Perfect Timing: Time-of-flight Mass Spectrometry†

✍ Scribed by M. Guilhaus; V. Mlynski; D. Selby

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 403 KB
• Volume: 11
• Category: Article
• ISSN: 0951-4198
• DOI: 10.1002/(sici)1097-0231(19970615)11:9<951::aid-rcm785>3.0.co;2-h

✦ Synopsis

In the 1990s time-of-flight mass spectrometry (TOFMS) has reestablished itself as a mainstream technique in mass spectrometry. There have been several developments which have contributed to this. The development of the technique of matrix-assisted laser desorption/ionization (MALDI), a pulsed ionization method, has provided a user-friendly, low-cost window on the high mass regime for the molecular biologist. The availability of high-speed computers has allowed efficient processing of TOF data on the microsecond time-scale. The emergence of practical ion optical approaches for space, time and velocity focusing have improved the resolving power and sensitivity of TOFMS far beyond its limited performance in previous decades. Improved technologies for digitizing fast signals have facilitated the resolution of signals separated by only a few nanoseconds. The coupling of continuous ionization sources such as electrospray ionization (ESI), plasma and electron ionization with orthogonal acceleration TOF mass analysers has been an area of considerable progress in which the high speed and 'full-scan' sensitivity advantages of TOF are being exploited in applications involving high-speed chromatographic separations or transient sample introduction methods. The stability of the mass scale in TOFMS combined with the ability to provide resolving powers (m/∆m full width at half maximum) of several thousand provides excellent mass accuracy in important techniques such as ESI. TOF mass analysers are being deployed as the final analyser in hybrid tandem instruments. Commercial instruments now combine quadrupoles and double-focusing mass spectrometers with TOF analysers. Ion-traps have also been coupled with TOF instruments.