Effects of bifunctional interactions in the chemical ionization mass spectrometry of carboxylic acids and methyl esters

Abstract

AbstractThe methane chemical ionization mass spectra of dodecan‐1, 10‐dioic acid and the methyl ester show enhanced water and methanol elimination relative to monofunctional analogs. Elimination of acetic acid from 1,10‐diacetoxydecane, however, was reduced relative to 1‐acetoxydecane. This appears to be the result of bifunctional interactions. The steric requirement of this interaction is shown in an homologous series of dicarboxyl compounds. The change in interfunctional separation is shown to affect the proton and ammonium ion affinities in the ammonia chemical ionization spectra of the dicarboxyl compounds in a manner explained in terms of proton and ammonium ion complex formation. The observation is extended to various other functional groups.