An External Source 7 T Fourier Transform Ion Cyclotron Resonance Mass Spectrometer with Electrostatic Ion Guide

✍ Scribed by Forest M. White; Jarrod A. Marto; Alan G. Marshall

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 538 KB
• Volume: 10
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(199611)10:14<1845::aid-rcm749>3.0.co;2-#

✦ Synopsis

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.