title: An external source 7 T Fourier transform ion cyclotron resonance mass spectrometer with electrostatic ion guide.
abstract: An external source 7 T Fourier transform ion cyclotron resonance (FTICR) mass spectrometer offers three main novel features. First, a 9-way ion-source cross allows for mounting of up to three ionization sources simultaneously, thereby minimizing 'downtime' for changing ion sources. Second, an electrostatic (wire-in-cylinder) ion guide transports the ions approximately 1.5 m from the ion source to the ion trap for mass analysis, through a large magnetic field gradient. Third, the system operates from a modular data system described elsewhere in this issue. Luteinizing hormone-releasing hormone (LH-RH) matrix-assisted laser desorption/ionization (MALDI) FTICR positive-ion mass spectra exhibit signal-to-noise ratio greater than 1000:1 and mass resolving power, m/delta m 50% > 100,000. Laser-induced fragmentation of bradykinin demonstrates the ability of the ion guide to transmit both molecular and fragment ions simultaneously. Ultra-high resolution (average resolving power approximately 400,000) was achieved for poly(ethylene glycol) of specified number-average molecular weight, Mn approximately 3400. Future installation of an electrospray source to the ion-source cross should allow for better characterization of the performance of the ion guide.
authors.affiliation: Center for Interdisciplinary Magnetic Resonance, National High Magnetic Field Laboratory, Florida State University, Tallahassee 32310, USA.
authors.forename: F M
authors.initials: FM
authors.lastname: White
authors.forename: J A
authors.initials: JA
authors.lastname: Marto
authors.forename: A G
authors.initials: AG
authors.lastname: Marshall
mesh_terms: D001920:Bradykinin / Q000737:chemistry; D017357:Cyclotrons; D001330:Electronic Data Processing; D005583:Fourier Analysis; D007987:Gonadotropin-Releasing Hormone / Q000737:chemistry; D013058:Mass Spectrometry / Q000295:instrumentation*; D011092:Polyethylene Glycols / Q000737:chemistry; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007987:Gonadotropin-Releasing Hormone; D011092:Polyethylene Glycols; D001920:Bradykinin