FORMATION OF DIMERS DURING ELECTRON-CAPTURE MASS-SPECTROMETRY OF SUBSTITUTED HYDROQUINONES

Negative ion electron capture mass spectrometry, using carbon dioxide- buffered thermal electrons, of formyl-, acetyl- and benzyol-hydroquino nes is shown to lead to the formation of the corresponding hydroquinon e dimers, often to a significant extent; the dimer predominates for ni trohydroquinone. Mixed dimers can be formed from pairs of different su bstrates. For some of the hydroquinones, a major peak in the spectrum suggests that oxidation to the corresponding quinone occurs competitiv ely. Tentative explanations of these phenomena are presented. (C) 1997 by John Whey & Sons, Ltd.