ION-MOLECULE REACTIONS OF 2-METHOXYETHANOL WITH KETONES, ALDEHYDES, ALCOHOLS AND PHENOLS UNDER CHEMICAL-IONIZATION CONDITIONS

2-Methoxyethanol has been used as a chemical ionization (CI) reagent g as in a conventional ion source and it has been found to produce numer ous reagent ions, including an ion at m/z 89, [CH3OCH2CH2OCH2](+). The se ions react with different classes of compounds, e.g. by formation o f variety of adduct ions. Neutral ketones (RC(O)R') were observed to y ield without exception [M - R + 44](+) and/or [M - R' + 44](+) product ions. Similarly, for aldehydes the formation of the product ion [M - H + 44](+) is common. Selectivity was noticed especially for the neutr al alcohols studied, which resulted in the formation of [M + 27](+) an d [M + 89](+) product ions, and also for the neutral phenol studied, w hich resulted in the formation of [M + 13](+), [M + 27](+) and [M + 89 ](+) product ions. There is a clear correlation between the structure of isomeric neutral alcohols studied and the abundances of the product ion [M + 89](+); the more hindered the alcohol, the lower is the abun dance of the [M + 89](+) ion. The [M + 13](+) product ion for phenols is a characteristic fragment of the [M + 89](+) ion produced by elimin ation of neutral 2-methoxyethanol. The greatest abundance of the [M 13] + ion for m-cresol acid the use of labelled compounds and labelled reagent gases, CD3OCH2CH2OH and CH3OCH2CH2OD, suggest that the additi on occurs mainly to the aromatic ring, ortho and para positions being more favoured. The collision-induced dissociation technique was used t o characterize the structures of the product ions.