Rapid Commun Mass Spectrom. 2016 Jun 15;30(11):1332-8. doi: 10.1002/rcm.7567.
Deprotonation effect of tetrahydrofuran-2-carbonitrile buffer gas dopant in ion mobility spectrometry.
Rapid communications in mass spectrometry : RCM
Roberto Fernandez-Maestre, Dairo Meza-Morelos, Ching Wu
Affiliations
Affiliations
- Universidad de Cartagena, Campus de San Pablo, Programa de Química, Cartagena, Colombia.
- Excellims Corporation, 20 Main Street, Acton, MA, USA.
PMID: 27173115
DOI: 10.1002/rcm.7567
Abstract
RATIONALE: When dopants are introduced into the buffer gas of an ion mobility spectrometer, spectra are simplified due to charge competition.
METHODS: We used electrospray ionization to inject tetrahydrofuran-2-carbonitrile (F, 2-furonitrile or 2-furancarbonitrile) as a buffer gas dopant into an ion mobility spectrometer coupled to a quadrupole mass spectrometer. Density functional theory was used for theoretical calculations of dopant-ion interaction energies and proton affinities, using the hybrid functional X3LYP/6-311++(d,p) with the Gaussian 09 program that accounts for the basis set superposition error; analytes structures and theoretical calculations with Gaussian were used to explain the behavior of the analytes upon interaction with F.
RESULTS: When F was used as a dopant at concentrations below 1.5 mmol m(-3) in the buffer gas, ions were not observed for α-amino acids due to charge competition with the dopant; this deprotonation capability arises from the production of a dimer with a high formation energy that stabilized the positive charge and created steric hindrance that deterred the equilibrium with analyte ions. F could not completely strip other compounds of their charge because they either showed steric hindrance at the charge site that deterred the approach of the dopant (2,4-lutidine, and DTBP), formed intramolecular bonds that stabilized the positive charge (atenolol), had high proton affinity (2,4-lutidine, DTBP, valinol and atenolol), or were inherently ionic (tetraalkylammonium ions).
CONCLUSIONS: This selective deprotonation suggests the use of F to simplify spectra of complex mixtures in ion mobility and mass spectrometry in metabolomics, proteomics and other studies that generate complex spectra with thousands of peaks. Copyright © 2016 John Wiley & Sons, Ltd.
Copyright © 2016 John Wiley & Sons, Ltd.
Publication Types
