MS/MS with high detection efficiency and mass resolving power for product ions in Fourier transform ion cyclotron resonance mass spectrometry.
We present a new FT-ICR method for MS/MS of trapped ions. Parent ions isolated in the source trap of a dual-trap FT-ICR/MS instrument are subjected to off-resonance dipolar excitation to promote collision-induced dissociation (CID), while product ions are simultaneously axialized by broad-band azimuthal quadrupolar excitation in the presence of argon collision gas. In this way, radial diffusional loss of product ions is greatly reduced; moreover, the axialized product ions may then be efficiently transferred to the analyzer trap for high-resolution detection. Significant improvements in FT-ICR detection efficiency, mass resolving power (m/delta m > or = 20,000 at m/z < or = 1000), and mass accuracy (< or = 50 ppm for peptide fragments of m/z < or = 1000) are demonstrated for CID product ions of the cyclic peptide, gramicidin S.
Guan
S
S
National High Magnetic Field Laboratory, Florida State University, Tallahassee 32306-4005.
Marshall
A G
AG
Wahl
M C
MC
D000595:Amino Acid Sequence; D017357:Cyclotrons; D005583:Fourier Analysis; D006096:Gramicidin / Q000032:analysis; D007477:Ions; D013058:Mass Spectrometry; D008969:Molecular Sequence Data
D007477:Ions; D006096:Gramicidin