Search

The reaction mass spectrometry of cyclic glycols and monosaccharides with methylene chloride as reagent was studied. In the presence of ammonia, it was found that methylene chloride reacted stereoselectively with the quasi-molecular ions of cyclic glycols and monosaccharides to form characteristic ions, by comparison of the relative abundances of which the stereoisomers of cyclopentane-l,2-diols and cyclohexane-l,2-diols and some monosaccharides could be definitely distinguished.

The chemical ionization (CI) mass spectrometry of fumaric and maleic acids and their esters with methylene chloride as reagent gas is described. The introduction of methylene chloride to the CI(CH 4 ) plasma led to the formation of new characteristic ions in addition to the protonation and the subsequent fragmentation, revealing diagnostic information on the configuration of geometrical isomers. The new characteristic ions have been found to arise from the addition of the reactant ion of methylene chloride, [CH 2 CI] + , to the substrates and, for higher dialkyl esters, from the further McLafferty rearrangement of the addudt ion [M+CH 2 CI] +