Details
| Original language | English |
|---|---|
| Pages (from-to) | 1810-1820 |
| Number of pages | 11 |
| Journal | Journal of the American Society for Mass Spectrometry |
| Volume | 32 |
| Issue number | 7 |
| Early online date | 25 Jun 2021 |
| Publication status | Published - 7 Jul 2021 |
Abstract
Classical ion mobility spectrometers (IMS) operated at ambient pressure, often use atmospheric pressure chemical ionization (APCI) sources to ionize organic compounds. In APCI, reactant ions ionize neutral analyte molecules via gas-phase ion-molecule reactions. The positively charged reactant ions in purified, dry air are H3O+, NO+, and O2+•. However, the hydration of reactant ions in classical IMS operated at ambient pressure renders ionization of certain analytes difficult. In contrast to classical IMS operated at ambient pressure, High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) are operated at a decreased pressure of 10-40 mbar, allowing operation at high reduced electric field strengths of up to 120 Td. At such high reduced field strengths, ions reach high effective temperatures causing collision-induced cluster dissociation of the hydrated gas-phase ions, allowing ionization of nonpolar and low proton affinity analytes. The reactant ion population, consisting of H3O+(H2O)n, NO+(H2O)m, and O2+•(H2O)p with an individual abundance that strongly depends on the reduced field strength, differs from the reactant ion population in IMS operated at ambient pressure, which affects the ionization of analyte molecules. In this work, we investigate the influence of reduced field strength on the product ion formation of aromatic hydrocarbons used as model substances. A HiKE-IMS-MS coupling was used to identify the detected ion species. The results show that the analytes form parent cations via charge transfer with NO+(H2O)m and O2+•(H2O)p depending on ionization energy and protonated parent molecules via proton transfer and ligand switching with H3O+(H2O)n mainly depending on proton affinity.
Keywords
- APCI, corona discharge ionization, high kinetic energy ion mobility spectrometry, HiKE-IMS, IMS, ion mobility spectrometry, ionization
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Structural Biology
- Chemistry(all)
- Spectroscopy
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In: Journal of the American Society for Mass Spectrometry, Vol. 32, No. 7, 07.07.2021, p. 1810-1820.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Influence of Reduced Field Strength on Product Ion Formation in High Kinetic Energy Ion Mobility Spectrometry (HiKE-IMS)
AU - Schaefer, Christoph
AU - Allers, Maria
AU - Kirk, Ansgar T.
AU - Schlottmann, Florian
AU - Zimmermann, Stefan
N1 - Funding Information: Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - 318063177.
PY - 2021/7/7
Y1 - 2021/7/7
N2 - Classical ion mobility spectrometers (IMS) operated at ambient pressure, often use atmospheric pressure chemical ionization (APCI) sources to ionize organic compounds. In APCI, reactant ions ionize neutral analyte molecules via gas-phase ion-molecule reactions. The positively charged reactant ions in purified, dry air are H3O+, NO+, and O2+•. However, the hydration of reactant ions in classical IMS operated at ambient pressure renders ionization of certain analytes difficult. In contrast to classical IMS operated at ambient pressure, High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) are operated at a decreased pressure of 10-40 mbar, allowing operation at high reduced electric field strengths of up to 120 Td. At such high reduced field strengths, ions reach high effective temperatures causing collision-induced cluster dissociation of the hydrated gas-phase ions, allowing ionization of nonpolar and low proton affinity analytes. The reactant ion population, consisting of H3O+(H2O)n, NO+(H2O)m, and O2+•(H2O)p with an individual abundance that strongly depends on the reduced field strength, differs from the reactant ion population in IMS operated at ambient pressure, which affects the ionization of analyte molecules. In this work, we investigate the influence of reduced field strength on the product ion formation of aromatic hydrocarbons used as model substances. A HiKE-IMS-MS coupling was used to identify the detected ion species. The results show that the analytes form parent cations via charge transfer with NO+(H2O)m and O2+•(H2O)p depending on ionization energy and protonated parent molecules via proton transfer and ligand switching with H3O+(H2O)n mainly depending on proton affinity.
AB - Classical ion mobility spectrometers (IMS) operated at ambient pressure, often use atmospheric pressure chemical ionization (APCI) sources to ionize organic compounds. In APCI, reactant ions ionize neutral analyte molecules via gas-phase ion-molecule reactions. The positively charged reactant ions in purified, dry air are H3O+, NO+, and O2+•. However, the hydration of reactant ions in classical IMS operated at ambient pressure renders ionization of certain analytes difficult. In contrast to classical IMS operated at ambient pressure, High Kinetic Energy Ion Mobility Spectrometers (HiKE-IMS) are operated at a decreased pressure of 10-40 mbar, allowing operation at high reduced electric field strengths of up to 120 Td. At such high reduced field strengths, ions reach high effective temperatures causing collision-induced cluster dissociation of the hydrated gas-phase ions, allowing ionization of nonpolar and low proton affinity analytes. The reactant ion population, consisting of H3O+(H2O)n, NO+(H2O)m, and O2+•(H2O)p with an individual abundance that strongly depends on the reduced field strength, differs from the reactant ion population in IMS operated at ambient pressure, which affects the ionization of analyte molecules. In this work, we investigate the influence of reduced field strength on the product ion formation of aromatic hydrocarbons used as model substances. A HiKE-IMS-MS coupling was used to identify the detected ion species. The results show that the analytes form parent cations via charge transfer with NO+(H2O)m and O2+•(H2O)p depending on ionization energy and protonated parent molecules via proton transfer and ligand switching with H3O+(H2O)n mainly depending on proton affinity.
KW - APCI
KW - corona discharge ionization
KW - high kinetic energy ion mobility spectrometry
KW - HiKE-IMS
KW - IMS
KW - ion mobility spectrometry
KW - ionization
UR - http://www.scopus.com/inward/record.url?scp=85110276958&partnerID=8YFLogxK
U2 - 10.15488/14299
DO - 10.15488/14299
M3 - Article
C2 - 34170133
AN - SCOPUS:85110276958
VL - 32
SP - 1810
EP - 1820
JO - Journal of the American Society for Mass Spectrometry
JF - Journal of the American Society for Mass Spectrometry
SN - 1044-0305
IS - 7
ER -