Electron ionization induced fragmentation pathways of trichloroanisole

Author(s)

Mendes, Monica ; Bou-Debes, Daniel ; Eden, Samuel ; Bundaleski, Nenad ; Teodoro, Orlando M. N. D. ; Cornetta, Lucas M. ; da Silva, Filipe Ferreira

• Document type: Journal article
• Source: Physical Chemistry Chemical Physics; v. 25, n. 37, p. 7-pg., 2023-09-27.

Abstract

Trichloroanisole (TCA) is one of the most significant contaminants in cork stoppers. The presence of TCA leads to an unpleasant odor known as "cork taint", resulting in high economic losses for the cork and wine industries. Hence, the detection, quantification, and characterization of TCA are essential to address this concern. The present study investigates the electron-driven fragmentation pathways of TCA through electron ionization mass spectrometry as a function of electron energy (0-100 eV), and the results are supported by theoretical characterization of ionization potentials, dissociation thresholds, and electron ionization cross sections. The appearance energies of ten cations were measured, including the first experimental evaluation of the molecule's ionization energy at 8.8 & PLUSMN; 0.3 eV, in excellent agreement with the calculations (8.83 eV). For lower energies, around 20 eV, the parent cation accounted for more than 60% of the total ion signal, followed by its demethylated fragment. Taken together, these ion signals could be used as fingerprints of TCA in industrial quality control by low-energy electron ionization mass spectrometry. Fifty other fragments have been identified at higher electron energies, revealing the very rich fragmentation pattern of TCA. This work probes electron-driven ionization of TCA. New fragment ions are identified by mass spectrometry and experimental appearance energies show excellent agreement with calculated threshold energies for the most significant pathways. (AU)

• FAPESP's process: 20/04822-9 - Breaking matter complexity with resonant inelastic x-ray scattering: the role of different conformers and their respective nuclear dynamics
• Grantee: Lucas Medeiros Cornetta
• Support Opportunities: Scholarships in Brazil - Post-Doctoral