Field desorption mass spectrometry characteristics

Mass Spectrometry. A review on biochemical applications of mass spectrometry deals largely with carotenoids. Field-desorption m.s. of carotenoids gives the molecular ion as the base peak, with very few fragment ions. Eighteen carotenoids were examined by this technique. A fragment ion at M-68 on electron impact seems to be characteristic for acyclic carotenoids with a 1,2,7,8-tetrahydro end-group. ... 

Remarkably, however, textbooks on mass spectrometry hardly comprise the multifaceted aspects of the gas-phase ion chemistry of phenols and of their consequences for the characteristics of the mass spectra of phenolic compounds . A great many insights into the fundamentals and developments for analytical applications have been collected during the past four decades or so, and research is actively continued in this field. As a special circumstance, a number of phenolic compounds play a crucial—and yet not completely understood—role as energy-transferring media and protonating reagents in an extremely important, modern ionization method of mass spectrometry, viz. matrix-assisted laser desorption/ionization (MALDI) . ... 

The analysis of NMR spectra of high resolution in solid phase as well as the results of mass-spectrometry investigation of water and methanol desorption from trimethylsilylated aerosil surface with no OH-groups [64,115] testify a nonhydroxylic nature of the sites of adsorption of small water amounts. A correspondence has been fixed of three characteristic regions of the sorbed water and methanol elimination with desorption maxima related to probable destruction of hydrogen-bonded (low-temperature maximum) and coordinate adsorption complexes of various structure (high-temperature maximum) by the help of desorption-field mass-spectrometry [116,117]. 

Principles and Characteristics As well known, transformation of atoms and high mass organic molecules from a surface-adsorbed state into the gas phase (for mass spectrometric detection) may be achieved by various methods, including field desorption, plasma desorption, laser desorption, fast atom bombardment (FAB) and ion sputtering. These techniques address different analytical problem areas. For example, the development of the laser desorption (LD) technique has been prompted by the desire to study thermally labile and high mass compounds by mass spectrometry. 

---