Chapter 3
The Interpretation of Reflectron Time-of-Flight Mass Spectra Ronald C. Beavis
Downloaded by UNIV LAVAL on October 2, 2015 | http://pubs.acs.org Publication Date: December 21, 1993 | doi: 10.1021/bk-1994-0549.ch003
Department of Physics, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3X7, Canada
The time-of-flight mass spectrometer is currently undergoing a renaissance as an analytical instrument in biochemistry. This paper will discuss the ion optics of these instruments in detail, with particular emphasis on "reflectron" type instruments and the effects produced by the unimolecular decomposition of an ion while it is passing through a reflectron mass analyzer. The simplest time-of-flight mass analyzer is a "linear" device, which measures the flight time of a pulse of ions from an ion source to a detector, through a region of field-free vacuum (Figure 1). In a linear machine, the detector faces towards the ion source. The ions from the source are all assumed to have the same kinetic energy. The mass measurement is obtained by applying the following simple equation: 7*=
