Reduction processes in fast atom bombardment mass spectrometry: Interdependence of analyte and matrix redox potentials

Abstract

The reduction of selected redox indicator dyes during fast atom bombardment mass spectrometry was investigated in several different matrices. Reduction is indicated by the incorporation of one or more hydrogens into the cation of the dye. The extent of reduction of the analyte can be related to the E 1/2 value of the reduction potential of the dye. Selection of matrix also influences the reduction, the reducing power decreasing in the order glycerol greater than sulfolane greater than thioglycerol greater than hydroxyethyl disulfide greater than nitrobenzyl alcohol. Evidence is given suggesting that reduction is initiated by exposure of the analyte-matrix mixture to atom bombardment. It is shown that reduction can be controlled by the addition of metal ions with a very low reduction potential to the matrix to act as electron scavengers.

Reduction in Desorption Mass Spectrometry: Multiple Protonation on Flavins without Charge Increment.

“…1c) in agreement with a previous report by Kyranos and Vouros, in which importance of relative redox potentials were described. 3) As a consequence, we then assumed that the hydrogen atom was attributable to the flavin reduction. In an attempt to prove this hypothesis, glycerol-d 5 a: The right spectrum is the lower mass region of a-cyano-4-hydroxycinnamic acid.…”

“…5), 6) , 9) Naturally, reduction in the FAB mode is a phenomenon much depended on a) Dept relative redox potentials of the matrix and analyte. 3) Although multiple protonation on MALDI is commonly observed as doubly-and triply-charged ions of proteins, reduction on MALDI has not been much accounted. Recently, however, Karas et al proposed a new model for MALDIMS concerned with the charge status.…”

Sequence of pig lens aldose reductase and electrospray mass spectrometry of non‐covalent and covalent complexes

“…thioerythritol [38] since a shift of 2Da was observed. As no disulfide bridge was detected in the structure of AR [16,391 (unpublished crystallographic results), the disulfide bridge…”

Structural Characterization of Paramagnetic Octahedral Homoscor‐Pionate (Polypyrazolylborate) Cobalt Complexes by 1H and 13C NMR Spectroscopy and by FAB‐Mass Spectrometry

“…Kyranos and Vouros [27] reported that, in the FAB-MS spectra of dyes in G, reduction phenomena are important due to the presence of electrons in the matrix. These reductions can be prevented adding some CuC12 crystals (Fig.…”