Unlocking PAH Ionization in Negative-Mode ESI Orbitrap MS Using Tetramethylammonium Hydroxide: A Petroleomic Strategy.

ABSTRACT: The selective ionization of cyclopentadiene-derived polycyclic aromatic hydrocarbons (PAHs) in complex matrices remains a persistent challenge in direct ionization mass spectrometry, particularly under atmospheric pressure ionization (API) conditions. In this study, tetramethylammonium hydroxide (TMAH) was evaluated as a solvent modifier to enhance the ionization efficiency of PAHs in negative-ion mode using high-resolution Orbitrap MS. A systematic assessment with equimolar mixtures of neutral and acidic model compounds was performed to elucidate the fundamental effects of TMAH on ion suppression, deprotonation mechanisms, and gas-phase ion chemistry. The incorporation of TMAH significantly improved the detection of weakly acidic and neutral PAHs by promoting efficient gas-phase deprotona

SUBMITTER: de Aguiar DVA 

PROVIDER: S-EPMC12492404 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature