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Bifunctional interaction and its effect on the esterification of dicarboxylic acids in chemical ionization mass spectrometry
Author(s) -
Wengang Chai,
Guanghui Wang,
Zhiling Xu,
Jiongguang Pan,
Shumin Duan
Publication year - 1983
Publication title -
organic mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0030-493X
DOI - 10.1002/oms.1210180206
Subject(s) - chemistry , dicarboxylic acid , chemical ionization , phthalic acid , mass spectrum , mass spectrometry , protonation , fumaric acid , molecule , maleic acid , intramolecular force , reagent , organic chemistry , bifunctional , electrospray ionization , methanol , medicinal chemistry , ion , ionization , chromatography , catalysis , copolymer , polymer
The chemical ionization mass spectra of different dicarboxylic acids, including saturated and unsaturated aliphatic, aromatic, hydroxyl and amino‐substituted dicarboxylic acids, have been studied using pure methanol as the reagent gas. Biomolecular monoesterification and diesterification product ions [M+15] + and [M+29] + , and adduct ion [M+33] + , were observed, in addition to the protonated molecule [MH] + and unimolecular water elimination product ions. The formation of a protonated molecule with bridged intramolecular hydrogen bond, and its effect on the esterification of dicarboxylic acids is discussed. Geometric isomers, such as maleic and fumaric acid, and ortho and meta isomers of phthalic acids can be distinguished from each other by methanol chemical ionization mass spectra. When ethanol was used as the reagent gas, similar mass spectra of some dicarboxylic acids were obtained.