formation of only the analyte molecular radical cation. In addition, the molecular radical cation of ferrocenenot the protonated moleculewas produced when 2,5-dihydroxybenzoic acid was used as the matrix, indicating that a matrix commonly used to form protonated polar analytes can, in addition, function as an electron-transfer MALDI matrix.


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País:     Colombia

Autor(es):   

Año:     2017

ISSN:    10440305

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