title: Fourier Transform Ion Cyclotron Resonance Mass Spectrometry at the Cyclotron Frequency.
abstract: The phenomenon of ion cyclotron resonance allows for determining mass-to-charge ratio, m/z, of an ensemble of ions by means of measurements of their cyclotron frequency, ωc. In Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), the ωcquantity is usually unavailable for direct measurements: the resonant state is located close to the reduced cyclotron frequency (ω+), whereas the ωcand the corresponding m/z values may be calculated via theoretical derivation from an experimental estimate of the ω+quantity. Here, we describe an experimental observation of a new resonant state, which is located close to the ωcfrequency and is established because of azimuthally-dependent trapping electric fields of the recently developed ICR cells with narrow aperture detection electrodes. We show that in mass spectra, peaks close to ω+frequencies can be reduced to negligible levels relative to peaks close to ωcfrequencies. Due to reduced errors with which the ωcquantity is obtained, the new resonance provides a means of cyclotron frequency measurements with precision greater than that achieved when ω+frequency peaks are employed. The described phenomenon may be considered for a development into an FT-ICR MS technology with increased mass accuracy for applications in basic research, life, and environmental sciences. Graphical Abstract ᅟ.
authors.affiliation: Spectroswiss Sàrl, EPFL Innovation Park, 1015, Lausanne, Switzerland.
authors.forename: Konstantin O
authors.initials: KO
authors.lastname: Nagornov
authors.affiliation: Spectroswiss Sàrl, EPFL Innovation Park, 1015, Lausanne, Switzerland.
authors.forename: Anton N
authors.initials: AN
authors.lastname: Kozhinov
authors.affiliation: Spectroswiss Sàrl, EPFL Innovation Park, 1015, Lausanne, Switzerland. tsybin@spectroswiss.ch.
authors.forename: Yury O
authors.initials: YO
authors.lastname: Tsybin
keywords: Cyclotron frequency; FT; FTMS; Fourier transform; Fourier transform mass spectrometry; ICR; Ion cyclotron resonance; Ion motion; Magnetron frequency; Mass accuracy; Reduced cyclotron frequency