Ion-molecule reactions relevant to the detection of atmospheric oxidized mercury by chemical ionization mass spectrometry

Francisco J. Guzman, Matthew Cooper, John Antley, Joseph Bozzelli, Alexei Khalizov

Research output: Contribution to conferencePaperpeer-review

Abstract

Mercury is a persistent environmental pollutant arising from anthropogenic and natural sources. Gaseous oxidized mercury (GOM) is significantly more water soluble than elemental Hg and should be the main form responsible for deposition unto environmental sinks, however, the speciation of GOM is poorly understood due to its relatively low concentrations and labile nature. We investigated ion-molecule chemistry of gas-phase HgCl2 with SF6 -, CO3 -, and CO2·O2 - reagent ions by ion-drift chemical ionization mass spectrometry. Additionally, DFT and ab-initio computations coupled with rate constant calculations based on average dipole orientation (ADO) theory were used to evaluate the product stability, elucidate reaction pathways and corroborate experimental results. We found that the reaction of HgCl2 with SF6 -, CO3 -, and CO2·O2 - forms HgCl2·F- , HgCl2·CO3 -, HgCl2O- , and HgCl2O2 - product ions. These reactions are efficient in converting gaseous oxidized mercury to molecular ions, although competing reactions with O3, NOx, and H2O may limit their application in atmospheric applications. The calculated stability of the complexes is in the 11 to 57 kcal-mol-1range.

Original languageEnglish (US)
StatePublished - Jan 1 2018
Event2018 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2018 - State College, United States
Duration: Mar 4 2018Mar 7 2018

Other

Other2018 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2018
CountryUnited States
CityState College
Period3/4/183/7/18

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Physical and Theoretical Chemistry
  • Chemical Engineering(all)

Keywords

  • And ADO theory
  • Detection of oxidized mercury
  • Reaction thermochemistry

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