Spectrometry of Biomolecules

With this type of MS, ions are generated by bombarding the vapor-phase sample with electrons at high energy. These electrons are emitted by a hot tungsten or rhenium wire, or filament, and are accelerated toward an electron trap that is held at about +70 V. The impact of these electrons with the sample molecules generates ions according to Eq. 15.1  

Bianalytical Chemistry, by Susan R. Mikkelsen and Eduardo Corton ISBN 0-471-54447-7 Copyright 2004 John Wiley Sons, Inc. 

Therefore, given fixed B, r, and V values, only ions of a particular m/z value will reach the ion detector to generate a signal. Ions that are too heavy (m/z too large) impact with the outer wall of the magnetic sector, while lighter ions (small m/z) have small radii of curvature and impact with the inner wall. Mass spectrometers allow either B or V (or both) to be scanned to detect ions of interest at particular m/z values. 

Mass spectrometry is a well-established technique J.J. Thompson designed the first mass spectrometer in 1912. The methods for ion production in these early times were limited to gaseous samples (or low vapor pressure molecules) for analytical 

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R. D. Macfarlane. Mass Spectrometry of Biomolecules From PDMS to MALDI. Brazilian J. Phys., 29(1999) 415-420. 

B. Spengler. Post-Source Decay Analysis in Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry of Biomolecules. J. Mass Spectrom., 32(1997) 1019-1036. 

Spengler, B. (1 997) Post-source decay analysis in matrix-assisted laser desorption/ionization mass spectrometry of biomolecules. Journal of Mass Spectrometry 32, 1019-1036. 

V. A. Pokrovskiy. Temperature-programmed desorption mass spectrometry of biomolecules, Rapid Commun. Mass Spectrom. 9, 588-591 (1995). 

Mass Spectrometry of Biomolecules 444 [ WHY DO THESE TOPICS MATTER ] 444... 

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