Appearance energy

From MS Terms Wiki
Revision as of 01:38, 20 July 2009 by Kkmurray (talk | contribs)
Jump to navigation Jump to search

Obsolete Template

Orange Book


IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the Orange Book). Definitive Rules, 1979.

Appearance energy

The minimum energy that must be imparted to an atom, molecule, radical or other molecular entities to produce a specified ion. The term 'appearance potential' is not recommended.

IUPAC 1997 Orange Book Chapter 12
Index of Orange Book Terms

Gold Book


IUPAC. Compendium of Chemical Terminology, 2nd ed. (the Gold Book). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).

Appearance energy

Refers to ionization of a molecule or atom by electron collision or photon absorption. In mass spectrometry it has often been reported as the voltage which corresponds to the minimum energy of the electrons in the ionizing beam necessary for the production of a given fragment ion. In photoionization it is the minimum energy of the quantum of light which produces ionization of the absorbing molecule.


PAC, 1990, 62, 2167 (Glossary of atmospheric chemistry terms (Recommendations 1990)) on page 2175

PAC, 1991, 63, 1541 (Recommendations for nomenclature and symbolism for mass spectroscopy (including an appendix of terms used in vacuum technology). (Recommendations 1991)) on page 1546

IUPAC Gold Book
Index of Gold Book Terms