ELECTRON IONIZATION AND POSITIVE-ION CHEMICAL-IONIZATION MASS-SPECTRAOF N-(2-HYDROXYETHYL)ALKYLAMIDES

A family of 12 (7 saturated and 5 unsaturated) long chain fatty acid N -(2-hydroxyethyl)amides has been investigated by electron ionization ( EI) and positive-ion chemical ionization (PICI) mass spectrometry. Thi s paper presents the mass spectra and structures of the main ions obta ined by EI and PICI (using methane as reactant gas). The discussion of the fragmentation pattern is made in correlation with the methyl bran ch position in aliphatic compounds and the double bond position in mon ounsaturated compounds. A quantitative correlation of the ratio [M-H2O + H](+)/[M - H2O - H](+), in the PICI mass spectra, with the number o f double bonds, C atoms, and aliphatic H atoms is made. (C) 1997 by Jo hn Wiley & Sons, Ltd.