Structural Characterization of Methylenedianiline Regioisomers by Ion Mobility-Mass Spectrometry and Tandem Mass Spectrometry. 4. 3-Ring and 4-Ring Isomers.

ABSTRACT: Matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) is used to characterize methylenedianiline (MDA) 3-ring and 4-ring species. Building on our previous MALDI-MS 2-ring MDA isomer study, here we compare 3-ring and 4-ring electrospray ionization (ESI) and MALDI results. In ESI, 3-ring and 4-ring MDAs each form a single [M + H]⁺ parent ion. However, in MALDI, each MDA multimer forms three unique precursor ions: [M + H]⁺, [M^•]⁺, and [M - H]⁺. In this study, 3-ring and 4-ring MDA precursors are characterized to identify the unique fragment ions formed and their respective fragmentation pathways. In addition to the three possible precursors, the 3-ring and 4-ring species are higher-order oligomer precursors in polyureth

SUBMITTER: Crescentini TM 

PROVIDER: S-EPMC6324837 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature