On the use of scans at a constant ratio of B/E for studying decompositions of peptide metal(II)-ion complexes formed by electrospray ionization
✍ Scribed by M. Cameron Sullards; Jeanette Adams
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 331 KB
- Volume
- 6
- Category
- Article
- ISSN
- 1044-0305
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✦ Synopsis
The use of sector mass spectrometers to study metastable ion decompositions of peptide metal-ion complexes formed by electrospray ionization is discussed. Products that are formed by charge-separation reactions are characterized by large kinetic energy release distributions. This causes scans at a constant B/E to give incorrect product ion abundances and possibly incorrect mass assignments. Two instrumental methods exist that can be used either to detect the ions or to estimate relative ion abundances: a floated collision cell or mass-analyzed ion kinetic energy spectrometry (MIKES) scans. The floated collision cell, by virtue of an altered B/E scan law, however, discriminates against important metastable ion reactions that occur outside the cell. MIKES scans provide a clearer estimate of product ions that arise by metastable ion charge-separation reactions. Problems with pseudotandem (first field-free region) experiments are also discussed.